2018 |
Martinez-de-Rioja, Eduardo; Encinar, Jose A; Pino, Antonio Garcia; Gonzalez-Valdes, Borja; Hum, Sean Victor; Tienda, Carolina Bifocal Design Procedure for Dual-Reflectarray Antennas in Offset Configurations Artículo de revista IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, 17 (8), pp. 1421-1425, 2018, ISSN: 1536-1225. @article{MartinezdeRioja2018, title = {Bifocal Design Procedure for Dual-Reflectarray Antennas in Offset Configurations}, author = {Eduardo Martinez-de-Rioja and Jose A Encinar and Antonio Garcia Pino and Borja Gonzalez-Valdes and Sean Victor Hum and Carolina Tienda}, doi = {10.1109/LAWP.2018.2848719}, issn = {1536-1225}, year = {2018}, date = {2018-08-01}, journal = {IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS}, volume = {17}, number = {8}, pages = {1421-1425}, abstract = {This letter presents a new bifocal design procedure for dual-reflectarray antennas (DRAAs) in offset configurations. The technique starts by considering an axially symmetric geometry with the reflectarrays placed in parallel planes, which allows the rotation of a two-dimensional bifocal design around the symmetry axis. To reach a more compact configuration and to obtain smoother phase distributions, the reflectarrays are tilted and their phases are adjusted by means of a ray-tracing routine. The technique has been validated by numerical simulations through the comparison with a previous center-fed dual-reflectarray prototype. Finally, the simulations of an offset DRAA with tilted reflectarrays are presented, providing 0.56 degrees beam spacing at 20 GHz for multispot satellite applications in Ka-band.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This letter presents a new bifocal design procedure for dual-reflectarray antennas (DRAAs) in offset configurations. The technique starts by considering an axially symmetric geometry with the reflectarrays placed in parallel planes, which allows the rotation of a two-dimensional bifocal design around the symmetry axis. To reach a more compact configuration and to obtain smoother phase distributions, the reflectarrays are tilted and their phases are adjusted by means of a ray-tracing routine. The technique has been validated by numerical simulations through the comparison with a previous center-fed dual-reflectarray prototype. Finally, the simulations of an offset DRAA with tilted reflectarrays are presented, providing 0.56 degrees beam spacing at 20 GHz for multispot satellite applications in Ka-band. |
Perez-Palomino, Gerardo; Page, J E; Arrebola, Manuel; Encinar, Jose A A Design Technique Based on Equivalent Circuit and Coupler Theory for Broadband Linear to Circular Polarization Converters in Reflection or Transmission Mode Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 66 (5), pp. 2428-2438, 2018, ISSN: 0018-926X. @article{PerezPalomino2018, title = {A Design Technique Based on Equivalent Circuit and Coupler Theory for Broadband Linear to Circular Polarization Converters in Reflection or Transmission Mode}, author = {Gerardo Perez-Palomino and J E Page and Manuel Arrebola and Jose A Encinar}, doi = {10.1109/TAP.2018.2809664}, issn = {0018-926X}, year = {2018}, date = {2018-05-01}, journal = {IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, volume = {66}, number = {5}, pages = {2428-2438}, abstract = {A new approach to designing frequency selective surface (FSS)-based linear to circular polarization (LP-CP) converters is presented. It is based on the use of FSSs which exhibit dual diagonal symmetry, and a novel four-port equivalent circuit able to describe the electrical behavior of the cells for the two linear incident polarizations at the same time. The equivalent circuit allows the use of standardized branch line coupler theory to design LP-CP converters comprising a cascade of an arbitrary number of layers, whose synthesis includes the phase and makes it possible to achieve prescribed electrical conditions systematically. A full design procedure has been developed using the new approach and several designs in both transmission and reflection modes are presented and evaluated. It has been proven that single layer reflective converters exhibit large bandwidths as the two reflected field components are in quadrature independently of the frequency. One of these devices was designed and showed an axial ratio <0.2 dB within the band from 21.5 to 28.5 GHz. The reflective LP-CP converters designed was also manufactured and tested, and the measurements were used to validate the design procedure.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new approach to designing frequency selective surface (FSS)-based linear to circular polarization (LP-CP) converters is presented. It is based on the use of FSSs which exhibit dual diagonal symmetry, and a novel four-port equivalent circuit able to describe the electrical behavior of the cells for the two linear incident polarizations at the same time. The equivalent circuit allows the use of standardized branch line coupler theory to design LP-CP converters comprising a cascade of an arbitrary number of layers, whose synthesis includes the phase and makes it possible to achieve prescribed electrical conditions systematically. A full design procedure has been developed using the new approach and several designs in both transmission and reflection modes are presented and evaluated. It has been proven that single layer reflective converters exhibit large bandwidths as the two reflected field components are in quadrature independently of the frequency. One of these devices was designed and showed an axial ratio <0.2 dB within the band from 21.5 to 28.5 GHz. The reflective LP-CP converters designed was also manufactured and tested, and the measurements were used to validate the design procedure. |
Echeveste, Jose Ignacio; Gonzalez-de-Aza, Miguel A; Rubio, Jesus; Zapata, Juan Synthesis of coupled antenna arrays using digital phase control via integer programming Artículo de revista IET MICROWAVES ANTENNAS & PROPAGATION, 12 (6), pp. 999-1003, 2018, ISSN: 1751-8725. @article{Echeveste2018, title = {Synthesis of coupled antenna arrays using digital phase control via integer programming}, author = {Jose Ignacio Echeveste and Miguel A Gonzalez-de-Aza and Jesus Rubio and Juan Zapata}, doi = {10.1049/iet-map.2017.0838}, issn = {1751-8725}, year = {2018}, date = {2018-05-01}, journal = {IET MICROWAVES ANTENNAS & PROPAGATION}, volume = {12}, number = {6}, pages = {999-1003}, abstract = {A pattern synthesis technique for real and coupled antenna arrays by using digital phase-only excitation weights is introduced here. The method is formulated as an integer linear programming problem incorporating a fast full-wave analysis of the array, based on the finite element method and spherical mode expansions. The method achieves radiation patterns with specified pointing directions, main lobe widths, minimum sidelobe level, and prescribed nulls, controlled by digital phase shifters.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A pattern synthesis technique for real and coupled antenna arrays by using digital phase-only excitation weights is introduced here. The method is formulated as an integer linear programming problem incorporating a fast full-wave analysis of the array, based on the finite element method and spherical mode expansions. The method achieves radiation patterns with specified pointing directions, main lobe widths, minimum sidelobe level, and prescribed nulls, controlled by digital phase shifters. |
Tienda, Carolina; Encinar, Jose A; Barba, Mariano; Arrebola, Manuel Dual-Polarization Ku-Band Compact Spaceborne Antenna Based on Dual-Reflectarray Optics Artículo de revista SENSORS, 18 (4), 2018, ISSN: 1424-8220. @article{Tienda2018, title = {Dual-Polarization Ku-Band Compact Spaceborne Antenna Based on Dual-Reflectarray Optics}, author = {Carolina Tienda and Jose A Encinar and Mariano Barba and Manuel Arrebola}, doi = {10.3390/s18041100}, issn = {1424-8220}, year = {2018}, date = {2018-04-01}, journal = {SENSORS}, volume = {18}, number = {4}, abstract = {This article demonstrated an accurate analysis technique for dual-reflectarray antennas that take into account the angle of incidence of the impinging electric field on the main reflectarray cells. The reflected field on the sub and the main reflectarray surfaces is computed using Method of Moments in the spectral domain and assuming local periodicity. The sub-reflectarray is divided into groups of elements and the field radiated by each group is used to compute the incident and reflected field on the main reflectarray cells. A 50-cm demonstrator in Ku-band that provides European coverage has been designed, manufactured and tested to validate the analysis technique. The measured radiation patterns match the simulations and they fulfill the coverage requirements, achieving a cross-polar discrimination better than 25 dB in the frequency range: 12.975-14.25 GHz.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This article demonstrated an accurate analysis technique for dual-reflectarray antennas that take into account the angle of incidence of the impinging electric field on the main reflectarray cells. The reflected field on the sub and the main reflectarray surfaces is computed using Method of Moments in the spectral domain and assuming local periodicity. The sub-reflectarray is divided into groups of elements and the field radiated by each group is used to compute the incident and reflected field on the main reflectarray cells. A 50-cm demonstrator in Ku-band that provides European coverage has been designed, manufactured and tested to validate the analysis technique. The measured radiation patterns match the simulations and they fulfill the coverage requirements, achieving a cross-polar discrimination better than 25 dB in the frequency range: 12.975-14.25 GHz. |
Encinar, Jose A; Florencio, Rafael; Arrebola, Manuel; Natera, Miguel Alejandro Salas; Barba, Mariano; Page, J E; Boix, Rafael R; Toso, Giovanni Dual-polarization reflectarray in Ku-band based on two layers of dipole arrays for a transmit-receive satellite antenna with South American coverage Artículo de revista INTERNATIONAL JOURNAL OF MICROWAVE AND WIRELESS TECHNOLOGIES, 10 (2, SI), pp. 149-159, 2018, ISSN: 1759-0787. @article{Encinar2018, title = {Dual-polarization reflectarray in Ku-band based on two layers of dipole arrays for a transmit-receive satellite antenna with South American coverage}, author = {Jose A Encinar and Rafael Florencio and Manuel Arrebola and Miguel Alejandro Salas Natera and Mariano Barba and J E Page and Rafael R Boix and Giovanni Toso}, doi = {10.1017/S1759078717001209}, issn = {1759-0787}, year = {2018}, date = {2018-03-01}, journal = {INTERNATIONAL JOURNAL OF MICROWAVE AND WIRELESS TECHNOLOGIES}, volume = {10}, number = {2, SI}, pages = {149-159}, abstract = {A 1.1-m reflectarray antenna has been designed, manufactured, and tested to fulfill the requirements of a satellite antenna in Ku-band that provides South-American coverage in Tx and Rx. The reflectarray cells consist of four dipoles for each polarization in two dielectric layers, selected because of their simplicity and high performance. The dipole dimensions are optimized in all the reflectarray cells to accomplish the prescribed radiation patterns, by iteratively calling an analysis routine based on method of moments in spectral domain and local periodicity. The measured radiation patterns of the manufactured antenna have been satisfactorily compared with simulations and with a three-layer reflectarray previously designed, manufactured, and tested for the same mission.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A 1.1-m reflectarray antenna has been designed, manufactured, and tested to fulfill the requirements of a satellite antenna in Ku-band that provides South-American coverage in Tx and Rx. The reflectarray cells consist of four dipoles for each polarization in two dielectric layers, selected because of their simplicity and high performance. The dipole dimensions are optimized in all the reflectarray cells to accomplish the prescribed radiation patterns, by iteratively calling an analysis routine based on method of moments in spectral domain and local periodicity. The measured radiation patterns of the manufactured antenna have been satisfactorily compared with simulations and with a three-layer reflectarray previously designed, manufactured, and tested for the same mission. |
Montejo-Garai, Jose R; Saracho-Pantoja, Irene O; Ruiz-Cruz, Jorge A; Rebollar, Jesus M High-performance 16-way Ku-band radial power combiner based on the TE01-circular waveguide mode Artículo de revista REVIEW OF SCIENTIFIC INSTRUMENTS, 89 (3), 2018, ISSN: 0034-6748. @article{MontejoGarai2018a, title = {High-performance 16-way Ku-band radial power combiner based on the TE01-circular waveguide mode}, author = {Jose R Montejo-Garai and Irene O Saracho-Pantoja and Jorge A Ruiz-Cruz and Jesus M Rebollar}, doi = {10.1063/1.5022056}, issn = {0034-6748}, year = {2018}, date = {2018-03-01}, journal = {REVIEW OF SCIENTIFIC INSTRUMENTS}, volume = {89}, number = {3}, abstract = {This work presents a 16-way Ku-band radial power combiner for high power and high frequency applications, using the very low loss TE01 circular waveguide mode. The accomplished design shows an excellent performance: the experimental prototype has a return loss better than 30 dB, with a balance for the amplitudes of (+/- 0.15 dB) and (+/- 2.5 degrees) for the phases, in a 16.7% fractional bandwidth (2 GHz centered at 12 GHz). For obtaining these outstanding specifications, required, for instance, in high frequency amplification or on plasma systems, a rigorous step-by-step procedure is presented. First, a high-purity mode transducer has been designed, from the TE10 mode in the rectangular waveguide to the TE01 mode in the circular waveguide, with very high attenuation (>50 dB) for the other propagating and evanescent modes in the circular waveguide. This transducer has been manufactured and measured in a back-to-back configuration, validating the design process. Second, an E-plane 16-way radial power divider has been designed, where the power is coupled from the 16 non-reduced-height radial standard waveguides into the TE01 circular waveguide mode, improving the insertion loss response and removing the usual tapered transformers of previous designs limiting the power handling. Finally, both the transducer and the divider have been assembled to make the final radial combiner. The prototype has been carefully manufactured, showing very good agreement between the measurements and the full-wave simulations. Published by AIP Publishing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work presents a 16-way Ku-band radial power combiner for high power and high frequency applications, using the very low loss TE01 circular waveguide mode. The accomplished design shows an excellent performance: the experimental prototype has a return loss better than 30 dB, with a balance for the amplitudes of (+/- 0.15 dB) and (+/- 2.5 degrees) for the phases, in a 16.7% fractional bandwidth (2 GHz centered at 12 GHz). For obtaining these outstanding specifications, required, for instance, in high frequency amplification or on plasma systems, a rigorous step-by-step procedure is presented. First, a high-purity mode transducer has been designed, from the TE10 mode in the rectangular waveguide to the TE01 mode in the circular waveguide, with very high attenuation (>50 dB) for the other propagating and evanescent modes in the circular waveguide. This transducer has been manufactured and measured in a back-to-back configuration, validating the design process. Second, an E-plane 16-way radial power divider has been designed, where the power is coupled from the 16 non-reduced-height radial standard waveguides into the TE01 circular waveguide mode, improving the insertion loss response and removing the usual tapered transformers of previous designs limiting the power handling. Finally, both the transducer and the divider have been assembled to make the final radial combiner. The prototype has been carefully manufactured, showing very good agreement between the measurements and the full-wave simulations. Published by AIP Publishing. |
Ruiz-Cruz, Jorge A; Montejo-Garai, Jose R; Leal-Sevillano, Carlos A; Rebollar, Jesus M Orthomode Transducers With Folded Double-Symmetry Junctions for Broadband and Compact Antenna Feeds Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 66 (3), pp. 1160-1168, 2018, ISSN: 0018-926X. @article{RuizCruz2018, title = {Orthomode Transducers With Folded Double-Symmetry Junctions for Broadband and Compact Antenna Feeds}, author = {Jorge A Ruiz-Cruz and Jose R Montejo-Garai and Carlos A Leal-Sevillano and Jesus M Rebollar}, doi = {10.1109/TAP.2018.2794364}, issn = {0018-926X}, year = {2018}, date = {2018-03-01}, journal = {IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, volume = {66}, number = {3}, pages = {1160-1168}, abstract = {Orthomode transducers (OMTs) using folded six-port waveguide junctions are presented for obtaining the maximum compactness in antenna feeds with very wide performance. The proposed junctions are based on the well-known turnstile and Boifot configurations, having two symmetry planes for keeping the isolation between orthogonal polarizations and the control of higher order modes. The folded arms provide a combined effect: good matching with very significant size reduction, especially in the transversal plane, reducing mass in satellite systems and allowing feeding eventual dense horn antenna arrays. Two Ku-band OMTs are presented in order to illustrate the advantages of the introduced junctions. The first design covers the band 10.4-18.8 GHz (57.5%) with 24 dB return loss. The second OMT, for the 12.60-18.25 GHz band, has measured return loss better than 29 dB in the design band and insertion loss smaller than 0.11 dB for both polarizations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Orthomode transducers (OMTs) using folded six-port waveguide junctions are presented for obtaining the maximum compactness in antenna feeds with very wide performance. The proposed junctions are based on the well-known turnstile and Boifot configurations, having two symmetry planes for keeping the isolation between orthogonal polarizations and the control of higher order modes. The folded arms provide a combined effect: good matching with very significant size reduction, especially in the transversal plane, reducing mass in satellite systems and allowing feeding eventual dense horn antenna arrays. Two Ku-band OMTs are presented in order to illustrate the advantages of the introduced junctions. The first design covers the band 10.4-18.8 GHz (57.5%) with 24 dB return loss. The second OMT, for the 12.60-18.25 GHz band, has measured return loss better than 29 dB in the design band and insertion loss smaller than 0.11 dB for both polarizations. |
Moran-Lopez, Ana; Corcoles, Juan; Ruiz-Cruz, Jorge A; Montejo-Garai, Jose R; Rebollar, Jesus M Robust Calculation of the Modes in Parabolic Cylinder Metallic Waveguides by Means of a Root-Finding Method for Bivariate Functions Artículo de revista IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, 66 (2), pp. 623-632, 2018, ISSN: 0018-9480. @article{MoranLopez2018, title = {Robust Calculation of the Modes in Parabolic Cylinder Metallic Waveguides by Means of a Root-Finding Method for Bivariate Functions}, author = {Ana Moran-Lopez and Juan Corcoles and Jorge A Ruiz-Cruz and Jose R Montejo-Garai and Jesus M Rebollar}, doi = {10.1109/TMTT.2017.2777969}, issn = {0018-9480}, year = {2018}, date = {2018-02-01}, journal = {IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, volume = {66}, number = {2}, pages = {623-632}, abstract = {This paper addresses the robust mode computation of the metallic hollow cylindrical waveguide with parabolic contour. Although this waveguide can be solved by separation of variables, it has not been fully characterized in a systematic way in the past. This is not only due to its challenging manufacture, which nowadays can be addressed by modern techniques, but also because of its more complex resolution, involving root finding in a pair of coupled functions with two variables. In order to solve this system, this paper proposes the use of a recently published algorithm for bivariate problems, which is applied for the first time to waveguide mode computation. The method, properly combined with the even and odd Taylor functions, allows obtaining the modes in a systematic and robust way, avoiding, in comparison with previous works, graphical means and the use of starting points from which to iterate. All the modal solutions for symmetrical and asymmetrical cases are solved at once over a wide domain of search with proven high accuracy (relative difference with respect to results from a finite-element method in the order of 10(-5) for more than 1600 modes).}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper addresses the robust mode computation of the metallic hollow cylindrical waveguide with parabolic contour. Although this waveguide can be solved by separation of variables, it has not been fully characterized in a systematic way in the past. This is not only due to its challenging manufacture, which nowadays can be addressed by modern techniques, but also because of its more complex resolution, involving root finding in a pair of coupled functions with two variables. In order to solve this system, this paper proposes the use of a recently published algorithm for bivariate problems, which is applied for the first time to waveguide mode computation. The method, properly combined with the even and odd Taylor functions, allows obtaining the modes in a systematic and robust way, avoiding, in comparison with previous works, graphical means and the use of starting points from which to iterate. All the modal solutions for symmetrical and asymmetrical cases are solved at once over a wide domain of search with proven high accuracy (relative difference with respect to results from a finite-element method in the order of 10(-5) for more than 1600 modes). |
Neufeld, E; Carrasco, Eduardo; Murbach, M; Balzano, Q; Christ, A; Kuster, N Theoretical and numerical assessment of maximally allowable power-density averaging area for conservative electromagnetic exposure assessment above 6 GHz Artículo de revista BIOELECTROMAGNETICS, 39 (8), pp. 617-630, 2018, ISSN: 0197-8462. @article{ISI:000450844400005, title = {Theoretical and numerical assessment of maximally allowable power-density averaging area for conservative electromagnetic exposure assessment above 6 GHz}, author = {E Neufeld and Eduardo Carrasco and M Murbach and Q Balzano and A Christ and N Kuster}, doi = {10.1002/bem.22147}, issn = {0197-8462}, year = {2018}, date = {2018-01-01}, journal = {BIOELECTROMAGNETICS}, volume = {39}, number = {8}, pages = {617-630}, abstract = {The objective of this paper is to determine a maximum averaging area for power density (PD) that limits the maximum temperature increase to a given threshold for frequencies above 6 GHz. This maximum area should be conservative for any transmitter at any distance >2 mm from the primary transmitting antennas or secondary field-generating sources. To derive a generically valid maximum averaging area, an analytical approximation for the peak temperature increase caused by localized exposure was derived. The results for a threshold value of 1 K temperature rise were validated against simulations of a series of sources composed of electrical and magnetic elements (dipoles, slots, patches, and arrays) that represented the spectrum of relevant transmitters. The validation was successful for frequencies in which the power deposition occurred superficially (i.e., >10 GHz). In conclusion, the averaging area for a PD limit of 10 W/m(2) that conservatively limits the temperature increase in the skin to less than 1 K at any distance >2 mm from the transmitters is frequency dependent, increases with distance, and ranges from 3 cm(2) at <10 GHz to 1.9 cm(2) at 100 GHz. In the far-field, the area depends additionally on distance and the antenna array aperture. The correlation was found to be worse at lower frequencies (<10 GHz) and very close to the source, the systematic evaluation of which is part of another study to investigate the effect of different coupling mechanisms in the reactive near-field on the ratio of temperature increase to incident power density. The presented model can be directly applied to any other PD and temperature thresholds. Bioelectromagnetics. 39:617-630, 2018. (c) 2018 Wiley Periodicals, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The objective of this paper is to determine a maximum averaging area for power density (PD) that limits the maximum temperature increase to a given threshold for frequencies above 6 GHz. This maximum area should be conservative for any transmitter at any distance >2 mm from the primary transmitting antennas or secondary field-generating sources. To derive a generically valid maximum averaging area, an analytical approximation for the peak temperature increase caused by localized exposure was derived. The results for a threshold value of 1 K temperature rise were validated against simulations of a series of sources composed of electrical and magnetic elements (dipoles, slots, patches, and arrays) that represented the spectrum of relevant transmitters. The validation was successful for frequencies in which the power deposition occurred superficially (i.e., >10 GHz). In conclusion, the averaging area for a PD limit of 10 W/m(2) that conservatively limits the temperature increase in the skin to less than 1 K at any distance >2 mm from the transmitters is frequency dependent, increases with distance, and ranges from 3 cm(2) at <10 GHz to 1.9 cm(2) at 100 GHz. In the far-field, the area depends additionally on distance and the antenna array aperture. The correlation was found to be worse at lower frequencies (<10 GHz) and very close to the source, the systematic evaluation of which is part of another study to investigate the effect of different coupling mechanisms in the reactive near-field on the ratio of temperature increase to incident power density. The presented model can be directly applied to any other PD and temperature thresholds. Bioelectromagnetics. 39:617-630, 2018. (c) 2018 Wiley Periodicals, Inc. |
Douglas, M G; Pfeifer, S; Kuhn, S; Neufeld, E; Pokovic, K; Carrasco, Eduardo; Samaras, T; Christ, A; Capstick, M H; Kuster, N Solutions for EM Exposure Assessment of 5G Wireless Devices Artículo en actas 2018 JOINT IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY AND 2018 IEEE ASIA-PACIFIC SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY (EMC/APEMC), pp. 92-94, IEEE; IEEE Electromagnet Compatibil Soc; APEMC EMC; Zhejiang Univ; EMC Lab; Inst High Performance Comp, Agcy Sci & Technol Res; Nanyang Technol Univ; Natl Univ SIngapore; Antennas & Propagat Soc; CMA Int Consultants Pte ltd; Rohde & Schwarz; CST; e2i; AMETEK; ETS LINDGREN 2018, ISBN: 978-1-5090-5997-3, (Joint 60th IEEE International Symposium on Electromagnetic Compatibility (EMC) / IEEE Asia-Pacific Symposium on Electromagnetic Compatibility (APEMC), Singapore, SINGAPORE, MAY 14-18, 2018). @inproceedings{ISI:000439259800053, title = {Solutions for EM Exposure Assessment of 5G Wireless Devices}, author = {M G Douglas and S Pfeifer and S Kuhn and E Neufeld and K Pokovic and Eduardo Carrasco and T Samaras and A Christ and M H Capstick and N Kuster}, doi = {10.1109/isemc.2018.8394066}, isbn = {978-1-5090-5997-3}, year = {2018}, date = {2018-01-01}, booktitle = {2018 JOINT IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY AND 2018 IEEE ASIA-PACIFIC SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY (EMC/APEMC)}, pages = {92-94}, organization = {IEEE; IEEE Electromagnet Compatibil Soc; APEMC EMC; Zhejiang Univ; EMC Lab; Inst High Performance Comp, Agcy Sci & Technol Res; Nanyang Technol Univ; Natl Univ SIngapore; Antennas & Propagat Soc; CMA Int Consultants Pte ltd; Rohde & Schwarz; CST; e2i; AMETEK; ETS LINDGREN}, abstract = {A novel measurement system and a 3D field reconstruction method are described for determining the power density in the close near field of wireless devices transmitting at frequencies from 6 - 110 GHz. Measurements are compared against simulated results. The accuracy is better than 0.5 dB for distances greater than lambda/5 from the radiating source.}, note = {Joint 60th IEEE International Symposium on Electromagnetic Compatibility (EMC) / IEEE Asia-Pacific Symposium on Electromagnetic Compatibility (APEMC), Singapore, SINGAPORE, MAY 14-18, 2018}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } A novel measurement system and a 3D field reconstruction method are described for determining the power density in the close near field of wireless devices transmitting at frequencies from 6 - 110 GHz. Measurements are compared against simulated results. The accuracy is better than 0.5 dB for distances greater than lambda/5 from the radiating source. |
Zang, Jiawei; Carrasco, Eduardo; Wang, X; Encinar, Jose A; A., Alvarez-Melcon; Gomez-Diaz, Juan Sebastian SIW-based reflectarray antennas with sharp gain selectivity and large bandwidth Artículo en actas 2018. @inproceedings{Zang2018, title = {SIW-based reflectarray antennas with sharp gain selectivity and large bandwidth}, author = {Jiawei Zang and Eduardo Carrasco and X Wang and Jose A Encinar and Alvarez-Melcon A. and Juan Sebastian Gomez-Diaz}, doi = {10.1109/apusncursinrsm.2018.8609279}, year = {2018}, date = {2018-01-01}, abstract = {This contribution proposes to couple resonant patches with substrate integrated waveguides (SIW)through various slots to design reflective unit-cells with large bandwidth and very sharp frequency response. Such performance is achieved by appropriately combining the patch and slots resonances, while the required phase delay is obtained by adjusting the SIW length. The proposed cell is planar, easy to manufacture, low-loss, and can operate from micro to millimeter waves. A reflect array based on this unit-cell has been designed and analyzed at 9 GHz, exhibiting a 3 dB bandwidth of 18% and a sharp gain selectivity over 16 dB.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } This contribution proposes to couple resonant patches with substrate integrated waveguides (SIW)through various slots to design reflective unit-cells with large bandwidth and very sharp frequency response. Such performance is achieved by appropriately combining the patch and slots resonances, while the required phase delay is obtained by adjusting the SIW length. The proposed cell is planar, easy to manufacture, low-loss, and can operate from micro to millimeter waves. A reflect array based on this unit-cell has been designed and analyzed at 9 GHz, exhibiting a 3 dB bandwidth of 18% and a sharp gain selectivity over 16 dB. |
Quintana, X; Geday, M A; Oton, J M; Perez-Palomino, Gerardo; Carrasco, Eduardo; Encinar, Jose A Liquid Crystals Tuneable Millimetre Wave Reflectarray Artículo en actas 7th Workshop on Liquid Crystals for Photonic (Jastrzebia Gora, Poland), 2018. @inproceedings{, title = {Liquid Crystals Tuneable Millimetre Wave Reflectarray}, author = {X Quintana and M A Geday and J M Oton and Gerardo Perez-Palomino and Eduardo Carrasco and Jose A Encinar}, year = {2018}, date = {2018-01-01}, booktitle = {7th Workshop on Liquid Crystals for Photonic (Jastrzebia Gora, Poland)}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Carrasco, Eduardo; Encinar, Jose A Developments in Antenna Analysis and Design Capítulo de libro {Mittra, R} (Ed.): DEVELOPMENTS IN ANTENNA ANALYSIS AND DESIGN, VOL 2, 2 , Capítulo Reflectarray Antennas, pp. 323-359, IET, 2018, ISBN: 978-1-78561-891-8; 978-1-78561-890-1. @inbook{Carrasco2018, title = {Developments in Antenna Analysis and Design}, author = {Eduardo Carrasco and Jose A Encinar}, editor = {R} {Mittra}, doi = {10.1049/sbew543g_ch10}, isbn = {978-1-78561-891-8; 978-1-78561-890-1}, year = {2018}, date = {2018-01-01}, booktitle = {DEVELOPMENTS IN ANTENNA ANALYSIS AND DESIGN, VOL 2}, volume = {2}, pages = {323-359}, publisher = {IET}, chapter = {Reflectarray Antennas}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } |
Pino, Antonio; Rodriguez-Vaqueiro, Yolanda; Gonzalez-Valdes, Borja; Rubinos, Oscar; Martinez-de-Rioja, Eduardo; Encinar, Jose A; Toso, Giovanni Design of a Bifocal dual Reflectarray System with Parabolic Main Surface for a Multifed Space Antenna Artículo en actas 2018 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING, pp. 1407-1408, Inst Elect & Elect Engineers Antennas & Propagat Soc; USNC; URSI; Inst Elect & Elect Engineers 2018, ISSN: 1522-3965, (IEEE-Antennas-and-Propagation-Society International Symposium on Antennas and Propagation / USNC/URSI National Radio Science Meeting, Boston, MA, JUL 08-13, 2018). @inproceedings{Pino2018, title = {Design of a Bifocal dual Reflectarray System with Parabolic Main Surface for a Multifed Space Antenna}, author = {Antonio Pino and Yolanda Rodriguez-Vaqueiro and Borja Gonzalez-Valdes and Oscar Rubinos and Eduardo Martinez-de-Rioja and Jose A Encinar and Giovanni Toso}, issn = {1522-3965}, year = {2018}, date = {2018-01-01}, booktitle = {2018 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING}, pages = {1407-1408}, organization = {Inst Elect & Elect Engineers Antennas & Propagat Soc; USNC; URSI; Inst Elect & Elect Engineers}, series = {IEEE Antennas and Propagation Society International Symposium}, abstract = {This communication presents the design of a dual bifocal reflectarray (RA) system consisting of a parabolic main RA and a flat RA subreflector. The concepts of path length shift and virtual normal are introduced to describe the synthesis procedure. An application example is presented for being used as multifed onboard antenna in satellite communications.}, note = {IEEE-Antennas-and-Propagation-Society International Symposium on Antennas and Propagation / USNC/URSI National Radio Science Meeting, Boston, MA, JUL 08-13, 2018}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } This communication presents the design of a dual bifocal reflectarray (RA) system consisting of a parabolic main RA and a flat RA subreflector. The concepts of path length shift and virtual normal are introduced to describe the synthesis procedure. An application example is presented for being used as multifed onboard antenna in satellite communications. |
Pino, Antonio; Rodriguez-Vaqueiro, Yolanda; Gonzalez-Valdes, Borja; Acuna, Marcos Arias; Martinez-de-Rioja, Daniel; Encinar, Jose A; Toso, Giovanni A Multibeam Parabolic Reflectarray for Onboard Tx and Rx Satellite Antennas at the Ka band Artículo en actas 2018 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING, pp. 1409-1410, Inst Elect & Elect Engineers Antennas & Propagat Soc; USNC; URSI; Inst Elect & Elect Engineers 2018, ISSN: 1522-3965, (IEEE-Antennas-and-Propagation-Society International Symposium on Antennas and Propagation / USNC/URSI National Radio Science Meeting, Boston, MA, JUL 08-13, 2018). @inproceedings{Pino2018a, title = {A Multibeam Parabolic Reflectarray for Onboard Tx and Rx Satellite Antennas at the Ka band}, author = {Antonio Pino and Yolanda Rodriguez-Vaqueiro and Borja Gonzalez-Valdes and Marcos Arias Acuna and Daniel Martinez-de-Rioja and Jose A Encinar and Giovanni Toso}, issn = {1522-3965}, year = {2018}, date = {2018-01-01}, booktitle = {2018 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING}, pages = {1409-1410}, organization = {Inst Elect & Elect Engineers Antennas & Propagat Soc; USNC; URSI; Inst Elect & Elect Engineers}, series = {IEEE Antennas and Propagation Society International Symposium}, abstract = {The design and performance of a multi-fed reflectarray antenna built on a parabolic surface is addressed in this communication. The proposed design can be used as onboard satellite Tx and Rx antenna in Ka-band and it is able to reduce to half the required number of antennas due to the ability of the reflectarray to produce two beams per horn by polarization discrimination. An application example providing up to 108 beams by only two antennas is described.}, note = {IEEE-Antennas-and-Propagation-Society International Symposium on Antennas and Propagation / USNC/URSI National Radio Science Meeting, Boston, MA, JUL 08-13, 2018}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } The design and performance of a multi-fed reflectarray antenna built on a parabolic surface is addressed in this communication. The proposed design can be used as onboard satellite Tx and Rx antenna in Ka-band and it is able to reduce to half the required number of antennas due to the ability of the reflectarray to produce two beams per horn by polarization discrimination. An application example providing up to 108 beams by only two antennas is described. |
Ramirez-Torres, Mario; Ferreras, Marta; Hernandez, Clara; Garcia-de-la-Cueva, Carlos; Barba, Mariano; Perez-Palomino, Gerardo; Encinar, Jose A; Sierra-Castaner, Manuel; Grajal, Jesus; Vazquez-Roy, Jose-Luis; Rajo-Iglesias, Eva Technological Developments for a Space-borne Orbital Debris Radar at 94 GHz Artículo en actas 2018 IEEE RADAR CONFERENCE (RADARCONF18), pp. 564-569, IEEE; IEEE Instrumentat Measurement Soc; Geoscience & Remote sensing soc; Aerospace & Electronic Syst Soc 2018, ISSN: 1097-5764, (IEEE Radar Conference, Oklahoma City, OK, APR 23-27, 2018). @inproceedings{RamirezTorres2018, title = {Technological Developments for a Space-borne Orbital Debris Radar at 94 GHz}, author = {Mario Ramirez-Torres and Marta Ferreras and Clara Hernandez and Carlos Garcia-de-la-Cueva and Mariano Barba and Gerardo Perez-Palomino and Jose A Encinar and Manuel Sierra-Castaner and Jesus Grajal and Jose-Luis Vazquez-Roy and Eva Rajo-Iglesias}, doi = {10.1109/radar.2018.8378621}, issn = {1097-5764}, year = {2018}, date = {2018-01-01}, booktitle = {2018 IEEE RADAR CONFERENCE (RADARCONF18)}, pages = {564-569}, organization = {IEEE; IEEE Instrumentat Measurement Soc; Geoscience & Remote sensing soc; Aerospace & Electronic Syst Soc}, series = {IEEE Radar Conference}, abstract = {This paper describes the design and some technological developments for a 94-GHz heterodyne chirp radar prototype for space debris detection. We use off-the-shelf components for both the signal generation and the acquisition subsystems, and W-band GaN solid-state technology for the high-power Tx/Rx modules. Several radiating structures are considered in order to expand the system for monopulse tracking operation.}, note = {IEEE Radar Conference, Oklahoma City, OK, APR 23-27, 2018}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } This paper describes the design and some technological developments for a 94-GHz heterodyne chirp radar prototype for space debris detection. We use off-the-shelf components for both the signal generation and the acquisition subsystems, and W-band GaN solid-state technology for the high-power Tx/Rx modules. Several radiating structures are considered in order to expand the system for monopulse tracking operation. |
Gil, Jose M; Gómez, Rafael; Gonzalez-de-Aza, Miguel A; Garcia, Jesus Higher-Order Basis Functions for an Enhanced Approximation of the Magnetic-Field Integral Equation Artículo en actas London, UK, 2018. @inproceedings{Gil2018a, title = {Higher-Order Basis Functions for an Enhanced Approximation of the Magnetic-Field Integral Equation}, author = {Jose M Gil and Rafael Gómez and Miguel A Gonzalez-de-Aza and Jesus Garcia}, year = {2018}, date = {2018-01-01}, address = {London, UK}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Rubio, Jesús; Garcia, Alfonso Gómez; Alcalá, Rafael Gómez; Campos-Roca, Yolanda; Garcia, Jesus; Gonzalez-de-Aza, Miguel A; Gil, Jose M; Zapata, Juan An Efficient Methodology for SIW Circuits Analysis Artículo en actas Coimbra, Portugal, 2018. @inproceedings{Rubio2018, title = {An Efficient Methodology for SIW Circuits Analysis}, author = {Jesús Rubio and Alfonso Gómez Garcia and Rafael Gómez Alcalá and Yolanda Campos-Roca and Jesus Garcia and Miguel A Gonzalez-de-Aza and Jose M Gil and Juan Zapata}, year = {2018}, date = {2018-01-01}, address = {Coimbra, Portugal}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Buesa-Zubiria, Ana María; Esteban, J Design of Five-Way Bagley Polygon Power Dividers in Rectangular Waveguide Artículo de revista IEEE Transactions on Microwave Theory and Techniques, 66 (1), pp. 116-127, 2018, ISSN: 0018-9480. @article{BuesaZubiria2018, title = {Design of Five-Way Bagley Polygon Power Dividers in Rectangular Waveguide}, author = {Ana María Buesa-Zubiria and J Esteban}, doi = {10.1109/TMTT.2017.2738002}, issn = {0018-9480}, year = {2018}, date = {2018-01-01}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {66}, number = {1}, pages = {116-127}, abstract = {Power combiners are in general complex to manufacture and do not show a compact structure when more than two output ports are needed. To overcome these problems, the design of a five-way Bagley polygon in rectangular waveguide is presented. The proposed geometry is simple, suitable for an efficient optimization, and allows its fabrication by milling. A five-way Ku-band E-plane rectangular waveguide Bagley polygon for a 17% fractional bandwidth is designed, manufactured and measured. The measured results show return loss better than 28 dB and amplitude and phase imbalances below +-0.2 dB and +-5º, respectively, which, along with the waveguide low losses, leads to a 98% efficiency as power combiner.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Power combiners are in general complex to manufacture and do not show a compact structure when more than two output ports are needed. To overcome these problems, the design of a five-way Bagley polygon in rectangular waveguide is presented. The proposed geometry is simple, suitable for an efficient optimization, and allows its fabrication by milling. A five-way Ku-band E-plane rectangular waveguide Bagley polygon for a 17% fractional bandwidth is designed, manufactured and measured. The measured results show return loss better than 28 dB and amplitude and phase imbalances below +-0.2 dB and +-5º, respectively, which, along with the waveguide low losses, leads to a 98% efficiency as power combiner. |
2017 |
Polo-Lopez, Lucas; Ruiz-Cruz, Jorge A; Montejo-Garai, Jose R; Rebollar, Jesus M Analysis of Waveguide Devices Involving Lateral and Transverse Perfect Magnetic Wall Boundary Conditions by the Mode-Matching Method Artículo de revista RADIO SCIENCE, 52 (9), pp. 1223-1234, 2017, ISSN: 0048-6604, (URSI-Commission-B International Symposium on Electromagnetic Theory (EMTS), Espoo, FINLAND, AUG 14-18, 2016). @article{PoloLopez2017, title = {Analysis of Waveguide Devices Involving Lateral and Transverse Perfect Magnetic Wall Boundary Conditions by the Mode-Matching Method}, author = {Lucas Polo-Lopez and Jorge A Ruiz-Cruz and Jose R Montejo-Garai and Jesus M Rebollar}, doi = {10.1002/2017RS006327}, issn = {0048-6604}, year = {2017}, date = {2017-09-01}, journal = {RADIO SCIENCE}, volume = {52}, number = {9}, pages = {1223-1234}, organization = {URSI, Commiss B}, abstract = {This contribution presents the analysis of waveguide problems involving general boundary conditions of perfect magnetic wall. This type of boundary condition is used in electromagnetic solvers very commonly when the device under analysis has physical symmetry, in order to speed up the computation time. This paper is focused on extending its use in problems having this type of boundary condition in the lateral and transverse walls of the waveguides involved in the problem. The presented formulation, based on the mode-matching method, will be applied to classical waveguide devices, but also to address radiating problems with a novel formulation. Different applications will be targeted, and the simulation results will be compared with those obtained by other numerical techniques (based on different solvers), validating the presented approach as another suitable tool for computer-aided design.}, note = {URSI-Commission-B International Symposium on Electromagnetic Theory (EMTS), Espoo, FINLAND, AUG 14-18, 2016}, keywords = {}, pubstate = {published}, tppubtype = {article} } This contribution presents the analysis of waveguide problems involving general boundary conditions of perfect magnetic wall. This type of boundary condition is used in electromagnetic solvers very commonly when the device under analysis has physical symmetry, in order to speed up the computation time. This paper is focused on extending its use in problems having this type of boundary condition in the lateral and transverse walls of the waveguides involved in the problem. The presented formulation, based on the mode-matching method, will be applied to classical waveguide devices, but also to address radiating problems with a novel formulation. Different applications will be targeted, and the simulation results will be compared with those obtained by other numerical techniques (based on different solvers), validating the presented approach as another suitable tool for computer-aided design. |
Nematollahi, Hoda; Laurin, Jean-Jacques; Barba, Mariano; Encinar, Jose A Realization of Focused Beam and Shaped Beam Transmitarrays Based on Broadband Unit Cells Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 65 (8), pp. 4368-4373, 2017, ISSN: 0018-926X. @article{Nematollahi2017, title = {Realization of Focused Beam and Shaped Beam Transmitarrays Based on Broadband Unit Cells}, author = {Hoda Nematollahi and Jean-Jacques Laurin and Mariano Barba and Jose A Encinar}, doi = {10.1109/TAP.2017.2717969}, issn = {0018-926X}, year = {2017}, date = {2017-08-01}, journal = {IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, volume = {65}, number = {8}, pages = {4368-4373}, abstract = {A focused beam and a shaped beam four-layer transmitarray (TA) antenna operating in the K-band have been designed, fabricated, and measured. Four-layer unit cells allowing a transmission phase range of 360 degrees are used. The gain of the beam-focusing TA is 30.3 dB at 19 GHz with an aperture efficiency of 34.9%. Compared with TAs proposed in the literature, the presented antenna bandwidth is almost two times larger with a -1 dB gain bandwidth of 18% and a -3 dB gain bandwidth of 25.5%. A second TA radiating a shaped beam was designed, and its measured pattern correlates well with theoretical calculations. The sensitivity of the proposed unit cells to fabrication errors and the effect of oblique incidence are also studied.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A focused beam and a shaped beam four-layer transmitarray (TA) antenna operating in the K-band have been designed, fabricated, and measured. Four-layer unit cells allowing a transmission phase range of 360 degrees are used. The gain of the beam-focusing TA is 30.3 dB at 19 GHz with an aperture efficiency of 34.9%. Compared with TAs proposed in the literature, the presented antenna bandwidth is almost two times larger with a -1 dB gain bandwidth of 18% and a -3 dB gain bandwidth of 25.5%. A second TA radiating a shaped beam was designed, and its measured pattern correlates well with theoretical calculations. The sensitivity of the proposed unit cells to fabrication errors and the effect of oblique incidence are also studied. |
Headland, D; Niu, T; Carrasco, Eduardo; Abbott, D; Sriram, S; Bhaskaran, M; Fumeaux, C; Withayachumnankul, W Terahertz Reflectarrays and Nonuniform Metasurfaces Artículo de revista IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, 23 (4), 2017, ISSN: 1077-260X. @article{ISI:000395874900001, title = {Terahertz Reflectarrays and Nonuniform Metasurfaces}, author = {D Headland and T Niu and Eduardo Carrasco and D Abbott and S Sriram and M Bhaskaran and C Fumeaux and W Withayachumnankul}, doi = {10.1109/JSTQE.2016.2640452}, issn = {1077-260X}, year = {2017}, date = {2017-07-01}, journal = {IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS}, volume = {23}, number = {4}, abstract = {This paper covers our recent work on terahertz reflectarray antennas, providing a broad, critical perspective, and contrasting different approaches. The reflectarray antenna is a well-established device that offers significant control and freedom over the directionality and characteristics of its radiation pattern. Such a capability is critical to the successful development of commercially viable terahertz technologies. In this paper, the design, fabrication, and experimental characterization of four terahertz reflectarray devices is presented, based on two different classes of terahertz resonator. The first class is the metallic resonator, and three such reflectarray devices are presented, with each offering its own particular birefringent behavior. The second class is the dielectric resonator, which promises higher efficiency than the metallic resonator, and one such reflectarray device is presented. Devices such as these provide significant design freedom for defining particular beam-shaping operations for diverse application requirements. It is hoped that, with future advances in terahertz resonator technology, reflectarray antennas will prove instrumental in facilitating numerous promising applications of the terahertz range, including high-volume communications, noninvasive medical imaging, and security screening.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper covers our recent work on terahertz reflectarray antennas, providing a broad, critical perspective, and contrasting different approaches. The reflectarray antenna is a well-established device that offers significant control and freedom over the directionality and characteristics of its radiation pattern. Such a capability is critical to the successful development of commercially viable terahertz technologies. In this paper, the design, fabrication, and experimental characterization of four terahertz reflectarray devices is presented, based on two different classes of terahertz resonator. The first class is the metallic resonator, and three such reflectarray devices are presented, with each offering its own particular birefringent behavior. The second class is the dielectric resonator, which promises higher efficiency than the metallic resonator, and one such reflectarray device is presented. Devices such as these provide significant design freedom for defining particular beam-shaping operations for diverse application requirements. It is hoped that, with future advances in terahertz resonator technology, reflectarray antennas will prove instrumental in facilitating numerous promising applications of the terahertz range, including high-volume communications, noninvasive medical imaging, and security screening. |
Florencio, Rafael; Boix, Rafael R; Encinar, Jose A; Toso, Giovanni Optimized Periodic MoM for the Analysis and Design of Dual Polarization Multilayered Reflectarray Antennas Made of Dipoles Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 65 (7), pp. 3623-3637, 2017, ISSN: 0018-926X. @article{Florencio2017, title = {Optimized Periodic MoM for the Analysis and Design of Dual Polarization Multilayered Reflectarray Antennas Made of Dipoles}, author = {Rafael Florencio and Rafael R Boix and Jose A Encinar and Giovanni Toso}, doi = {10.1109/TAP.2017.2702700}, issn = {0018-926X}, year = {2017}, date = {2017-07-01}, journal = {IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, volume = {65}, number = {7}, pages = {3623-3637}, abstract = {A hybrid version of the Method of Moments (MoM) is applied to the analysis of the scattering of plane waves by periodic multilayered structures containing dipoles at two metallization levels. The MoM matrix entries involving basis functions (BFs) at different metallization levels are computed in the spectral domain as double infinite summations with fast exponential convergence. The MoM matrix entries involving BFs at the same metallization level are computed in the spatial domain as double integrals, which require low-order quadrature rules. The integrands are cross correlations between BFs times multilayered periodic Green's functions (MPGFs). The cross correlations between BFs are obtained in terms of elliptic integrals of first and second kind. Also, the MPGFs are accurately interpolated in 4-D in terms of both the spatial variables and the angles of incidence. The hybrid MoM proposed is used in the design of dual polarization reflectarray antennas under the local periodicity assumption. Thanks to the 4-D interpolation of the MPGFs, which minimizes the total number of MPGFs that have to be computed per reflectarray element, the proposed hybrid MoM is shown to be around 15 times faster than the standard spectral domain MoM in the design of the antennas.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A hybrid version of the Method of Moments (MoM) is applied to the analysis of the scattering of plane waves by periodic multilayered structures containing dipoles at two metallization levels. The MoM matrix entries involving basis functions (BFs) at different metallization levels are computed in the spectral domain as double infinite summations with fast exponential convergence. The MoM matrix entries involving BFs at the same metallization level are computed in the spatial domain as double integrals, which require low-order quadrature rules. The integrands are cross correlations between BFs times multilayered periodic Green's functions (MPGFs). The cross correlations between BFs are obtained in terms of elliptic integrals of first and second kind. Also, the MPGFs are accurately interpolated in 4-D in terms of both the spatial variables and the angles of incidence. The hybrid MoM proposed is used in the design of dual polarization reflectarray antennas under the local periodicity assumption. Thanks to the 4-D interpolation of the MPGFs, which minimizes the total number of MPGFs that have to be computed per reflectarray element, the proposed hybrid MoM is shown to be around 15 times faster than the standard spectral domain MoM in the design of the antennas. |
Martinez-de-Rioja, Eduardo; Encinar, Jose A; Barba, Mariano; Florencio, Rafael; Boix, Rafael R; Losada, Vicente Dual Polarized Reflectarray Transmit Antenna for Operation in Ku- and Ka-Bands With Independent Feeds Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 65 (6), pp. 3241-3246, 2017, ISSN: 0018-926X. @article{MartinezdeRioja2017, title = {Dual Polarized Reflectarray Transmit Antenna for Operation in Ku- and Ka-Bands With Independent Feeds}, author = {Eduardo Martinez-de-Rioja and Jose A Encinar and Mariano Barba and Rafael Florencio and Rafael R Boix and Vicente Losada}, doi = {10.1109/TAP.2017.2689059}, issn = {0018-926X}, year = {2017}, date = {2017-06-01}, journal = {IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, volume = {65}, number = {6}, pages = {3241-3246}, abstract = {A reflectarray antenna capable of operating independently in the transmit frequencies (from a satellite) in Ku-band (11-13 GHz) and Ka-band (19-20 GHz) has been proposed and demonstrated. To prove that independent beams can be optimized in each frequency band using separate feeds, a 25-cm demonstrator that generates a focused beam in dual polarization (linear or circular) has been designed, manufactured, and tested. The reflectarray cells comprise two stacked sets of coupled parallel dipoles for each polarization, which permits an independent optimization of the phase for each frequency and polarization. The simulated and measured radiation patterns for both copolar and cross-polar components are in good agreement in Ku- and Ka-bands.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A reflectarray antenna capable of operating independently in the transmit frequencies (from a satellite) in Ku-band (11-13 GHz) and Ka-band (19-20 GHz) has been proposed and demonstrated. To prove that independent beams can be optimized in each frequency band using separate feeds, a 25-cm demonstrator that generates a focused beam in dual polarization (linear or circular) has been designed, manufactured, and tested. The reflectarray cells comprise two stacked sets of coupled parallel dipoles for each polarization, which permits an independent optimization of the phase for each frequency and polarization. The simulated and measured radiation patterns for both copolar and cross-polar components are in good agreement in Ku- and Ka-bands. |
Echeveste, Jose Ignacio; Gonzalez-de-Aza, Miguel A; Rubio, Jesus; Craeye, Christophe Gradient-Based Aperiodic Array Synthesis of Real Arrays With Uniform Amplitude Excitation Including Mutual Coupling Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 65 (2), pp. 541-551, 2017, ISSN: 0018-926X. @article{IgnacioEcheveste2017, title = {Gradient-Based Aperiodic Array Synthesis of Real Arrays With Uniform Amplitude Excitation Including Mutual Coupling}, author = {Jose Ignacio Echeveste and Miguel A Gonzalez-de-Aza and Jesus Rubio and Christophe Craeye}, doi = {10.1109/TAP.2016.2638359}, issn = {0018-926X}, year = {2017}, date = {2017-02-01}, journal = {IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, volume = {65}, number = {2}, pages = {541-551}, abstract = {This paper proposes the synthesis of aperiodic arrays of realistic antennas excited with uniform amplitude, where the mutual coupling between elements is rigorously taken into account. A cost function that involves the expression of the radiated field of the coupled array is obtained and its gradient is evaluated in order to move the elements in the corresponding direction at each iteration. The synthesis method involves the calculation of the gradient of the field radiated by the coupled array, which is obtained analytically by using a full-wave method based on the generalized scattering matrix, spherical mode expansions and rotation, and translation properties of spherical waves.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper proposes the synthesis of aperiodic arrays of realistic antennas excited with uniform amplitude, where the mutual coupling between elements is rigorously taken into account. A cost function that involves the expression of the radiated field of the coupled array is obtained and its gradient is evaluated in order to move the elements in the corresponding direction at each iteration. The synthesis method involves the calculation of the gradient of the field radiated by the coupled array, which is obtained analytically by using a full-wave method based on the generalized scattering matrix, spherical mode expansions and rotation, and translation properties of spherical waves. |
Prado, Daniel Rodriguez; Arrebola, Manuel; Pino, Marcos R; Florencio, Rafael; Boix, Rafael R; Encinar, Jose A; Las-Heras, Fernando Efficient Crosspolar Optimization of Shaped-Beam Dual-Polarized Reflectarrays Using Full-Wave Analysis for the Antenna Element Characterization Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 65 (2), pp. 623-635, 2017, ISSN: 0018-926X. @article{Prado2017, title = {Efficient Crosspolar Optimization of Shaped-Beam Dual-Polarized Reflectarrays Using Full-Wave Analysis for the Antenna Element Characterization}, author = {Daniel Rodriguez Prado and Manuel Arrebola and Marcos R Pino and Rafael Florencio and Rafael R Boix and Jose A Encinar and Fernando Las-Heras}, doi = {10.1109/TAP.2016.2633950}, issn = {0018-926X}, year = {2017}, date = {2017-02-01}, journal = {IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, volume = {65}, number = {2}, pages = {623-635}, abstract = {A method for the optimization of the crosspolar component of dual-polarized reflectarrays using full-wave analysis at the element level is described and demonstrated. The reflectarray full-wave analysis is based on local periodicity (LP) and integrated within the optimization process in order to accurately characterize the crosspolar far field. The proposed method is based on the generalized Intersection Approach framework using the Levenberg-Marquardt Algorithm as backward projector, and the employed full-wave analysis is based on the Method of Moments assuming Local Periodicity (MoM-LP). Several strategies to accelerate the computations are exploited, such as the parallelization of all the algorithm building blocks. To minimize the impact of MoM-LP in the optimization process, a strategy to reduce the number of MoM-LP calls is described, further accelerating the algorithm. Moreover, the convergence is improved by working with the squared field amplitude, alleviating the trap problem of local optimizers. This method allows to optimize the crosspolar component in the whole visible region or only in the coverage zone to facilitate the convergence, reducing computing time and memory usage. Two test cases are provided to validate the technique, one with an isoflux pattern for global Earth coverage and another with European coverage for direct broadcast satellite application.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A method for the optimization of the crosspolar component of dual-polarized reflectarrays using full-wave analysis at the element level is described and demonstrated. The reflectarray full-wave analysis is based on local periodicity (LP) and integrated within the optimization process in order to accurately characterize the crosspolar far field. The proposed method is based on the generalized Intersection Approach framework using the Levenberg-Marquardt Algorithm as backward projector, and the employed full-wave analysis is based on the Method of Moments assuming Local Periodicity (MoM-LP). Several strategies to accelerate the computations are exploited, such as the parallelization of all the algorithm building blocks. To minimize the impact of MoM-LP in the optimization process, a strategy to reduce the number of MoM-LP calls is described, further accelerating the algorithm. Moreover, the convergence is improved by working with the squared field amplitude, alleviating the trap problem of local optimizers. This method allows to optimize the crosspolar component in the whole visible region or only in the coverage zone to facilitate the convergence, reducing computing time and memory usage. Two test cases are provided to validate the technique, one with an isoflux pattern for global Earth coverage and another with European coverage for direct broadcast satellite application. |
Dressel, S; Gosselin, M -C; Capstick, M H; Carrasco, Eduardo; Weyland, M S; Scheidegger, S; Neufeld, E; Kuster, N; Bodis, S; Bley, Rohrer C Novel hyperthermia applicator system allows adaptive treatment planning: Preliminary clinical results in tumour-bearing animals Artículo de revista VETERINARY AND COMPARATIVE ONCOLOGY, 16 (2), pp. 202-213, 2017, ISSN: 1476-5810. @article{ISI:000432037700007, title = {Novel hyperthermia applicator system allows adaptive treatment planning: Preliminary clinical results in tumour-bearing animals}, author = {S Dressel and M -C Gosselin and M H Capstick and Eduardo Carrasco and M S Weyland and S Scheidegger and E Neufeld and N Kuster and S Bodis and Rohrer C Bley}, doi = {10.1111/vco.12340}, issn = {1476-5810}, year = {2017}, date = {2017-01-01}, journal = {VETERINARY AND COMPARATIVE ONCOLOGY}, volume = {16}, number = {2}, pages = {202-213}, abstract = {Hyperthermia (HT) as an adjuvant to radiation therapy (RT) is a multimodality treatment method to enhance therapeutic efficacy in different tumours. High demands are placed on the hardware and treatment planning software to guarantee adequately planned and applied HT treatments. The aim of this prospective study was to determine the effectiveness and safety of the novel HT system in tumour-bearing dogs and cats in terms of local response and toxicity as well as to compare planned with actual achieved data during heating. A novel applicator with a flexible number of elements and integrated closed-loop temperature feedback control system, and a tool for patient-specific treatment planning were used in a combined thermoradiotherapy protocol. Good agreement between predictions from planning and clinical outcome was found in 7 of 8 cases. Effective HT treatments were planned and verified with the novel system and provided improved quality of life in all but 1 patient. This individualized treatment planning and controlled heat exposure allows adaptive, flexible and safe HT treatments in palliatively treated animal patients.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hyperthermia (HT) as an adjuvant to radiation therapy (RT) is a multimodality treatment method to enhance therapeutic efficacy in different tumours. High demands are placed on the hardware and treatment planning software to guarantee adequately planned and applied HT treatments. The aim of this prospective study was to determine the effectiveness and safety of the novel HT system in tumour-bearing dogs and cats in terms of local response and toxicity as well as to compare planned with actual achieved data during heating. A novel applicator with a flexible number of elements and integrated closed-loop temperature feedback control system, and a tool for patient-specific treatment planning were used in a combined thermoradiotherapy protocol. Good agreement between predictions from planning and clinical outcome was found in 7 of 8 cases. Effective HT treatments were planned and verified with the novel system and provided improved quality of life in all but 1 patient. This individualized treatment planning and controlled heat exposure allows adaptive, flexible and safe HT treatments in palliatively treated animal patients. |
Douglas, M G; Portelli, L; Carrasco, Eduardo; Christ, A; Jain, N; Loader, B; Kuster, N Robust and Comprehensive Validation of SAR Array Systems: Antennas, Procedures, and Acceptance Criteria Artículo en actas Joint Meeting of the Bioelectromagnetics Society (BEMS) and the European BioElectromagnetics Association (EBEA), 2017. @inproceedings{, title = {Robust and Comprehensive Validation of SAR Array Systems: Antennas, Procedures, and Acceptance Criteria}, author = {M G Douglas and L Portelli and Eduardo Carrasco and A Christ and N Jain and B Loader and N Kuster}, year = {2017}, date = {2017-01-01}, booktitle = {Joint Meeting of the Bioelectromagnetics Society (BEMS) and the European BioElectromagnetics Association (EBEA)}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Echeveste, Jose Ignacio; Craeye, Christophe; Rubio, Jesus; Gonzalez-de-Aza, Miguel A; Zapata, Juan Optimization of the array element positions based on the analytical dependence of the mutual coupling in the GSM finite array formulation Artículo en actas 2017 IEEE MTT-S INTERNATIONAL CONFERENCE ON NUMERICAL ELECTROMAGNETIC AND MULTIPHYSICS MODELING AND OPTIMIZATION FOR RF, MICROWAVE, AND TERAHERTZ APPLICATIONS (NEMO), pp. 245-247, IEEE MTT S 2017, ISBN: 978-1-5090-4837-3, (IEEE-MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), Seville, SPAIN, MAY 17-19, 2017). @inproceedings{Echeveste2017b, title = {Optimization of the array element positions based on the analytical dependence of the mutual coupling in the GSM finite array formulation}, author = {Jose Ignacio Echeveste and Christophe Craeye and Jesus Rubio and Miguel A Gonzalez-de-Aza and Juan Zapata}, isbn = {978-1-5090-4837-3}, year = {2017}, date = {2017-01-01}, booktitle = {2017 IEEE MTT-S INTERNATIONAL CONFERENCE ON NUMERICAL ELECTROMAGNETIC AND MULTIPHYSICS MODELING AND OPTIMIZATION FOR RF, MICROWAVE, AND TERAHERTZ APPLICATIONS (NEMO)}, pages = {245-247}, organization = {IEEE MTT S}, abstract = {Positions of array antenna elements are optimized taking advantage of the analytical dependence of the mutual coupling in the Generalized Scattering Matrix (GSM) finite array formulation. First, spatial derivatives for the GSM formulation are analytically computed. Then, they are applied to the synthesis of uniform amplitude finite arrays, by rotating the elements of the array or by changing their positions, through a gradient-based optimization method.}, note = {IEEE-MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), Seville, SPAIN, MAY 17-19, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Positions of array antenna elements are optimized taking advantage of the analytical dependence of the mutual coupling in the Generalized Scattering Matrix (GSM) finite array formulation. First, spatial derivatives for the GSM formulation are analytically computed. Then, they are applied to the synthesis of uniform amplitude finite arrays, by rotating the elements of the array or by changing their positions, through a gradient-based optimization method. |
Echeveste, Jose Ignacio; Rubio, Jesus; Gonzalez-de-Aza, Miguel A; Craeye, Christophe Pattern Synthesis of Coupled Antenna Arrays via Element Rotation Artículo de revista IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, 16 , pp. 1707-1710, 2017, ISSN: 1536-1225. @article{IgnacioEcheveste2017a, title = {Pattern Synthesis of Coupled Antenna Arrays via Element Rotation}, author = {Jose Ignacio Echeveste and Jesus Rubio and Miguel A Gonzalez-de-Aza and Christophe Craeye}, doi = {10.1109/LAWP.2017.2668397}, issn = {1536-1225}, year = {2017}, date = {2017-01-01}, journal = {IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS}, volume = {16}, pages = {1707-1710}, abstract = {In this work, a pattern synthesis method is presented for coupled antenna arrays via element rotation. The array is rigorously analyzed with a hybrid and full-wave analysis method based on the 3-D finite element method, modal analysis, generalized scattering matrix, and rotation and translation properties of spherical waves, including mutual coupling effects. The co- and cross-polar components are optimized by means of a gradient method, according to a specific cost function, via successive rotations of the elements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work, a pattern synthesis method is presented for coupled antenna arrays via element rotation. The array is rigorously analyzed with a hybrid and full-wave analysis method based on the 3-D finite element method, modal analysis, generalized scattering matrix, and rotation and translation properties of spherical waves, including mutual coupling effects. The co- and cross-polar components are optimized by means of a gradient method, according to a specific cost function, via successive rotations of the elements. |
Geaney, Ciaran; Sun, Jianwei; Hum, Sean Victor; Martinez-de-Rioja, Eduardo; Encinar, Jose A Synthesis of a Multi-beam Dual Reflectarray Antenna Using Genetic Algorithms Artículo en actas 2017 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING, pp. 1179-1180, IEEE Antennas & Propagat Soc; Inst Elect & Elect Engineers; USNC; URSI 2017, ISSN: 1522-3965, (International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, San Diego, CA, JUL 09-14, 2017). @inproceedings{Geaney2017, title = {Synthesis of a Multi-beam Dual Reflectarray Antenna Using Genetic Algorithms}, author = {Ciaran Geaney and Jianwei Sun and Sean Victor Hum and Eduardo Martinez-de-Rioja and Jose A Encinar}, issn = {1522-3965}, year = {2017}, date = {2017-01-01}, booktitle = {2017 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING}, pages = {1179-1180}, organization = {IEEE Antennas & Propagat Soc; Inst Elect & Elect Engineers; USNC; URSI}, series = {IEEE Antennas and Propagation Society International Symposium}, abstract = {This paper presents the results of an initial study on the use of genetic algorithms to synthesize multi-beam patterns for dual-reflectarray antennas operating with a single feed per beam architecture. Under the simple two-dimensional center-fed case considered, the method shows promise when compared to a traditional bifocal synthesis method with regard to spillover efficiency.}, note = {International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, San Diego, CA, JUL 09-14, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } This paper presents the results of an initial study on the use of genetic algorithms to synthesize multi-beam patterns for dual-reflectarray antennas operating with a single feed per beam architecture. Under the simple two-dimensional center-fed case considered, the method shows promise when compared to a traditional bifocal synthesis method with regard to spillover efficiency. |
Prado, Daniel Rodriguez; Arrebola, Manuel; Pino, Marcos R; Las-Heras, Fernando; Encinar, Jose A Efficient Computation of the Reflectarray Far Fields in Adaptive Grids for Speed Improvement Artículo en actas 2017 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING, pp. 1181-1182, IEEE Antennas & Propagat Soc; Inst Elect & Elect Engineers; USNC; URSI 2017, ISSN: 1522-3965, (International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, San Diego, CA, JUL 09-14, 2017). @inproceedings{Prado2017a, title = {Efficient Computation of the Reflectarray Far Fields in Adaptive Grids for Speed Improvement}, author = {Daniel Rodriguez Prado and Manuel Arrebola and Marcos R Pino and Fernando Las-Heras and Jose A Encinar}, issn = {1522-3965}, year = {2017}, date = {2017-01-01}, booktitle = {2017 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING}, pages = {1181-1182}, organization = {IEEE Antennas & Propagat Soc; Inst Elect & Elect Engineers; USNC; URSI}, series = {IEEE Antennas and Propagation Society International Symposium}, abstract = {A technique for the efficient computation of the radiation patterns of reflectarray antennas in an adaptive grid for speed improvement is presented. It relies on the use of the Non-Uniform Fast Fourier Transform (NUFFT) to efficiently compute the spectrum functions. This new application of the NUFFT improves computing times and memory usage, with regard to the use of the FFT, for very directive reflectarrays in which a high resolution in the UV grid is needed to correctly characterize the main beam and adjacent secondary lobes.}, note = {International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, San Diego, CA, JUL 09-14, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } A technique for the efficient computation of the radiation patterns of reflectarray antennas in an adaptive grid for speed improvement is presented. It relies on the use of the Non-Uniform Fast Fourier Transform (NUFFT) to efficiently compute the spectrum functions. This new application of the NUFFT improves computing times and memory usage, with regard to the use of the FFT, for very directive reflectarrays in which a high resolution in the UV grid is needed to correctly characterize the main beam and adjacent secondary lobes. |
Martinez-de-Rioja, Eduardo; Encinar, Jose A; Geaney, Ciaran; Hum, Sean Victor; Pino, Antonio Study of Bifocal Dual Reflectarray Configurations for Multi-Beam Antennas in Ka-Band Artículo en actas 2017 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING, pp. 1183-1184, IEEE Antennas & Propagat Soc; Inst Elect & Elect Engineers; USNC; URSI 2017, ISSN: 1522-3965, (International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, San Diego, CA, JUL 09-14, 2017). @inproceedings{MartinezdeRioja2017a, title = {Study of Bifocal Dual Reflectarray Configurations for Multi-Beam Antennas in Ka-Band}, author = {Eduardo Martinez-de-Rioja and Jose A Encinar and Ciaran Geaney and Sean Victor Hum and Antonio Pino}, issn = {1522-3965}, year = {2017}, date = {2017-01-01}, booktitle = {2017 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING}, pages = {1183-1184}, organization = {IEEE Antennas & Propagat Soc; Inst Elect & Elect Engineers; USNC; URSI}, series = {IEEE Antennas and Propagation Society International Symposium}, abstract = {This paper describes the design of multi-beam dual reflectarray antennas for operation in the Ka-band satellite transmission band (around 20 GHz), using the bifocal design concept to improve antenna performance. This technique has been first applied to obtain beam compression with adjacent feeds, resulting in low radiation efficiency. Then it has been used without beam compression to correct beam aberration, showing better results than an equivalent single-focus reference reflector. The simulated radiation patterns in the elevation plane and the amplitude distributions of the incident field on each reflectarray have been calculated for different antenna configurations.}, note = {International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, San Diego, CA, JUL 09-14, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } This paper describes the design of multi-beam dual reflectarray antennas for operation in the Ka-band satellite transmission band (around 20 GHz), using the bifocal design concept to improve antenna performance. This technique has been first applied to obtain beam compression with adjacent feeds, resulting in low radiation efficiency. Then it has been used without beam compression to correct beam aberration, showing better results than an equivalent single-focus reference reflector. The simulated radiation patterns in the elevation plane and the amplitude distributions of the incident field on each reflectarray have been calculated for different antenna configurations. |
Florencio, Rafael; Boix, Rafael R; Encinar, Jose A Numerical Advances in the Full-Wave Analysis of Periodic Multilayered Structures with Application to Reflectarray Antennas Artículo en actas {Gurel, L} (Ed.): 2017 COMPUTING AND ELECTROMAGNETICS INTERNATIONAL WORKSHOP (CEM'17), pp. 3-4, ABAKUS 2017, ISBN: 978-1-5386-1732-8, (International Workshop on Computing and Electromagnetics (CEM), Barcelona, SPAIN, JUN 21-24, 2017). @inproceedings{Florencio2017a, title = {Numerical Advances in the Full-Wave Analysis of Periodic Multilayered Structures with Application to Reflectarray Antennas}, author = {Rafael Florencio and Rafael R Boix and Jose A Encinar}, editor = {L} {Gurel}, isbn = {978-1-5386-1732-8}, year = {2017}, date = {2017-01-01}, booktitle = {2017 COMPUTING AND ELECTROMAGNETICS INTERNATIONAL WORKSHOP (CEM'17)}, pages = {3-4}, organization = {ABAKUS}, abstract = {A novel hybrid spectral-spatial method of moments (MoM) approach is introduced for the analysis of multilayered periodic structures containing either patches or dipoles in the unit cell. The novel hybrid MoM approach and the pure spectral MoM approach are both applied to the analysis and design of reflectarray antennas made of patches or dipoles under the local periodicity assumption. The results indicate that the hybrid approach is always at least one order of magnitud faster than the spectral approach in the analysis and design of the antennas.}, note = {International Workshop on Computing and Electromagnetics (CEM), Barcelona, SPAIN, JUN 21-24, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } A novel hybrid spectral-spatial method of moments (MoM) approach is introduced for the analysis of multilayered periodic structures containing either patches or dipoles in the unit cell. The novel hybrid MoM approach and the pure spectral MoM approach are both applied to the analysis and design of reflectarray antennas made of patches or dipoles under the local periodicity assumption. The results indicate that the hybrid approach is always at least one order of magnitud faster than the spectral approach in the analysis and design of the antennas. |
Tienda, Carolina; Encinar, Jose A; Barba, Mariano; Arrebola, Manuel Dual Reflectarray Antennas for Contoured Beam and Beam Scanning Applications Artículo en actas 2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP), pp. 76-79, Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech 2017, ISSN: 2164-3342, (11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017). @inproceedings{Tienda2017, title = {Dual Reflectarray Antennas for Contoured Beam and Beam Scanning Applications}, author = {Carolina Tienda and Jose A Encinar and Mariano Barba and Manuel Arrebola}, issn = {2164-3342}, year = {2017}, date = {2017-01-01}, booktitle = {2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)}, pages = {76-79}, organization = {Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech}, series = {Proceedings of the European Conference on Antennas and Propagation}, abstract = {Two dual reflectarray antennas able to provide an European coverage and beam scanning over 8 degrees respectively have been presented. An accurate technique has been proposed for the analysis of dual-reflectarray antennas, which takes into account the angle of incidence of the field impinging on main reflectarray cells. Two 50-cm antenna demonstrators with the same geometry have been manufactured and measured in a compact range. The measured radiation patterns for the contoured beam antenna are in good concordance with the simulations and practically fulfill the coverage requirements with a cross-polar discrimination better than 25 dB in the frequency band 12.975 GHZ-14.25 GHz. The measured radiation patterns of the beam scanning antenna are in good agreement with the simulations for transmit and receive frequency bands in Ku-band with a cross-polar discrimination better than 30 dB within a scanning range of +/- 4 degrees.}, note = {11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Two dual reflectarray antennas able to provide an European coverage and beam scanning over 8 degrees respectively have been presented. An accurate technique has been proposed for the analysis of dual-reflectarray antennas, which takes into account the angle of incidence of the field impinging on main reflectarray cells. Two 50-cm antenna demonstrators with the same geometry have been manufactured and measured in a compact range. The measured radiation patterns for the contoured beam antenna are in good concordance with the simulations and practically fulfill the coverage requirements with a cross-polar discrimination better than 25 dB in the frequency band 12.975 GHZ-14.25 GHz. The measured radiation patterns of the beam scanning antenna are in good agreement with the simulations for transmit and receive frequency bands in Ku-band with a cross-polar discrimination better than 30 dB within a scanning range of +/- 4 degrees. |
Encinar, Jose A; Florencio, Rafael; Arrebola, Manuel; Salas, M A; Barba, Mariano; Boix, Rafael R; Toso, Giovanni Dual-Polarization Reflectarray in Ku-band Based on Two Layers of Dipole-Arrays for a Transmit-Receive Satellite Antenna with South American Coverage Artículo en actas 2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP), pp. 80-83, Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech 2017, ISSN: 2164-3342, (11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017). @inproceedings{Encinar2017, title = {Dual-Polarization Reflectarray in Ku-band Based on Two Layers of Dipole-Arrays for a Transmit-Receive Satellite Antenna with South American Coverage}, author = {Jose A Encinar and Rafael Florencio and Manuel Arrebola and M A Salas and Mariano Barba and Rafael R Boix and Giovanni Toso}, issn = {2164-3342}, year = {2017}, date = {2017-01-01}, booktitle = {2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)}, pages = {80-83}, organization = {Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech}, series = {Proceedings of the European Conference on Antennas and Propagation}, abstract = {A 1.1-m reflectarray antenna has been designed, manufactured and tested to fulfil the requirements of a satellite antenna in Ku-band that provides South American coverage in Tx and Rx. The reflectarray cells consist of four dipoles for each polarization in two dielectric layers, which were selected because of their simplicity and high performance. The dipole dimensions are optimized in all the reflectarray cells to accomplish the prescribed radiation patterns, by iteratively calling an analysis routine based on MoM-SD and local periodicity. The measured radiation patterns of the manufactured antenna have been satisfactorily compared with simulations and with a 3-layer reflectarray previously designed for the same mission.}, note = {11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } A 1.1-m reflectarray antenna has been designed, manufactured and tested to fulfil the requirements of a satellite antenna in Ku-band that provides South American coverage in Tx and Rx. The reflectarray cells consist of four dipoles for each polarization in two dielectric layers, which were selected because of their simplicity and high performance. The dipole dimensions are optimized in all the reflectarray cells to accomplish the prescribed radiation patterns, by iteratively calling an analysis routine based on MoM-SD and local periodicity. The measured radiation patterns of the manufactured antenna have been satisfactorily compared with simulations and with a 3-layer reflectarray previously designed for the same mission. |
Perez-Palomino, Gerardo; Barba, Mariano; Encinar, Jose A; Cahill, Robert; Dickie, Raymond; Baine, Paul Liquid Crystal Based Beam Scanning Reflectarrays and Their Potential in SATCOM Antennas Artículo en actas 2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP), pp. 3428-3431, Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech 2017, ISSN: 2164-3342, (11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017). @inproceedings{PerezPalomino2017, title = {Liquid Crystal Based Beam Scanning Reflectarrays and Their Potential in SATCOM Antennas}, author = {Gerardo Perez-Palomino and Mariano Barba and Jose A Encinar and Robert Cahill and Raymond Dickie and Paul Baine}, issn = {2164-3342}, year = {2017}, date = {2017-01-01}, booktitle = {2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)}, pages = {3428-3431}, organization = {Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech}, series = {Proceedings of the European Conference on Antennas and Propagation}, abstract = {This paper presents recent developments in Liquid Crystal-based reflectarray antennas for mm-wave applications, future perspectives for this technology and its particular use in SATCOM applications.}, note = {11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } This paper presents recent developments in Liquid Crystal-based reflectarray antennas for mm-wave applications, future perspectives for this technology and its particular use in SATCOM applications. |
Martinez-de-Rioja, Eduardo; Encinar, Jose A; Pino, Antonio; Gonzalez-Valdes, Borja; Tienda, Carolina; Hum, Sean Victor; Toso, Giovanni Application of Bifocal Concept to Dual Reflectarray Configurations for Multi-Beam Satellite Antennas in Ka-Band Artículo en actas 2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP), Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech 2017, ISSN: 2164-3342, (11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017). @inproceedings{MartinezdeRioja2017b, title = {Application of Bifocal Concept to Dual Reflectarray Configurations for Multi-Beam Satellite Antennas in Ka-Band}, author = {Eduardo Martinez-de-Rioja and Jose A Encinar and Antonio Pino and Borja Gonzalez-Valdes and Carolina Tienda and Sean Victor Hum and Giovanni Toso}, issn = {2164-3342}, year = {2017}, date = {2017-01-01}, booktitle = {2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)}, organization = {Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech}, series = {Proceedings of the European Conference on Antennas and Propagation}, abstract = {This contribution describes the design of a multibeam dual reflectarray antenna for operation in transmission in Ka-band (20 GHz). The bifocal design concept has been used to obtain an improved performance for the off-axis beams with respect to the single focused antenna. The required phase-shift distributions are initially obtained with the reflectarrays in parallel planes, and then adjusted to compensate the tilting of both reflectarrays in the final Cassegrain configuration. The simulated radiation patterns in the elevation and azimuth orthogonal planes have been calculated for the two beams generated by the focuses, and then the multi-beam performance of the antenna has been evaluated.}, note = {11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } This contribution describes the design of a multibeam dual reflectarray antenna for operation in transmission in Ka-band (20 GHz). The bifocal design concept has been used to obtain an improved performance for the off-axis beams with respect to the single focused antenna. The required phase-shift distributions are initially obtained with the reflectarrays in parallel planes, and then adjusted to compensate the tilting of both reflectarrays in the final Cassegrain configuration. The simulated radiation patterns in the elevation and azimuth orthogonal planes have been calculated for the two beams generated by the focuses, and then the multi-beam performance of the antenna has been evaluated. |
Gil, Jose M; Zapata, Juan; Garcia, Jesus; Gomez, Rafael ON THE HIGHER-ORDER APPROXIMATIONS FOR EFFICIENT COMPUTATIONAL ELECTROMAGNETICS Artículo en actas 2017 IEEE MTT-S INTERNATIONAL CONFERENCE ON NUMERICAL ELECTROMAGNETIC AND MULTIPHYSICS MODELING AND OPTIMIZATION FOR RF, MICROWAVE, AND TERAHERTZ APPLICATIONS (NEMO), pp. 242-244, IEEE MTT S 2017, ISBN: 978-1-5090-4837-3, (IEEE-MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), Seville, SPAIN, MAY 17-19, 2017). @inproceedings{Gil2017, title = {ON THE HIGHER-ORDER APPROXIMATIONS FOR EFFICIENT COMPUTATIONAL ELECTROMAGNETICS}, author = {Jose M Gil and Juan Zapata and Jesus Garcia and Rafael Gomez}, isbn = {978-1-5090-4837-3}, year = {2017}, date = {2017-01-01}, booktitle = {2017 IEEE MTT-S INTERNATIONAL CONFERENCE ON NUMERICAL ELECTROMAGNETIC AND MULTIPHYSICS MODELING AND OPTIMIZATION FOR RF, MICROWAVE, AND TERAHERTZ APPLICATIONS (NEMO)}, pages = {242-244}, organization = {IEEE MTT S}, note = {IEEE-MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), Seville, SPAIN, MAY 17-19, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Gil, Jose M; Gonzalez-de-Aza, Miguel A; Gómez, Rafael; Garcia, Jesus Loop-star decomposition for any higher-order elements for the surface integral equation Artículo en actas San Petersbourg, Rusia, 2017. @inproceedings{Gil2017a, title = {Loop-star decomposition for any higher-order elements for the surface integral equation}, author = {Jose M Gil and Miguel A Gonzalez-de-Aza and Rafael Gómez and Jesus Garcia}, year = {2017}, date = {2017-01-01}, address = {San Petersbourg, Rusia}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Saracho-Pantoja, Irene O; Montejo-Garai, Jose R; Rebollar, Jesus M; Ruiz-Cruz, Jorge A Low-Cost Additive Manufacturing: A New Approach to Microwave Waveguide Engineering Education through 3D Printing Artículo de revista INTERNATIONAL JOURNAL OF ENGINEERING EDUCATION, 33 (2, A), pp. 741-750, 2017, ISSN: 0949-149X. @article{SarachoPantoja2017, title = {Low-Cost Additive Manufacturing: A New Approach to Microwave Waveguide Engineering Education through 3D Printing}, author = {Irene O Saracho-Pantoja and Jose R Montejo-Garai and Jesus M Rebollar and Jorge A Ruiz-Cruz}, issn = {0949-149X}, year = {2017}, date = {2017-01-01}, journal = {INTERNATIONAL JOURNAL OF ENGINEERING EDUCATION}, volume = {33}, number = {2, A}, pages = {741-750}, abstract = {This paper explains the applications of additive manufacturing to microwave waveguide engineering education, in particular the advantages of the low-cost technique called Fused Filament Fabrication. The promptness to print models, the variety of feasible geometries previously unachievable by subtractive methods and specially the reduced price, make manufacturing designs available to students and small labs without great resources. In addition, it gives students the opportunity to be involved in a full design process, including the manufacturing and measurement of their own devices, with the invaluable experience which it entails. In order to illustrate the process, several well-known passive waveguide devices working in Ku band have been printed, metallized and measured: a band-pass filter, a diplexer, a branch-line coupler and a horn antenna. Finally, the analysis of results proves the potential of 3D printing, although the main limitations are also highlighted to give a deep insight of this new technology.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper explains the applications of additive manufacturing to microwave waveguide engineering education, in particular the advantages of the low-cost technique called Fused Filament Fabrication. The promptness to print models, the variety of feasible geometries previously unachievable by subtractive methods and specially the reduced price, make manufacturing designs available to students and small labs without great resources. In addition, it gives students the opportunity to be involved in a full design process, including the manufacturing and measurement of their own devices, with the invaluable experience which it entails. In order to illustrate the process, several well-known passive waveguide devices working in Ku band have been printed, metallized and measured: a band-pass filter, a diplexer, a branch-line coupler and a horn antenna. Finally, the analysis of results proves the potential of 3D printing, although the main limitations are also highlighted to give a deep insight of this new technology. |
Moran-Lopez, Ana; Corcoles, Juan; Ruiz-Cruz, Jorge A; Montejo-Garai, Jose R; Rebollar, Jesus M Dual-Mode Filters in Equilateral Triangular waveguides with Wide Spurious-Free Response Artículo en actas 2017 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM (IMS), pp. 1188-1191, IEEE Microwave Theory & Tech Soc 2017, ISSN: 0149-645X, (IEEE-Microwave-Theory-and-Techniques-Society International Microwave Symposium (IMS) / Session on Women in Microwaves (WIM), Honolulu, HI, JUN 04-09, 2017). @inproceedings{MoranLopez2017, title = {Dual-Mode Filters in Equilateral Triangular waveguides with Wide Spurious-Free Response}, author = {Ana Moran-Lopez and Juan Corcoles and Jorge A Ruiz-Cruz and Jose R Montejo-Garai and Jesus M Rebollar}, issn = {0149-645X}, year = {2017}, date = {2017-01-01}, booktitle = {2017 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM (IMS)}, pages = {1188-1191}, organization = {IEEE Microwave Theory & Tech Soc}, series = {IEEE MTT-S International Microwave Symposium}, abstract = {Modern satellite communication systems require high performance filters with great compactness and low mass. These features are traditionally offered by dual mode filters. During the last decades, several designs have been implemented using waveguides with different cross-sections such as rectangular, circular or elliptical, where different coupling structures have been proposed. In this paper, a novel implementation using the equilateral triangular waveguide is introduced. One main advantage of this proposed structure is its wide spurious-free window in comparison with other dual-mode implementations. Moreover, the modes of the equilateral triangular waveguide are also analytic, and the full-wave design can be carried out with the efficient Mode-Matching technique. Thus, this type of implementation proves to be as suitable as other structures with analytical waveguides (i.e. the classic rectangular structures), having at the same time a wide spurious-free window response.}, note = {IEEE-Microwave-Theory-and-Techniques-Society International Microwave Symposium (IMS) / Session on Women in Microwaves (WIM), Honolulu, HI, JUN 04-09, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Modern satellite communication systems require high performance filters with great compactness and low mass. These features are traditionally offered by dual mode filters. During the last decades, several designs have been implemented using waveguides with different cross-sections such as rectangular, circular or elliptical, where different coupling structures have been proposed. In this paper, a novel implementation using the equilateral triangular waveguide is introduced. One main advantage of this proposed structure is its wide spurious-free window in comparison with other dual-mode implementations. Moreover, the modes of the equilateral triangular waveguide are also analytic, and the full-wave design can be carried out with the efficient Mode-Matching technique. Thus, this type of implementation proves to be as suitable as other structures with analytical waveguides (i.e. the classic rectangular structures), having at the same time a wide spurious-free window response. |
Moran-Lopez, Ana; Corcoles, Juan; Ruiz-Cruz, Jorge A; Montejo-Garai, Jose R; Rebollar, Jesus M Direct computation of parabolic waveguide modes via a bivariate root-finding algorithm Artículo en actas 2017 IEEE MTT-S INTERNATIONAL CONFERENCE ON NUMERICAL ELECTROMAGNETIC AND MULTIPHYSICS MODELING AND OPTIMIZATION FOR RF, MICROWAVE, AND TERAHERTZ APPLICATIONS (NEMO), pp. 152-154, IEEE MTT S 2017, ISBN: 978-1-5090-4837-3, (IEEE-MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), Seville, SPAIN, MAY 17-19, 2017). @inproceedings{MoranLopez2017a, title = {Direct computation of parabolic waveguide modes via a bivariate root-finding algorithm}, author = {Ana Moran-Lopez and Juan Corcoles and Jorge A Ruiz-Cruz and Jose R Montejo-Garai and Jesus M Rebollar}, isbn = {978-1-5090-4837-3}, year = {2017}, date = {2017-01-01}, booktitle = {2017 IEEE MTT-S INTERNATIONAL CONFERENCE ON NUMERICAL ELECTROMAGNETIC AND MULTIPHYSICS MODELING AND OPTIMIZATION FOR RF, MICROWAVE, AND TERAHERTZ APPLICATIONS (NEMO)}, pages = {152-154}, organization = {IEEE MTT S}, abstract = {The cylindrical parabolic waveguide is one of the waveguides whose modal spectra can be characterized quasi-analytically. The associated non-linear system of equations has already been accurately solved in the past, combining homotopy with shooting methods. However, a novel algorithm for bivariate problems has been found to be a good alternative for the root-finding process, allowing to solve all roots at once in a specified subdomain, without any starting points and covering a wide range of the involved variables. Accurate root values are reached, proving the good performance of the algorithm.}, note = {IEEE-MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), Seville, SPAIN, MAY 17-19, 2017}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } The cylindrical parabolic waveguide is one of the waveguides whose modal spectra can be characterized quasi-analytically. The associated non-linear system of equations has already been accurately solved in the past, combining homotopy with shooting methods. However, a novel algorithm for bivariate problems has been found to be a good alternative for the root-finding process, allowing to solve all roots at once in a specified subdomain, without any starting points and covering a wide range of the involved variables. Accurate root values are reached, proving the good performance of the algorithm. |
Abdo-Sánchez, E; Camacho-Peñalosa, C; Martín-Guerrero, T M; Esteban, J Equivalent Circuits for Nonsymmetric Reciprocal Two Ports Based on Eigenstate Formulation Artículo de revista IEEE Transactions on Microwave Theory and Techniques, 65 (12), pp. 4812-4822, 2017, ISSN: 0018-9480. @article{AbdoSanchez2017, title = {Equivalent Circuits for Nonsymmetric Reciprocal Two Ports Based on Eigenstate Formulation}, author = {E Abdo-Sánchez and C Camacho-Peñalosa and T M Martín-Guerrero and J Esteban}, doi = {10.1109/TMTT.2017.2708103}, issn = {0018-9480}, year = {2017}, date = {2017-01-01}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {65}, number = {12}, pages = {4812-4822}, abstract = {Equivalent circuit topologies for two-port reciprocal nonsymmetric structures are proposed as an extension of the well-known symmetric lattice network. An eigenstate formulation approach that allows the separation of the eigenmodes in the equivalent circuit, as in the symmetric lattice network, is adopted. Four topologies based on series or parallel immittances with the combined use of some transformers are proposed. Particular cases, such as symmetric networks and parallel and series single elements, are derived from the proposed topologies. Moreover, power dissipation in these topologies is also analyzed. A modification in the reference planes is further introduced to achieve power dissipation orthogonality in the two branches of the circuit, as happens in the symmetric lattice network. Additionally, real transformation ratios for the transformers and nonnegative real parts for the immittances are obtained. Finally, the equivalent circuit is extracted for a complementary strip slot with different degrees of asymmetry. This illustrative example confirms the usefulness of the proposed topologies, which can be regarded as an extension of the symmetric lattice network, since they preserve the eigenstate decomposition.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Equivalent circuit topologies for two-port reciprocal nonsymmetric structures are proposed as an extension of the well-known symmetric lattice network. An eigenstate formulation approach that allows the separation of the eigenmodes in the equivalent circuit, as in the symmetric lattice network, is adopted. Four topologies based on series or parallel immittances with the combined use of some transformers are proposed. Particular cases, such as symmetric networks and parallel and series single elements, are derived from the proposed topologies. Moreover, power dissipation in these topologies is also analyzed. A modification in the reference planes is further introduced to achieve power dissipation orthogonality in the two branches of the circuit, as happens in the symmetric lattice network. Additionally, real transformation ratios for the transformers and nonnegative real parts for the immittances are obtained. Finally, the equivalent circuit is extracted for a complementary strip slot with different degrees of asymmetry. This illustrative example confirms the usefulness of the proposed topologies, which can be regarded as an extension of the symmetric lattice network, since they preserve the eigenstate decomposition. |
2016 |
Abdo-Sánchez, E; Camacho-Peñalosa, C; Martín-Guerrero, T M; Page, J E; Esteban, J Circuit Modelling of Electromagnetic Structures by Means of the Lattice Network Artículo en actas Proceedings of the XI Iberian Meeting on Computational Electromagnetics (EIEC), pp. 93-96, Las Caldas, Asturias (Spain), 2016. @inproceedings{AbdoSanchez2016a, title = {Circuit Modelling of Electromagnetic Structures by Means of the Lattice Network}, author = {E Abdo-Sánchez and C Camacho-Peñalosa and T M Martín-Guerrero and J E Page and J Esteban}, year = {2016}, date = {2016-11-01}, booktitle = {Proceedings of the XI Iberian Meeting on Computational Electromagnetics (EIEC)}, pages = {93-96}, address = {Las Caldas, Asturias (Spain)}, abstract = {The use of the lattice network for circuit modelling of electromagnetic symmetric structures is discussed. Several examples are presented, ranging from coupled-line circuits and radiating elements to planar circuit resonators and frequency selective surfaces. The conclusion is always the superior performance of the lattice network in terms of physical realizability of the equivalent circuit elements, and thus, an improved physical insight.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } The use of the lattice network for circuit modelling of electromagnetic symmetric structures is discussed. Several examples are presented, ranging from coupled-line circuits and radiating elements to planar circuit resonators and frequency selective surfaces. The conclusion is always the superior performance of the lattice network in terms of physical realizability of the equivalent circuit elements, and thus, an improved physical insight. |
Headland, D; Carrasco, Eduardo; Nirantar, S; Withayachumnankul, W; Gutruf, P; Schwarz, J; Abbott, D; Bhaskaran, M; Sriram, S; Perruisseau-Carrier, J; Fumeaux, C Dielectric Resonator Reflectarray as High-Efficiency Nonuniform Terahertz Metasurface Artículo de revista ACS PHOTONICS, 3 (6), pp. 1019-1026, 2016, ISSN: 2330-4022. @article{ISI:000378195300016, title = {Dielectric Resonator Reflectarray as High-Efficiency Nonuniform Terahertz Metasurface}, author = {D Headland and Eduardo Carrasco and S Nirantar and W Withayachumnankul and P Gutruf and J Schwarz and D Abbott and M Bhaskaran and S Sriram and J Perruisseau-Carrier and C Fumeaux}, doi = {10.1021/acsphotonics.6b00102}, issn = {2330-4022}, year = {2016}, date = {2016-06-01}, journal = {ACS PHOTONICS}, volume = {3}, number = {6}, pages = {1019-1026}, abstract = {Advances in terahertz technology rely on the combination of novel materials and designs. As new devices are demonstrated to address the terahertz gap, the ability to perform high-efficiency beam control will be integral to making terahertz radiation a practical technology. Here, we use a metasurface composed of nonuniform dielectric resonator antennas on a ground plane to achieve efficient beam focusing at 1 THz. The dielectric resonators are made of high resistivity silicon, which is a low-loss, nondispersive material for terahertz waves. The resonators operate around the resonance of the displacement current in the silicon, which is crucial to attaining high efficiency. The reflectarray's capacity to focus terahertz radiation is experimentally verified, and hence by the principle of antenna reciprocity, it can also be employed as a terahertz collimator. The demonstrated device can therefore be deployed for high-gain terahertz antennas. Further measurements show that the loss of the reflectarray is negligible, which confirms the high efficiency of the dielectric resonators. This finding will enable the design of efficient flat-profile terahertz reflectarrays and metasurfaces to serve arbitrary beam control requirements in the near and far fields.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Advances in terahertz technology rely on the combination of novel materials and designs. As new devices are demonstrated to address the terahertz gap, the ability to perform high-efficiency beam control will be integral to making terahertz radiation a practical technology. Here, we use a metasurface composed of nonuniform dielectric resonator antennas on a ground plane to achieve efficient beam focusing at 1 THz. The dielectric resonators are made of high resistivity silicon, which is a low-loss, nondispersive material for terahertz waves. The resonators operate around the resonance of the displacement current in the silicon, which is crucial to attaining high efficiency. The reflectarray's capacity to focus terahertz radiation is experimentally verified, and hence by the principle of antenna reciprocity, it can also be employed as a terahertz collimator. The demonstrated device can therefore be deployed for high-gain terahertz antennas. Further measurements show that the loss of the reflectarray is negligible, which confirms the high efficiency of the dielectric resonators. This finding will enable the design of efficient flat-profile terahertz reflectarrays and metasurfaces to serve arbitrary beam control requirements in the near and far fields. |
Echeveste, Jose Ignacio; Gonzalez-de-Aza, Miguel A; Rubio, Jesus; Zapata, Juan Near-Optimal Shaped-Beam Synthesis of Real and Coupled Antenna Arrays via 3-D-FEM and Phase Retrieval Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 64 (6), pp. 2189-2196, 2016, ISSN: 0018-926X. @article{IgnacioEcheveste2016, title = {Near-Optimal Shaped-Beam Synthesis of Real and Coupled Antenna Arrays via 3-D-FEM and Phase Retrieval}, author = {Jose Ignacio Echeveste and Miguel A Gonzalez-de-Aza and Jesus Rubio and Juan Zapata}, doi = {10.1109/TAP.2016.2546299}, issn = {0018-926X}, year = {2016}, date = {2016-06-01}, journal = {IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, volume = {64}, number = {6}, pages = {2189-2196}, abstract = {This paper proposes the application of the phase-retrieval algorithm to the shaped-beam synthesis of real antenna arrays via convex optimization. Near-optimal solutions are obtained with this method that do not yield local minima and do not need initial points to converge. The method takes into account the real radiation pattern of the elements that make up the array and the mutual coupling between them with a matrix formulation based on the finite-element method (FEM) and the spherical wave expansion. Numerical results for microstrip and dielectric resonator antennas are presented.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper proposes the application of the phase-retrieval algorithm to the shaped-beam synthesis of real antenna arrays via convex optimization. Near-optimal solutions are obtained with this method that do not yield local minima and do not need initial points to converge. The method takes into account the real radiation pattern of the elements that make up the array and the mutual coupling between them with a matrix formulation based on the finite-element method (FEM) and the spherical wave expansion. Numerical results for microstrip and dielectric resonator antennas are presented. |
Tienda, Carolina; Encinar, Jose A; Barba, Mariano; Arrebola, Manuel Analysis, Design and Demonstration of a Dual-Reflectarray Antenna in Ku-band for European Coverage Artículo de revista APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL, 31 (5), pp. 498-508, 2016, ISSN: 1054-4887. @article{Tienda2016, title = {Analysis, Design and Demonstration of a Dual-Reflectarray Antenna in Ku-band for European Coverage}, author = {Carolina Tienda and Jose A Encinar and Mariano Barba and Manuel Arrebola}, issn = {1054-4887}, year = {2016}, date = {2016-05-01}, journal = {APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL}, volume = {31}, number = {5}, pages = {498-508}, abstract = {An accurate technique has been proposed for the analysis of dual-reflectarray antennas, which takes into account the angle of incidence of the field impinging on main reflectarray cells. The technique has been applied to the analysis and design of a contoured beam antenna in Ku-band that provides a European coverage. The reflected field on the sub-reflectarray is computed using Spectral-Domain Method of Moments assuming local periodicity, as customary. The subreflectarray is divided in groups of elements and the radiation from each group is used to compute the incident and reflected fields on the main reflectarray cells. Different degrees of accuracy can be achieved depending on the number of groups considered. A 50-cm antenna demonstrator has been manufactured and measured in a compact range. The measured radiation patterns are in good concordance with the simulations and practically fulfill the coverage requirements with a cross-polar discrimination better than 25 dB in the frequency band 12.975 GHZ - 14.25 GHz.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An accurate technique has been proposed for the analysis of dual-reflectarray antennas, which takes into account the angle of incidence of the field impinging on main reflectarray cells. The technique has been applied to the analysis and design of a contoured beam antenna in Ku-band that provides a European coverage. The reflected field on the sub-reflectarray is computed using Spectral-Domain Method of Moments assuming local periodicity, as customary. The subreflectarray is divided in groups of elements and the radiation from each group is used to compute the incident and reflected fields on the main reflectarray cells. Different degrees of accuracy can be achieved depending on the number of groups considered. A 50-cm antenna demonstrator has been manufactured and measured in a compact range. The measured radiation patterns are in good concordance with the simulations and practically fulfill the coverage requirements with a cross-polar discrimination better than 25 dB in the frequency band 12.975 GHZ - 14.25 GHz. |
Echeveste, Jose Ignacio; Gonzalez-de-Aza, Miguel A; Zapata, Juan Shaped Beam Synthesis of Real Antenna Arrays via Finite-Element Method, Floquet Modal Analysis, and Convex Programming Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 64 (4), pp. 1279-1286, 2016, ISSN: 0018-926X. @article{IgnacioEcheveste2016a, title = {Shaped Beam Synthesis of Real Antenna Arrays via Finite-Element Method, Floquet Modal Analysis, and Convex Programming}, author = {Jose Ignacio Echeveste and Miguel A Gonzalez-de-Aza and Juan Zapata}, doi = {10.1109/TAP.2016.2526038}, issn = {0018-926X}, year = {2016}, date = {2016-04-01}, journal = {IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, volume = {64}, number = {4}, pages = {1279-1286}, abstract = {A shaped beam synthesis methodology for planar arrays with control of the ripple amplitude in the shaped region, and constraints on the sidelobe and cross-polar levels, is proposed in this paper. A previously developed synthesis formulation for designing finite impulse response (FIR) filters by transforming a nonconvex synthesis problem to a convex optimization scheme enforcing conjugate symmetric excitation weights, is extended to real and coupled radiating elements of complex geometry, taking into account mutual coupling effects. The optimization procedure is integrated with a finite array approach simulating different array environments. This approach is based on the infinite array model through a Floquet modal- and general scattering matrix (GSM)-based analysis, where the periodic radiating element is characterized from a hybrid and full-wave analysis procedure combining the FEM, modal analysis, and domain decomposition technique. Numerical results of different synthesized beam patterns are presented for arrays of open-ended apertures and microstrip antennas.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A shaped beam synthesis methodology for planar arrays with control of the ripple amplitude in the shaped region, and constraints on the sidelobe and cross-polar levels, is proposed in this paper. A previously developed synthesis formulation for designing finite impulse response (FIR) filters by transforming a nonconvex synthesis problem to a convex optimization scheme enforcing conjugate symmetric excitation weights, is extended to real and coupled radiating elements of complex geometry, taking into account mutual coupling effects. The optimization procedure is integrated with a finite array approach simulating different array environments. This approach is based on the infinite array model through a Floquet modal- and general scattering matrix (GSM)-based analysis, where the periodic radiating element is characterized from a hybrid and full-wave analysis procedure combining the FEM, modal analysis, and domain decomposition technique. Numerical results of different synthesized beam patterns are presented for arrays of open-ended apertures and microstrip antennas. |
Leal-Sevillano, Carlos A; Montejo-Garai, Jose R; Ruiz-Cruz, Jorge A; Rebollar, Jesus M Wideband Equivalent Circuit for Multi-Aperture Multi-Resonant Waveguide Irises Artículo de revista IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, 64 (3), pp. 724-732, 2016, ISSN: 0018-9480. @article{LealSevillano2016, title = {Wideband Equivalent Circuit for Multi-Aperture Multi-Resonant Waveguide Irises}, author = {Carlos A Leal-Sevillano and Jose R Montejo-Garai and Jorge A Ruiz-Cruz and Jesus M Rebollar}, doi = {10.1109/TMTT.2016.2520462}, issn = {0018-9480}, year = {2016}, date = {2016-03-01}, journal = {IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, volume = {64}, number = {3}, pages = {724-732}, abstract = {In this paper it is shown that the traditional shunt admittance represented by a rational function yields an accurate wideband equivalent circuit for multi-aperture waveguide irises. The electromagnetic analysis of the structures reveals two different types of resonant phenomena. The first type of resonance is associated with the cutoff frequency of the mode. The second type or antiresonace corresponds to short-circuit TEM modes. These antiresonances are generated when the asymmetry of the iris allows the excitation of electric fields with opposite phases at contiguous apertures. The proposed equivalent circuit is a shunt admittance represented by a rational function. This rational function is analytically obtained from the singular points (resonances and antiresonances) identified in the full-wave analysis. It is straight-forward to obtain the circuit elements from the rational function by following the classical one-port synthesis leading to Foster's or Cauers's canonical realizations. One advantage of the proposed equivalent circuit is that it represents the electromagnetic behavior of complicated structures with a minimum number of circuit elements or degrees of freedom. Several examples, with different number of apertures and symmetry, are presented to illustrate the proposed general equivalent circuit. Finally, the proposed procedure is extended to the case of arbitrary shaped irises, such as those used in frequency-selective surfaces.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper it is shown that the traditional shunt admittance represented by a rational function yields an accurate wideband equivalent circuit for multi-aperture waveguide irises. The electromagnetic analysis of the structures reveals two different types of resonant phenomena. The first type of resonance is associated with the cutoff frequency of the mode. The second type or antiresonace corresponds to short-circuit TEM modes. These antiresonances are generated when the asymmetry of the iris allows the excitation of electric fields with opposite phases at contiguous apertures. The proposed equivalent circuit is a shunt admittance represented by a rational function. This rational function is analytically obtained from the singular points (resonances and antiresonances) identified in the full-wave analysis. It is straight-forward to obtain the circuit elements from the rational function by following the classical one-port synthesis leading to Foster's or Cauers's canonical realizations. One advantage of the proposed equivalent circuit is that it represents the electromagnetic behavior of complicated structures with a minimum number of circuit elements or degrees of freedom. Several examples, with different number of apertures and symmetry, are presented to illustrate the proposed general equivalent circuit. Finally, the proposed procedure is extended to the case of arbitrary shaped irises, such as those used in frequency-selective surfaces. |
2018 |
Bifocal Design Procedure for Dual-Reflectarray Antennas in Offset Configurations Artículo de revista IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, 17 (8), pp. 1421-1425, 2018, ISSN: 1536-1225. |
A Design Technique Based on Equivalent Circuit and Coupler Theory for Broadband Linear to Circular Polarization Converters in Reflection or Transmission Mode Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 66 (5), pp. 2428-2438, 2018, ISSN: 0018-926X. |
Synthesis of coupled antenna arrays using digital phase control via integer programming Artículo de revista IET MICROWAVES ANTENNAS & PROPAGATION, 12 (6), pp. 999-1003, 2018, ISSN: 1751-8725. |
Dual-Polarization Ku-Band Compact Spaceborne Antenna Based on Dual-Reflectarray Optics Artículo de revista SENSORS, 18 (4), 2018, ISSN: 1424-8220. |
Dual-polarization reflectarray in Ku-band based on two layers of dipole arrays for a transmit-receive satellite antenna with South American coverage Artículo de revista INTERNATIONAL JOURNAL OF MICROWAVE AND WIRELESS TECHNOLOGIES, 10 (2, SI), pp. 149-159, 2018, ISSN: 1759-0787. |
High-performance 16-way Ku-band radial power combiner based on the TE01-circular waveguide mode Artículo de revista REVIEW OF SCIENTIFIC INSTRUMENTS, 89 (3), 2018, ISSN: 0034-6748. |
Orthomode Transducers With Folded Double-Symmetry Junctions for Broadband and Compact Antenna Feeds Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 66 (3), pp. 1160-1168, 2018, ISSN: 0018-926X. |
Robust Calculation of the Modes in Parabolic Cylinder Metallic Waveguides by Means of a Root-Finding Method for Bivariate Functions Artículo de revista IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, 66 (2), pp. 623-632, 2018, ISSN: 0018-9480. |
Theoretical and numerical assessment of maximally allowable power-density averaging area for conservative electromagnetic exposure assessment above 6 GHz Artículo de revista BIOELECTROMAGNETICS, 39 (8), pp. 617-630, 2018, ISSN: 0197-8462. |
Solutions for EM Exposure Assessment of 5G Wireless Devices Artículo en actas 2018 JOINT IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY AND 2018 IEEE ASIA-PACIFIC SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY (EMC/APEMC), pp. 92-94, IEEE; IEEE Electromagnet Compatibil Soc; APEMC EMC; Zhejiang Univ; EMC Lab; Inst High Performance Comp, Agcy Sci & Technol Res; Nanyang Technol Univ; Natl Univ SIngapore; Antennas & Propagat Soc; CMA Int Consultants Pte ltd; Rohde & Schwarz; CST; e2i; AMETEK; ETS LINDGREN 2018, ISBN: 978-1-5090-5997-3, (Joint 60th IEEE International Symposium on Electromagnetic Compatibility (EMC) / IEEE Asia-Pacific Symposium on Electromagnetic Compatibility (APEMC), Singapore, SINGAPORE, MAY 14-18, 2018). |
SIW-based reflectarray antennas with sharp gain selectivity and large bandwidth Artículo en actas 2018. |
Liquid Crystals Tuneable Millimetre Wave Reflectarray Artículo en actas 7th Workshop on Liquid Crystals for Photonic (Jastrzebia Gora, Poland), 2018. |
Developments in Antenna Analysis and Design Capítulo de libro {Mittra, R} (Ed.): DEVELOPMENTS IN ANTENNA ANALYSIS AND DESIGN, VOL 2, 2 , Capítulo Reflectarray Antennas, pp. 323-359, IET, 2018, ISBN: 978-1-78561-891-8; 978-1-78561-890-1. |
Design of a Bifocal dual Reflectarray System with Parabolic Main Surface for a Multifed Space Antenna Artículo en actas 2018 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING, pp. 1407-1408, Inst Elect & Elect Engineers Antennas & Propagat Soc; USNC; URSI; Inst Elect & Elect Engineers 2018, ISSN: 1522-3965, (IEEE-Antennas-and-Propagation-Society International Symposium on Antennas and Propagation / USNC/URSI National Radio Science Meeting, Boston, MA, JUL 08-13, 2018). |
A Multibeam Parabolic Reflectarray for Onboard Tx and Rx Satellite Antennas at the Ka band Artículo en actas 2018 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING, pp. 1409-1410, Inst Elect & Elect Engineers Antennas & Propagat Soc; USNC; URSI; Inst Elect & Elect Engineers 2018, ISSN: 1522-3965, (IEEE-Antennas-and-Propagation-Society International Symposium on Antennas and Propagation / USNC/URSI National Radio Science Meeting, Boston, MA, JUL 08-13, 2018). |
Technological Developments for a Space-borne Orbital Debris Radar at 94 GHz Artículo en actas 2018 IEEE RADAR CONFERENCE (RADARCONF18), pp. 564-569, IEEE; IEEE Instrumentat Measurement Soc; Geoscience & Remote sensing soc; Aerospace & Electronic Syst Soc 2018, ISSN: 1097-5764, (IEEE Radar Conference, Oklahoma City, OK, APR 23-27, 2018). |
Higher-Order Basis Functions for an Enhanced Approximation of the Magnetic-Field Integral Equation Artículo en actas London, UK, 2018. |
An Efficient Methodology for SIW Circuits Analysis Artículo en actas Coimbra, Portugal, 2018. |
Design of Five-Way Bagley Polygon Power Dividers in Rectangular Waveguide Artículo de revista IEEE Transactions on Microwave Theory and Techniques, 66 (1), pp. 116-127, 2018, ISSN: 0018-9480. |
2017 |
Analysis of Waveguide Devices Involving Lateral and Transverse Perfect Magnetic Wall Boundary Conditions by the Mode-Matching Method Artículo de revista RADIO SCIENCE, 52 (9), pp. 1223-1234, 2017, ISSN: 0048-6604, (URSI-Commission-B International Symposium on Electromagnetic Theory (EMTS), Espoo, FINLAND, AUG 14-18, 2016). |
Realization of Focused Beam and Shaped Beam Transmitarrays Based on Broadband Unit Cells Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 65 (8), pp. 4368-4373, 2017, ISSN: 0018-926X. |
Terahertz Reflectarrays and Nonuniform Metasurfaces Artículo de revista IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, 23 (4), 2017, ISSN: 1077-260X. |
Optimized Periodic MoM for the Analysis and Design of Dual Polarization Multilayered Reflectarray Antennas Made of Dipoles Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 65 (7), pp. 3623-3637, 2017, ISSN: 0018-926X. |
Dual Polarized Reflectarray Transmit Antenna for Operation in Ku- and Ka-Bands With Independent Feeds Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 65 (6), pp. 3241-3246, 2017, ISSN: 0018-926X. |
Gradient-Based Aperiodic Array Synthesis of Real Arrays With Uniform Amplitude Excitation Including Mutual Coupling Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 65 (2), pp. 541-551, 2017, ISSN: 0018-926X. |
Efficient Crosspolar Optimization of Shaped-Beam Dual-Polarized Reflectarrays Using Full-Wave Analysis for the Antenna Element Characterization Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 65 (2), pp. 623-635, 2017, ISSN: 0018-926X. |
Novel hyperthermia applicator system allows adaptive treatment planning: Preliminary clinical results in tumour-bearing animals Artículo de revista VETERINARY AND COMPARATIVE ONCOLOGY, 16 (2), pp. 202-213, 2017, ISSN: 1476-5810. |
Robust and Comprehensive Validation of SAR Array Systems: Antennas, Procedures, and Acceptance Criteria Artículo en actas Joint Meeting of the Bioelectromagnetics Society (BEMS) and the European BioElectromagnetics Association (EBEA), 2017. |
Optimization of the array element positions based on the analytical dependence of the mutual coupling in the GSM finite array formulation Artículo en actas 2017 IEEE MTT-S INTERNATIONAL CONFERENCE ON NUMERICAL ELECTROMAGNETIC AND MULTIPHYSICS MODELING AND OPTIMIZATION FOR RF, MICROWAVE, AND TERAHERTZ APPLICATIONS (NEMO), pp. 245-247, IEEE MTT S 2017, ISBN: 978-1-5090-4837-3, (IEEE-MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), Seville, SPAIN, MAY 17-19, 2017). |
Pattern Synthesis of Coupled Antenna Arrays via Element Rotation Artículo de revista IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, 16 , pp. 1707-1710, 2017, ISSN: 1536-1225. |
Synthesis of a Multi-beam Dual Reflectarray Antenna Using Genetic Algorithms Artículo en actas 2017 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING, pp. 1179-1180, IEEE Antennas & Propagat Soc; Inst Elect & Elect Engineers; USNC; URSI 2017, ISSN: 1522-3965, (International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, San Diego, CA, JUL 09-14, 2017). |
Efficient Computation of the Reflectarray Far Fields in Adaptive Grids for Speed Improvement Artículo en actas 2017 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING, pp. 1181-1182, IEEE Antennas & Propagat Soc; Inst Elect & Elect Engineers; USNC; URSI 2017, ISSN: 1522-3965, (International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, San Diego, CA, JUL 09-14, 2017). |
Study of Bifocal Dual Reflectarray Configurations for Multi-Beam Antennas in Ka-Band Artículo en actas 2017 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING, pp. 1183-1184, IEEE Antennas & Propagat Soc; Inst Elect & Elect Engineers; USNC; URSI 2017, ISSN: 1522-3965, (International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, San Diego, CA, JUL 09-14, 2017). |
Numerical Advances in the Full-Wave Analysis of Periodic Multilayered Structures with Application to Reflectarray Antennas Artículo en actas {Gurel, L} (Ed.): 2017 COMPUTING AND ELECTROMAGNETICS INTERNATIONAL WORKSHOP (CEM'17), pp. 3-4, ABAKUS 2017, ISBN: 978-1-5386-1732-8, (International Workshop on Computing and Electromagnetics (CEM), Barcelona, SPAIN, JUN 21-24, 2017). |
Dual Reflectarray Antennas for Contoured Beam and Beam Scanning Applications Artículo en actas 2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP), pp. 76-79, Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech 2017, ISSN: 2164-3342, (11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017). |
Dual-Polarization Reflectarray in Ku-band Based on Two Layers of Dipole-Arrays for a Transmit-Receive Satellite Antenna with South American Coverage Artículo en actas 2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP), pp. 80-83, Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech 2017, ISSN: 2164-3342, (11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017). |
Liquid Crystal Based Beam Scanning Reflectarrays and Their Potential in SATCOM Antennas Artículo en actas 2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP), pp. 3428-3431, Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech 2017, ISSN: 2164-3342, (11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017). |
Application of Bifocal Concept to Dual Reflectarray Configurations for Multi-Beam Satellite Antennas in Ka-Band Artículo en actas 2017 11TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP), Microwave Vision Grp; Comp Simulat Technol AG; Keysight Technologies Inc; Altair Engn GmbH; ESA; ANSYS; CEA Leti; Telecom ParisTech 2017, ISSN: 2164-3342, (11th European Conference on Antennas and Propagation (EUCAP), Paris, FRANCE, MAR 19-24, 2017). |
ON THE HIGHER-ORDER APPROXIMATIONS FOR EFFICIENT COMPUTATIONAL ELECTROMAGNETICS Artículo en actas 2017 IEEE MTT-S INTERNATIONAL CONFERENCE ON NUMERICAL ELECTROMAGNETIC AND MULTIPHYSICS MODELING AND OPTIMIZATION FOR RF, MICROWAVE, AND TERAHERTZ APPLICATIONS (NEMO), pp. 242-244, IEEE MTT S 2017, ISBN: 978-1-5090-4837-3, (IEEE-MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), Seville, SPAIN, MAY 17-19, 2017). |
Loop-star decomposition for any higher-order elements for the surface integral equation Artículo en actas San Petersbourg, Rusia, 2017. |
Low-Cost Additive Manufacturing: A New Approach to Microwave Waveguide Engineering Education through 3D Printing Artículo de revista INTERNATIONAL JOURNAL OF ENGINEERING EDUCATION, 33 (2, A), pp. 741-750, 2017, ISSN: 0949-149X. |
Dual-Mode Filters in Equilateral Triangular waveguides with Wide Spurious-Free Response Artículo en actas 2017 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM (IMS), pp. 1188-1191, IEEE Microwave Theory & Tech Soc 2017, ISSN: 0149-645X, (IEEE-Microwave-Theory-and-Techniques-Society International Microwave Symposium (IMS) / Session on Women in Microwaves (WIM), Honolulu, HI, JUN 04-09, 2017). |
Direct computation of parabolic waveguide modes via a bivariate root-finding algorithm Artículo en actas 2017 IEEE MTT-S INTERNATIONAL CONFERENCE ON NUMERICAL ELECTROMAGNETIC AND MULTIPHYSICS MODELING AND OPTIMIZATION FOR RF, MICROWAVE, AND TERAHERTZ APPLICATIONS (NEMO), pp. 152-154, IEEE MTT S 2017, ISBN: 978-1-5090-4837-3, (IEEE-MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), Seville, SPAIN, MAY 17-19, 2017). |
Equivalent Circuits for Nonsymmetric Reciprocal Two Ports Based on Eigenstate Formulation Artículo de revista IEEE Transactions on Microwave Theory and Techniques, 65 (12), pp. 4812-4822, 2017, ISSN: 0018-9480. |
2016 |
Circuit Modelling of Electromagnetic Structures by Means of the Lattice Network Artículo en actas Proceedings of the XI Iberian Meeting on Computational Electromagnetics (EIEC), pp. 93-96, Las Caldas, Asturias (Spain), 2016. |
Dielectric Resonator Reflectarray as High-Efficiency Nonuniform Terahertz Metasurface Artículo de revista ACS PHOTONICS, 3 (6), pp. 1019-1026, 2016, ISSN: 2330-4022. |
Near-Optimal Shaped-Beam Synthesis of Real and Coupled Antenna Arrays via 3-D-FEM and Phase Retrieval Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 64 (6), pp. 2189-2196, 2016, ISSN: 0018-926X. |
Analysis, Design and Demonstration of a Dual-Reflectarray Antenna in Ku-band for European Coverage Artículo de revista APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL, 31 (5), pp. 498-508, 2016, ISSN: 1054-4887. |
Shaped Beam Synthesis of Real Antenna Arrays via Finite-Element Method, Floquet Modal Analysis, and Convex Programming Artículo de revista IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 64 (4), pp. 1279-1286, 2016, ISSN: 0018-926X. |
Wideband Equivalent Circuit for Multi-Aperture Multi-Resonant Waveguide Irises Artículo de revista IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, 64 (3), pp. 724-732, 2016, ISSN: 0018-9480. |
