@article {20_TAP_EDUARDO_PABLO_BOWTIE_UNITARIO, title = {Bow-Tie-Shaped Radiating Element for Single and Dual Circular Polarization}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {68}, number = {2}, year = {2020}, month = {Feb}, pages = {754-764}, keywords = {Antennas, Aperture antennas, bow-tie rotator, orthogonal polarizations}, issn = {1558-2221}, doi = {10.1109/TAP.2019.2943357}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares and J A Ruiz-Cruz} } @article {20_EDUARDO_MONOPULSE_DIFUSSION, title = {Diffusion-bonded W-band monopulse array antenna for space debris radar}, journal = {AEU - International Journal of Electronics and Communications}, volume = {116}, year = {2020}, pages = {153061}, abstract = {In this letter, the design and fabrication of a W-band high-gain monopulse array antenna are presented. The antenna is conceived as a proof of concept for a space debris detection project to develop an on-board radar for a satellite system. The antenna array consists of 16 by 16 circularly polarized radiating cavities fed by a corporate waveguide network with an amplitude taper. An underlying monopulse beamforming network is implemented in waveguide technology as well, providing monopulse capability in both main radiating planes. By means of diffusion bonding, the antenna has been fabricated in a single piece, despite its intricate, multilayer topology. Moreover, the experimental performance shows high agreement with simulations, which is remarkable due to the high sensitivity to manufacturing tolerances at this frequency. Over a 10\% bandwidth is experimentally achieved for efficiency over a 75\%, axial ratio under 3~dB and impedance matching under -10~dB.}, keywords = {millimeter wave technology, Planar arrays, radar antennas}, issn = {1434-8411}, doi = {https://doi.org/10.1016/j.aeue.2019.153061}, url = {http://www.sciencedirect.com/science/article/pii/S1434841119320436}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @article {20_EDU_PABLO_ARRAY_GUIA_CUADRADA, title = {Dual Circularly Polarized Array Antenna based on Corporate Feeding Network in Square Waveguide Technology}, journal = {IEEE Transactions on Antennas and Propagation}, year = {2020}, pages = {1-1}, keywords = {Antenna arrays, omnidirectional antennas, Slot antennas}, issn = {1558-2221}, doi = {10.1109/TAP.2020.3019355}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares and J A Ruiz-Cruz} } @conference {20_EUCAP2020_ARRAY_DUAL_BOWTIE_EDUARDO, title = {Dual Circularly Polarized Waveguide Array Antenna Formed by Full-Metallic Bow-tie Radiating Cavities}, booktitle = {2020 14th European Conference on Antennas and Propagation (EuCAP)}, year = {2020}, month = {March}, pages = {1-5}, abstract = {A full-metallic dual circularly polarized antenna based on an array of bow-tie shaped radiating elements is presented in this contribution. The radiating element, formed by a bow-tie shaped cavity, can generate dual circular polarization. It is fed by a square waveguide path that supports the two degenerate modes TE10 and TE01. The excitation of the TE10 mode in the input port generates left-hand circular polarization while the TE01 mode generates right-hand circular polarization. Furthermore, a dual circularly polarized array antenna formed by bow-tie radiating elements has been designed. The two degenerate modes TE10 and TE01 are supported by a four-way feeding network implemented in square waveguide technology. Both the single radiating element and the dual circularly polarized array have been fabricated by CNC milling techniques. A pure circular polarization performance, high gain or high efficiency have been obtained, experimentally validating the dual circularly polarized bow-tie element in an array configuration.}, keywords = {antenna diversity, Aperture antennas, Dual-polarized antennas, waveguide arrays}, doi = {10.23919/EuCAP48036.2020.9135228}, author = {E Garcia-Marin and P Sanchez-Olivares and J L Masa-Campos and J A Ruiz-Cruz and J Herranz-Alpanseque} } @article {20_ANTENA_ARRAY_DUAL_SLOT_BOMBARDERO_KUMAR, title = {Dual-linearly polarized travelling-wave array antenna based on triple plus slots fed by square waveguide}, journal = {AEU - International Journal of Electronics and Communications}, volume = {119}, year = {2020}, pages = {153176}, abstract = {A dual-linearly polarized travelling-wave array antenna design at Ku-band composed by a novel single element named as triple plus slot is presented. It is formed by a plus slot with an additional pair of short auxiliary slots. The generation of the dual polarization is based on the two degenerated modes TE10 and TE01 supported by a square waveguide following a series feeding topology. Following the operation principle of the conventional plus slot, the transversal slot is only excited by the TE10 mode to generate vertical polarization while the longitudinal slot is only excited by the TE01 mode to generate horizontal polarization. The auxiliary slots provide new degrees of freedom to the antenna design process that allow to accomplish some strict requirements and overcome some design issues. Thus, the proposed triple plus slot has been experimentally validated in a dual-linearly polarized travelling-wave array configuration. The antenna has been fabricated and measured, providing some features such as high efficiency (>80\%), high gain (>13~dB) with a 1~dB-gain bandwidth higher than 10\%, grating lobe mitigation, high isolation between orthogonal polarizations (>25~dB) as well as a fractional impedance bandwidth (S11~<~-14~dB) higher than 11.7\% (from 16 to 18~GHz).}, keywords = {Antenna arrays, Dual-polarized antennas, Slot antennas}, issn = {1434-8411}, doi = {https://doi.org/10.1016/j.aeue.2020.153176}, url = {http://www.sciencedirect.com/science/article/pii/S1434841119332042}, author = {P Sanchez-Olivares and J L Masa-Campos and E Garcia-Marin and D Barrio-Tejedor and P Kumar} } @article {20_TAP_PABLO_ESCALONA_SLOT_CONFORMAL_CIRCULAR_WAVEGUIDE, title = {High-Gain Conical-Beam Traveling-Wave Array Antenna Based on a Slotted Circular Waveguide at $Ku$ -Band}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {68}, number = {8}, year = {2020}, month = {Aug}, pages = {6435-6440}, abstract = {A high-gain conical-beam traveling-wave array antenna based on a slotted circular waveguide is designed at the higher part of Ku-band. A single radiating element is formed by a ring of eight equally spaced slots fed by a circular waveguide. The excitation of the nonfundamental TM01 mode provides a uniform feeding distribution to each slot, generating an omnidirectional radiation performance. Thus, an array antenna formed by 48 rings of slots is proposed following the design rules of traveling-wave arrays. Every ring is properly designed to achieve a uniform power distribution and consequently maximum directivity for the array antenna performance. The distance between elements is also adjusted to obtain the better input matching response and mitigate the grating lobe appearance, generating a high-gain conical-beam radiation performance suitable for satellite and fifth-generation communications. The proposed antenna design has been manufactured in plastic material by using a 3-D printing process and plated by a spray metallization process. A -10 dB impedance bandwidth higher than 23\%, high-gain values around 13.5 dB, or total efficiency higher than 98\% has been achieved for the whole frequency band.}, keywords = {Antenna arrays, antenna radiation patterns, circular waveguides, Couplings, Dipole antennas, omnidirectional antennas, Slot antennas}, issn = {1558-2221}, doi = {10.1109/TAP.2020.2970031}, author = {P Sanchez-Olivares and J L Masa-Campos and E Garcia-Marin and D Escalona-Moreno} } @conference {20_EUCAP2020_LENTE_BOULDER_EDUARDO, title = {Ka-band Multi-beam Planar Lens Antenna for 5G Applications}, booktitle = {2020 14th European Conference on Antennas and Propagation (EuCAP)}, year = {2020}, month = {March}, pages = {1-5}, abstract = {A low-cost solution for multi-beam antenna systems is explored for 5G applications in the 26-GHz band. A 4-port stacked-patch microstrip antenna is used as feeder of a perforated flat lens. Each feeder is placed in a different position with respect to the lens, yielding four high-directivity independent beams. The beams cover an angular range from broadside to a 30-degree steering with a gain over 18 dB. The antenna has been implemented by low-cost processes, employing Printed Circuit Board fabrication for the feeder and 3D printing for the lens.}, keywords = {5G mobile communication, Beam steering, Microstrip antennas}, doi = {10.23919/EuCAP48036.2020.9135364}, author = {E Garcia-Marin and D S Filipovic and J L Masa-Campos and P Sanchez-Olivares} } @article {20_LENTE_PARCHES_BOULDER_EDUARDO, title = {Low-cost lens antenna for 5G multi-beam communication}, journal = {Microwave and Optical Technology Letters}, volume = {n/a}, number = {n/a}, year = {2020}, abstract = {Abstract A planar dielectric lens has been designed for low-cost multi-beam antennas in the 26-GHz band of 5G communications. The lens feeder is a stacked-patch microstrip antenna with four input ports, thus permitting four independent high-directivity radiation beams. Maximum steering of 25{\textdegree} can be attained, which a simulated gain over 18 dB for all scanning angles. The antenna has been implemented with low-cost manufacturing techniques. The feeder is fabricated as a printed circuit board, while the lens is realized as a perforated 3D-printed dielectric piece. Experimental results confirm the multi-beam capability of the lens system, suggesting that the spillover efficiency can be improved in further works.}, keywords = {5G mobile communication, Beam steering, Microstrip antennas}, doi = {10.1002/mop.32486}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/mop.32486}, author = {E Garcia-Marin and D S Filipovic and J L Masa-Campos and P Sanchez-Olivares} } @article {20_IEEE ACCESS_LUCAS POLO_ARRAY DESFASADORES TORNILLOS, title = {Mechanically Reconfigurable Linear Phased Array Antenna Based on Single-Block Waveguide Reflective Phase Shifters With Tuning Screws}, journal = {IEEE Access}, volume = {8}, year = {2020}, pages = {113487-113497}, abstract = {This work presents the design and prototyping of a reconfigurable phased array in Ku band (16 to 18 GHz) implemented in waveguide technology. The design is based on the use of a novel seamless waveguide module integrating four reconfigurable phase shifters to adjust the relative phase shift between the unitary elements of a linear array, which are illuminated uniformly by a corporate waveguide feeding network. The phase shifters are implemented by a 90{\textdegree} hybrid coupler in waveguide technology where two of its ports are loaded with a tunable reactive load, implemented in this proof of concept with a tuning screw. The four phase shifters have been manufactured in a single part using direct metal laser sintering, avoiding the losses related to bad electric contacts and misalignments associated to multipart devices. This also simplifies the assembly of the full phased array, leading to a modular approach with three parts whose design can be addressed separately. The experimental results for the complete array antenna show great performance and demonstrate that the main-lobe of the radiation pattern can be effectively scanned continuously between the angles -25{\textdegree} and 25{\textdegree}, with a high efficiency in the whole design band thanks to the proposed waveguide implementation.}, keywords = {antenna radiation patterns, Beam steering, Couplers, Fasteners, linear antenna arrays, phase shifters, Phased arrays}, issn = {2169-3536}, doi = {10.1109/ACCESS.2020.3003193}, author = {L Polo-Lopez and J L Masa-Campos and A T Muriel-Barrado and P Sanchez-Olivares and E Garcia-Marin and J C{\'o}rcoles and J A Ruiz-Cruz} } @article {19_ANT_MAG_PABLO_PAULA_CONFORMADA_DIODOSPIN_3_5GHZ, title = {Circular Conformal Array Antenna With Omnidirectional and Beamsteering Capabilities for 5G Communications in the 3.5-GHz Range [Wireless Corner]}, journal = {IEEE Antennas and Propagation Magazine}, volume = {61}, number = {4}, year = {2019}, month = {Aug}, pages = {97-108}, keywords = {5G communications, 5G mobile communication, 5G terrestrial communications, Antenna arrays, antenna radiation patterns, array elements, array signal processing, Beam steering, circular conformal array antenna, Conformal antenna, Conformal antennas, conformal structure, double-stacked microstrip patches, eight-way tunable feeding network, frequency 3.5 GHz, Frequency measurement, microstrip, microstrip antenna arrays, octagonal holding structure, omnidirectional antennas, omnidirectional radiation, P-i-n diodes, Power dividers, single radiating elements, T-junction operation modes, TFN network, tunable T-junctions}, issn = {1558-4143}, doi = {10.1109/MAP.2019.2920049}, author = {P Sanchez-Olivares and P Sanchez-Dancausa and J L Masa-Campos and M Iglesias-Menendez-de-la-Vega and E Garcia-Marin} } @conference {19_URSI_PABLO_CONICAL_ARRAY_SLOTTED_ESCALONA, title = {Conical-beam travelling-wave array antenna based on slotted circular waveguide at Ku-band}, booktitle = {Simposium Nacional URSI 2019}, year = {2019}, month = {September}, abstract = {A high-gain conical-beam travelling-wave array antenna based on a slotted circular waveguide is designed at the higher part of Ku-band (16-18 GHz). The single radiating element is formed by a ring of equally spaced slots fed by a circular waveguide. The excitation of the TM01 mode provides a uniform feeding distribution to each slot, generating an omnidirectional radiation performance. Thus, an array antenna formed by 48 rings of slots is proposed following the conventional design rules of travelling-wave arrays. Every ring is optimized to achieve a uniform power distribution and consequently maximum directivity for the array antenna performance. The distance between elements is also adjusted to obtain the better input matching response and mitigate the grating lobe appearance, generating a high-gain conical-beam radiation performance suitable for satellite communications. The proposed design has been manufactured by using a 3D printing process. Input matching under -15 dB, high-gain values around 13.5 dB or total efficiency higher than 98\% have been achieved for the whole frequency band.}, author = {P Sanchez-Olivares and J L Masa-Campos and D Escalona-Moreno and E Garcia-Marin} } @conference {19_URSI_EDUARDO_MONOPULSO_DIF_BONDING, title = {Diffusion-bonded circularly polarized W-band monopulse array antenna}, booktitle = {Simposium Nacional URSI 2019}, year = {2019}, month = {September}, abstract = {A W-band circularly polarized antenna array with monopulse capability has been designed and fabricated by diffusion bonding of copper plates. The antenna is presented as a proof of concept for a space debris radar project. A waveguide monopulse beamforming network provides monopulse operation in the two main radiation planes. The feeding network is implemented in waveguide technology as well, with corporate topology and amplitude tapering to ensure adequate radiation patterns for the monopulse system. Circular polarization is straightforwardly achieved by hexagonal-shaped radiating cavities. Experimental results validate diffusion bonding for complex multilayer antenna fabrication at W-band, providing a bandwidth over 10\% for axial ratio under 3 dB, impedance matching under -10 dB and total efficiency over 75\%.}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @conference {19_EUCAP_PABLO_ANTENA_BOMBARDERO, title = {Dual Polarized Travelling-Wave Array Antenna Formed by Printed Cross Slots}, booktitle = {2019 13th European Conference on Antennas and Propagation (EuCAP)}, year = {2019}, month = {March}, pages = {1-5}, keywords = {Antenna arrays, Antenna measurements, Arrayed waveguide gratings, Couplings, dual linear polarization, dual polarization, dual polarized array antenna, dual polarized travelling-wave array antenna, electromagnetic wave polarisation, linear antenna arrays, linear orthogonal polarizations, longitudinal slots, microstrip antenna arrays, mutual coupling effects, printed cross slots, rectangular waveguides, slot antenna arrays, Slot antennas, square waveguide feeding, transversal slots}, issn = {null}, url = {https://ieeexplore.ieee.org/document/8740194}, author = {P Sanchez-Olivares and J L Masa-Campos and P Kumar and E Garcia-Marin} } @conference {19_IMWS_AMP_EDUARDO_INKJET_PATCH_MALAGA, title = {Ink-jet Implementation of Stacked-Patch Antenna for Wireless Applications}, booktitle = {2019 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP)}, year = {2019}, month = {July}, pages = {151-153}, keywords = {antenna bandwidth, Antenna measurements, Antennas, Bandwidth, conductive silver ink, dielectric materials, frequency 5.0 GHz, high-impact polystyrene substrate, Hip, ink jet printing, ink-jet implementation, ink-jet printing, Kapton film, Kapton layer, mechanical stability, microstrip, Microstrip antennas, microstrip lines, Patch antennas, silver, stacked-patch antenna, Substrates, Three-dimensional printing, wireless applications, Wireless LAN}, issn = {null}, doi = {10.1109/IMWS-AMP.2019.8880078}, author = {E Garcia-Marin and E M{\'a}rquez-Segura and P Sanchez-Olivares and J L Masa-Campos and J A Ruiz-Cruz and C Camacho-Pe{\~n}alosa} } @article {19_ANT_MAG_EDUARDO_5G_SIW, title = {Planar Array Topologies for 5G Communications in Ku Band [Wireless Corner]}, journal = {IEEE Antennas and Propagation Magazine}, volume = {61}, number = {2}, year = {2019}, month = {April}, pages = {112-133}, keywords = {5G communication environment, 5G communications, 5G mobile communication, antenna array, Antenna arrays, antenna feeds, antenna radiation patterns, dielectric losses, directivity performance, feeding network configurations, Ku band, microstrip, microstrip antenna arrays, Microstrip antennas, microstrip dielectric loss, planar antenna arrays, planar array topologies, radiating elements, SIW feeding network, SIW technologies, substrate integrated waveguide, substrate integrated waveguides, Substrates, two-level corporate feeding network}, issn = {1558-4143}, doi = {10.1109/MAP.2019.2895633}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @article {19_ANT_MAG_EDUARDO_5G_SIW, title = {Planar Array Topologies for 5G Communications in Ku Band [Wireless Corner]}, journal = {IEEE Antennas and Propagation Magazine}, volume = {61}, number = {2}, year = {2019}, month = {April}, pages = {112-133}, keywords = {5G communication environment, 5G communications, 5G mobile communication, antenna array, Antenna arrays, antenna feeds, antenna radiation patterns, dielectric losses, directivity performance, feeding network configurations, Ku band, microstrip, microstrip antenna arrays, Microstrip antennas, microstrip dielectric loss, planar antenna arrays, planar array topologies, radiating elements, SIW feeding network, SIW technologies, substrate integrated waveguide, substrate integrated waveguides, Substrates, two-level corporate feeding network}, issn = {1558-4143}, doi = {10.1109/MAP.2019.2895633}, author = {E. Garcia-Marin and J. L. Masa-Campos and P. Sanchez-Olivares} } @conference {19_EUCAP_EDUARDO_MONOPULSO_DIFF_BONDING, title = {W-band Monopulse Antenna Array Manufactured by Diffusion Bonding}, booktitle = {2019 13th European Conference on Antennas and Propagation (EuCAP)}, year = {2019}, month = {March}, pages = {1-5}, keywords = {16 circularly polarized radiating cavities, antenna feeds, antenna radiation patterns, array signal processing, beamforming network, copper sheets, corporate waveguide feeding network, Diffusion bonding, diffusion bonding technology, electromagnetic wave polarisation, etching, etching proces, frequency 90.0 GHz to 98.0 GHz, impedance matching, input matching, millimeter wave technology., millimetre wave antenna arrays, monopulse capabilities, noise figure -10.0 dB, noise figure -15.0 dB, noise figure -20.0 dB, noise figure 2.0 dB, Planar arrays, principal radiation planes, radar antennas, simulated axial ratio, Taylor distribution, W-band monopulse array antenna}, issn = {null}, url = {https://ieeexplore.ieee.org/document/8739388}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @article {18_IJEC_BAZIL_MIMO, title = {(3.1{\textendash}20) GHz MIMO antennas}, journal = {AEU - International Journal of Electronics and Communications}, volume = {94}, year = {2018}, month = {september}, pages = {348-358}, abstract = {In this paper, a super-wideband (SWB) printed monopole antenna has been designed and manufactured. The measured frequency band in terms of reflection coefficient is from 3.1 to 20 GHz under a -10 dB criteria, thanks to the inclusion of a taper impedance adapter. This single antenna has been used to implement and analyze several MIMO antenna configurations, where the isolation between the compounding elements has been checked and optimized to improve the Envelope Correlation Coefficient. Two elements MIMO configurations (parallel ports or orthogonal diversity), as well as four element MIMO antennas with parallel ports are presented. Non continuous ground planes of the MIMO antenna elements with the inclusion of L shaped thin strips are proposed as valid structures to significantly improve the side by side mutual coupling from an initial peak value of 15 dB to better than 24 dB within the entire frequency band. In all the presented MIMO antenna structures, the measured values demonstrate good performance up to 20 GHz, both in reflection and isolation. Nevertheless, the influence of the mutual coupling effects has been checked as more significant in the lower part of the frequency band, especially in the 4 element MIMO configuration. The inclusion of the L shaped strips in the ground plane significantly mitigates this effect. Although the antennas have only been measured up to 20 GHz (upper frequency limit of the laboratory Vector Network Analyzer), simulations show satisfactory antennas{\textquoteright} performance up to 50 GHz.}, keywords = {MIMO antenna, Polarization diversity MIMO antenna, SWB antenna}, issn = {1434-8411}, doi = {https://doi.org/10.1016/j.aeue.2018.07.026}, url = {https://www.sciencedirect.com/science/article/pii/S1434841118310823}, author = {B T Ahmed and P Sanchez-Olivares and J L Masa-Campos and F Moreno-Vazquez} } @conference {18_URSI_PABLO_SANCHEZ, title = {Conformal Patch Array Antenna with Switchable Omnidirectional or Sectorial Coverage at 3.5 GHz}, booktitle = {Simposium Nacional URSI 2018}, year = {2018}, month = {September}, abstract = {A circularly conformal array antenna with beam steering capabilities as well as omnidirectional performance in S-band is presented. The single radiating elements are formed by double stacked microstrip patches placed on the planar faces of an octagonal supporting structure fabricated with a 3D printer. An eight-way tunable feeding network in microstrip technology is designed, manufactured and integrated into the conformal structure in order to excite the array elements. Novel tunable T-junctions based on PIN diodes are proposed to form the tunable feeding network. This novel T-junction allows a splitting configuration with uniform distribution to the two output ports, or a switching mode to deliver the signal to either output port. In all T-junction operation modes, a good input matching performance is achieved. The tunable feeding network is integrated into the conformal antenna and digitally controlled by a microcontroller Arduino UNO. A total of 29 states, grouped in 6 modes with a global matching bandwidth of 17.2\% can be selected. An omnidirectional radiation as well as beam steered directional patterns (covering 360 deg) can be electronically selected. The proposed antenna is able for future 5G terrestrial communications in the 3.5 GHz IMT range.}, author = {P Sanchez-Olivares and P P Sanchez-Dancausa and J L Masa-Campos and M Iglesias-Menendez-de-la-Vega and E Garcia-Marin} } @article {18_COMM_MAG_EDUARDO_DIFF_BONDING1, title = {Diffusion Bonding Manufacturing of High Gain W-Band Antennas for 5G Applications}, journal = {IEEE Communications Magazine}, volume = {56}, number = {7}, year = {2018}, month = {July}, pages = {21-27}, abstract = {The incoming 5G systems propose unprecedented communication capabilities that require a maximization of the channel and spectrum exploitation. Waveguide antenna arrays can play an important role in 5G environments due to their high performance in terms of efficiency and bandwidth. Moreover, higher frequencies appear necessary in order to achieve the requirements of channel capacity and spectrum bandwidth. At millimeter-wave frequencies, new challenges for the design and fabrication of the communication devices are encountered. The feasibility of traditional manufacturing techniques and conventional additive manufacturing processes severely decreases, since part tolerances, assembly, and alignment become critical for the antenna performance. In order to illustrate the possibilities of the diffusion bonding technique applied to waveguide antennas operating in the W-band of 5G systems, a circularly polarized cavity array has been successfully manufactured. This manufacturing process provides the advantages of both traditional and additive manufacturing. A 5.6 percent effective bandwidth at 90 GHz has been experimentally obtained with reflected power under 10 percent, axial ratio below 3 dB, and antenna efficiency over 50 percent.}, keywords = {5G mobile communication, Antenna arrays, Diffusion bonding, Three-dimensional printing}, issn = {0163-6804}, doi = {10.1109/MCOM.2018.1700986}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @conference {18_EUCAP_PABLOSANCHEZ_Array_RPS_varactor, title = {Electronically reconfigurable microstrip array antenna with reflective phase shifters at Ku band}, booktitle = {12th European Conference on Antennas and Propagation (EuCAP 2018)}, year = {2018}, month = {April}, pages = {1-5}, keywords = {Patch antennas, phase shifters, Phased arrays}, doi = {10.1049/cp.2018.1134}, author = {E Garcia-Marin and P Sanchez-Olivares and J Herranz-Alpanseque and A J Martin-Trueba and J L Masa-Campos and J C{\'o}rcoles-Ortega} } @article {18_AWPL_EDUARDO-GARCIA_EVALUATION_ADD_MANUF, title = {Evaluation of Additive Manufacturing Techniques Applied to Ku-Band Multilayer Corporate Waveguide Antennas}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {17}, number = {11}, year = {2018}, month = {Nov}, pages = {2114-2118}, keywords = {additive manufacturing techniques, Antenna arrays, antenna feeds, antenna layers, antenna prototypes, Aperture antennas, axial ratio, conventional milling, corporate-fed waveguide array antenna, digital communication, direct broadcasting by satellite, direct metal laser sintering, DMLS antenna, electrical performance, end-user digital broadcast satellite communications, gain ratio, impedance matching, intricate multilayer structure, Ku-band multilayer corporate waveguide antennas, laser sintering, layered manufacturing, Metals, Milling, multilayer structure, multilayers, Planar arrays, prototypes, rapid prototyping (industrial), reference prototype, reliability, satellite antennas, single block fabrication, slot antenna arrays, stereolithography, Three-dimensional printing, waveguide antenna implementation}, issn = {1536-1225}, doi = {10.1109/LAWP.2018.2866631}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares and J A Ruiz-Cruz} } @conference {18_URSI_EDUARDO_GARCIA, title = {Fabricaci{\'o}n por Diffusion Bonding de Agrupaciones de Antenas en Gu{\'\i}a de Onda para Banda W}, booktitle = {Simposium Nacional URSI 2018}, year = {2018}, month = {September}, abstract = {Millimeter-wave radiating systems appear attractive for radiofrequency applications like radio-positioning or telecommunications. High-gain array antennas can be implemented in reduced-size devices in this part of the frequency spectrum. Waveguide implementations seem indispensable to mitigate the dissipation losses inherent to these frequencies. Nevertheless, the implementation of multilayer waveguide array antennas is a challenge. Electrical contact between the antenna layers must be guaranteed to prevent power leakage, which is ensured only in part with mechanical tightening. Additive manufactured antenna arrays provide electrical continuity, although dimensional accuracy diminishes and dissipation losses increase owing to surface roughness and reduced conductivity. In this context, diffusion bonding allows complex multilayer designs by joining accurately-etched metallic sheets without additional sticking or tightening material. A corporate-fed waveguide antenna array is presented in this paper to experimentally validate this manufacturing technique for W-band implementations.}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @conference {8439652, title = {Implementation of Millimeter Wave Antenna Arrays by Diffusion Bonding}, booktitle = {2018 11th Global Symposium on Millimeter Waves (GSMM)}, year = {2018}, month = {May}, pages = {1-4}, keywords = {Antenna arrays, Diffusion bonding, Millimeter wave communication, Millimeter wave radar, millimeter wave technology, Planar arrays}, doi = {10.1109/GSMM.2018.8439652}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @article {18_TAP_PABLO-SANCHEZ_WG-SLOT-ARRAY-TUNING-SCREWS, title = {Mechanical Technique to Customize a Waveguide-Slot Radiating Performance}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {66}, year = {2018}, pages = {426-431}, abstract = {A mechanical technique to tune the radiating performance of a waveguide-fed slot is presented. Three metallic tuning screws are introduced through the bottom wall of the feeding waveguide. The field radiated by the slot is mechanically controlled with the insertion length of the tuning screws and a good input matching response is also maintained. One of the tuning screws modifies the slot coupling parameter as well as the phase of the transmitted signal, while the other pair of screws compensates the impedance mismatch introduced by the first one. A five-element traveling-wave (TW) linear array antenna has been designed and manufactured as a proof of concept to validate the performance of the tuning screws. Several improvements such as a main beam steering range of 17{\textdegree}, an enhancement of the antenna efficiency, the mitigation of the undesirable grating lobe appearance typical of TW air-waveguide-fed arrays, as well as the compensation of the mutual coupling effects or manufacturing tolerance errors could be experimentally achieved by using the proposed mechanism based on tuning screws.}, keywords = {linear arrays, Slot antennas, waveguide arrays}, issn = {0018-926X}, doi = {10.1109/TAP.2017.2772078}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=8103014}, author = {P Sanchez-Olivares and J L Masa-Campos and J Hernandez-Ortega} } @article {18_AWPL_PABLO-SANCHEZ_CORPORATE-ARRAY-TUNING-SCREWS, title = {Mechanically Reconfigurable Linear Array Antenna Fed by a Tunable Corporate Waveguide Network With Tuning Screws}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {17}, number = {8}, year = {2018}, month = {Aug}, pages = {1430-1434}, abstract = {A mechanical technique to provide beam-steering capabilities to a linear array antenna is presented. The methodology is based on the insertion of metallic tuning screws into power dividers in rectangular waveguide technology. These tuning screws establish a short circuit between the top and bottom plates of the waveguide, and a phase change in the transmitted signal is then generated. Therefore, the phase difference between the output ports of a conventional waveguide divider can be controlled with these tuning screws. A corporate waveguide feeding network with several tuning screws has been designed. This tunable waveguide network is used to feed an aperture stacked patch array, forming the final mechanically reconfigurable linear array. Seven different phase configurations have been synthetized by using the tuning screws, which provide a noncontinuous angular scanning. In particular, a main beam steering from -26{\textdegree} to +26{\textdegree} with 13 discrete radiation patterns has been obtained. The use of waveguide technology makes the proposed reconfigurable antenna suitable for low-loss and high-power applications. Total efficiency values higher than 90\% have been achieved for every configuration.}, keywords = {Aperture-coupled antennas, Beam steering, Electromagnetic waveguides, Fasteners, linear antenna arrays, microwave antenna arrays, Tuning, waveguide arrays}, issn = {1536-1225}, doi = {10.1109/LAWP.2018.2848911}, url = {https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=8388289}, author = {P Sanchez-Olivares and J L Masa-Campos and A T Muriel-Barrado and R Villena-Medina and G M Fernandez-Romero} } @conference {17_EUCAP_EDUARDOGARCIA_4x4_stackedPatch_eucap, title = {W-band array antenna for radar detection of space debris}, booktitle = {12th European Conference on Antennas and Propagation (EuCAP 2018)}, year = {2018}, month = {April}, pages = {1-4}, keywords = {millimeter wave technology, Planar arrays, radar antennas}, doi = {10.1049/cp.2018.0737}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @article {17_IET_TFM-PAULA-SANCHEZ_CONF-ARRAY-SWITCHED, title = {Circularly conformal patch array antenna with omnidirectional or electronically switched directive beam}, journal = {IET Microwaves, Antennas and Propagation}, volume = {11}, year = {2017}, pages = {2253-2259}, abstract = {A circularly conformal array antenna of double stacked microstrip patches is presented in two radiation versions: omnidirectional and electronically switched directive beam. Every single element is disposed on an eight-faced regular prism structure built in 3D print technology. The omnidirectional pattern is achieved in the azimuth plane by using a microstrip uniform power divider to equally excite the circular antenna. The switched directive beam coverage is obtained by replacing the uniform power divider with an electronically switched power divider. Four switched beams of 90{\textdegree} angular separation are digitally configured. A fractional matching bandwidth of 17.2\% has been measured for both omnidirectional and switched beam prototypes. The conformal antenna was entirely manufactured by using both printed circuit board and 3D printing technologies. Therefore, a very compact, low cost and light weight antenna design has been implemented, suitable to many applications such as Worldwide Interoperability for Microwave Access, wireless local area network, unmanned aerial vehicles or direction finding.}, issn = {1751-8725}, doi = {10.1049/iet-map.2017.0195}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=8221750}, author = {P Sanchez-Olivares and P P Sanchez-Dancausa and J L Masa-Campos} } @article {17_AWPL_PABLO-SANCHEZ_RADIALWG_ARRAY_OMNI, title = {Compact Omnidirectional Conformal Array Antenna in Waveguide Technology}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {16}, year = {2017}, pages = {1102-1105}, abstract = {A conformal array antenna has been designed in the waveguide technology in order to obtain an omnidirectional radiation pattern in the azimuth plane at the Ku-band. The antenna shape is a regular prism, where the single radiating elements, which consist of a rectangular waveguide ended on a cavity{\textendash}slot, are placed on the planar faces of the prism. The physical dimensions as well as the number of faces of the regular prism have been optimized following the conformal array formulation in order to achieve a minimum ripple omnidirectional pattern. An eight-faced regular prism with an apothem of 20.6 mm has been selected as the radiating structure. The single elements are fed by an eightway radial waveguide power divider symmetrically excited by a 50-Ω SMA input port. The use of waveguide technology to design the single elements and the feeding network makes the conformal array suitable for low losses and high-power applications. Several prototypes have been manufactured in order to experimentally validate the antenna performance. An omnidirectional pattern with a maximum ripple of 1.6 dB in the azimuth plane, 95.3\% efficiency, and 11.7\% input matching bandwidth has been measured..}, keywords = {Conformal antennas, omnidirectional antennas, slot arrays}, issn = {1536-1225}, doi = {10.1109/LAWP.2016.2622919}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7725535}, author = {P Sanchez-Olivares and R V Haro-Baez and P P Sanchez-Dancausa and J L Masa-Campos and J A Ruiz Cruz} } @conference {17_URSI_EDUARDO-GARCIA_diffusionbonding_antenna, title = {Diffusion-bonded Circularly Polarized Corporate-Fed Cavity Array for W-band}, booktitle = {Simposium Nacional URSI 2017}, year = {2017}, month = {September}, abstract = {A circularly polarized radiating cavity array has been designed at 94 GHz and manufactured by the innovative technique of diffusion bonding of thin metallic layers, introduced to the European research community for the first time. The array is composed of 16x16 radiating elements, fed by a two-level waveguide corporate feeding network with uniform distribution. A 5.5 \% bandwidth has been experimentally achieved with matching under -10 dB and axial ratio below 3 dB. At 90 GHz, 30.6 dBi gain and 0.4 dB axial ratio have been measured. The experimental results are considered successful and further improvements in the manufacturing process are expected to refine the performance of the antenna in future prototypes.}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @article {17_MOTL_PFC_ALFONSO_MURIEL, title = {H-plane corporate waveguide-fed 4-aperture-stacked circular microstrip patch linear array for Ku band applications}, journal = {Microwave and Optical Technology Letters}, volume = {59}, number = {9}, year = {2017}, pages = {2216-2223}, abstract = {In this article, a linearly polarized 4-element linear array in Ku band is presented. The single element consists of a circular microstrip patch capacitively coupled to a printed slot-end WR-51 waveguide. A corporate waveguide feeding network at H-plane is designed, which is composed of bends, T and Y-junctions. An optimization process with septums and irises is performed to get the best possible matching coefficient. An antenna prototype has been manufactured and measured. A maximum gain of 12.6 dBi, up to 91.6\% radiation efficiency and 13\% bandwidth (16 to 18.3 GHz) has been experimentally achieved.}, issn = {1098-2760}, doi = {10.1002/mop.30711}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mop.30711/epdf}, author = {A T Muriel-Barrado and J L Masa-Campos and P Sanchez-Olivares} } @conference {17_EUCAP_EDUARDOGARCIA_4x4_stackedPatch_eucap, title = {Implementation of 4 {\texttimes} 4 stacked patch array with corporate feeding network for Ku-band applications}, booktitle = {Antennas and Propagation (EUCAP), 2017 11th European Conference on}, year = {2017}, month = {March}, pages = {1967-1971}, abstract = {In this work, the experimental implementation of a 4 x 4 stacked-patch array with linear polarization and a corporate feeding network for Ku-band is exposed. The feeding network is split into two levels, with an initial power distribution in Substrate Integrated Waveguide and a second distribution in microstrip technology. The experimental results show a matching coefficient better than -10 dB in a 15.9\% bandwidth. In addition, the measured gain attains 16.8 dBi, 0.8 dB below the simulated gain, while radiation efficiency is 66 \%. The structure is validated for higher-gain arrays, and hence designs of 8 x 8 and 16 x 16 radiating elements are also proposed and the simulated results presented. Therefore, antennas with several gain values are available in order to suit the different elements of the communication system, such as the end user and the base station.}, keywords = {antenna, array, corporate feeding, linear polarization, microstrip, replication., SIW, stacked patch}, doi = {10.23919/EuCAP.2017.7928530}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7928530}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @article {17_TAP_PABLO-SANCHEZ_RECONF_RADIALWG_ARRAY, title = {Mechanically Reconfigurable Conformal Array Antenna Fed by Radial Waveguide Divider With Tuning Screws}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {65}, year = {2017}, pages = {4886-4890}, abstract = {A conformal array antenna with a reconfigurable radiation pattern in the azimuth plane at Ku band is presented. An eight-faced prism has been set as 3-D antenna structure. The radiating element consists of a rectangular waveguide ended on a slotted cavity. A radial waveguide network (RWGN) fed by a symmetrically placed coaxial probe has been implemented to equally feed each radiating element obtaining an omnidirectional behavior in the azimuth plane. The insertion of several metallic tuning screws (TSs) provides a reconfiguration mechanism of the electric field distribution in the RWGN and modifies the conformal array antenna amplitude feeding. Eight different configurations generating directional radiation patterns can be tuned by means of the insertion of certain TSs. In addition, the symmetrical positioning of them allows performing a main beam scanning every 45{\textdegree} in the azimuth plane. Several prototypes have been manufactured and measured to experimentally validate the antenna performance. A total of 65 different radiation patterns have been experimentally obtained using the proposed TSs, which provides a simple, low-loss, and low-cost reconfigurability mechanism to the presented conformal array antenna.}, keywords = {Conformal antenna, Slot antennas, waveguide arrays}, issn = {0018-926X}, doi = {10.1109/TAP.2017.2723918}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7970137\&isnumber=8024125}, author = {P Sanchez-Olivares and J L Masa-Campos} } @conference {17_EUCAP_PABLOSANCHEZ_SingleSlot_TuningScrews_eucap, title = {Mechanically reconfigurable waveguide-slot single element using tuning screws}, booktitle = {Antennas and Propagation (EUCAP), 2017 11th European Conference on}, year = {2017}, month = {March}, pages = {1962-1966}, abstract = {A mechanically reconfigurable waveguide-slot single radiating element is presented. The tuning mechanism consists on three metallic screws introduced through the bottom wall of the feeding waveguide. The insertion length of the tuning screws and the distance to the slot are used to control the radiated signal as well as to maintain a good input matching response. Several prototypes with different slot lengths have been manufactured to experimentally validate the reconfigurable performance. The proposed triple tuning screw waveguide-slot radiator provides a low cost and simple mechanism to conform a reconfigurable array antenna.}, keywords = {reconfigurable antenna, Slot antennas, waveguide antennas.}, doi = {10.23919/EuCAP.2017.7928264}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7928264}, author = {P Sanchez-Olivares and J L Masa-Campos and J Hernandez-Ortega} } @article {murbach2017pregnant, title = {Pregnant women models analyzed for RF exposure and temperature increase in 3T RF shimmed birdcages}, journal = {Magnetic resonance in medicine}, volume = {77}, number = {5}, year = {2017}, pages = {2048{\textendash}2056}, author = {Murbach, Manuel and Neufeld, Esra and Samaras, Theodoros and J C{\'o}rcoles and Robb, Fraser J and Kainz, Wolfgang and Kuster, Niels} } @conference {17_URSI_PABLO-SANCHEZ_conformalarray_reconfig, title = {Reconfigurable Conformal Antenna in Radial Waveguide Technology}, booktitle = {Simposium Nacional URSI 2017}, year = {2017}, month = {September}, abstract = {This work proposes a compact conformal array antenna using radial waveguide technology. The conformal structure is approximated as a regular prism with planar faces to obtain a significant manufacturing cost reduction. It provides a mechanical technique to reconfigure the antenna radiation pattern in the azimuth plane, based on the insertion of several metallic screws into the radial feeding network. Depending on the inserted-screw configuration, the electric field distribution in the radial waveguide network is modified. Therefore, the feeding distribution of the single radiating elements is controlled. The radiation pattern can be mechanically reconfigured from omnidirectional to directional behavior, achieving a main beam scanning every 45 deg in the azimuth plane.}, author = {P Sanchez-Olivares and J L Masa-Campos and E Garcia-Marin} } @conference {17_NEMO_EDU_JUAN_CAD2_ANTENNA, title = {Slotted Waveguide Antenna Design by Segmented Simulation and Multi-Objective Genetic Algorithm}, booktitle = {IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave and Terahertz Applications (NEMO)}, year = {2017}, month = {May}, abstract = {A progressive-wave antenna automated design technique is presented in this work. By means of a simulation method based on spherical wave expansion and generalized scattering matrix, full-wave analysis of a slotted waveguide array can be efficiently performed. Since coupling effects are considered in the simulation, a final antenna design can be obtained without any further modification required on it. In order to achieve such design, a multi-objective optimization based on Nondominated Sorting Genetic Algorithm Version III (NSGA-III) state-of-theart genetic algorithm is carried out. At the working frequency of 17 GHz, final design provides a 16.6 dBi gain, Side-Lobe Levels lower than -18.3 dB and a 0.6\% power waste at the output port. A -15-dB matching bandwidth of an 8.8\% is obtained. The results have been validated with commercial-software simulations.}, author = {E Garcia-Marin and J C{\'o}rcoles and J Rubio and J L Masa-Campos and P Sanchez-Olivares} } @conference {16_EUCAP_EDUARDOGARCIA_patcharray4x4, title = {4 {\texttimes} 4 stacked patch array with siw and microstrip corporate feeding network for ku-band}, booktitle = {Antennas and Propagation (EUCAP), 2016 10th European Conference on}, year = {2016}, month = {April}, pages = {1-4}, abstract = {A 4 {\texttimes} 4 linearly-polarized stacked-patch array with a fully corporate feeding network for Ku-band is presented in its work. Antenna replication in larger arrays is straightforward with this corporate approach, which in addition prevents unintended main beam steering. The feeding structure is divided in two levels, where the first power distribution is made in Substrate Integrated Waveguide and the second in microstrip technology. This procedure takes advantage of the strengths of each technology, combining waveguide low losses with microstrip versatility. A 18.4-dBi gain is attained in simulation with matching better than -14 dB in the entire bandwidth.}, keywords = {antenna, array, corporate feeding, linear polarization, microstrip, replication, SIW, stacked patch}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @conference {16_URSI_PABLO-SANCHEZ_conformalarray_omni, title = {Agrupaci{\'o}n Conformada con Alimentaci{\'o}n en Gu{\'\i}a de Onda Radial para Cobertura Omnidireccional en Banda Ku}, booktitle = {Simposium Nacional URSI 2016}, year = {2016}, month = {September}, abstract = {A conformal array antenna fed by a radial waveguide divider has been designed in order to obtain an omnidirectional performance at Ku band. The single radiating elements consist on a waveguide ended on a cavity-slot and they have been placed on the regular prism faces conforming the final antenna shape. The array dimensions as well as the number of faces have been optimized to generate a maximum ripple in the omnidirectional pattern, obtaining an eight-faced regular prism antenna with an apothem of 20.6 mm. The single radiating elements are fed by an equal power eight-way radial waveguide divider. The use of waveguide technology makes the structure suitable for high power applications. The conformal array have been manufactured in order to experimentally validate the antenna performance. An omnidirectional pattern with a maximum ripple of 1.6 dB in the azimuth plane, a total efficiency of 98.8\% and an input matching bandwidth of 11.7\% has been measured.}, author = {P Sanchez-Olivares and R V Haro-Baez and P P Sanchez-Dancausa and J L Masa-Campos and J A Ruiz Cruz} } @conference {16_URSI_EDUARDO-GARCIA_4by4patcharray, title = {Agrupaci{\'o}n plana de parches apilados con alimentaci{\'o}n corporativa en tecnolog{\'\i}a mixta SIW-microstrip para banda Ku}, booktitle = {Simposium Nacional URSI 2016}, year = {2016}, month = {September}, abstract = {A 4 x 4 linearly-polarized stacked-patch array with a fully corporate feeding network for Ku-band is presented in its work. Antenna replication in larger arrays is straightforward with this corporate approach, which in addition prevents unintended main beam steering. The feeding structure is divided in two levels, where the first power distribution is made in Substrate Integrated Waveguide and the second in microstrip technology. This procedure takes advantage of the strengths of each technology, combining waveguide low losses with microstrip versatility. A 18.6-dBi gain is attained in simulation with matching better than -14 dB in the entire bandwidth.}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @article {16_AWPL_JUAN-CORCOLES_CAD_SLOTTED_ANTENNA, title = {Computer Automated Design of an Irregular Slotted Waveguide Array for Ku-Band}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {15}, year = {2016}, pages = {1593-1597}, abstract = {A computer automated design methodology to synthesize a progressive wave array antenna is presented. The proposed method is based on the generalized-scattering matrix and spherical wave expansion analysis of the array. Mutual coupling effects between radiating elements are inherently considered in the design process. A linearly polarized 24-element irregular slotted array antenna at Ku-band is presented to describe the proposed computer automated design methodology. A prototype has been manufactured to experimentally validate the antenna performance. At the design frequency (17 GHz), 15.9 dB realized gain and 97\% efficiency (excluding aluminum losses) values are achieved. Although the array is designed at a single frequency, it shows an overall experimental 7\% usable bandwidth.}, keywords = {Array antenna, computer automated design, generalized scattering matrix, slot, spherical wave expansion}, issn = {1536-1225}, doi = {10.1109/LAWP.2016.2517928}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7381600}, author = {J C{\'o}rcoles and P Sanchez-Olivares and J Rubio and J L Masa-Campos and J. Zapata} } @conference {16_EUCAP_PABLOSANCHEZ_conformal_array_omni_eucap, title = {Conformal Array Antenna Fed by Radial-Waveguide Divider for Omnidirectional Coverage at Ku Band}, booktitle = {Antennas and Propagation (EUCAP), 2016 10th European Conference on}, year = {2016}, month = {April}, pages = {1-5}, abstract = {A conformal array antenna for omnidirectional coverage in the azimuth plane at Ku band is presented. An eightfaced prism structure has been used to obtain the omnidirectional radiation pattern following a maximum theoretical ripple criterion. The radiating element consists of a rectangular waveguide ended on a cavity-slot. An equal power eight-way radial-waveguide divider has been designed to feed each radiating element. The use of waveguide technology minimizes the propagation losses and makes the structure suitable for high power applications with omnidirectional coverage requirements. The achieved simulation results show a maximum realized gain of 2.4 dB, a maximum ripple of 1.5 dB for the omnidirectional pattern and a matching bandwidth of 16.2\% around 17 GHz.}, keywords = {antenna, conformal array, omnidirectional pattern., radial-waveguide}, author = {P Sanchez-Olivares and R V Haro-Baez and P P Sanchez-Dancausa and J L Masa-Campos and J A Ruiz Cruz} } @conference {16_URSI_RAUL-HARO_radial_divider, title = {Desarrollo de Redes Divisoras de Potencia con N-puertos}, booktitle = {Simposium Nacional URSI 2016}, year = {2016}, month = {September}, abstract = {Power division/combination is a very important function for achieving high-performance power amplification in microwave and millimeter-wave systems. This function allows the use of simpler individual amplifiers to provide microwave/millimeter wave high power signals. In this paper we address the development of divider/combiners in waveguide technology for large number of ports. Radial waveguide dividers will be studied, starting from the S-parameters representing the N-port waveguide junction, and ending with the full-wave simulations. Two different designs in this technology are studied, radial divider and conical radial divider. The experimental evaluation will come from a prototype at Ku-band, fabricated and tested in order to validate the design.}, author = {R V Haro-Baez and J L Masa-Campos and J A Ruiz Cruz and P Sanchez-Olivares and E V Carrera} } @conference {16_URSI_JESUS-RUBIO_dao_slotted_array, title = {Dise{\~n}o Automatizado por Ordenador de una Agrupaci{\'o}n de Ranuras con Alimentaci{\'o}n en Gu{\'\i}a de Onda}, booktitle = {Simposium Nacional URSI 2016}, year = {2016}, month = {September}, abstract = {A Computer Automated Design method based on the generalized-scattering matrix and spherical wave expansion analysis is used to configure a linearly polarized 24-element slotted array antenna at Ku band. The mutual coupling effects between slots have been considered in the proposed methodology. Therefore, it is possible to remove the typical compensation step in the design process. The computing costs of the whole antenna optimization process is significantly reduced using the proposed method compared to the commercial full-wave simulation tools. An antenna prototype has been manufactured in order to experimentally validate the antenna performance. A realized gain and efficiency values of 15.9 dB and 97\% have been measured at the design frequency (17 GHz), respectively.}, author = {J C{\'o}rcoles and P Sanchez-Olivares and J Rubio and J L Masa-Campos and J. Zapata} } @article {16_2x2_patcharray_Eduardo_MOTL, title = {Linearly polarized small patch array fed by corporate SIW network}, journal = {Microwave and Optical Technology Letters}, volume = {58}, number = {3}, year = {2016}, month = {Mar.}, pages = {587 - 593}, abstract = {In this article, a linearly polarized 2 {\texttimes} 2 patch array uniformly fed by a corporate substrate integrated waveguide network for Ku band is presented. Undesired main beam steering is avoided by means of a fully corporate feeding network, although grating lobes may appear due to greater separation between radiating elements. Moreover, a reduced patch separation to avoid grating lobe appearance leads to an antenna matching coefficient degradation due to the proximity of antenna discontinuities. In consequence, a tradeoff approach has been developed, achieving a measured 4.1\% matching bandwidth and a measured gain of 13.27 dBi, which corresponds to an 86\% radiation efficiency. Good agreement between simulated and measured results is observed in all cases}, issn = {1098-2760}, doi = {10.1002/mop.29628}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mop.29628/epdf}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @article {16_PIERC_PAULA-SANCHEZ_TFG, title = {Omnidirectional Conformal Patch Antenna at S-Band with 3D Printed Technology}, journal = {Progress In Electromagnetics Research C}, volume = {64}, year = {2016}, pages = {43-50}, abstract = {A conformal patch array antenna with omnidirectional pattern in the azimuth plane at S-band is presented. A theoretical study of the generated ripple in the omnidirectional radiation pattern according to the number of faces that conform the array has been computed. A six-faced regular prism 3D structure has been chosen following a maximum 3 dB ripple criteria in the omnidirectional radiation pattern. A rectangular microstrip patch fed by a microstrip line has been designed as single radiating element. An equal power divider has been designed as feeding network in microstrip technology to feed each radiating element. Several prototypes have been manufactured and measured to validate the theoretical and simulated results. The entire conformal array has been assembled on a hexagonal regular prism manufactured in PolyLactic Acid (PLA) material using a 3D printer. In spite of the complexity of the proposed antenna structure, the used manufacturing processes, such as microstrip and 3D printing, allows to perform a low cost, low weight and compact final antenna. A higher radiated field ripple than the expected one is generated due to small deviations between experimental and theoretical critical parameters such as the feeding network performance or the 3 dB beam-width of the single element radiation pattern. A maximum ripple value of 4 dB has been experimentally obtained in the omnidirectional radiating pattern.}, issn = {1937-8718}, doi = {doi:10.2528/PIERC1602241}, url = {http://www.jpier.org/PIERC/pier.php?paper=16022410}, author = {P P Sanchez-Dancausa and J L Masa-Campos and P Sanchez-Olivares and E Garcia Marin} } @conference {15_EUCAP_EDUARDOGARCIA_patcharray2x2, title = {2 {\texttimes} 2 stacked patch array with corporate SIW feeding network}, booktitle = {Antennas and Propagation (EUCAP), 2015 9th European Conference on}, year = {2015}, month = {April}, pages = {1-4}, abstract = {A linearly polarized 2x2 patch array fed by a corporate Substrate Integrated Waveguide network for Ku band is presented. The utilization of a corporate topology in the feeding network prevents the antenna from suffering an unintended main lobe tilt dispersion. Nevertheless, the interelement spacing increases, and so does the Side-Lobe Level. Reducing this spacing implies closer discontinuities, such as bends and T-junctions. This degrades the reflection coefficient. Hence, a tradeoff solution has been designed and manufactured, achieving a Side-Lobe Level better than -11 dB and a measured bandwidth similar to the expected in the simulation stage, being 4.1 \% at -10 dB. The measured gain reaches 13.27 dB, which corresponds to an 86\% radiation efficiency.}, keywords = {antenna, array, corporate feed, linear polarization., SIW, stacked patch}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @conference {15_URSI_EDUARDO-GARCIA_patcharray2x2, title = {Agrupaci{\'o}n Plana de Doble Parche Apilado con Alimentaci{\'o}n Corporativa sobre SIW}, booktitle = {Simposium Nacional URSI 2015}, year = {2015}, month = {September}, abstract = {In this work, a planar stacked patch array for Ku band fed by a fully corporate Substrate Integrated Waveguide network is proposed. Corporate topology prevents an unintended main beam steering effect that reduces the antenna bandwidth in progressive wave structures. Nevertheless, an increase in the spacing between radiating elements occurs, worsening the Side- Lobe Level figure. A reduction in such spacing implies closer discontinuities, namely bends and power dividers, and thus reflection coefficient is degraded. Therefore, a tradeoff solution is presented, where a measured Side-Lobe Level better that -11 dB and 4.1\% reflection bandwidth are achieved, showing good agreement with the simulated results. A measured gain of 13.27 dBi is attained, corresponding to an 86\% radiation efficiency.}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} } @conference {15_URSI_PAULA-SANCHEZ_conformalomniarray, title = {Conformal Patch Array Antenna at 3.5 GHz for Omnidirectional Coverage}, booktitle = {Simposium Nacional URSI 2015}, year = {2015}, month = {September}, abstract = {A conformal patch array antenna with an omnidirectional pattern in the azimuth plane at S band is presented. A theoretical study of the ripple generated in the omnidirectional radiation pattern according to the number of faces that conform the array has been analyzed. A six faced prism 3D structure has been chosen following a maximum 3 dB ripple criteria in the omnidirectional radiation pattern. A rectangular microstrip patch fed by a microstrip line has been designed as the single radiating element. To feed each radiating element an equal power division feeding network has been designed in microstrip technology. Several prototypes have been manufactured and measured. Finally, the entire conformal array has been assembled on a regular hexagonal prism fabricated in Polylactic acid material using a 3D printer to validate the theoretical and the simulation results. Higher field ripple than expected in the omnidirectional radiating pattern has been obtained in the experimental results, demonstrating that the 3 dB beamwidth of the single radiating element is a critical parameter to design for a good 3D array performance.}, author = {P P Sanchez-Dancausa and J L Masa-Campos and P Sanchez-Olivares} } @conference {15_URSI_JORGE_INVITADA, title = {Desarrollo de componentes pasivos con divisi{\'o}n/combinaci{\'o}n de potencia para sistemas de comunicaciones}, booktitle = {Simposium Nacional URSI 2015}, year = {2015}, month = {September}, abstract = {This paper addresses the development of passive devices for communication systems working at the microwave frequency band, but also at millimeter-wave and terahertz frequencies. A brief review of different types of passive devices that the authors have been developed for different applications will be made. The paper will be focused on the devices for the last stage of the transmitter/receiver chain in communications systems, where the antennas and other components such as filters, multiplexers, polarizers, dividers/combiners, etc are an essential part. The application of these devices to power combination techniques will be also outlined, which can be used in high-power amplification, but also in other problems as antenna arrays.}, author = {B Taha-Ahmed and J C{\'o}rcoles-Ortega and R V Haro-Baez and C A Leal-Sevillano and J L Masa-Campos and J R Montejo-Garai and E Garcia-Marin and A Mor{\'a}n-L{\'o}pez and L Polo-Lopez and J M Rebollar-Machain and J A Ruiz-Cruz and P Sanchez-Olivares} } @conference {15_APCASE_RAULHARO_divradial, title = {Development of Radial Waveguide Dividers with Large Number of Ports}, booktitle = {Computer Aided System Engineering (APCASE), 2015 Asia-Pacific Conference on}, year = {2015}, month = {July}, pages = {58-62}, abstract = {Power division/combination is a very important function for achieving high-performance power amplification in microwave and millimeter-wave systems, allowing the use of simpler individual amplifiers to provide microwave/millimeter wave high power signals. In this paper we address the development of divider/combiners in waveguide technology for large number of ports. Radial waveguide dividers will be studied, starting from the S-parameters representing the N-port waveguide junction, and ending with the full-wave simulations. Two different designs in this technology are studied. The experimental evaluation will come from a prototype at Ku-band, fabricated and tested in order to validate the design.}, keywords = {antenna, array, corporate feed, linear polarization., SIW, stacked patch}, author = {R V Haro-Baez and J L Masa-Campos and J A Ruiz-Cruz and P Sanchez-Olivares and E V Carrera} } @article {14_IET_SERGIO-CASAS_rwpatcharray, title = {Design and characterisation model for a linearly polarised patch array fed by serial rectangular waveguide network}, journal = {IET Microwaves, Antennas \& Propagation}, volume = {8}, number = {14}, year = {2014}, month = {November}, pages = {1204-1210}, abstract = {A novel method for considering radiating structures independently to their feeding networks is presented. The integration of both parts separately designed suffers a critical misalignment with the theoretical behaviour caused by the mutual coupling effects between adjacent elements. This method analyses radiated near E-field monitors to adjust the whole antenna after joining both independently designed parts. A linearly polarised patch array fed by a rectangular waveguide with internal coupling patches for X band (11{\textendash}12 GHz) has been designed to validate the method performance. A double stacked microstrip patch structure with an integrated phase compensation microstrip line has been used as radiating element. The coupling patches inside the waveguide are connected to the external radiating patches by means of metallic probes. The presented method requires changes in the feeding structure as in the radiating elements. Several prototypes have been manufactured and measured: the feeding waveguide structure connectorised, the radiating patches connectorised, the union of both with SMA transitions and the final integration into the complete antenna. 18.5 dBi gain and 85\% efficiency peak values, as well as 6\% usable bandwidth have been experimentally achieved.}, issn = {1751-8725}, doi = {10.1049/iet-map.2013.0379}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6955144}, author = {S Casas-Olmedo and J L Masa-Campos and P Sanchez-Olivares} } @conference {14_URSI_SERGIO-CASAS_rwpatcharray, title = {Design Method of Linear Patch Arrays Fed by Waveguide Feeding Networks}, booktitle = {Simposium Nacional URSI 2014}, year = {2014}, month = {September}, abstract = {A novel method for considering radiating structures independently to their feeding networks is presented. The integration of both parts separately designed suffers a critical misalignment with the theoretical behavior caused by the mutual coupling effects between adjacent elements. This method analyses radiated near E-field monitors to adjust the whole antenna after joining both independently designed parts. A Linearly Polarized Patch Array fed by a Rectangular Waveguide with internal coupling patches for X band (11 GHz - 12 GHz) has been designed to validate the method performance. A double stacked microstrip patch structure with an integrated phase compensation microstrip line has been used as radiating element. The coupling patches inside the waveguide are connected to the external radiating patches by means of metallic probes. The presented method requires changes in the feeding structure as in the radiating elements. Several prototypes have been manufactured and measured: the feeding waveguide structure connectorized, the radiating patches connectorized, the union of both with SMA transitions, and the final integration into the complete antenna. 18.5 dBi gain and 85\% efficiency peak values have been experimentally achieved.}, author = {S Casas-Olmedo and J L Masa-Campos and P Sanchez-Olivares} } @article {14_TAP_SANCHEZ-OLIVARES_PFC, title = {Novel Four Cross Slot Radiator With Tuning Vias for Circularly Polarized SIW Linear Array}, journal = {Antennas and Propagation, IEEE Transactions on}, volume = {62}, number = {4}, year = {2014}, month = {April}, pages = {2271-2275}, abstract = {A substrate integrated waveguide (SIW) linear array is presented with a new circularly polarized (CP) element. The single radiator consists of four cross tilted slots. In addition, a pair of tuning metallic vias is included to improve the reflection of longest slots. A 16-element antenna prototype with -26-dB Taylor distribution and 1.5\% residual power was designed, manufactured and measured to verify the new slot performance in an array configuration. A 17-dB peak gain, 1.86-dB axial ratio and 80\% radiation efficiency were experimentally achieved at 17 GHz. A 3\% usable bandwidth was obtained owing to frequency main beam tilt dispersion.}, keywords = {16-element antenna prototype, antenna, Antenna measurements, antenna radiation patterns, array configuration, Arrays, circular polarization (CP), circularly polarized element, circularly polarized linear array, Couplings, four cross slot radiator, four cross tilted slots, frequency 17 GHz, frequency main beam tilt dispersion, linear antenna arrays, linear array, metallic vias, microwave antenna arrays, radiation efficiency, Reflection, single radiator, SIW linear array, slot, slot antenna arrays, substrate integrated waveguide, substrate integrated waveguide (SIW), substrate integrated waveguides, Substrates, Taylor distribution, Tuning, tuning via, tuning vias}, issn = {0018-926X}, doi = {10.1109/TAP.2014.2299823}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6710164}, author = {P Sanchez-Olivares and J L Masa-Campos} } @conference {13_DESE_Masa-CamposRuiz-CruzCorcoles-OrtegaEtAl_AntenasplanasBajasPerdidas, title = {Antenas planas con redes de alimentaci{\'o}n de bajas p{\'e}rdidas y control de apuntamiento para aplicaciones de defensa y seguridad}, booktitle = {Congreso Nacional de I+D en Defensa y Seguridad}, year = {2013}, month = {Nov}, pages = {1-8}, abstract = {En el presente art{\'\i}culo se presentan distintas opciones de antenas de bajo perfil, bajas p{\'e}rdidas y apuntamiento variable seg{\'u}n la banda de operaci{\'o}n de los sistemas de defensa y seguridad. Empezando por las antenas enteramente en tecnolog{\'\i}a impresa, pasando por las gu{\'\i}as de onda sobre sustrato y las gu{\'\i}as de ondas met{\'a}licas, los dise{\~n}os mostrados ofrecen un buen rendimiento en ganancia adecuado a la banda de frecuencias. Varios prototipos han sido implementados y testeados en banda S, X y Ku para validar las ideas planteadas.}, author = {J L Masa-Campos and J A Ruiz-Cruz and J C{\'o}rcoles-Ortega and B Taha-Ahmed and P Sanchez-Olivares and P Pascual-Garcia} } @article {13_AWPL_GARCIA-VALVERDE_PFC, title = {Linear Patch Array Over Substrate Integrated Waveguide for Ku-Band}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {12}, year = {2013}, pages = {257-260}, abstract = {A linearly polarized patch array with direct probe feed over substrate integrated waveguide (SIW) network (LP-PASIW) for Ku-band is presented. A double-stacked microstrip patch structure has been used as radiating elements. Internal SIW coupling patches are placed inside the SIW to obtain the desired radiation pattern. The internal coupling and external radiating patches are connected by means of copper vias. A mutual coupling model is also proposed to adjust the radiation and reflection properties of the array. An antenna prototype has been manufactured and measured. At 17.7 GHz, 16 dBi and 80\% peak gain and efficiency values are obtained. Although a 10\% reflection bandwidth (17-18.6 GHz) is achieved, the usable bandwidth is reduced to 3\% due to array beam tilt dispersion.}, keywords = {antenna feeds, antenna prototype, antenna radiation patterns, Antennas, array beam tilt dispersion, Arrays, bandwidth 17 GHz to 18.6 GHz, Brain modeling, Couplings, direct probe feed, double-stacked microstrip patch structure, Double-stacked patch, efficiency 80 percent, electromagnetic wave polarisation, external radiating patches, frequency 17.7 GHz, hybrid LSM$^{{rm y}{\textquoteright}}$ mode, internal coupling patches, internal SIW coupling patches, linearly polarized patch array, LP-PASIW, microstrip antenna arrays, microwave antenna arrays, Mutual coupling, mutual coupling model, radiating elements, radiation pattern, Reflection, substrate integrated waveguide (SIW), substrate integrated waveguide network, substrate integrated waveguides, Substrates, waveguide antenna arrays}, issn = {1536-1225}, doi = {10.1109/LAWP.2013.2245623}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6451111\&tag=1}, author = {D Garcia-Valverde and J L Masa-Campos and P Sanchez-Olivares and B Taha-Ahmed and J C{\'o}rcoles} } @article {13_PIERC_Sanchez-OlivaresMasa-CamposRuiz-CruzEtAl_SIW2DPlanar4CrossSlotsTuningvias, title = {SIW 2D Planar Array with Four Cross Slots Radiator and Tuning Vias}, journal = {Progress In Electromagnetics Research C}, volume = {40}, year = {2013}, pages = {83-92}, abstract = {A Substrate Integrated Waveguide (SIW) planar array is presented using a right handed circularly polarized (RHCP) element with four crossed tilted radiating slots. In addition, a pair of metallic tuning vias is included to really improve the reflection of longest slots. A corporate feeding network over SIW has been designed for distributing the input signal to 128 radiating elements, divided into 8 progressive wave linear arrays of 16 elements each. The designed planar array has been manufactured and measured to verify the antenna performance. 25.5 dB gain, 2.33 dB axial ratio, as well as 85\% radiation efficiency values have been experimentally achieved at 17 GHz. A 3\% usable bandwidth (16.75-17.25 GHz) is obtained due to the typical frequency main beam tilt dispersion in the elevation plane of the progressive wave arrays.}, issn = {1937-8718}, doi = {10.2528/PIERC13040905}, url = {http://www.jpier.org/PIERC/pier.php?paper=13040905}, author = {P Sanchez-Olivares and J L Masa-Campos and J A Ruiz-Cruz and B Taha-Ahmed} } @conference {APS-URSI-2013, title = {SIW patch array with internal coupling patches}, booktitle = {Antennas and Propagation Society International Symposium (APSURSI), 2013 IEEE}, year = {2013}, month = {July}, pages = {1800-1801}, abstract = {A Substrate Integrated Waveguide (SIW) has been used to feed a progressive wave linear array of 16 double stacked patches. The amplitude and phase performance has been achieved by means of coupling patches, which are placed inside the SIW. An antenna prototype has been manufactured with a multilayer PCB structure. 16 dBi and 80 \% peak gain and efficiency values at 17.7 GHz have been measured. A 10\% reflection bandwidth (17 - 18.6 GHz) is achieved, although the usable bandwidth is reduced to 3\% due to the typical array beam tilt dispersion of this kind of designs.}, keywords = {Antenna measurements, antenna prototype, Antennas, array beam, Arrays, bandwidth 17 GHz to 18.6 GHz, Couplings, double stacked patches, Gain, internal coupling patches, linear antenna arrays, microstrip antenna arrays, Nonhomogeneous media, PCB structure, printed circuits, progressive wave linear array, SIW patch array, substrate integrated waveguide, substrate integrated waveguides, Substrates, tilt dispersion}, issn = {1522-3965}, doi = {10.1109/APS.2013.6711559}, author = {J L Masa-Campos and D Garcia-Valverde and P Sanchez-Olivares and B Taha-Ahmed} } @conference {13_URSI_SANCHEZ-OLIVARES_tuningvias, title = {Tuning Vias Four Cross Slot Planar Array over Substrate Integrated Waveguide}, booktitle = {Simposium Nacional URSI 2013}, year = {2013}, month = {September}, abstract = {A Substrate Integrated Waveguide (SIW) planar array is presented using a circularly polarized (CP) four crossed tilted radiating slots. In addition, a pair of metallic tuning vias is included to really improve the reflection of longest slots. A corporate feeding network over SIW has been designed for distributing the input signal to 128 radiating elements, divided into eight 16-elements progressive wave linear arrays. The designed planar array has been manufactured and measured to verify the antenna performance. 25.5 dB peak gain, 2.33 dB axial ratio and 85\% radiation efficiency values have been experimentally achieved at 17 GHz. Although the specified operation band is 16.3 to 17.7 GHz (Ku band), a 3\% usable bandwidth is obtained due to the typical frequency main beam tilt dispersion in the elevation plane of the progressive wave antennas.}, author = {P Sanchez-Olivares and J L Masa-Campos} } @conference {12_EUCAP_SANCHEZ-OLIVARES_16siw, title = {Slot radiator with tuning vias for circularly polarized SIW linear array}, booktitle = {Antennas and Propagation (EUCAP), 2012 6th European Conference on}, year = {2012}, month = {March}, pages = {3716-3720}, abstract = {A 16-element circularly polarized (CP) Substrate Integrated Waveguide (SIW) linear array antenna with -26 dB Taylor distribution and 2\% residue power at 17 GHz is designed. The single element consists of four crossed inclined radiating slots. In this configuration, reflection goals on the linear array are not fully achieved. For this reason a tuning element is included on some of the individual radiating elements, which consists of a pair of metallic vias that greatly enhances the reflection of longest slots. Therefore, the antenna reflection is also improved. A global antenna prototype is manufacture to check the new slot element performance in an array configuration. The specified operation band is 16.3 to 17.7 GHz.}, keywords = {16-element circularly-polarized SIW linear array antenna, antenna radiation patterns, antenna reflection, Arrays, circular polarization (CP), electromagnetic wave polarisation, frequency 16.3 GHz to 17.7 GHz, linear antenna arrays, metallic vias, prototypes, radiating elements, Reflection, slot antenna arrays, Slot antennas, Slot array antenna, slot radiator, slot reflection, substrate integrated waveguide, substrate integrated waveguide (SIW), substrate integrated waveguides, Substrates, Taylor distribution, Tuning, tuning element, tuning via, tuning vias}, doi = {10.1109/EuCAP.2012.6205816}, author = {P Sanchez-Olivares and J L Masa-Campos} } @conference {11_EIEC_Montejo-GaraiLeal-SevillanoRuiz-CruzEtAl_DesignofContiguous-BandOMUX, title = {Design of Contiguous-Band Elliptic-Response Manifold Output Multiplexers by Efficient Cancellation of Reactive Impedance Parts}, booktitle = {Proc. VIII Encuentro Ib{\'e}rico de Electromagnetismo Computacional (in Spanish)}, year = {2011}, month = {Nov.}, pages = {1}, abstract = {In recent years, there has been an increasing demand for satellite communication channels with a complex response, motivated by a most effective use of the radiofrequency spectrum. This means that more channels have to be combined in the output multiplexer (OMUX) after power amplification. In this paper, a synthesis technique based on the Cauer ladder development has been developed to design the singly terminated filters for manifold multiplexers. A procedure for the synthesis and design of contiguous band manifold output multiplexers based on singly terminated filters with elliptic response is considered. The zero shifting technique leads to the synthesis of a driving{\^a}{\texteuro}{\textquotedblleft}point impedance including transmission zeros at finite real frequencies. The synthesized canonical forms have different topologies, number of reactive constant elements and reactive part of the driving impedances with different frequency responses. These characteristics have been intensively analyzed to find the most suitable combination in the multiplexing process to match the channels to the manifold. Using the methodology presented in this work a four-channel multiplexer for Ku-band operation has been designed, manufactured and measured. The input{\^a}{\texteuro}{\textquotedblleft}output ports are standard WR75. The prototype has been manufactured in brass using low-cost milling technique and is formed in one block where all the cavities and irises have the same height. The unloaded Q for the brass cavities is 2500 and therefore the expected insertion losses at central frequency of the higher channel are approximately 2.5 dB. The final paper will show a comparison between the full-wave simulation using the mode-matching method (including losses) and the measurements of the input reflection coefficient and the transmission of the manufactured multiplexer.}, author = {Montejo-Garai, J R and C A Leal-Sevillano and J A Ruiz-Cruz and Rebollar, J M and Rogla, L and Sobrino, S} } @conference {11_URSIESP_Montejo-GaraiLeal-SevillanoRuiz-CruzEtAl_DisenoOMUXCancelacion, title = {Dise{\~n}o de Multiplexores Manifold de Salida y Banda Contigua con Respuesta El{\'\i}ptica Mediante la Cancelaci{\'o}n Eficiente de la Parte Reactiva de la Impedancia}, booktitle = {Proc. 2011 Simposium Nacional URSI (in Spanish)}, year = {2011}, month = {Sept.}, pages = {1-4}, abstract = {A procedure for the synthesis and design of contiguous band manifold output multiplexers based on singly terminated filters with elliptic response is presented. The zero-shifting technique leads to the synthesis of a driving-point impedance including transmission zeros at finite real frequencies. The synthesized canonical forms have different topologies, number of reactive constant elements and reactive part of the driving impedances with different frequency responses. These characteristics have been intensively analyzed to find the most suitable combination in the multiplexing process to match the channels to the manifold. A Ku-band four-channel elliptic-response multiplexer has been designed in H-plane rectangular waveguide, manufactured and measured in order to show the proposed approach.}, author = {Montejo-Garai, J R and C A Leal-Sevillano and J A Ruiz-Cruz and Rebollar, J M and Rogla, L and Sobrino, S} } @article {15_RadialLineIEEE, title = {Linearly Polarized Radial Line Patch Antenna With Internal Rectangular Coupling Patches}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {59}, number = {8}, year = {2011}, month = {Aug.}, pages = {3049 - 3052}, abstract = {A linearly polarized radial line patch antenna with internal coupling patches is presented. A non-resonant antenna structure has been designed, with a 0.68 ?0 radial spacing between element rings. A uniform amplitude and phase feed scheme has been implemented. Therefore, a phase compensation microstrip structure (external to the radial waveguide) has been included for a broadside radiation beam. Likewise, a compensation method has been used to avoid internal reflection problems in the waveguide. An antenna prototype has been built. 28.2 dBi gain and 70\% efficiency peak values have been measured at DBS band, with reasonable agreement between simulations and measurements.}, keywords = {Internal rectangular coupling patch, microstrip phase compensation line, radial line patch antenna (RLPA)}, issn = {0018-926X}, doi = {10.1109/TAP.2011.2158945}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=5784312}, author = {J L Masa-Campos and Sierra-P{\'e}rez, M} } @article {7_Stacked_Patch_X_bandMOTL, title = {Monopulse beam-scanning planar array antenna in L band}, journal = {Microwave and Optical Technology Letters}, volume = {51}, number = {6}, year = {2009}, month = {Jun.}, pages = {1419-1424}, abstract = {A planar antenna is presented as part of a Signal Identification System working at 1.06 GHz. The antenna presents a monopulse radiation pattern. Likewise, a scanning of the main beam direction is achieved in a {\textpm}45{\textdegree} azimuth coverage. A limited 3 dB amplitude drop of the received signal at the edges of the angular scanning area is only permitted. Furthermore, a broad beamwidth is required in the single element of the array. A rectangular linearly polarized double stacked patch has been then designed, with a significant size reduction in the nonresonant length, to increase the azimuth beamwidth of the array single element. The whole antenna structure is composed of 18 elements, which have been distributed in six columns of three patches per column. The feeding network of the array has been developed in microstrip technology, with small individual circuits connected by coaxial cables, to reduce the global losses of the system. The designed compact antenna and the transmitting and receiving equipments will be placed inside a POD on the top part of an airplane. A prototype antenna has been manufactured and measured in three different beam pointing directions. Satisfactory results have been achieved in the entire frequency band.}, keywords = {beam-scanning array, monopulse system, stacked patch}, issn = {0895-2477}, doi = {10.1002/mop.23516}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mop.23516/abstract}, author = {J L Masa-Campos and S{\'a}nchez-Sevilleja, S and Dom{\'\i}nguez-Grano-de-Oro, C and Sierra-P{\'e}rez, M and Fernandez-Jambrina, J L} } @article {8_ParallelplateIEEE, title = {Parallel Plate Patch Antenna With Internal Rectangular Coupling Patches and TEN0 Mode Excitation}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {57}, number = {7}, year = {2009}, month = {Jul.}, pages = {2185-2189}, abstract = {A parallel plate waveguide antenna is presented with microstrip patches as radiating elements. Rectangular patches are also placed inside the waveguide as coupling field structures from the waveguide to the radiating elements. The connections from the coupling to the radiating patches are made by means of vias. The field propagated along the parallel plate waveguide corresponds to a high order TE mode, creating virtual smaller rectangular waveguides in the parallel plate structure. An antenna prototype has been manufactured and measured. A 60\% efficiency and 27 dBi antenna gain were obtained; with a 6.5\% reflection bandwidth. Nevertheless, the resonant behaviour becomes evident in the radiation pattern measurements.}, keywords = {Microstrip coupling horizontal lines, parallel plate waveguide, patch antenna, virtual waveguide}, issn = {0018-926X}, doi = {10.1109/TAP.2009.2021969}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=4907131}, author = {J L Masa-Campos and Klinger, S and Sierra-P{\'e}rez, M} } @article {10_GEODAMOTL, title = {Triangular planar array of a pyramidal adaptive antenna for satellite communications at 1.7 GHz}, journal = {Microwave and Optical Technology Letters}, volume = {51}, number = {11}, year = {2009}, month = {Nov.}, pages = {2633 - 2639}, abstract = {Nowadays, satellite communications are basic for the human lifestyle. In this way, a smart, conformal, and multiarray antenna (GEODA) is being developed in order to receive signals from several satellites simultaneously in the 1.7 GHz working band. An adaptive beam system is able to follow the signals from the satellite constellation. The complex structure of the antenna is based in a 3D composition of planar arrays with triangular shape. These arrays are divided into subarrays of three patches (Cells), composing the single control element for the arrays main beam direction management. Fifteen cells (45 radiating elements) compose each triangular array of the GEODA antenna. In this article, a triangular array prototype is implemented and measured. Likewise, an individual characterization of the array components is presented.}, keywords = {adaptive antenna, branch-line coupler, double stacked patch, planar array}, issn = {0895-2477}, doi = {10.1002/mop.24692}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mop.24692/abstract}, author = {J L Masa-Campos and Montesinos-Ortego, I and Sierra-P{\'e}rez, M} } @article {08_PIER_Ruiz-CruzMontejo-GaraiRebollar_CompactKuTriplexer, title = {Compact Full Ku-Band Triplexer With Improved E-Plane Power Divider}, journal = {Progress in Electromagnetic Research}, volume = {86}, year = {2008}, month = {October}, pages = {39-51}, abstract = {An improved E-plane power divider for compact waveguide triplexers with large separation between channels is presented. The configuration of the divider aims to exploit the different behavior of the device for frequency bands with large separation, leading to a very asymmetric E-plane junction. H-plane filters with inductive windows are used for each channel, in order to obtain reduced insertion losses and lower sensitivity than in metal-insert E-plane filters. The resultant triplexer configuration is very compact, and its design is analyzed and optimized by Mode-Matching. The experimental results of a full Ku-band prototype for communications satellite systems show a very good agreement with the expected simulated response.}, issn = {1559-8985}, doi = {10.2528/PIER08082803}, url = {http://ceta.mit.edu/pier/pier86/03.08082803.pdf}, author = {J A Ruiz-Cruz and Montejo-Garai, J R and Rebollar, J M and Sobrino, S.} } @article {6_Monopulse_L_BandMOTL, title = {Monopulse beam-scanning planar array antenna in L band}, journal = {Microwave and Optical Technology Letters}, volume = {50}, number = {7}, year = {2008}, month = {Jul.}, pages = {1812-1819}, abstract = {A planar antenna is presented as part of a Signal Identification System working at 1.06 GHz. The antenna presents a monopulse radiation pattern. Likewise, a scanning of the main beam direction is achieved in a {\textpm}45{\textdegree} azimuth coverage. A limited 3 dB amplitude drop of the received signal at the edges of the angular scanning area is only permitted. Furthermore, a broad beamwidth is required in the single element of the array. A rectangular linearly polarized double stacked patch has been then designed, with a significant size reduction in the nonresonant length, to increase the azimuth beamwidth of the array single element. The whole antenna structure is composed of 18 elements, which have been distributed in six columns of three patches per column. The feeding network of the array has been developed in microstrip technology, with small individual circuits connected by coaxial cables, to reduce the global losses of the system. The designed compact antenna and the transmitting and receiving equipments will be placed inside a POD on the top part of an airplane. A prototype antenna has been manufactured and measured in three different beam pointing directions. Satisfactory results have been achieved in the entire frequency band.}, keywords = {beam-scanning array, monopulse system, stacked patch}, issn = {0895-2477}, doi = {10.1002/mop.23516}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mop.23516/abstract}, author = {J L Masa-Campos and S{\'a}nchez-Sevilleja, S and Dom{\'\i}nguez-Grano-de-Oro, C and Sierra-P{\'e}rez, M and Fernandez-Jambrina, J L} } @article {4_Omni_antenna_parasiticstripsMOTL, title = {Circularly polarized omnidirectional millimeter wave monopole with parasitic strip elements}, journal = {Microwave and Optical Technology Letters}, volume = {49}, number = {3}, year = {2007}, month = {Mar.}, pages = {664-668}, abstract = {A circularly polarized omnidirectional millimeter wave monopole with parasitic strip elements for a system of arrival signal direction detection in millimeter band is presented. As a consequence of the radiation pattern requirements, the proposed antenna consists of a conical skirt monopole with a polarizer radome. The polarizer converts a wave from linear to circular polarization. The proposed antenna has the advantage to be robust, low cost, and easy to fabricate with conventional materials and printed circuit technology. The study presents simulation and experimental results obtained with an antenna prototype that validate the design.}, keywords = {arrival signal direction detection system, Circular polarization, millimeter antenna, omnidirectional antenna}, issn = {0895-2477}, doi = {10.1002/mop.22237}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mop.22237/abstract}, author = {Fern{\'a}ndez, J M and J L Masa-Campos and Sierra-P{\'e}rez, M} } @article {5_Omni_antenna_slotsMOTL, title = {Omnidirectional circularly polarized slot antenna fed by a cylindrical waveguide in millimeter band}, journal = {Microwave and Optical Technology Letters}, volume = {49}, number = {3}, year = {2007}, month = {Mar.}, pages = {638-642}, abstract = {A circularly polarized slotted array antenna is presented. The array is fed by a circular waveguide propagating the TM01, to properly generate the required polarization. An omnidirectional azimuth radiation pattern is obtained, as well as a ?10{\textdegree}/+30{\textdegree} elevation antenna coverage. Low losses are achieved because of the waveguide feed. The slot array is mechanized over the metallic wall of the circular waveguide. Furthermore, the antenna presents a solid and rigid mechanical structure, which guarantees an optimum and repetitive response in a manufacturing process. A prototype antenna has been designed and measured. Satisfactory results have been obtained. The slotted array takes part from a signal detection system centered in 36.85 GHz.}, keywords = {Circular polarization, conformal slotted waveguide array, transversal magnetic mode, waveguide to coaxial transition}, issn = {0895-2477}, doi = {10.1002/mop.22207}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mop.22207/abstract}, author = {J L Masa-Campos and Fern{\'a}ndez, J M and Sierra-P{\'e}rez, M} } @article {05_IEEETMTT_Ruiz-CruzSabbaghZakiEtAl_Canonicalridgewaveguide, title = {Canonical ridge waveguide filters in LTCC or metallic resonators}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {53}, number = {1}, year = {2005}, month = {Jan.}, pages = {174-182}, abstract = {A new physical realization of an elliptic function filter response is proposed for achieving compact size, wide bandwidth, wide spurious free stopband and high-selectivity performance. The filter configuration can be implemented in conventional waveguide technology or embedded in a multilayer low-temperature co-fired ceramic structure for integration with other circuitry in a chip module. The filter is analyzed using rigorous mode matching. To validate the concept, prototypes of four- and six-cavity elliptic filters are designed following a systematic procedure. Approximate synthesis is used to obtain initial dimensions of the filter and the desired optimum response is obtained by means of a final full-wave optimization. The results are verified with other numerical methods and with the measurements of a fourth-order waveguide filter.}, keywords = {band-pass filters, canonical ridge waveguide filters, cavity resonator filters, ceramics, chip module, circuit optimisation, elliptic filters, elliptic function filter response, four cavity elliptic filters design, fourth order waveguide filter, full-wave optimization, metallic resonators, microwave filters, mode matching, multilayer low temperature cofired ceramic structure, multilayers, numerical methods, prototypes, resonators, ridge waveguides, six cavity elliptic filters design, spurious free stopband filter, waveguide filters band pass filters, waveguide technology}, issn = {0018-9480}, doi = {10.1109/TMTT.2004.839324}, url = {http://ieeexplore.ieee.org/iel5/22/30125/01381687.pdf?tp=\&arnumber=1381687\&isnumber=30125}, author = {J A Ruiz-Cruz and El Sabbagh, M A and Zaki, K A and Rebollar, J M and Zhang, Y} } @article {3_CouplingJMOEA, title = {Coupling Characterization and Compensation Model for Antenna Arrays}, journal = {Journal of Microwaves, Optoelectronics and Electromagnetic Applications}, volume = {4}, number = {2}, year = {2005}, month = {Dec.}, pages = {95-110}, abstract = {Coupling is an important aspect to be considered in the design process of antenna arrays. The real feeding radiated coefficients can be quite different from the theoretical ones because of this effect. In this paper, a characterization and compensation model is presented. This procedure is capable of matching each element of the array. All the parameters of the array coupling model are obtained through the measurement of scattering parameters and radiation patterns of the individual elements. Some practical applications to linear patch arrays are presented.}, issn = {1516-7399}, url = {http://www.jmoe.org/site-number?id=3}, author = {J L Masa-Campos and Fern{\'a}ndez, J M and Sierra-Casta{\~n}er, M and Sierra-P{\'e}rez, M} } @article {2_RadiallineMOTL, title = {Radial Line Planar Antenna with Microstrip Feeding Coupling Lines}, journal = {Microwave and Optical Technology Letters}, volume = {46}, number = {4}, year = {2005}, month = {Aug.}, pages = {305-311}, abstract = {Radial-line antennas are an excellent choice for a high-gain and efficient design, as they present an easy manufacturing process due to their planar structure. In this paper, a new feeding mechanism, from the transmitting radial waveguide to the radiating elements, is proposed. This coupling structure is based on microstrip lines placed inside the radial waveguide and connected to each radiating patch. By changing the dimensions of the microstrip lines, it is possible to achieve the desired feeding configuration. In order to check the validity of the new feeding mechanism, coupled field measurements are done in the radial waveguide. Likewise, a prototype antenna is manufactured in order to evaluate the behavior of the microstrip coupling lines when the radiating patches are connected to them. The results obtained from this prototype are presented and discussed and future research is proposed.}, keywords = {double stacked patch antenna, microstrip coupling lines, radial line planar antenna (RLPA)}, issn = {0895-2477}, doi = {10.1002/mop.20973}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mop.20973/abstract}, author = {J L Masa-Campos and Sierra-P{\'e}rez, M} } @conference {05_APS_CorcolesSalazar_SelfAdaptiveFEM, title = {Self-adaptive algorithms based on h-refinement applied to finite element method}, booktitle = {Antennas and Propagation Society International Symposium, 2005 IEEE}, volume = {4B}, year = {2005}, month = {July}, pages = {197-200 vol. 4B}, abstract = {Two error indicators of the solution of an electromagnetic problem by the finite element method (FEM) and two local refinement algorithms for tetrahedral meshes are developed and combined to build up different self-adaptive (h-refinement) algorithms. 2nd order curl-conforming Nedelec tetrahedral elements are used. The performance of the different methods is checked and compared by means of the electromagnetic analysis of resonant cavities.}, keywords = {2nd order curl-conforming Nedelec tetrahedral elements, cavity resonators, computational electromagnetics, Convergence, Eigenvalues and eigenfunctions, Electromagnetic analysis, electromagnetic problem, Erbium, error indicators, finite element analysis, finite element method, finite element methods, h-refinement, Least squares approximation, Maxwell equations, Performance analysis, Resonance, resonant cavities, self-adaptive algorithms, Software performance, tetrahedral meshes}, doi = {10.1109/APS.2005.1552777}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=1552777}, author = {J C{\'o}rcoles-Ortega and Salazar-Palma, M} } @article {1_CouplingmodelMOTL, title = {Estimation of the patch-array-coupling model through radiated-field measurements}, journal = {Microwave and Optical Technology Letters}, volume = {43}, number = {1}, year = {2004}, month = {Oct.}, pages = {59-65}, abstract = {In the design process of array antennas, coupling is one of the most important elements to be considered. The real feeding-radiated coefficients can be quite different from the theoretical ones because of this effect. In this paper, a characterization method is presented that allows each element to be matched from the array. All the parameters of the array-coupling model are obtained through the measurement of scattering parameters and radiation patterns. Two practical applications for a linear patch array are presented.}, keywords = {array, coupling, patch antenna, planar antenna}, issn = {0895-2477}, doi = {10.1002/mop.20375}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mop.20375/abstract}, author = {Fern{\'a}ndez, J M and J L Masa-Campos and Sierra-Casta{\~n}er, M and Castellanos, D and Sierra-P{\'e}rez, M} } @conference {04_IMS_Ruiz-CruzElZakiEtAl_Full-wavedesignof, title = {Full-wave design of canonical ridge waveguide filters}, booktitle = {2004 IEEE MTT-S International Microwave Symposium Digest}, volume = {2}, year = {2004}, month = {June}, pages = {603-606}, abstract = {A new physical realization of an elliptic function filter response is proposed for achieving compact size, wide bandwidth, wide spurious free stop band and high selectivity performance. The canonical ridge waveguide filter configuration is analyzed using rigorous mode-matching. To validate the concept, a prototype that realizes the coupling matrix of a canonical four cavity elliptic filter is designed following a systematic procedure. Approximate synthesis is used to obtain initial dimensions of the filter and the desired optimum response is obtained by means of a final full-wave optimization. The results are verified with other numerical method and a prototype will be built for testing.}, keywords = {band-pass filters, coupling matrix, elliptic filters, elliptic function filter, filtering theory, full-wave design, full-wave optimization, mode matching, mode-matching, waveguide filters canonical ridge waveguide filters, wide bandwidth, wide spurious free stop band}, issn = {0149-645X}, doi = {10.1109/MWSYM.2004.1336056}, url = {http://ieeexplore.ieee.org/iel5/9277/29472/01336056.pdf?tp=\&isnumber=\&arnumber=1336056}, author = {J A Ruiz-Cruz and El Sabbagh, M A and Zaki, K A and Rebollar, J M} } @conference {04_7thFEMWorkshop_CorcolesetAl_TwoLocalRefinement, title = {Two local refinement algorithms for tetrahedral meshes}, booktitle = {7th International Workshop on Finite Elements for Microwave Engineering}, year = {2004}, month = {May}, pages = {1}, author = {J C{\'o}rcoles-Ortega and Llorente-Romano, S and Salazar-Palma, M} }