Papers by Eduardo García Marín
IEEE Antennas and Wireless Propagation Letters, 2022
Sensors
Two types of cost-efficient antennas based on dielectric gradient index dielectric lens have been... more Two types of cost-efficient antennas based on dielectric gradient index dielectric lens have been designed for 5G applications at 28 GHz. The first is a linearly polarized flat lens antenna (LP-FLA) for terrestrial 5G communications. The second is a novel circularly polarized stepped lens antenna (CP-SLA) for 5G satellite services. An efficient design method is presented to optimize and conform the lens topology to the radiation pattern coming from the antenna feeder. The LP-FLA is fed by a traditional linearly polarized pyramidal horn antenna (PHA). The CP-SLA is fed by an open-ended bow-tie waveguide cavity (BCA) antenna. This cavity feeder (BCA), using cross-sections with bow-tie shapes, allows having circular polarization at the desired frequency bandwidth. The two types of presented antennas have been manufactured in order to verify their performance by an easy, low-cost, three-dimensional (3D) printing technique based on stereolithography. The peak realized gain value for the ...
El presente documento versa sobre el trabajo de diseño, simulación, construcción y medida de una ... more El presente documento versa sobre el trabajo de diseño, simulación, construcción y medida de una agrupación radiante bidimensional, operante en la banda Ku de frecuencias, con polarización lineal y apoyada sobre tecnología de guía de onda impresa (SIW). Su principal característica es el uso de una red de alimentación de tipo corporativo en su totalidad, frente a otros diseños donde esta topología se combina con estructuras de tipo serie. La antena planteada podría tener aplicación en sistemas de comunicación por satélite o de radiolocalización. Inicialmente se ha contemplado el empleo de ranuras como elementos radiantes, diseñando primero una red de alimentación de tipo paralelo. Sin embargo, las fuertes restricciones de separación entre los elementos, impuestas para obtener un buen comportamiento en radiación, han obligado a cambiar a una conformación de elementos de tipo parche. Concretamente, se ha recurrido a la tecnología de parches apilados, buscando un ancho de banda mayor en...
IEEE Access, 2020
This work presents the design and prototyping of a reconfigurable phased array in Ku band (16 to ... more 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 • 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 • and 25 • , with a high efficiency in the whole design band thanks to the proposed waveguide implementation.
Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Escuela Politécnica Superior, ... more Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Escuela Politécnica Superior, Departamento de Tecnología Electrónica y de las Comunicaciones. Fecha de Lectura: 14-07-2021Esta tesis ha sido financiada por el Ministerio de Economía, Industria y Competitividad (MINECO) del Gobierno de España a través de los proyectos TEC2013-47106-C3-2-R (TECOAMP), TEC2014-55735-C3-1-R (ENABLING5G) y TEC2016-76070-C3-1-R (AEI/FEDER, UE) (ADDMATE); y el Gobierno de la Comunidad de Madrid a través del proyecto S2013/ICE-3000 (SPADERADAR-CM)
Micromachines
Some recent waveguide-based antennas are presented in this paper, designed for the next generatio... more Some recent waveguide-based antennas are presented in this paper, designed for the next generation of communication systems operating at the millimeter-wave band. The presented prototypes have been conceived to be manufactured using different state-of-the-art techniques, involving subtractive and additive approaches. All the designs have used the latest developments in the field of manufacturing to guarantee the required accuracy for operation at millimeter-wave frequencies, where tolerances are extremely tight. Different designs will be presented, including a monopulse antenna combining a comparator network, a mode converter, and a spline profile horn; a tunable phase shifter that is integrated into an array to implement reconfigurability of the main lobe direction; and a conformal array antenna. These prototypes were manufactured by diverse approaches taking into account the waveguide configuration, combining parts with high-precision milling, electrical discharge machining, direc...
2017 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), 2017
A progressive-wave antenna automated design technique is presented in this work. By means of a si... more 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-the-art 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.
2019 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP), 2019
In this work, a stacked-patch antenna for wireless applications in the 5 GHz band has been design... more In this work, a stacked-patch antenna for wireless applications in the 5 GHz band has been designed and fabricated by ink-jet printing. Conductive silver ink is selectively applied on a thin Kapton film to generate the microstrip lines. The Kapton layer is fixed to a High-Impact Polystyrene (HIPS) substrate, which provides mechanical stability and improves the antenna bandwidth. The experimental results of the prototypes show that the performance strongly depends on an accurate electrical characterization of the dielectric materials, as well as an effective union of the multiple layers of the antenna. The sources of deviations between computed and measured results have been determined by further simulations.
In this letter, additive manufacturing technologies have been evaluated for waveguide antenna arr... more In this letter, additive manufacturing technologies have been evaluated for waveguide antenna array prototyping at Ku band. Direct metal laser sintering (DMLS) and stereolithography have been assessed in terms of manufacturing limitations, electrical performance, accuracy, cost and weight, compared with traditional manufacturing methods. This assessment is performed on a corporate-fed waveguide array antenna for end-user digital broadcast satellite communications at Ku band. The objective is to manufacture this intricate multilayer structure as a single block, in order to prevent contact and leakage issues in the interface between antenna layers. This monolithic implementation is unfeasible with conventional milling in aluminum, renowned in the literature for its reliability in waveguide antenna implementation. A prototype has been machined with such technique as a reference for experimental results. A single block fabrication has been possible by DMLS, presenting a similar performa...
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Papers by Eduardo García Marín