Open Access
Conical versus gaussian profiled corrugated horn antennas
(IEEE, 2002) Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, a study of two equal size corrugated horn antennas; a conical and a gaussian profiled horn antenna (GPHA) has been developed. It will be demonstrated that GPHA´s provide lower sidelobes and wider bandwidths, while conical corrugated horn antennas offer higher directivities for the same aperture. Both type of antennas provide low crosspolar levels.
Open Access
Resultados experimentales de la mejora de potencia radiada por un dipolo mediante un superstrato left-handed
(2006) Sáenz Sáinz, Elena; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Maagt, Peter de; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper a comparison between the measured radiation performances of a single dipole and a dipole with a left handed superstrate based on a finite periodic repetition of a unit cell is presented. First of all the return losses and resonant frequency of the dipole has been measured for different sizes of the superstrate, having a good impedance matching and a decrease in the resonant frequency as the number of cells increase. By using an anechoic chamber and a receiver horn antenna, the power transmitted at boresight has been measured for different frequencies, observing a filtering behaviour due to the resonant characteristic of the superstrate and an improvement of the power transmitted at the resonant frequency of around 3.5 dB. Comparing the H and E plane radiation patterns of a dipole and the dipole with superstrate, more symmetrical and directive radiation patterns can be observed. Finally, a comparison between the simulated and measured aperture efficiency is presented with a good agreement between them.
Open Access
Mejoras de los parametros de radiacion de una antena choque-gaussiana para cobertura global
(2004) Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Extremely low sidelobe horn antennas are often required for the actual technology. This type of horn antennas is important to avoid interference with other systems. In this paper a novel design, consisting in attaching together a choked-waveguide antenna with a classical pure gaussian output corrugated horn is presented. A radiation pattern with very low sidelobes and crosspolar levels in a very short profile is obtained. This antenna shape was firstly presented in [1]. In this paper an improvement in size, weight, bandwidth and crosspolar level of the design is shown. This idea of horn antenna has been patented and PCT extended to several countries; Flann Microwave Ltd. has the rights to commercialize it and has sold several antennas of this type at the moment.
Open Access
A gap waveguide-based compact rectangular waveguide to a packaged microstrip inline transition
(MDPI, 2020) Pérez Escudero, José Manuel; Torres García, Alicia E.; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Institute of Smart Cities - ISC
In this paper two different simple to design and easy to manufacturing transitions from a microstrip to rectangular waveguide based on ridge and groove gap waveguides are studied. The first one is based on a combination of a groove and ridge gap waveguide. In this case, the microstrip substrate occupies the whole bottom metallic housing block, namely, the transition and the gap between the bed of nails and the lid; therefore, it does not require any substrate shaping. Nevertheless, the transition needs to replace groove waveguide by ridge gap waveguide sections to avoid higher-order mode excitation. In the second approach, based on only a groove gap waveguide, the substrate is shaped to be only in the microstrip section, that is, outside the bed of nails area. This leads to a simplification of the design procedure. Prototypes of both transitions have been characterized, showing good agreement with the simulations taking into account the manufacturing tolerances. Performance comparable to the state-of-the-art in this frequency band has been achieved.
Open Access
Optimization of a pin surface as a solution to suppress cavity modes in a packaged W-band microstrip receiver
(IEEE, 2014) Rebollo Mugueta, Ainara; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A pin surface structure has been used in the upper metal plate of a packaged W-band RF front-end receiver in order to suppress the propagation of unwanted modes. A full parametric analysis of the periodic structure within the irreducible Brillouin zone has been carried out in order to understand the behavior of the pin surface and determine the optimum dimensions for its operation in the full W-band. Resonances suppression has been demonstrated in the W-band both in simulation and experimentally.
Open Access
SCATTMAT: a mode matching and generalized scattering matrix code for personal computers in a windows environment
(1997) Liberal, Antonio; Río Bocio, Carlos del; Gonzalo García, Ramón; Sorolla Ayza, Mario; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, a computer aided design tool is presented to simulate symmetrical radially deformed circular waveguide microwave components. This tool works with the well-known “Mode Matching and Scattering Matrix” techniques, and it has been developed in C++ language in a Windows environment, to obtain the most friendly interface between the user and the code. The most important feature of the presented code is that it includes the possibility to display the internal mode power evolution along the component. The code has been successfully validated with numerical and experimental results from different authors.
Open Access
Antena corrugada con perfil gaussiano de gran ancho de banda
(2001) Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
En este trabajo se presenta el diseño de una antena de bocina corrugada con más de un 40% de ancho de banda. Los patrones de radiación medidos coinciden muy bien con los simulados. Esta antena se puede usar en aplicaciones que requieran un gran ancho de banda con bajos lóbulos laterales (< -28 dB), baja polarización cruzada (< -30 dB) y con requerimientos en potencia reflejada no demasiado restrictivos (< -15 dB).
Open Access
Superbackscattering antenna arrays
(IEEE, 2015) Liberal Olleta, Íñigo; Ederra Urzainqui, Íñigo; Gonzalo García, Ramón; Ziolkowski, Richard W.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
This article discusses the theory, design and practical implementation of superbackscattering antenna arrays. In analogy with Uzkov’s maximal directivity theorem, it is demonstrated that the maximal backscattering cross-section, normalized to the wavelength squared, of a linear array of N isotropic scatterers whose separation tends to zero is N2(N + 1)2=(4pi). This analytical result is validated via numerical optimization of the excitation coefficients, and the same procedure is utilized to assess the maximal backscattering of arrays of electric Hertzian dipoles (EHDs). It is found that electrically small arrays of two and three EHDs can enhance the backscattering by factors of 6.22 and 22.01, respectively, with respect to the maximum value generated by a single element. In addition, physical realizations of arrays featuring comparable enhancement factors can be straightforwardly designed by using a simple procedure inspired by Yagi-Uda antenna concepts. The practical implementations of such arrays based on copper wires and printed circuit technologies is also addressed.
Open Access
Silicon integrated subharmonic mixer on a photonic-crystal platform
(IEEE, 2021) Torres García, Alicia E.; Pérez Escudero, José Manuel; Teniente Vallinas, Jorge; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
This paper presents a planar silicon integrated subharmonic mixer on top of a photonic-crystal platform. The local oscillator (LO) power is injected through a 2D photoniccrystal (PC) slab to a resonant cavity that effectively couples the signal to a planar bow-tie antenna. The same antenna, which is printed on the top of the PC cavity, contains an antiparallel Schottky diode pair which performs the down-conversion. The proposed design is a simple, easy to integrate, low cost, low profile device. Moreover, the described fabrication process is compatible with active components integration. The performance of the design has been experimentally demonstrated showing good agreement with the simulation and is comparable with the stateof-the-art of planar mixers. The work presented here is based on concepts and technologies from electronics and photonics domains and may be a good starting point for the creation of new devices, allowing the integration and upgrading of existing techniques from both worlds.
Open Access
A multipolar analysis of near-field absorption and scattering processes
(IEEE, 2013) Liberal Olleta, Íñigo; Ederra Urzainqui, Íñigo; Gonzalo García, Ramón; Ziolkowski, Richard W.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A multipolar formulation is adopted to investigate the absorption and scattering processes involved in near-field interactions. This approach allows one to determine the upper bounds for the absorbed and radiated powers that would be achieved by an ideal lossless sensor, which are of particular interest, for example, to wireless power transfer (WPT), wireless sensors and near-field coupled radiators. The multipolar formulation also helps to extricate the fundamental compromises that must be addressed in the design of such systems, as well as to identify strategies that could approach their best possible performances. The general theory is illustrated with an example consisting of a coated sensor illuminated by a Hertzian dipole, which is a representative example of any scattering or radiating system based on small resonators. The example also serves to compare the performance characteristics obtained with different phenomena such as multipolar resonances, phaseinduced interference effects and cloaking.