Open Access
High efficient dipole antennas by using left-handed superstrates
(2004) Sáenz Sáinz, Elena; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Maagt, Peter de; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
This paper deals with pass band properties of Left Handed Media (LHM) to enhance dipole antenna performances. The LHM properties have been used in order to make high directivity antennas with good return loss features. The LHM structure is used as superstrate and placed over a dipole antenna. This superstrate is determining the characteristics of radiation patterns. Simulations of different types of LHM configurations are presented. The improvements of the radiation and matching parameters for each configuration are presented. High efficient antennas are obtained with this technique.
Open Access
Remote sensing for plant water content monitoring: a review
(MDPI, 2021) Quemada Mayoral, Carlos; Pérez Escudero, José Manuel; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Santesteban García, Gonzaga; Torres Molina, Nazareth; Iriarte Galarregui, Juan Carlos; Institute of Smart Cities - ISC; Institute for Multidisciplinary Research in Applied Biology - IMAB
Las redes sociales se han convertido en una de las principales fuentes de información, especialmente entre los más jóvenes. Al mismo tiempo, se ha incrementado la producción y circulación de información falsa o fake news a través de las redes. En este contexto, resulta crucial que los jóvenes adquieran estrategias y competencias para realizar una lectura crítica de la información que consumen. Este estudio busca analizar el comportamiento del alumnado de secundaria ante la información falsa y el efecto de una intervención didáctica, realizada online durante la pandemia de la covid-19, cuyo objetivo era que el alumnado desarrollara competencias para detectar noticias falsas. Se trata de una investigación participativa con un diseño de pre-test y post-test. Los resultados muestran que el alumnado incrementó su competencia para identificar algunos tipos de falsedad como la información no probada y la información tergiversada, si bien tuvo problemas para reconocer información descontextualizada o el uso de lenguaje discriminatorio. Las estrategias que más utilizó son la comprobación de datos en internet y el uso de verificadores. Se observaron comportamientos diferenciados entre el alumnado que identificó la información falsa y el que no lo hizo. Las conclusiones apuntan a la necesidad de trabajar en el aula de forma integral, extensiva y transversal la evaluación de la información partiendo de las habilidades que el alumnado ya posee.
Open Access
Diseño de filtros en guía rectangular usando estructuras PBG's
(2000) Mendióroz, Luis; Martínez de Espronceda Cámara, Beatriz; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A new application of dielectric periodic structures (also known as PBG) to build and design waveguide filters is presented. The periodic structures have some stop frequency bands, band gaps, defined by the geometry, within any mode can propagate through the structure. One could use this particular feature of the periodic structures to implement waveguide filters, or any other device with some frequency dependence [1,2]. In particular, we will focus in the description through an example of all the different effects produced by this kind of structures within a rectangular waveguide.
Open Access
Diseño y medida de una antena choke-gaussiana
(2002) Goñi Campión, David; Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A new design of corrugated horn antenna for global earth coverage from a geostationary satellite to obtain very low sidelobes and crosspolar levels with a really compact design in a quite wide bandwidth is presented in this paper. We compare this horn performance with the designs of other authors. Measurements show a really impressive radiation patterns with sidelobe levels below –43 dB in a certain bandwidth.
Open Access
EBG superstrate antenna for WAAS bands
(2008) Osés de León, Ángel; Iriarte Galarregui, Juan Carlos; Ederra Urzainqui, Íñigo; Gonzalo García, Ramón; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Multiband antennas can simplify considerably the complexity of receivers and transmitters, reducing the size and the mass of the conventional configurations. On the other hand, applications with high directivity requirements need array designs to comply with the directivity specifications using conventional technology. EBG superstrate designs have been satisfactory applied to single band applications using a single EBG superstrate layer. The number of number of radiating elements of conventional technology designs are considerably reduced when using EBG technology. Dual band configurations have also been designed in a single layer, but when working frequencies are too close a second EBG layer is needed. A dual layer EBG superstrate which can easily be adjusted to the desired operational frequencies is presented. The design has been realized to comply with the navigation antenna requirements of Wide Area Augmentation system (WAAS) application in L1 and L2 bands.
Open Access
SCATTMAT: herramienta C.A.D. para el análisis de componentes en guía de onda circular con variaciones simétricas del radio
(1996) Liberal, Antonio; Lahera, Miguel; Río Bocio, Carlos del; Gonzalo García, Ramón; Sorolla Ayza, Mario; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, a C.A.D. tool to simulate simmetrical radial deformation microwave devices, using the modal analysis and scattering matrix techniques is presented. The code has been developed in C++ language, working with Windows resources, in a personal computer. The user can obtain as graphic result the internal evolution of power along the component. The profile component is defined using a 2-D function because of the simmetrical variations. The results have been succesfully tested with experimental results of differents authors.
Open Access
Moisture content estimation models of flour matrices in the 67-110 GHz frequency range using a nondestructive and contactless monitoring system
(IEEE, 2023) Quemada Mayoral, Carlos; Ederra Urzainqui, Íñigo; Beruete Díaz, Miguel; Gonzalo García, Ramón; Iriarte Galarregui, Juan Carlos; Estadística, Informática y Matemáticas; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Estatistika, Informatika eta Matematika; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This work addresses the lack of moisture content estimation models for food products in the millimeter-wave frequency range and showcases the potential of this range for designing compact, cost-effective, and in-line food moisture sensors. The moisture content estimation models developed in this study are intended for flour-based mixtures in the 67-110 GHz frequency range and are derived by means of a nondestructive and contactless monitoring system. To this aim, data obtained by continuous-wave (CW) vector network analyzer (VNA) spectroscopy is used to create two different models, both with a coefficient of determination ( R2 ) of 0.97. One model is based on the theoretical response obtained by means of the Looyenga effective medium theory (EMT) model, while the other is based on measured data. Both models have been experimentally validated with root mean square error (RMSE) values of 0.4% and 0.35%, respectively. These small estimation errors show the potential of this frequency range to design compact, cost-effective, and in-line food moisture sensors. This research contributes to improving quality control and monitoring of moisture levels in flour-based mixtures.
Open Access
Very short and efficient feeder design from monomode waveguide
(IEEE, 1997) Gonzalo García, Ramón; Teniente Vallinas, Jorge; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, we present an original and short corrugated horn antenna profile to obtain the HE11 corrugated circular waveguide mode exciting with a pure TE11 monomode smooth circular waveguide mode. We will obtain a far field pattern with a very low crosspolarization, high symmetry and very low sidelobes in a wide frequency band. The proposed corrugated antenna has a longitudinal section composed of two hyperbolic profiles in series, one concave and the other convex united at a point, such that the derivative is continuous. Superimposed there is an additional tapering of the corrugation depth that goes from λ/2 at taper input to λ/4 within the first hyperbola. This original synthesis procedure has been successfully tested by computational simulation. The calculation method has been validated with experimental results of other authors.
Open Access
Electromangetic force density in electrically and magnetically polarizable media
(American Physical Society, 2013) Liberal Olleta, Íñigo; Ederra Urzainqui, Íñigo; Gonzalo García, Ramón; Ziolkowski, Richard W.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The force density induced by electromagnetic fields in electrically and magnetically polarizable media is studied analytically. Different formulations of the force density as a function of field-related quantities, including the spatial derivatives of the fields, gradients of the field intensity, phase gradients, electromagnetic power flow (Poynting vector field), and kinetic momentum flow, are introduced. These formulations retain certain symmetries with respect to the force expressions introduced in previous works for an isolated particle but also point out fundamental differences, such as the suppression of recoil forces, negative radiation pressure, and far-field gradient forces. It is shown how these analytical formulations also provide the necessary means to elucidate the sign of the force density in complex media and how they can assist the design of sources to manipulate clouds of particles. The theory is illustrated with numerical examples of an insulated Hertzian dipole immersed in different media, including lossy dielectrics, media with negative permittivity and permeability, and zero-index media.
Open Access
Línea de transmisión cuasi-óptica con modos gaussianos de orden superior para sistemas basados en gyrotrones tecnológicos para aplicaciones cerámicas
(1997) Río Bocio, Carlos del; Gonzalo García, Ramón; Möbius, Arnold; Sorolla Ayza, Mario; Thumm, Manfred; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, a description of a new compact microwave oven system based on a tecnological gyrotron for material processing applications is presented. The whole system has been designed by the Institute of Applied Physics in Nizhny Novgorod (Russia) and nowadays is installed in the Forschungszentrum (Karlsruhe, Germany). It consists ot a technological gyrotron working at 30 GHz giving 10 Kw CW in the TE02 circular waveguide mode, a quasi-optical transmission line (optimized in this work) and the final very oversized cavity or applicator. The original transmission line had a transmission efficiency of about 70%, by using a Vlasov launcher to generate a fundamental gaussian beam from the TE02 mode. The power was driven through a total of three mirrors. The improved design presented here increases the transmission efficiency up to 91%, by using a higher order gaussian beam mode, azimuthaly polarized and conical profile, by using only two ellipsoidal mirrors.