Miguel Ferrando Bataller

The Theory of Characteristic Modes Revisited: A Contribution to the Design of Antennas for Modern Applications

The objective of this paper is to summarize the work that has been developed by the authors for the last several years, in order to demonstrate that the Theory of Characteristic Modes can be used to perform a systematic design of different types of antennas. Characteristic modes are real current modes that can be computed numerically for conducting bodies of arbitrary shape. Since characteristic modes form a set of orthogonal functions, they can be used to expand the total current on the surface of the body. However, this paper shows that what makes characteristic modes really attractive for antenna design is the physical insight they bring into the radiating phenomena taking place in the antenna. The resonance frequency of modes, as well as their radiating behavior, can be determined from the information provided by the eigenvalues associated with the characteristic modes. Moreover, by studying the current distribution of modes, an optimum feeding arrangement can be found in order to obtain the desired radiating behavior.

Planar single-wire antennas at millimeter-wave frequencies

Single-wire waveguides are becoming deeply studied at high frequencies due to their low-loss and low-dispersive behavior. In this paper, a planar version of this waveguide is used to design two kinds of antennas. Firstly, a surface-wave antenna is designed taking advantage of the slow-wave behavior of the fundamental mode. This low-loss antenna (it does not use any dielectric) presents an end-fire pattern. To obtain a different pattern, a periodic leaky-wave antenna is proposed. This antenna is obtained by attaching dipoles to the laterals of the waveguide. The resulting structure has a beam that scans from backward to forward as frequency varies. Both antennas are ideal for millimeter and submillimeter-wave frequencies due to the ease of fabrication and low losses. This paper shows both designs and presents several results.

Geometrical representation infinitely smooth curves and surfaces for higher order computational electromagnetics

This paper shows a new interpolation technique to produce infinitely differentiable curves from a finite set of interpolating points. The technique will be very useful for the implementation of higher order numerical and asymptotical methods in computational electromagnetics. In this paper we show the 2D case (for curves). We will present a generalization for surfaces in the oral session during the symposium

Sampled Antenna Array Digital Beamforming for LTE-Advanced

In this paper, a beamforming system for LTE- Advanced based on Array sampling technology is proposed. Antenna Array that has been designed covers LTE mid and high bands. RF multiplexer 8x1 switch has been designed and simulated. The system is composed of agile RF frontend and FPGA digital signal processing unit.

Analysis of crossed dipole to obtain circular polarization applying Characteristic Modes techniques

The crossed dipole is a common type of antenna that is used to generate circularly polarized radiation in a wide frequency range. This antenna was originally developed in the 1930s and today is used in many wireless communication systems, including broadcast services, satellite communications, mobile communications, global navigation systems satellite system (GNSS), radio frequency identification (RFID), wireless local area networks (WLANs) and global interoperability for microwave access (WiMAX). This paper shows that it is possible to obtain circular polarization with two cross dipoles with different lengths and connected in parallel by applying the Theory of Characteristic Modes. The results obtained using this new approach is consistent with those obtained using the normal method of analysis of input admittances.

Recursos on-line sobre experiencias innovadoras en competencias transversales para profesores y alumnos

Una de las principales amenazas detectadas para desarrollar la formacion en competencias es la capacidad del profesorado para desarrollarlas en el dia a dia de sus clases, lo cual puede traducirse en una desmotivacion del profesorado ante este reto. En este momento es esencial una importante labor de formacion tanto para el profesorado como para el alumno, sobre todo en lo que respecta a como trabajar, desarrollar y evaluar las competencias transversales en la realidad de una asignatura determinada. El objetivo general de este trabajo es contribuir a la implementacion de las competencias transversales a la realidad de las titulaciones, a traves de la recopilacion, seleccion y creacion de recursos online y su posterior estructuracion y difusion. Asi, se ha procedido a recopilar y seleccionar recursos electronicos ya existentes, clasificandolos segun la competencia transversal a la que contribuyan y segun su destinatario (profesor o alumno), entre otros. Los resultados muestran una importante disparidad cuantitativa y cualitativa entre recursos correspondientes a distintas competencias. Este trabajo tiene un caracter marcadamente multidisciplinar, y no tiene como objetivo una recopilacion exhaustiva de materiales, sino establecer un sistema de organizacion de mayor utilidad para el profesorado.

Desarrollo de competencias transversales para promover la excelencia del alumnado

Esta comunicacion describe el trabajo realizado en el ultimo ano dentro del Proyecto de Innovacion Docente “Desarrollo de competencias transversales para promover la excelencia del alumnado” por el Equipo de Innovacion y Calidad Educativa (EICE) GRIPAU en la Universitat Politecnica de Valencia (UPV). GRIPAU es un equipo multidisciplinar de profesores, centrado en promover la innovacion y mejorar la calidad del aprendizaje en Educacion Superior. En este trabajo GRIPAU ha puesto en practica una metodologia docente que facilita la adquisicion de diferentes competencias transversales por parte del alumno, permitiendole avanzar hacia la excelencia, entendida esta desde el punto de vista de su desarrollo integral. Se han realizado experiencias piloto de desarrollo de competencias transversales en asignaturas de diferentes titulaciones, estableciendo una pauta comun de actuacion. Para cada competencia se ha realizado una valoracion inicial del nivel de partida del alumnado, se ha desarrollado la competencia dando al estudiante las directrices adecuadas, y se ha evaluado el grado de consecucion y el nivel de excelencia alcanzado por el alumno en dicha competencia tras cursar la asignatura. El resultado de estas experiencias constituye un conjunto de buenas practicas para otros docentes de como trabajar competencias transversales de forma estructurada y coherente.

Antenas de múltiple haz conmutado

This article gives special attention to synthesize the appropriate pattern and to propose the passive beamforming networks with N input ports, which allows to simultaneously generating one beam for each input with requirements such as low side lobe,high gain, crossover level and orthogonality condition. This multiple beam system could be a candidate for base-station demands in wireless communication services.

Síntesis con agrupaciones circulares de dipolos

This article describes the synthesis of radiation patterns with circular antenna arrays using the finite dipole in front of a metallic infinite cylinder. The used technique will be that of Fourier, and a method for synthesizing the radiation pattern with antenna array of N dipoles uniformly disposed around a circular ring of radio (b) an in front of a cylinder of radio (a) is proposed. The required excitation currents are determined from a deduced formula in the paper.

The Effect Of Array Spacing And The Influence Of The Radiation Pattern Of The Element In A Pattern Synthesis Of Uniform Circular Arrays

In this article, the effect of array spacing and the influence of the radiation pattern of the element have been considered in the synthesized radiation pattern using circular arrays of directive elements uniformly arranged.