Efficient and Accurate hybrid GO-Spectral Algorithm to Design Conformal Serrated-Edge Reflectors Operating as Collimators in Millimeter Wave Compact Ranges

This paper presents a hybrid analysis algorithm, which is used at Radiation Group (UPM) to carry out the design of a conformal serrated-edge reflector for the mm-Wave compact range UPM facility. Main features of this algorithm involve its capability of handling conformal serrated rim parabolic reflectors, accuracy and computational efficiency

Antenna Measurement System at 300 GHz for the Terasense Project

The aim of this paper is to introduce the design techniques used to develop the antenna measurement system for the Terasense Project. This project, funded by the Spanish Government, involves millimetre-wave systems design. One of these systems is an antenna measurement facility. The antenna measurement system operates in a banded range of frequency. The lower frequencies deal between 75–110 GHz (WR10 operation range) and the upper frequencies are set between 220–325 GHz (WR03). Among the different possible configurations, the reflector-based compact range is chosen. The quiet zone is generated by a serrated-edge reflector, fed by a low gain horn. In this paper we will focus on the reflector design. A serrations study is carried out and quiet zone acquisition results are obtained

Passive Microstrip Transmitarray Lens for Ku Band

The aim of this paper is to introduce a novel 12 GHz radiating design based on the idea of transmitarray lens device. In this document, an overview of the functioning of this kind of devices is given and the proposed transmitarray lens is studied, with architecture discussion and selection, as well as some ideas about the design, and manufacturing. In the document, some design, manufacturing and validation of the constituting elements of the lens (radiating elements, transmission circuits and transitions) are presented, together with a complete prototype of assembled transmitarray lens. Radiation pattern measurements in anechoic chamber, as well as gain and directivity values are offered

El cambio político en México: del presidencialismo autoritario al pacto por México (1926-2012)

El presente trabajo de investigación tiene como objetivo el documentar los principales elementos característicos del cambio político en nuestro país a partir de la etapa del presidencialismo hegemónico del PRI y hasta la implementación del “Pacto por México” así como las primeras reformas derivadas de este, comprendiendo de 1929 a 2012. Para la elaboración del presente texto, se empleó una metodología de carácter documental, la cual permitió el puntualizar de manera concisa los acontecimientos que de manera directa influyeron en una nueva configuración del sistema político mexicano, que pasó de ser un sistema político caracterizado por el dominio hegemónico de un solo partido político, el PRI, a ser un sistema político caracterizado por una pluralidad política y competitividad electoral, como consecuencia de una serie de reformas políticas y electorales que permitieron una alternancia en el poder ejecutivo de México. Las reformas electorales y al sistema de partidos en México, a su vez permitieron que el Congreso de la Unión ya no estuviese sumido al poder ejecutivo por la pluralidad partidista presente, por lo que la actividad legislativa, a partir de 1997 entró en una etapa en donde alcanzar acuerdos para realizar modificaciones constitucionales de suma importancia para el país se tornaba complicado debido a los distintos intereses e ideologías de los partidos presentes en las Cámaras del Congreso. En el presente trabajo se parte del supuesto de que el “Pacto por México” surge como la alternativa que ha permitido encontrar coincidencias para realizar reformas necesarias para el país

Signal to noise ratio maximization in quiet zone acquisitions for range assessment at sub-millimeter wavelengths

This paper proposes a quiet zone probing approach which deals with low dynamic range quiet zone acquisitions. Lack of dynamic range is a feature of millimeter and sub-millimeter wavelength technologies. It is consequence of the gradually smaller power generated by the instrumentation, that follows a f^α law with frequency, being α≥1 variable depending on the signal source’s technology. The proposed approach is based on an optimal data reduction scenario which redounds in a maximum signal to noise ratio increase for the signal pattern, with minimum information losses. After theoretical formulation, practical applications of the technique are proposed

An Efficient Hybrid GO-PWS Algorithm to Analyze Conformal Serrated-Edge Reflectors for Millimeter-Wave Compact Range

A method to analyze parabolic reflectors with arbitrary piecewise rim is presented in this communication. This kind of reflectors, when operating as collimators in compact range facilities, needs to be large in terms of wavelength. Their analysis is very inefficient, when it is carried out with fullwave/MoM techniques, and it is not very appropriate for designing with PO techniques. Also, fast GO formulations do not offer enough accuracy to reach performance results. The proposed algorithm is based on a GO-PWS hybrid scheme, using analytical as well as non-analytical formulations. On one side, an analytical treatment of the polygonal rim reflectors is carried out. On the other side, non-analytical calculi are based on efficient operations, such as M2 order 2-dimensional FFT. A combination of these two techniques in the algorithm ensures real ad-hoc design capabilities, reached through analysis speedup. The purpose of the algorithm is to obtain an optimal conformal serrated-edge reflector design through the analysis of the field quality within the quiet zone that it is able to generate in its forward half space

On characterizing skeletal muscle contraction properties. Experimental and simulation methodology

The main objective of this work is to characterize the fatigue contractile properties of threedifferent rat muscles (Tibialis Anterior, Extensor Digitorium Longus and Soleus) in order toobtain experimental parameters for numerical simulations.Experiments were conducted “in vivo" on three groups (n = 6) of male Wistar rats (210 +/- 11g)using a protocol developed by authors in previous works. Muscles were subjected to anelectrical stimulus to achieve tetanic contraction during ten seconds. Digital Image Correlationwas used during tests for 3D strain and displacements measurement that allow the correlationwith the finite element simulations.By means of Computed Tomography, a precise reconstruction of both bone and muscle of therat hindlimb geometry was obtained. The methodology proposed allows to obtain and validatecomputational simulations of skeletal muscle fatigue under different characteristics related tofiber types.6

Art therapy and migration: social inclusion throug landscape symbolic appropriation

Este artículo parte de una revisión bibliográfica sobre el tema del paisaje y su influencia en el individuo de forma tanto individual como grupal, personal y cultural. Se analiza el estado de la cuestión desde las perspectivas psicológica, social, cultural, geográfica y artística para realizar, a partir de ello, aportaciones interdisciplinares, especialmente dirigidas a colectivos de personas migrantes, que puedan abordarse a través del arteterapia. De este modo se pretende elaborar y reelaborar la práctica arteterapéutica con población migrante desde nuevas perspectivas que incluyan el estudio del paisaje y su influjo en el desarrollo individual y social.This work is essentially a literature review about landscapes and its influence on people. We analyze the state of affairs from psychological, social, cultural, geographic and artistic perspectives, to do interdisciplinary contributions that could be adressed through art therapy, at migrants groups. In this way, we are trying to develop and remake art therapy practice with migrant groups by new points of view interested in the landscape study and its influence on individual and social development

Characterization of wind-blown sediment transport with height in a highly mobile dune (SW Spain)

The Valdevaqueros dune is located at one of the windiest points of Europe, where the frequent occurrence of strong easterly winds has generated a highly mobile dune. Several rotating cup anemometers in vertical array and a self-designed vertical sand trap, were placed to retain the drift sands at different heights over the surface in order to determine theoretical and actual sand transport rates in the Valdevaqueros dune system. General results show that 90% of the wind-blown sand is transported within the first 20cm above the dune crest surface. Theoretical transport rates based on different empirical formulae were 0.33 to 0.78 times the in-situ sand transport rate detected, which was 2.08·10-2kgm-1s-1 under moderate wind power (mean speed ranging from 8.4 to 17.9ms-1). Analysis of different statistical grain-size parameters helped to understand sand transport distribution at different heights

Performance Comparison Between Serrated Edge and Rolled Edge Reflectors Inside CATR Facilities

CATR facilities are attractive antenna measurement facilities. Main reasons which contribute to this fact lie on its inherent reduced volume, on-the-fly measurements and the extension of both to a wide range of frequencies. However, these features rely on the assumption that the field collimation scheme is able to generate a plane wave distribution (quiet zone) where the AUT is to be placed and operated in RX mode. Unfortunately, electromagnetic theory states that this field distribution is not possible to be generated by a finite size scatterer operated as the collimator of a nonzero wavelength time-harmonic propagating field. This is the background of this paper, where two well-known electromagnetic field collimators will be discussed: the serrated edge reflector and the blended rolled edge reflector. To reach this purpose, electromagnetic hybrid analysis techniques developed at Technical University of Madrid will be applied