Application of Genetic Algorithms to the Manufacturing of Large Planar Array Antennas on RADAR Applications

A genetic algorithm (GA) is presented to obtain the best arrangement for the linear arrays (previously measured) used for the construction of a large planar array for radar applications. The designed algorithm allows the selection of the frequency and the pointing, furthermore the given weight of the different parameters of the radiation pattern (SLL, directivity…). Finally, some results are showed

Ku Band transmitarray lens for microwave applications

In this document a microstrip constrained lens device for Ku band, for microwave purpose, is presented. This paper offers an overview of artificial lens-type devices and the proposed transmitarray lens is thoroughly studied in terms of design and manufacturing, with architecture discussion and selection, along with the design, manufacturing and validation of all the forming components of the transmitarray (transmission circuits, radiating elements, etc.). Each element is properly characterized and assembled properly in the complete transmitarray prototype. Eventually, radiation pattern measurements as well as gain and directivity values, are provided to show the proper behaviour of the proposed transmitarray lens

Synthesis of circularly polarized radial line slot array

In previous articles, an easy way to analyse a slot array fed through a radial line was presented. The analysis was based on a circuit approach where circuit parameters have been estimated using the first propagation mode in the radial line and the far field theory. Here we study the design of a particular application for circularly polarised broadside antenna. The design defines the length, position and orientation of the slots in the antenna surface. The final analysis of the antenna gives a good behaviour in field diagrams and gain

Comparisons of Blockage Widths of Ideally Hard Cylinders of Different Cross-Sectional Shapes

In some applications the electromagnetic waves radiating from or being received by an antenna are obstructed by some mechanical structure. If the structure is part of or close to an antenna, the obstruction may represent aperture blockage causing increased sidelobes and reduced gain of the antenna. For example, the blocking structures can be struts or masts supporting the feed in reflectarrays or in reflectors. Usually in antennas, the direction of the incident wave is known, so the struts can be designed to reduce the blockage for a given direction of incidence

Análisis, diseño y realización de antenas planas ranuradas multisatélite

A review of designs of linearly polarized parallel-plate slot antennas developed by the authors is presented. Different combinations are described: broadside beam, one and dual tilted-beam, one and dual polarized antennas. The antenna structure, the analysis methods and the feasibility of getting a dual beam and dual linearly polarized antenna with interesting characteristics and low cost are analyzed. Several designs are proposed and their features are studied. As a conclusion, it can be said that parallel- plate slot arrays are quite promising

Diseño y construcción de antena plana de doble polarización basada en ranuras para recepción de TV por satélite

In this paper we design and make a double-polarization plane slot antenna for Digital Television Satellite reception. The prototype will fulfil the DVB specifications and furthermore it should be simple to construct and cheap. Therefore in the design process and in the implementation process exists a compromise between the specifications, low costs and simplicity

Measurement and simulation of reflector antenna

Well-established procedures are consolidated to determine the associated measurement uncertainty for a given antenna and measurements scenario [1-2]. Similar criteria for establishing uncertainties in numerical modelling of the same antenna are still to be established. In this paper, we investigate the achievable agreement between antenna measurement and simulation when external error sources are minimized. The test object, is a reflector fed by a wideband dual ridge horn (SR40-A and SH4000). The highly stable reference antenna has been selected to minimize uncertainty related to finite manufacturing and material parameter accuracy. Two frequencies, 10.7GHz and 18GHz have been selected for detailed investigation

RF Energy Harvesting System Based on an Archimedean Spiral Antenna for Low-Power Sensor Applications

This paper presents a radiofrequency (RF) energy harvesting system based on an ultrawideband Archimedean spiral antenna and a half-wave Cockcroft-Walton multiplier circuit. The antenna was proved to operate from 350 MHz to 16 GHz with an outstanding performance. With its use, radio spectrum measurements were carried out at the Telecommunication Engineering School (Universidad Politécnica de Madrid) to determine the power level of the ambient signals in two different scenarios: indoors and outdoors. Based on these measurements, a Cockcroft-Walton multiplier and a lumped element matching network are designed to operate at 800 MHz and 900 MHz frequency bands. To correct the frequency displacement in the circuit, a circuit model is presented that takes into account the different parasitic elements of the components and the PCB. With an input power of 0 dBm, the manufactured circuit shows a rectifying efficiency of 30%. Finally, a test is carried out with the full RF energy harvesting system to check its correct operation. Thus, the RF system is placed in front of a transmitting Vivaldi antenna at a distance of 50 cm. The storage capacitor has a charge of over 1.25 V, which is enough to run a temperature sensor placed as the load to be supplied. This demonstrates the validity of the RF energy harvesting system for low-power practical applications.This research was funded in part by the project TIN2016-75097-P of the Spanish Research and Development National Program, and in part by the project TEC2017-85529-C3-1-R of the Ministerio de Economía y Empresa

Comparison of reflector antenna measurements and simulations

In antenna measurement, well-established procedures are consolidated to determine the associated measurement uncertainty for a given antenna and measurements scenario [1-2]. Similar criteria for establishing uncertainties in numerical modeling of the same antenna are still to be established. In this paper, we investigate the achievable agreement between antenna measurement and simulation when external error sources are minimized. The test object, is a reflector fed by a wideband dual ridge horn (SR40-A and SH4000) manufactured by MVG. This highly stable reference antenna has been selected to minimize uncertainty related to finite manufacturing and material parameter accuracy. Two frequencies, 10.7GHz and 18GHz have been selected for detailed investigation. The antenna has been measured by several measurement facilities (spherical, cylindrical and planar near field ranges) across Europe in the ? ? ? ? ? ? ? ? activity. The purpose of this intercomparison campaign is the comparison of the different antenna measurement facilities, throughout Europe, considering measurement procedures and uncertainty estimates. The antenna has been simulated using a full CAD model, in step compatible format and using different numerical methods from different software vendor

Regeneración de campus para la creación de un laboratorio vivo de sostenibilidad ("living lab") en el Campus de Excelencia Internacional de Moncloa

La Universidad Politécnica de Madrid (UPM) a través de su Centro de Innovación en Tecnología para el Desarrollo Humano (itdUPM) está propiciando la generación de conciencia, conocimiento y soluciones innovadoras que contribuyen al cumplimiento de los Objetivos de Desarrollo Sostenible a través de un edificio que sirve como laboratorio de prueba para nuevas tecnologías verdes y como plataforma de ideación colaborativa y activación social