A novel antena for airborne radar : tridimensional Yagi / Um novo tipo de antena para radar aerotransportado : Yagi tridimensional

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Embedded systems using Synthetic Aperture Radar (SAR), in orbital or airborne platforms, have often been used for remote sensing. When these systems are applied to vegetal cover and biomass studies, signals with frequency above 1 GHz do not properly penetrate in the vegetation. On the other hand, the use of signals with frequencies in P band (400 MHz) allows a deeper penetration, making possible the detection of the underlying terrain surface. The antenna choice for these systems is a very important point, because several of its parameters are directly linked to the system performance. The aim of this work is to develop a new kind of Yagi antenna efficient for airborne SAR systems: a combination of Quasi-Yagi and Yagi-Uda antennas. From the first, the microstrip balun is kept, in order to ensure a large bandwidth. The radiant elements (driver and directors), remain similar to those of Yagi-Uda antenna, in other words, cylindrical metal dipoles. The antenna was designed to be fixed to an aircraft body, using the fuselage to shape its radiation pattern. A novel Yagi antenna was proposed, called Tridimensional Yagi, and its main properties were analyzed by means of numerical simulations and experiments. The proposed antenna provides a lower radiation under the platform, enabling the use of two antennas simultaneously, one at each side of the aircraft. This new feature can considerably decrease the operational costs. Finally, a prototype was designed, and built to meet the requirements of a specified SAR system. Furthermore, experiments on return loss and radiation pattern have been carried out and compared to numerical simulations

ASSUNTO(S)

radar yagi antennas (electronics) antenas (eletronica) mapping airborne radar yagi 3d

ACESSO AO ARTIGO

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