Projeto e otimização de redes de antenas em bandas embarcadas em nanossatélite

Abstract

This work describes the application of the Firefly Algorithm (FA) for the optimization of linear and planar antenna arrays. In order to demonstrate the potential of this technique, radiation patterns with isoflux distribution, squared cosecant and beam steering with side lobe level control were synthesized. The first case consists of the synthesis of a radiation pattern with isoflux distribution with a non-uniformly spaced linear array composed of isotropic antennas operating in S-band (2.26 GHz) and installed on an 8-U nanosatellite. For this purpose, just the beamforming coefficients were optimized. In the second application, beyond beamforming coefficients, the positions of the elements were also optimized to synthesize a squared cosecant radiation pattern for a system operating at 2.595 GHz. Beam steering optimizations were carried out with side lobe level control for a non-uniformly spaced array. Then, a planar array was used to produce a three dimensional isoflux radiation pattern. Finally, the design, construction and validation of an adaptive 3×3 planar array of realistic microstrip antennas was presented. With this structure, two beam steering cases with side lobe level control were optimized. The main contribution of this work is to demonstrate the efficiency of the FA for the optimization of complex radiation patterns. Good agreement with the desired masks, both for ideal antenna arrays and for realistic arrays, has been obtained.