Pedro A. B. Leão

This work presents a simple formulation to synthesize amplitude and phase distributions at cylindrical apertures of omnidirectional dual-reflector antennas. Adopting a tapered amplitude, the phase is obtained to provide an omnidirectional cosecant-squared radiation pattern with low sidelobe levels. Initially, the synthesis formulation is validated by the aperture method. Then, two distinct omnidirectional dual-reflector configurations are shaped and their radiation patterns are simulated by full-wave method-of-moments analyses and by ANSYS HFSS, to illustrate the usefulness of the synthesis technique.

In the present work an analytical formulation to synthesize non-uniform phase distributions at cylindrical apertures is described. Assuming three distinct amplitude distributions, the respective phases are established to provide cosecant-squared radiation patterns. Non-uniform amplitude distributions are investigated and adopted to reduce sidelobe levels and unwanted ripples in the synthesized radiation patterns. Analytical results for the established amplitude and phase distributions at cylindrical apertures are presented. The radiation patterns for such distributions are obtained by aperture method analysis, successfully demonstrating the usefulness of the new analytical formulation.

Resumo-Este trabalho apresenta um protótipo de um posicionador de antenas automatizado e de baixo custo para medições de diagrama de radiação. Para o processo de automatização foi desenvolvido um algoritmo em Python para captura e processamento dos dados de potência recebida, medidos pelo analisador vetorial de redes, modelo FieldFox da Keysight. O microcontrolador utilizado foi um Arduino Uno,