Gaussian beam analysis of multiple beam reflector antennas

The design and performance analysis of multiple beam antennas (MBAs) is quite tedious requiring several iterations of first computing the radiation patterns of reflector antennas for all the beams using the physical optics method and then performing minimum coverage area directivity and copolar isolation evaluations for each beam. The whole process typically takes a few weeks to arrive at an optimal MBA design. The objective of this paper is to present a simplified analysis such that the complete design and performance analysis can be performed very efficiently using hand calculators. The analysis is based on approximating both the primary and secondary patterns as Gaussian beams and deriving simplified equations for the MBA design and performance evaluations. The results of the analysis presented agree well with the computations using the rigorous physical optics analysis of reflector antennas.