Numerical Investigation Into the Design of Shaped Dielectric Lens Antennas With Improved Angular Characteristics

The feasibility of designing a compact-size beam-switching dielectric lens antenna (DLA) with improved angular (scanning) characteristics is investigated numerically using in-house software based on the Muller boundary integral equations and hybrid genetic algorithm. It is demonstrated that joint optimization of the lens shape and feeding array parameters enables one to minimize the directivity degradation for ofi-axis feeds which is a well-known drawback of conventional extended hemielliptic DLAs fed by focal arrays. The key to success is found in proper shaping the lens proflle and using arrays of non-identical feeds.