DESIGN AND OPTIMIZATION OF SPHERICAL LENS ANTENNAS INCLUDING PRACTICAL FEED MODELS

A novel approach for the design and optimization of spherical lens antennas (SLAs) including practical feed model (PFM) is proposed. The vector spherical wave function expansions (VSWE) combined with difierential evolution (DE) algorithm is adopted for the optimal design of SLAs. Moreover, the near-fleld aperture distributions of a Ku band dielectric loaded horn feed and a Ka band corrugated horn feed were obtained using the full wave simulation and were then taken into account in the DE optimization. The performances of the optimized 2-layer design are compared with previous works, higher directivity is obtained. Additionally, the radiation characteristics of an optimized SLA are presented, and numerical results of a 650mm diameter 2-layer hemispherical lens antenna (HLA) with ground plane are compared to the experimental results, and good agreements are obtained. An investigation of the in∞uence of the various lens-to-feed distances as well as aperture sizes of SLA on the aperture e-ciency for a 2-layer design is also proposed.