Single- and double-shell shaped lens antennas with asymmetrical radiation characteristics

A computer-aided design (CAD) tool is proposed for the analysis and optimization of multi-shell Integrated Lens Antennas (ILAs) of arbitrary three-dimensional (3-D) shape and dielectric constitution. The analysis of the lens performance is carried out using the conventional hybrid geometrical / physical optics (GO/PO) method. The optimization of the lens shape is based on a binary genetic algorithm (GA) coupled to the GO/PO kernel. The ILAs considered here are single- and double-shell lenses of arbitrary shape. Two designs of single-shell lenses made in Rexolite and ceramic materials are presented and compared for non axis-symmetric Gaussian far-field specifications. The drawbacks of single-shell geometries are highlighted, and a double-shell ILA is designed in order to maximize the power transfer efficiency of the antenna. These results demonstrate that double-shell configurations can improve significantly the performance of ILAs of moderate size.