Full Wave Synthesis of Integrated Lens Antennas using FDTD and Genetic Algorithms

This paper describes a lens shaping optimization tool combining a genetic algorithm (GA) and a 2-D FDTD solver. This CAD tool has been implemented to synthesize two kinds of integrated lens antennas (ILAs), namely: 1) reduced-size ILAs with flat-top radiation patterns (in TM mode), and 2) compact ILAs with high aperture efficiency (in TE mode). In the first case, several optimization strategies are compared and discussed, including the design of single- and double-shell lenses optimized either at a single-frequency point or over a 10% bandwidth. In the second case, ILAs made of low-k and medium-k materials are designed and compared; in particular, it is shown that properly optimized lenses can exhibit excellent aperture efficiencies (ap140%) over a 20% frequency bandwidth.