Recent advances in shape optimization techniques of 3-D integrated lens antennas
Résumé
We describe here two design methodologies for the shape optimization of a particular kind of focusing devices, the so-called 3-D integrated lens antennas (ILAs). The objective is to determine the best lens shapes that comply with given radiation characteristics. The first technique is a step-wise approach: the first step consists in solving the synthesis problem using Geometrical Optics (GO) principles, and, in the second one, the GO shape is optimized locally to fulfill the target specifications. This approach leads to an ill-posed problem and is only applicable to single-shell configurations. To overcome these limitations, an alternative technique consists of a global optimization of the ILA, using genetic algorithms (GAs) for instance. The capabilities of both design tools are highlighted numerically. Future trends in the shape optimization of lens antennas are also discussed.