Design and optimization of three-dimensional integrated lens antennas with genetic algorithm

A computer-aided design tool for the optimization of three-dimensional integrated lens antennas (ILAs) is described. The optimization procedure is based on a genetic algorithm (GA) coupled to the hybrid geometrical/physical optics (GO/PO) method of analysis. It is the first time that this global numerical search technique has been applied to design 3-D shaped ILAs. To validate the proposed methodology and the numerical algorithms, two single-material ILAs are optimized and fabricated at 28 GHz. They radiate a sectoral beam and an elliptical Gaussian beam, respectively. The lens prototypes are fed by an aperture-coupled microstrip patch antenna. The influence of the lens dimensions and internal reflections on the far-field radiation patterns is also highlighted when designing shaped lenses. Comparison between experiments and numerical predictions (GO/PO and finite-difference time-domain) successfully validates our design tool.