Evolutional Design of Waveguide Slot Antenna With Dielectric Lenses

This paper reports novel design method of waveguide slot array antenna with dielectric lenses by using the evolutionary optimization. We adopt the micro-genetic algorithm (MGA) with the real-coded gene as the optimization method and the finite-difference time-domain (FDTD) method to evaluate the objective function. The purpose of this study is to establish the design method of the above antenna by optimizing slot length and offset parameters. In the optimization of the antenna aperture distribution, it is shown that the optimized aperture field becomes sufficiently uniform, and the side-lobe levels (SLL) are improved in comparison with those of conventional antennas. Another optimization in which the objective function is evaluated by the array factor controls directly the side-lobe levels, to design low side-lobe antennas. By using the proposed method, the target antenna is optimized to satisfy the given SLL. It is confirmed that the proposed design method is a promising tool for designing the antennas loaded with dielectric materials.