Performance improvement of planar array antenna by small spherical dielectric lenses

Abstract

This paper reports the performance improvement of the planar waveguide slot array antenna by loading the small spherical dielectric lenses. The proposed lens is sphere and small, and can be loaded on each slot independently. To design the antenna with the proposed lenses, other design parameters are fixed, and the optimal slot length is searched by using the finite difference time domain (FDTD) method. From both the calculated and the measured far-field radiation patterns, the optimized antenna with the proposed lenses shows good performance as the resonant uniformly distribution array. By comparing with the conventional antenna, it is found that the gain increase by loading small lens is estimated by 1.07 dB.