Evaluation of Low-Cost Compact Multi-beam Reflectarray Antenna

Abstract

A technique for the design of passive multi-beam reflectarray antennas based on a one-feed-per-beam configuration is presented. The reflection coefficients modeling the behavior of the reflectarray cells are selected to equalize the performance of all feeds in the system. An optimization process is proposed, which is based on the compensation of the phase errors in the reflected fields tangential fields associated to each feed position. Using this technique, a compact multi-beam antenna is designed. An offset focal arc geometry is introduced, which prevents feed blockage while providing wide-angle scanning ranges in a compact configuration (F/D below 0.7). Highly directive beams are simultaneously achieved for a 50-degree range while showing a scan loss of 0.4 dB, side-lobe levels (SLL) below -15 dB and minimal overall distortion in the beam shapes.