Broadband RCS Reduction of Microstrip Antenna Using Coding Frequency Selective Surface

In this letter, an optimized coding frequency selective surface (FSS) is designed using a genetic algorithm to reduce the radar cross section (RCS) of a microstrip antenna in a wide frequency band. The RCS reduction is realized by replacing the antenna ground plane with a coding FSS. By doing so, the maximum and average RCS reduction of the proposed structure in the X-band becomes 24 and 11.9 dB, respectively. A prototype of the proposed antenna and reference antennas were fabricated and tested. The measurement results were compared with full-wave simulation ones to benchmark the performance of the proposed antenna. Experimental results show that the 10 dB RCS reduction is from 6.25 to 12 GHz (63%).