Wideband Gain Enhancement and RCS Reduction of Fabry–Perot Resonator Antenna With Chessboard Arranged Metamaterial Superstrate

The simultaneous improvement in radiation and scattering performance of an antenna is normally considered as contradictory. In this paper, wideband gain enhancement and radar cross section (RCS) reduction of Fabry-Perot (FP) resonator antenna are both achieved by using chessboard arranged metamaterial superstrate (CAMS). The CAMS is formed by two kinds of frequency-selective surfaces. The upper surface of CAMS is designed to reduce RCS based on the phase cancellation principle, and the bottom surface is used to enhance antenna gain on the basis of FP resonator cavity theory. Both simulation and measured results indicate that compared with primary antenna, the gain of the proposed FP resonator antenna is enhanced by 4.9 dB at 10.8 GHz and the 3 dB gain bandwidth is from 9.4 to 11.1 GHz (16.58%). Meanwhile, the RCS of the proposed FP resonator antenna is reduced from 8 to 18 GHz, with peak reduction of 39.4 dB. The 10 dB RCS reduction is obtained almost from 9.6 to 16.9 GHz (55.09%) for arbitrary polarizations. Moreover, the in-band RCS is greatly reduced, owing to the combined effect of CAMS and FP resonator cavity.