RCS Reduction of Patch Array Antenna Using Anisotropic Resistive Metasurface

A resistive metasurface (RM) with anisotropic absorption/transmission performances is developed and applied in the radar cross section (RCS) reduction of a patch array antenna. The RM is nearly transparent at the copolarized operation band of antenna by using interdigital resonators, while it becomes absorptive in the case of out-of-band or cross-polarized incidence. The RM is applied as the superstrate of the patch array antenna. The integrated antenna is of low profile of only 7.27 mm. In the case of the in-band copolarized incidence, the degradation of the antenna gain due to the RM is only 0.7 dB; at cross-polarized or out-of-band copolarized incidence, the antenna itself performs as the ground plane for the RM, and the whole integrated structure becomes an absorber to significantly reduce the RCS of the antenna. The copolarized RCS reduction (RCSR) bandwidth is 5-9.1 GHz at the lower band and 11.4-16.1 GHz at the higher band, and the cross-polarized RCSR bandwidth is 5.5-16.3 GHz.