Isolation enhancement and RCS reduction MIMO antenna using polarization conversion metasurface

Abstract An isolation enhancement and radar cross section (RCS) reduction multiple input multiple output (MIMO) antenna is proposed with the simple rectangular polarization conversion metasurface (PCM). The distance between the compact antenna elements is only 0.19 λ . In order to enhance antenna isolation and reduce RCS, PCM unit and its image are loaded in the middle area, floor area and patch area of the antenna. The PCM not only weakens the coupling field between the ports, enhances the isolation of the antenna, but also affects the propagation of the incoming wave reflection wave and reduces the RCS of the antenna. Loading PCM to solve both coupling and scattering problems is an innovation in this paper. The relative size of the antenna is1.27 × 0.64 × 0.07 λ 0 3 , the working band is 4.28 GHz to 9.48 GHz, the relative bandwidth is 75.58%, and the isolation is increased to more than 16 dB. Other MIMO diversity parameters, such as envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), total active reflection coefficient (TARC), and channel capacity loss (CCL) are calculated and determined within the limits. The monostatic RCS reduction frequency band includes the in-band 6 GHz to 9.48 GHz and out-of-band 9.48 GHz to 22 GHz of the antenna, and the total relative bandwidth reaches 114.29%. In this paper, the metasurface improves the performance of antenna mutual coupling and scattering, and realizes the integrated design of metasurface antenna radiation and scattering, which is of great significance for antenna design.