A Miniaturized MIMO Antenna with Polarization Converter for Reduction of RCS and Mutual Coupling

This article proposes a miniaturized multiple-input-multiple-output (MIMO) antenna for reducing mutual coupling and radar cross section (RCS). The miniaturized antenna is composed of two radiation elements and two polarization converter (PC) cells. The PC cells are arranged between two radiation elements to realize RCS reduction and mutual coupling reduction simultaneously. The area size of the antenna is 0.69λ×0.37λ (λ is corresponding to the minimum cut-off frequency in open space). The proposed antenna operates at 7.4-8.9 GHz. Compared to reference MIMO antenna without PC cells, it can achieve maximum RCS reduction value of 6.4 dB and a maximum isolation amplitude of 27.8 dB. And the envelope correlation coefficient (ECC) value is given to indicate its excellent performance. The MIMO antenna with the characteristics of miniaturization, low mutual coupling and RCS reduction shows great potential in military applications.