Reducing the RCS of MIMO Antenna using Angularly Stable FSS

1.A systematic design procedure for reducing the MIMO antenna RCS has been presented in this paper. The RCS reduction has been achieved at 11.3 GHz, which is out-of-band as compared to antenna working frequency of 2.18 GHz. The design flow starts with developing an isolation enhancement network for MIMO antenna which is not going to disturb the RCS reduction process. Next, an incident-and polarization-angle insensitive frequency selective surface (FSS) is designed and its array is introduced in the place of a conventional ground plane of MIMO antenna. Designed FSS is introduced in such a way that the antenna characteristics and isolation among the antenna ports are preserved by achieving the RCS reduction of an antenna at the bandpass frequency of FSS. The proposed FSS is angularly stable, hence, almost constant RCS reduction has been found for most of the incident angles. The final proposed low RCS MIMO antenna has been fabricated and measured to validate the simulation results.