RCS Reduction of Eight-Port Multilayer MIMO Antenna Based on Linear-to-Circular Polarization Converter With Pattern Diversity Mechanism

This brief explains the design of an eight-port multilayer Multiple Input Multiple Output (MIMO) antenna with radar cross section (RCS) reduction along with a pattern diversity mechanism. The proposed MIMO antenna comprises five layers: layer-I is a linear to circular polarization converter; layer-II is a Teflon substrate layer; layer-III is the primary radiating layer, consists of coplanar waveguide feeding structure on one side and aperture coupled slots on another side; layer-IV is an air dielectric layer; and layer-V, consists of an octagonal-shaped reflector plate for isolation improvement. The proposed MIMO antenna offers a wider impedance bandwidth of 4.07-7.56 GHz (60%), axial ratio bandwidth of 4.3-5.06 GHz (14.86%), isolation better than 13 dB, peak gain of 8.05 dBi at 6.5 GHz, radiation efficiency better than 81% for the entire band, in-band RCS reduction of 49.42 dB, reduction in out-of-band RCS of 33 dB, and good pattern diversity mechanism.