Isolation and Gain Enhancement of MIMO Diversity Antenna using Metamaterial Absorber and Linear-to-Circular Polarization Converter

This work explains the design of a wideband two-port multilayer multiple-input-multiple-output (MIMO) array antenna with polarization diversity mechanism. The proposed antenna provides wider impedance bandwidth (IBW), circular polarization (CP) radiation, improved isolation, and higher gain performance due to the loading of dual-layer metasurface, which is based on a linear-to-circular polarization converter (LTC-PC). The intended MIMO antenna provides a wider IBW of 34.1% (4.61-6.69 GHz), higher gain of 10.12 dBic at 5.9 GHz, and isolation is better than 32 dB for the complete operating band. Furthermore, the antenna provides polarization diversity mechanism, with port-1 provides right-handed circular polarization (RHCP) radiation and port-2 provides left-handed circular polarization (LHCP) radiation.