Quad-Port Circularly Polarized MIMO Antenna for K band Applications

In this paper, a compact (25×25×1.6 mm
³
) four-port Hammer shaped patch antenna for K band (18-27GHz) applications is presented. Hammer shaped antenna work as band pass filter (BPF)) filtenna works like a communicating antenna for interweave CR (cognitive radio). The proposed antenna has| S11| less than −10 dB impedance bandwidth of 14.20% (20.86-24.05GHz) & 14.31
^%
(20.96-24.19)at port 1 & port 4 respectively. The −3dB ARBW of 2.3 GHz (20.3-24.05 GHz) confirms the circular polarization attributes. Maximum isolation between the four radiating elements is less than −22dB and envelope correlation coefficient (ECC) less than 0.05 and the value of DG obtained between ports 1–2, 1-3& 1–4 value range of 9.999 - 10 dB, 9.979 – 9.999 dB & 9.90 - 9.99 dB respectively is observed. Four-port MIMO patch antenna has been investigated in terms of simulated gain, return loss, radiation efficiency, radiation pattern & total active reflection coefficient (TARC). The proposed antenna is analyzed using HFSS software by ANSYS version 17.