A Wideband Circularly Polarized SIW MIMO Antenna Based on Coupled QMSIW and EMSIW Resonators for Sub-6 GHz 5G Applications
Priya Kumari, Sushrut Das
Abstract
A substrate-integrated waveguide (SIW) based circularly polarized (CP) multiple-input–multiple-output (MIMO) antenna is proposed in this letter for Sub-6 GHz 5G applications. Each element of the MIMO antenna is made up of coupled quarter-mode substrate-integrated waveguide and eighth-mode substrate-integrated waveguide resonators and these coupled resonators initiate the formation of the CP wave. An elliptical slot, etched on the common ground plane, provides the desired impedance and CP bandwidth. A T-shape ground slot has been used to enhance the port isolation (>21 dB) over the operating bandwidth. According to the measured data, the MIMO antenna possesses a 10 dB return loss bandwidth of 12.5% (5.25 GHz to 5.95 GHz) and a 3 dB axial ratio bandwidth of 10.8% (5.25 GHz to 5.85 GHz). Thus, the axial ratio bandwidth almost overlaps the return loss bandwidth. Moreover, different MIMO performance metrics are also analyzed.