A Compact Dual-Polarized MIMO Antenna With Distinct Diversity Performance for UWB Applications

In this letter, a simple compact dual-polarized ultrawideband (UWB) multiple-input-multiple-output (MIMO) antenna is presented with the circularly polarized band for WiMAX (5.5 GHz) and WLAN (5, 5.2 GHz) applications. The antenna parameters such as reflection coefficient, diversity performance, gain, axial ratio, and isolation have been studied on a fabricated prototype of the proposed antenna. The 3 dB axial-ratio bandwidth (ARBW) of 34.38% alongwith isolation between two ports has been achieved by introducing a rectangular vertical arm (I-parameter) in the ground plane. To enhance the isolation and -10 dB impedance bandwidth, L-shaped radiators have been incorporated in the rectangular feeds. The -10 dB impedance bandwidth of the proposed antenna is 112.05% with isolation > 17 dB. The envelope correlation coefficient is less than 0.01 (using S-parameter) and less than 0.15 (using far-field radiation pattern) in the entire operational bandwidth. The gain of the proposed antenna varies from 1.2 to 4.9 dBi. The performance of the proposed antenna makes it a suitable candidate for use in portable UWB applications as well as in wireless communication systems.