Design and Analysis of Four Element MIMO Antenna for Broadband Applications

A 2 × 2 (four-element) elliptical-shaped with hexagonal slot, self-isolated Multiple Input Multiple Output (MIMO) antenna system is proposed for the 3.43–22.7 GHz broadband application. The proposed geometry uses T-shaped stub placed diagonally on a ground plane to decouple the antenna element's radiation fields at lower frequencies. The proposed MIMO antenna size is 2.069λgx2.069λg; however, the size of the single elliptical element is 0.707λgx0.587λg. At 17.2 GHz, the maximum realized gain for the single element is 5 dBi. The MIMO antenna shows good diversity properties with isolation of more than −20 dB, envelope correlation coefficient (< 0.1), diversity gain (̴ 10 dB), mean effective gain ratio (≤ 3 dB), total active reflection coefficient (< −5 dB), and channel capacity loss (≤ 0.5 b/s/Hz) for the entire frequency bandwidth. The MIMO antenna is designed, fabricated, and experimentally verified. The measured and simulated results are in good agreement.