A 4x4 Planar UWB-MIMO Antenna with Dual Linear Polarization for WLAN/5G/WiFi/X-band

This paper describes a 4 × 4 planar ultra-wideband multiple-input multiple-output (UWB-MIMO) antenna with a compact size of 29.28 mm × 29.28 mm × 1 mm. The antenna employs a defected ground structure-assisted bandwidth improvement approach for achieving ultra-wideband operating bandwidth. Within the frequency range of 4.7 to 22 GHz, the isolation level of the proposed antenna is less than 20.5 dB. The envelope correlation coefficient (ECC) is good enough, less than 0.0027 with the diversity gain (DG) being nearly 10. All scenarios were simulated using CST Studio 2020. The proposed antenna was manufactured and tested. The test and simulation results are in good agreement.