A high performance UWB MIMO antenna with defected ground structure and U-shape branches

摘要

A binary ultra-wideband multiple-input-multiple-output (MIMO) antenna is proposedand fabricated. In order to increase the impedance bandwidth and resonancefrequency, U-shaped branches, defected ground structure, folded stepped impedancestubs, and window-shaped radiation patch slots are analyzed. The total size ofthe MIMO antenna is 80 mm × 35 mm, and the measured relative impedancebandwidth realizes 131% (2.57-12.2 GHz). Without the addition of a decouplingstructure and a metal isolation bar, the isolation measured by this work is less than−15 dB. The measured antenna gain is between 3.064 and 4.669 dBi. The measuredenvelope correlation coefficient value is less than 0.005, and diversity gain isalmost equal to 10 dB. The channel capacity loss obtained in the measurement isless than 0.4 bit/s/Hz in the bandwidth except for 9 to 10 GHz. Excellent propertiesmake it suitable for modern wireless communication applications.