A compact dual-element UWB-MIMO antenna with single band-notched characteristics

In this paper, a UWB MIMO (multi-input multi-output) antenna working from 3.3 GHz to 10 GHz with a single band notch at 4.5 GHz has been proposed. The antenna comprises of two circular microstrip patches of radius 6.4 mm with tapered microstrip feed line of input impedance 50 Ω connected to them. 1.6 mm thick FR4 substrate ( εr  = 4.4, tan δ  = 0.02) of length and width 38 mm × 38 mm has been used. Partial ground consisting staircase, T-shaped slot, and defected H-shape slot have been utilized to enhance bandwidth and improve isolation. Additionally, C-shaped slot has been created on radiating element to produce a notch at 4.5 GHz. The design achieves a maximum gain of 5.8 dBi at 8.5 GHz and minimum gain of 0.5 dBi at 4.5 GHz. Isolation between the ports is more than 20 dB in the major portion of band of operation. It goes greater than 25 dB in the notch band. Envelope correlation coefficient (ECC) and diversity gain (DG) of 0.0006 and approx. 9.99 dB respectively has been obtained. Channel capacity loss of <−10 dB has been achieved. The proposed antenna is acceptable candidate for UWB MIMO applications.