High isolation slot coupled antenna with integrated tunable self-interference cancellation circuitry

This letter presents a high interport isolation, compact dual polarised slot coupled monostatic patch antenna with integrated tunable analogue/RF self-interference cancellation (SIC) circuitry for 2.4/2.5 GHz In Band Full Duplex wireless applications. The presented antenna deploys hybrid feeding for improved interport isolation through polarisation diversity and integrated single-tap RF SIC circuitry provides additional isolation on top of antenna isolation. Brief mathematical description for deployed single-tap RF SIC is also presented. The implemented prototype of the proposed antenna module provides around 80 dB interport isolation for 20 MHz bandwidth and better than 97 dB peak isolation when measured in a lab in the presence of environmental reflections. Moreover, 20 MHz SIC bandwidth with 80 dB interport isolation can be tuned within antenna's 10 dB return loss impedance bandwidth of 60 MHz.