Simultaneous Transmit and Receive System with 1 GHz RF Cancellation Bandwidth

To address the challenges of the ever increasing spectrum demands, one approach is to implement in-band full duplex wireless systems. A popular approach for implementing full duplex communication without increasing resource utilization is the simultaneous transmit and receive (STAR) scheme. However, coupling of the high power transmit signals onto the colocated receiver leads to high signal interference in the operating frequency. Suppressing the high power self-interference is necessary for a successful STAR transceiver implementation, but is very challenging. In this paper, we present the design and implementation of RF self-interference cancellation filters, by suppressing the coupled signal 25dB across 1GHz bandwidth. This wideband cancellation should be contrasted to past cancellation that were narrowband and did not exceed ~100MHz bandwidth.