Robust Wideband Full Duplex Radios

Strong interference power can significantly desensitize a receiver as a result of intermodulation distortion products generated due to non-linear interaction between the interference and receiver circuitry. In particular, when a transmitter sends information on the same frequency band as the receiver, it generates an in-band signal often times 110+ dB higher than receiver sensitivity saturating the receiver. Conventional radios accommodate this self-generated interference (SI) either by time-division duplexing (TDD) or frequency-division duplexing (FDD) but at the cost of reduced capacity and energy efficiency. The ability to instead transmit and receive in the same frequency band simultaneously (i.e. full-duplex) will not only save energy and double the bandwidth but also provide new capabilities in active jamming and improved security that are important especially for military communications. In this SBIR, a robust wideband full duplex radio will be developed to achieve > 110dB suppression of the self-interference.