EBG-Based Self-Interference Cancellation to Enable mmWave Full-Duplex Wireless

Full-duplex (FD) wireless is a new technology that allows a wireless device to transmit and receive at the same time and on the same frequency. The key challenge to FD is self-interference (SI): a node’s transmitting signal generates significant interference to its own receiver. Recent works have proposed several techniques to reduce SI and enable FD but they are primarily specific to sub-6 GHz frequency bands. In this paper, we focus on mmWave frequencies and propose to design the antennas in a way that they reduce SI. In particular, we design a novel electromagnetic band gap (EBG) architecture and integrate it with the antenna array to reduce SI. Extensive simulations show that the proposed design reduces SI by more than 60 dB over 100 MHz of isolation bandwidth at 28 GHz frequency. We also show that the design has minimal impact on the antenna array gain, maintains the gain over large bandwidth, and has a return loss similar to a design with no EBG.