RF Self-Interference Reduction Techniques for Compact Full Duplex Radios

This paper describes three RF self-interference reduction techniques for full-duplex wireless links, which specifically target integration in compact radios. Concretely, a self-interference cancelling front-end, a dual-polarized antenna, and an electrical balance duplexer are proposed. Each technique offers specific benefits in terms of implementation density, self-interference rejection, bandwidth and flexibility. Depending on their characteristics, they can be adopted in different next-generation full-duplex applications and standards. All concepts are prototyped, and achieve at least 45dB of self-interference reduction over more than 10MHz bandwidth.