Phased array systems with in-band full-duplex (IBFD) technology can facilitate multifunction operation, such as integrated sensing and communications. Effective designs, however, require unique front-end circuits that can suppress the resulting self-interference and allow array scaling in both size and frequency. This paper presents the design of an IBFD front-end that integrates a power amplifier, low-noise amplifier, tunable canceller, and an antenna interface for element-level IBFD arrays. The circuit is implemented in the WIN Semiconductors NP12 0.12μm GaN process, and is designed with amplifiers that have a small-signal gain higher than 10 dB and an analog canceller with more than 40 dB of transmit-receive isolation enhancement at 3GHz
