A Compact Simultaneous Transmit and Receive Antenna with Circular Mode Phasing for Smartphones

This article discusses the design progression of the simultaneous transmit and receive (STAR) antenna applied to in-band full-duplex (IBFD) applications. Specifically, this antenna system is composed of four slots and a patch, and integrated into a mobile. The slot modes together with patch mode is analyzed, and the placement of the antennas is designed. The theoretical circular mode phasing is given along with simulation results. The proposed antenna can provide up to 70 dB of isolation over the desired frequencies. This system is with low profile, compact, high isolated performances, indicating the potential applications of high-rate, high-capacity, low-time delay terminal wireless communications.