AbstractThis paper presents a two-elements based, dual polarized, single layer, patch antenna array with improved isolation between transmit (T_x) and receive (R_x) ports for 2.4 GHz in-band full duplex (IBFD) or simultaneous transmit and receive wireless applications. The differential feeding deployed at the R_x port effectively suppresses the coupling which is termed as self-interference from the T_x port to achieve high T_x–R_x interport isolation. A simple 3 dB/180° ring hybrid coupler with nice amplitude and phase balance characteristics has been used for differential R_x operation. The mathematical description for a differential feeding based self-interference cancellation mechanism is also presented for the proposed dual polarized IBFD antenna array. The measurement results for the implemented prototype of the antenna array demonstrate very nice levels of T_x–R_x interport isolation. The implemented single layer, compact antenna array presents 10 dB return-loss bandwidth of more than 50 MHz for both T_x and R_x ports. The prototype achieves >80 dB peak interport isolation and 75 dB (65 dB) isolation in 20 MHz (50 MHz) bandwidth.