I. Introduction
A contemporary communication system consists of terminals, such as base stations, relays, and mobile devices. These terminals function in either half-duplex mode or out-of-band full-duplex mode, where they can only transmit or receive data at distinct times. Otherwise, they may send and receive data simultaneously, utilizing multiple frequency bands. Our wireless spectrum is limited, but the demand for it is increasing rapidly due to the growth in the use of wireless devices. Systems with better spectrum efficiency, such as in-band full-duplex (IBFD), may assist in resolving this issue. It can transmit and receive data simultaneously at a single frequency at the same time, resulting in a twofold increase in spectral efficiency. The primary challenge of IBFD antennas is self-interference (SI). SI refers to the undesired signal that is sent by the transmitting (Tx) port of the IBFD terminal and interrupts the desired signal at the receiver (Rx) port [1].