High Isolation Self-Interference Cancelation for Monostatic Simultaneous Transmit and Receive System

Wireless technology is growing at a fast rate to accommodate the expanding user demands. Currently, the radio frequency (RF) spectrum is overcrowded, hence more susceptible to signal fratricide and interference. To enhance spectrum access, in-band full duplex systems are implemented to achieve simultaneous transmission and reception (STAR) and doubleand double the spectral efficiency. However, STAR systems require suppression of the high power transmit signals that can leak to the receiver chain. It is observed that the interference signal imposed on the receiver by the transmitter is approximately 60–90 dB stronger than the desired received signal. This type of self-interference (SI) can significantly reduce the receiver’s dynamic range and often leads to its desensitization. Therefore, successful STAR implementation requires considerable isolation between the transmitter and receiver to reduce the SI signal.