Four-Port In-Band Full-Duplex Antenna System - Challenges and Solutions (Invited)

In-band full duplex (IBFD) communication has garnered significant attention due to its potential to enhance spectrum efficiency. In contrast to traditional two-port IBFD systems, four-port configurations offer advantages like increased diversity gain and channel capacity. However, achieving effective four-port systems is challenging due to various forms of self-interference. This paper presents an overview of two IBFD antenna systems featuring four isolated ports, outlining their operational principles and configurations. Performance analysis underscores the suitability of both systems for IBFD applications.