A Wideband High-Isolation Omnidirectional Antenna for In-Band Full Duplex Application

A wideband, high isolation, omnidirectional antenna for the IBFD application is proposed. The antenna is composed of a crossed loop antenna as the RX antenna, and a 2×2 monopole array as the TX antenna. To achieve high isolation, the crossed loop is excited with 90° phase procession. Based on the near-field cancellation technology, a high TX/RX isolation of more than 60 dB is achieved in the frequency range of 1.89 to 3.73 GHz. Besides, good omnidirectional radiation patterns are achieved across the entire frequency band.