High Isolation and High Gain Planar Patch Array for In-Band Full-Duplex Applications

This study proposes a dual polarized planar patch antenna array with high gain and high isolation between transmission and reception ports for full-duplex applications. The antenna system contains two arrays, each of which is composed of four identical single-ended microstrip rectangular patch antennas operating at 12.2 GHz. The first array is fed using corporate feeding technique, while series-fed method is used to feed the second array. The simulated bandwidths of transmit and receive operations are 1260 MHz and 810 MHz, respectively. The simulated results show good isolation, S_21, reaching -60 dB at the center frequency. The design also maintains peak realized gain from 6.7 dB to 7.6 dB through the entire band of interest. The high isolation characteristic of the antenna is suitable for cancelling the interference of transmitter on the receiving port. The antenna array also exhibits low cross-polarization, compact size, and good impedance matching.