A low-complexity compact dual-polarized patch antenna with high isolation and low cross-polarization for in-band full-duplex applications

This paper proposes a simple design of a dual-polarized microstrip patch antenna featuring compact dimensions, low cross-polarization, and high port isolation, specifically designed for full-duplex wireless applications. The antenna is implemented on a single-layer substrate, and size reduction is achieved through a capacitive loading technique. Additionally, capacitive loading also contributes to increasing polarization purity by suppressing cross-polarization radiation. A fabricated prototype with an overall size of at 5.6 GHz demonstrates stable performance across the frequency range of 5.53–5.62 GHz. Within this band, the antenna attains an isolation level exceeding 38 dB, a maximum broadside gain of approximately 4.3 dBi, and low cross-polarization radiation of less than dB. Compared to other related compact dual-polarized designs, the proposed antenna exhibits the best performance in terms of isolation and cross-polarization suppression, featuring a compact and simple structure.