High-Isolation, Low Cross-Polarization, Differential-Feed, Dual-Polarized Patch Antenna Array for a 2.45 GHz Retrodirective System Application

This paper presents a high-isolation, low cross-polarization, differential-feed, dual-polarized microstrip patch antenna array. By using differential feeding and coupled structure, the array realizes high port isolation, which is suited for the full duplex operating mode with two orthogonal linear polarizations of transmitting and receiving, respectively. Simulations results show isolation is greater than 40 dB at 2-5.2 GHz and greater than 60 dB at 2.42-2.47 GHz. The cross-polarization level is less than -40 dB on both the E and H planes. The proposed array has a simple structure to fabricate and practical for use in the retrodirective system.