A Broadband Dual-Polarized Magnetoelectric Dipole Antenna With High Isolation

A broadband, low-profile, and dual-polarized magnetoelectric dipole (MED) antenna with high isolation is proposed for in-band full-duplex applications. The proposed MED antenna is configured with a cross-dipole, copper cylinders, instead of the traditional vertical metal walls, and a ground. Two different feeding methods, a T-shaped strip connected with a T-junction power divider for Port 1 and a microstrip-to-slot coupling structure for Port 2, are designed to excite dual-polarized radiation. Compared to the previous works, the height of the MED antenna is from the conventional about 0.25 λ₀ to 0.15 λ₀, where λ₀ is the wavelength in free space at the center operating frequency. The broadband, dual-polarized, and high port-to-port isolation characteristics are reserved. A designed prototype is fabricated, and the measured results demonstrate an overlapped −10-dB impedance bandwidth of 1.73–2.70 GHz (43.8%), the port-to-port isolation of 44.1 dB, the average realized gains of 8.89 and 8.49 dBi, and the average radiation efficiency of 86.1% and 87.1% for Ports 1 and 2, respectively. These characteristics make the proposed antenna a promising candidate for in-band full-duplex base station systems.