Dual-Polarized Filtering Antenna for mm-Wave 5G Base Station Antenna Array

This paper presents a dual-polarized filtering antenna designed for a 5G mm-Wave base station phased array. The out-of-band radiation of a stacked patch antenna is suppressed by embedding filtering structures along with radiating patches and feed network. Four radiation nulls can be tuned by introducing a combination of open-loop and hairpin resonators at appropriate locations, and a bandpass filtering response can be achieved. The antenna design principles and simulated performance are discussed. The antenna operates in n257 and n258 mm-Wave bands, demonstrating -10 dB impedance bandwidth at 24.25—29.5 GHz. The realized gain remains stable between 5 and 6 dBi at all the operating frequencies. The isolation between the ports and cross-polar discrimination remain better than 20 dB in all the covered frequency range.