Compact Dual-Band Dual-Polarized Filtering Antenna Array for 4G/5G Base Station

This paper presents a dual-polarized miniaturized filtering antenna array designed for 4G and 5G multi-frequency applications. The proposed antenna array covers the 2.57-2.62 GHz (4G band 38) and 3.3-3.8 GHz (5G n78) frequency bands, achieving a peak in-band gain of 14.7 dBi. By incorporating parasitic structures, each antenna element exhibits effective filtering characteristics without extra filter circuit. The differential feeding and the filtering characteristics of the antenna elements together ensure that the array achieves a port isolation greater than 25 dB and cross-polarization levels below −25 dB. The antenna array maintains stable radiation patterns across the operating bands, making it a promising candidate for base station applications.