A Wideband Differentially-Fed Dual-Polarized Antenna Array for 5G/6G mmWave Application

In this article, a wideband millimeter-wave (mmWave) differentially-fed (DF) dual-polarized (DP) magneto-electric (ME) dipole antenna is proposed for the fifth and sixth generation (5G/6G) wireless communications. Benefitting from the delicately-designed cross-overlap differential feeding scheme deployed at the center of the perfectly-symmetrical antenna, the ME-dipole can be effectively excited to achieve wideband operation for both orthogonal polarizations. Meanwhile, the feeding and radiation structures can be located at the same metallic layer to reduce the profile height while maintaining a high port isolation. When the antenna element is excited by the ideal differential ports, a wide overlapped impedance bandwidth of about 58.3% (24.2-44.1 GHz), port isolation higher than 30 dB, a stable gain response with a peak gain of 7.5 dBi and symmetrical radiation patterns with low cross polarization levels less than −40 dB can be achieved. For proof-of-concept demonstration, a corresponding 1 × 4 phased array antenna is designed, fabricated and measured. A wide overlapped active impedance bandwidth of about 58% (24.7-44.8 GHz) and beam scanning characteristics of the array are experimentally verified. In virtue of wide bandwidth, simple and compact geometry, low profile, high integration, and ease of fabrication and miniaturization, the proposed antenna design is promising for diverse 5G/6G mmWave applications.