A Miniaturized Ultra-Wideband Millimeter-Wave Differentially-Fed Dual-Polarized Antenna for 5G/B5G Terminal Application

In this paper, a miniaturized ultra-wideband millimeter-wave (mmWave) differentially-fed (DF) dual-polarized (DP) antenna is proposed for the fifth generation (5G) and 5G-beyond (B5G) terminal application. The bended coaxial differential feeding structures are implemented to excite the taper-shaped dipoles for achieving a superior overlapped impedance bandwidth of $95 \%(24-67.3 \text{GHz})$ and high port-to-port isolation better than 5 dB, while maintaining a compact size of $4 \text{mm}^{*} 4 \text{mm} * 1 \text{mm}$. On top of that, a stable gain response with a peak gain of 6.1 dBi and symmetrical radiation patterns with low cross polarization levels less than $\mathbf{- 4 0} \text{dB}$ are obtained. Moreover, the antenna is based on a standard commercial printed circuit board (PCB) fabrication facility, which also owns low fabrication complexity and cost. Hence, the proposed antenna could be a promising candidate for a variety of $5 \text{G} / \text{B5G} \text{mmWave}$ applications.