Broadband Dual-Frequency Dual-Polarized Antenna for 5G Millimeter-Wave Applications

In this paper, a broadband dual-frequency dualpolarized antenna and its array are proposed for 5G mm-wave application. The design adopts fewer metal layers, which greatly reduces the difficulty of design and processing. Then, the proposed antenna uses multi-mode radiation structure and capacitive coupling feed to improve the bandwidth of the dual band so that it can cover 24.25-29.5 GHz and 37-43 GHz. Meanwhile, the cross-polarization is improved effectively using rotary differential feeding in a 2 × 2 array, and the cross-polarization level is better than -60 dB. Finally, the design also carries out 2 × 8 array and verifies the scanning performance of the array. The horizontal polarization 3-dB beam scanning width at 28 GHz and 39 GHz are ± 65° and ± 45°. The vertical polarization 3-dB beam scanning width at 28 GHz and 39 GHz are ± 51° and ± 35°.