A Wideband Dual-Polarized Endfire Antenna Array for 5G mm-Wave Smartphones

In this article, a dual-polarized (DP) endfire antenna array is proposed for the 5G smartphone applications. The antenna covers all five defined millimeter-wave (mm-wave) frequency bands, namely n257, n258, n259, n260, and n261, which are used for mobile communications. Electrical dipole antenna is used to achieve the horizontal polarization (HP), and a parasitic element is included for bandwidth enhancement. A shorted-patch antenna functions as a magnetic dipole facilitating the vertical polarization (VP). Additionally, the broadband operation is realized by a novel stacked structure consisting of two different shorted patches. A four-element antenna array is implemented with overall size of 22.6x5x1.6 mm(3). The operating frequency band of the proposed antenna array spans from 24 to 44 GHz with -10-dB reflection coefficient for both polarizations. The isolation between the array elements remains above 13 dB across the entire frequency band of interest. The peak realized gain varies from 8.4 to 10 dBi, and the spherical coverage at cdf = 100% and cdf = 50% of EIRP are 22.5 and 12.5 dBm, respectively. The measurement results of the fabricated antenna array agree well with the simulation results.