Low-Profile Wideband Dual-Polarized Antenna for Millimeter-Wave Beam Steering Applications

In this work, a dual-polarized endfire phased antenna array with a low-profile is proposed for millimeter-wave (mmW) beam steering application. The proposed antenna array is constructed by a $1\times5$ subarray with vertical polarization (V-pol) realized by novel SIW horn antenna and a $1\times4$ subarray with horizontal polarization (H-pol) realized by quasi-Yagi antenna. Characteristic mode theory (CMT) is employed to guide the wideband design for both V-pol and H-pol elements in the dual-polarized framework. A wide impedance bandwidth for V-pol radiation is 24.6–29.8 GHz, while that for H-pol radiation is 23.37–35.47 GHz. By integrating both subarrays, an overlapping bandwidth from 24.5 to 30 GHz is realized within a total profile of $0.15\lambda _{0} $ ; in addition, high isolation of −20 dB is achieved among most operation band for each element. Furthermore, the maximum realized gain for V-pol radiation and H-pol radiation are 11.4 and 11.6 dBi, respectively. Meanwhile, a wide beam scanning range of −45° to 42° for V-pol radiation and −45° to 39° for H-pol radiation with realized gain over 7 dBi is realized. In virtue of low-profile, wide bandwidth, easy integration, high isolation, and high gain, the proposed antenna array provides a promising candidate for future mmW vehicular applications.