Planar, Ultra-Wideband and Dual-Polarized Phased Array Antenna for Millimeter-Wave Vehicular Communication

In this paper, a planar dual-polarized phased array based on modified tightly coupled dipoles is proposed with a 3.28:1 bandwidth up to the V band. To achieve the dual-polarized ultra-wideband operation in the millimeter-wave band, tightly coupled dipoles are adopted as the array elements. Moreover, based on resonance analysis, the dipole is elaborately designed as an arrowhead shape to shift a TE-mode resonance out of the operating band. Due to a pair of capacitive patches connected to the dipole feeding structure, the highest operating frequency increases significantly, which in turn broadens the antenna bandwidth. To achieve improved wide-angle scanning ability, a meta-surface wide-angle impedance matching (MS-WAIM) layer is employed. The surface waves guided by the MS-WAIM layer are suppressed by adding cross-shaped metal structures at the critical positions within the WAIM layer. Simulated results indicate that the proposed array can scan up to ±60 ° in E/H planes with active VSWRs < 3. An 8 × 8 array prototype is fabricated to validate the accuracy of this design. The proposed antenna is suitable for millimeter-wave vehicular communications.