Investigation of Wideband Substrate-Integrated Vertically-Polarized Electric Dipole Antenna and Arrays for mm-Wave 5G Mobile Devices

In this work, a mm-Wave vertically-polarized electric dipole array solution for 5G wireless devices is presented. The dipole is fabricated using vias in a standard PCB process to fit at the phone or tablet edges featuring wideband operation with broad half-power beamwidth in the elevation plane (HPBWELEV), high gain and high front-to-back radiation ratio (F/B). For enhanced gain, parasitic-vias are added in front of the dipole as directors. To improve HPBW without sacrificing gain, the directors are implemented as V-shaped bisection parasitic-vias. A via-fence surrounds the dipole structure to suppress back radiation and enhance F/B. The dipole is connected to a parallel-strip line (PS) which is interfaced to the main SIW feed through a novel SIW-to-PS transition. Thorough investigation, optimization, and parametric study are provided for each design parameter of the proposed structure. A single dipole, 2x1, and 4x1 arrays were designed and fabricated showing close agreement between the simulated and measured results. The single-dipole operates over 7.23-GHz bandwidth with stable radiation performance. The 4x1 array achieves HPBWELEV of 133.1 degrees, F/B of 36.6-dB, cross-polarization less than -39.6-dB and 12.61-dBi gain with 95.8% radiation efficiency. The low cost, compactness, and good performance of the proposed dipole make it a competing candidate for the future 5G mobile devices transceivers.