Broadband Dual-Polarized Endfire Array With Compact Magneto-Electric Planar Yagi Antenna for mm-Wave Terminals

Abstract

Based on a newly proposed planar Yagi antenna with magnetic and electric dipoles, a compact <inline-formula> <tex-math notation= LaTeX >$1\\times 4$ </tex-math></inline-formula> broadband dual-polarized (DP) array with endfire radiation is designed in this paper. The magnetic Yagi antenna operates on the vertical polarization while the electric one operates on the horizontal one. The compact configuration of <inline-formula> <tex-math notation= LaTeX >$0.5\\,\\,\\lambda _{0}\\times 0.63\\,\\,\\lambda _{0}\\times 0.09\\,\\,\\lambda _{0}$ </tex-math></inline-formula> benefits from the novel half-mode magnetic Yagi antenna and the arrangement with the electric Yagi antenna. The broadband characteristic comes from the directors of the magnetic and electric Yagi antennas and the reflector of magnetic Yagi antenna. The simulation and the measurement verify this design. The measured common bandwidth of <inline-formula> <tex-math notation= LaTeX >$\\vert S_{11}\\vert < -10$ </tex-math></inline-formula> dB for both polarization ports is 23.8–30.1 GHz (23.7%), and the gains vary between 3 dBi and 4 dBi within 24.2–30 GHz band range. The <inline-formula> <tex-math notation= LaTeX >$1\\times 4$ </tex-math></inline-formula> DP array with <inline-formula> <tex-math notation= LaTeX >$0.5~\\lambda _{0}$ </tex-math></inline-formula> element space has the beam scanning range of ±43 ° at the endfire direction and the gain of higher than 7.1 dBi. The scanning performances are experimentally validated by two phase-shift feed networks for 0 ° and 30 ° main beam directions. The proposed endfire DP array has the good features of compact structure, a low profile and no clearance requirement, which is easy to integrate in 5G terminals.