A wideband dual-polarized crossed dipole antenna with controllable resonant modes and enhanced gain performance for wireless communication applications

Abstract

A wideband crossed dipole antenna for dual-polarized applications is presented in this paper. The antenna consists of a printed crossed dipole radiator loaded with periodic slots, four metal posts, four metal sidewalls and a metal reflector. The crossed dipole antenna is directly fed by a simple coaxial cable, achieving stable dual-polarization radiation characteristics. Here, two approaches are adopted to adjust the high and low resonant frequency of the antenna with large freedom. Firstly, four metal posts are introduced into conventional crossed dipole antenna, and their distance from the feeding point can independently adjust the lower resonant mode. Secondly, periodic slots are etched on the crossed dipole arms, and the upper resonant frequency can be controlled independently by altering the length of these slots. Also, the metal sidewalls on the ground are used herein to obtain enhanced gain property. To verify the feasibility of the proposed design, a prototype has been fabricated and measured. The measured results show good performance of a relative bandwidth of 64.3% for VSWR ≤ 2 (1.32-2.57 GHz). Moreover, the antenna has good unidirectional radiation performance and can achieve maximum gain of 9.1 dBi at 2.3 GHz.