A Low Profile Dual-Polarized Wideband Omnidirectional Antenna Based on AMC Reflector

A low-profile dual-polarized wideband omnidirectional antenna with artificial magnetic conductor (AMC) reflector is proposed. The proposed antenna is operated in the long term evolution band (1.7-2.7 GHz), and has a compact size of 200 mm x 200 mm x 30.6 mm (about 0.25 lambda height at 2.7 GHz). The antenna structure consists of a horizontally polarized circular loop antenna, a vertically polarized low-profile monopole antenna, and an AMC reflector. By carefully designing the reflection characteristics of the AMC reflector, the profile height of the proposed antenna is significantly reduced as compared with those of antennas backed by conventional perfect electric conductor (PEC) ground planes. Simulated and measured results show that the proposed antenna is able to achieve over 45% impedance bandwidth (VSWR < 1.8) with stable radiation patterns in the band of 1.7-2.7 GHz. Owing to the attractive wide bandwidth, low-profile configuration, and ease of fabrication, the proposed antenna is suitable for microbase station systems, especially for indoor ceiling antenna networking applications.