Novel Low-Profile Wideband Reconfigurable CP Antenna Array

Abstract

For future wireless communications, costeffective, low-profile circular polarization (CP) antennas with wide bandwidth and high directivity are highly desirable to increase system capacity and suppress polarization mismatch. In this paper, a wideband circular polarization antenna array integrated with a polarization-independent artificial magnetic conductor (AMC) is reported that meets the demands. First, a wideband CP reconfigurable antenna with a pair of crossbowtie radiators and a metal ground is presented to achieve a fractional bandwidth of 35.9%. By replacing the metal ground with a polarization-independent AMC ground, the antenna profile is reduced from 0.25λ 0 to 0.05λ 0 with only a slight bandwidth decrease. A wideband CP reconfigurable 4-element linear array is achieved using four of those elements. It is low profile (0.05 λ 0), and has a wide operating bandwidth (21.7%), and a high realized gain (13 dBic).