Planar wideband circularly polarized metasurface-based antenna array

Abstract

This paper presents a planar circularly polarized (CP) antenna array with a high-gain and wideband operation. The array is based on a sequentially rotated feeding network for a set of 2 × 2 CP metasurface-based antennas. The single element is a microstrip-line-fed slot antenna, which is coupled to a metasurface having 4 × 4 truncated corner square patches, to produce the CP radiation. The wideband characteristic of the design is obtained by a proper combination between the feeding network and the CP metasurface-based antennas. The proposed array, with an overall size of 50 × 50 × 2.032 mm3 (~1.60 × 1.60 × 0.065 λ0 at 9.6 GHz), has been fabricated and tested. The measurements resulted in an |S11| < –10 dB bandwidth of 7.88–12.0 GHz (41.45%) and a CP radiation bandwidth of 8.4–10.6 GHz (23.16%). In addition, the antenna yielded a broadside left-hand CP radiation with a peak gain of 13.5 dBic, a 3-dB gain bandwidth of 8.6–10.8 GHz (22.68%), and a radiation efficiency of >84%.