Bandwidth enhancement in Ka-Band circularly polarized reflectarray using stacked cross-bowtie elements

Abstract

In this paper, stacked element technique has been employed to broaden the bandwidth (BW) for circularly polarized (CP) reflectarray in the Ka-Band. A wideband double layer λ/4 unit cell with cross-bowtie elements, has been proposed. The element rotation technique has been used to obtain the phase characteristics of the unit cell. A 25×25 reflectarray has been designed for the full-wave analysis that provides higher aperture efficiency and wider RA bandwidth. The proposed antenna provides, 1-dB gain bandwidth of 33 %, 3-dB axial ratio (AR) bandwidth of 53 %, SLL of -18 dB, and a maximum aperture efficiency of 58 % (at 30 GHz).