A wideband quad-layer transmitarray antenna with double cross slot rings elements

Abstract

This paper introduces and studies a multi-layer frequency selective surface structure as a new unit-cell to design a wideband quad-layer transmitarray antenna. The proposed unit-cell consists of a double cross slot rings (DCSRs) on a rectangular patch. This unit-cell supports the transmission phase range response about 400° with magnitude better than −3 dB at 10 GHz and its sensitivity to the feed incident angle, up to 30°, is very low. To validate the design approach, a quad-layer transmitarray antenna, which each layer contains 169-element, is designed at 10 GHz and then fabricated and measured. The measured results show 1-dB gain bandwidth of 25% (9.75–12.53 GHz) with 23.34 dB maximum gain and 38.3% aperture efficiency at 10.3 GHz. Moreover, the 2-dB and 3-dB gain bandwidth are 31% (9.45–12.92 GHz) and 36% (9.30–13.35 GHz), respectively. As a result, the proposed element has the broadband performance and therefore can be a proper candidate to design wideband transmitarray antennas.