Aperture efficiency improvement of folded reflectarray using rectangle and split‐ring combined element

Abstract

In this Letter, the aperture efficiency of a folded reflectarray is improved using a proposed element. This element is designed with a simple structure using a rectangle and split-ring combined structure to obtain a more accurate reflection phase for the folded reflectarray than that of a conventional element in the millimetre wave frequency. Thus, a high aperture efficiency of 55.04% is obtained at 77 GHz. The element design concept and procedure are presented in detail.