Amplitude controlled reflectarray using non-uniform FSS reflection plane

A novel concept using non-uniform frequency selective surface (FSS) backed as a reflection plane for amplitude controlled reflectarray is proposed. First, a modified square-loop FSS element with broad reflection response band (from -22dB to 0dB) is designed. Then, a non-uniform FSS using the modified square-loop element is backed as a reflection plane for reflectarray. By properly controlling each element size of the FSS, the reflection amplitude from the reflectarray element can be sufficiently controlled and amplitude controlled reflectarray can be realized. A reflectarray using Dolph-Tschebyscheff weighting coefficients is implemented and a major-lobe to sidelobe ratios of up to 22 dB is obtained.