A Planar Reconfigurable Aperture With Lens and Reflectarray Modes of Operation

This paper presents the design and experimental characterization of a planar 6 × 6 fully reconfigurable array operating at 5.7 GHz, capable of functioning both as a reconfigurable array lens and a reconfigurable reflectarray. First, the design of the array element, which consists of two varactor diode-loaded patches coupled by a varactor diode-loaded slot, is reviewed. Next, the design and fabrication of a planar array is described, and the varactor biasing scheme is discussed in detail. Experimental results demonstrating 2-D beamforming are presented, where a broadside directivity of 20.8 dBi and a beam-scanning range of 50° by 50° is achieved for the lens mode. The ability of the array to also function as a reflectarray is also demonstrated, achieving a directivity of 19.4 dBi at broadside and a beam-scanning range of 60° by 30°. Not only is this array able to demonstrate full 2-D beamforming, it is also low-cost and easy to fabricate, making it very attractive for applications where high-gain beam-scanning is needed.