An x-band binary reflectarray with sub-wavelength ELC resonator elements

A binary reflectarray concept utilizing subwavelength electric LC (ELC) resonators mounted over a grounded substrate is presented. The design concept is based on a binary quantization of the array phase profile required to steer the reflected wavefront. Using a binary phase change simplifies the array element design and facilitates the development of dynamic reconfigurable reflectarrays. Subwavelength elements generate a binary phase pattern that can more accurately approximate the continuous phase pattern, reduce inter-element coupling, and maintain good performance over a wide swath of feed illumination angles. The use of ELC elements facilitates wideband operation and provides a simple means for integrating element switches at the backside of the array. Beamsteering feasibility of the binary reflectarray is demonstrated at X-band frequencies in simulations using full-wave analysis as well as field measurements of a 10×24 reflectarray.