inside view

A reflectarray generally entails a flat patterned reflecting surface that more often than not mimics the electromagnetic properties of curved solid reflectors. The patterned surface typically consists of etched (or printed) conductors in the form of canonical geometric shapes such as patches and loops, all of which reside on a supporting substrate with a conducting ground plane. Our work has extended the functionality of the metal elements to include both the traditional ability to reflect focused RF and microwave signals while simultaneously providing an arbitrary desired optical image in the form of an image mosaic. This is accomplished by concurrently varying the element´s reflection phase and optical metal density over the engineered surface. The design approach that truly facilitates this method is element fragmentation, whereby the shape of each reflectarray element is described by a grid of metal pixels, and the inclusion/exclusion of these metal regions leads to the flexibility in designing for reflection phase and metal density.