Printed Reflectarray Antennas for Space Applications
This chapter presents an overview of reflectarray antennas including their historical development, state of the art, and recent and future developments. Some examples of reflectarray antennas for space applications are presented.
A reflectarray is made up of an array of reflective elements providing a pre-adjusted phasing to form a focused beam when it is illuminated by a feed, in a similar way to a parabolic antenna. Printed reflectarrays combine certain advantages of reflector antennas and phased arrays. They are manufactured on a planar substrate using printed circuit technology and offer the possibility of beam steering as phased arrays; furthermore, the array elements are fed by an external source as in a reflector antenna, eliminating the complexity and losses of the feeding network used in planar arrays.
The concept of a reflectarray antenna was first proposed in 1963 by Berry et al. , as an aperture characterized by a surface impedance illuminated by a primary feed, where the surface impedance is synthesized to provide a prescribed radiation pattern. Different implementations of surface impedance were proposed in this reference, such as arrays of dipoles connected to transmission lines or open-ended waveguides terminated in short circuits. The capabilities of the reflectarray antenna were demonstrated by presenting measured radiation ...