Analysis and Design of Reflectarray Elements

A reflectarray antenna consists of a planar or conformal array of elements that are excited with a feed antenna. There are two steps in the design of a reflectarray, namely, the element design and the system design. This chapter explores the basics of designing the phase distribution on the reflectarray aperture. It outlines the phase tuning approaches for reflectarray elements. The chapter describes the numerical and analytical approaches for analysis of reflectarray phasing elements. It presents several examples of reflectarray phasing elements. It discusses the frequency behavior, effects of oblique excitation, and sources of phase error for reflectarray elements. The metallic waveguide simulator can accurately characterize the reflection properties of the element under certain conditions. The chapter introduces three different methodologies which enable the reflectarray elements to achieve phase tuning. The variable size square patch is perhaps the most popular element for reflectarrays.