Reflectarray Antennas

4Radiation Analysis Techniques

The design and analysis procedure for reflectarray elements and the reflectarray system were outlined in detail in Chapters 2 and 3, respectively. The next task is to calculate the radiation characteristics of reflectarray antennas, such radiation pattern, directivity, gain, and so on. This chapter focuses on radiation analysis techniques for reflectarray antennas. As discussed in earlier chapters, reflectarrays combine the numerous advantages of both printed arrays and parabolic reflectors and create the new hybrid high‐gain antenna [1]. In terms of analysis approaches for reflectarrays, it is implicit that they are essentially adapted from the analysis techniques developed for their predecessors over generations.

Various analysis approaches have been developed to calculate the radiation characteristics of the reflectarray. Most reflectarray analysis approaches approximate the elements on the reflectarray aperture as identical elements that form an array, and then array summation or far‐field transformation of currents is used to calculate the radiation pattern of the reflectarray antenna [2], [3]. Accurate characterization of the reflection coefficients of the reflectarray elements holds a significant importance in the radiation analysis for these approaches. These coefficients are therefore usually obtained with a full‐wave simulation technique, using an infinite‐array approach that takes into account the mutual coupling between the elements ...