Performance enhancement for a broadband spiral antenna using a frequency-selective surface and added backing cavity

This article newly proposes to embed a frequency-selective surface (FSS) in a backing cavity to reduce the back-lobe level and depolarization deficiency of a broadband spiral antenna.For demonstration, a single-arm rectangular spiral antenna backed by an FSS-added cavity was created and studied. The cavity-backed antenna has an enhanced main beam and an extremely low back lobe, in contrast with the original spiral antenna without cavity. In addition, the antenna backed by the FSS-added cavity shows better performance, especially in the depolarization reduction and main-beam enhancement, compared with the spiral antenna backed only by the cavity having no FSS. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:715–718, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26613