"This book covers the different Defected Ground Structure (DGS) techniques that can be applied to antenna designs. It begins by presenting the process of evolution of DGS starting from basic electromagnetic band gap structures. The book then addresses the modeling and analysis techniques explored so far since the inception of DGS in 2000. Next it introduces readers to early approach DGS application for antenna feed lines. It also describes the physics of higher order modes as the source of cross-polarized radiation and the technique of controlling the same with DGS integration techniques. Later topics include new design concepts for microstrip arrays, circularly polarized antenna design using DGS techniques, how DGS-integration would be possible to improve polarization purity, and recent applications of DGS in varied forms in ultra-wideband (UWB) printed antennas"-- Provided by publisher.