Defected Ground Structure for Microstrip Antennas

Defected Ground Structure (DGS) is relatively a new area of research and applications associated with printed circuits and antennas. This chapter addresses the fundamentals of the DGS from its evolution and modeling to the state-of-the-art applications. The DGS geometries reported so far include simple shapes such as rectangular dumbbell, circular dumbbell, spiral, “U”, “V”, “H, cross, concentric rings, etc. Also different complex structures like split ring resonators, or fractals have been examined. To stop the higher harmonics at the input of the microstrip element, proper bandstop characteristics in the feeding network have been explored using different DGS configurations. The DGS has been implemented to improve or modify the radiation properties of microstrip patches. Placing the DGS in between the two microstrip patches also has some useful applications in reducing mutual coupling between them. Controlled Vocabulary Terms microstrip antennas; microstrip filters; printed circuits