An Overview on Defected Ground Structure in Aspect of Microstrip Patch Antenna

Abstract

Micro strip patch antenna has gained a lot of attention now a day, only because of their attractive features like small size, low profile, low manufacturing cost and easy to integrate with other microwave circuits, but it has also some disadvantages like narrow bandwidth, low gain and low efficiency. Several techniques have been evolved to improve the various characteristics of antenna; they are photonic band gap (PBG), electromagnetic band gap structures (EBG), defected ground structure (DGS). Among three methods DGS is very versatile, it is being used in various microwave devices in microwave amplifiers, microwave oscillators, microwave filter design and in microwave coupling to reduce coupling etc. now a day it is being also used in the field of antenna design as to enhance bandwidth, improve gain, size reduction, harmonic suppression, reduce cross polarization etc. The equivalent of DGS is a simple LC resonator circuit. Inductance and capacitance value of ground varies with respect to the size and location of cut. As DGS is applied to the ground inductance and capacitance value increases because of that resonating frequency gets decreases. So by varying the size and location of cut in ground we can get a desired resonating frequency. In this paper, effect of various DGS in enhancement of antenna parameter is studied.