Return loss and bandwidth enhancement of microstrip antenna using Defected Ground Structure (DGS)

In this paper a modified inset-feed microstrip antenna is proposed to increase band width and return loss. The operating frequency of the antenna is 2.4 GHz ISM band. To enhance the performance of the antenna one DGS has been introduced under the patch area that is on the other side of substrate and little modification in the dimension of feed gap. The DGS has been optimized to provide a stop band at 2.4GHz. The stop band of the DGS added with stop band of the inset-feed rectangular antenna which is responsible for enhancement of return loss. The DGS on the ground plane increases fringing field which introduces parasitic capacitance. This parasitic capacitance increases the coupling between the conducting patch and the ground plane which is responsible for the enhancement of the bandwidth. The performance of the antenna is depends on the physical dimension of the antenna as well as location and shape of the DGS. Zealand IE3D is used for simulation and analysis of the proposed antenna.