In this paper a design of compact size microstrip antenna is presented that have its applications in UWB frequency range. The ground element of the proposed antenna is taken in the form of defected ground structure(DGS). The antenna is fed by a microstrip feeding technique and printed on a dielectric Fr4 substrate of dimension (30mm X 32 mm) permittivity er =4.4 and height h = 1.59 mm. The optimization on the microstrip has been done to accomplish an -10 dB return loss criterion. Moreover, in comparison with a simple ground, the proposed design enhances the bandwidth and improves input return loss. The antenna design parameters and performances have been investigated through a number of design simulations. Design parameters like substrate variation, feed size and defected ground plane which affect the performance of the antenna in terms of its frequency domain and time domain characteristics are investigated.

Keywords: Microstrip line feed, microstrip antenna, Omni-directional patterns, UWB