In this research paper, the design of C-shaped Defected Ground Structure (DGS) antenna is proposed to realize dualband characteristics for C-band and X-band applications. The proposed antenna consists of C-shaped slot incorporated in ground plane which resonates at two different frequencies (f r1 and f r2 ) of 7.41 GHz and 9.28 GHz which lie in C-band and X-band respectively. A very good return loss (S 11 ) of -30.79 dB and -40.75 dB are obtained at first and second resonant frequencies respectively for C-shaped DGS antenna. The Bandwidth of C-shaped DGS antenna is increased by 825 MHz and 1182.8 MHz respectively at two different bands than the bandwidth of the Conventional Rectangular Microstrip Patch Antenna (CRMPA). Also VSWR is much improved with C-shaped DGS antenna. The comparison of simulated results of proposed and CRMPA has also been presented in this paper. The main contribution of this paper is the miniaturization of ground plane of 23% using C-shaped DGS which is very much encouraging.