The primary barrier to implement microstrip patch antennas in modern broadband communication systems are their narrow bandwidth. For broadband antennas some of the characteristics are very essential like feed impedance matching, patch geometry optimization and suppression of surface waves etc. To improve impedance bandwidth low permittivity substrate with increased thickness is required. But by taking low permittivity with substrate thickness, the surface wave related problems will be raised. To overcome this problem a coplanar wave guide fed square patch monopole antenna with closed ground structure is proposed in this paper and electromagnetic band gap structure is added to the antenna design to enhance the impedance bandwidth, this being the aim of the present work. Antenna with square patch and closed ground structure is designed to resonate at dual band and by adding Electromagnetic Bandgap Structure ( EBG) structure without closed ground structure in the design the modified antenna is resonating at triple band. To enhance the bandwidth and to suppress the surface waves related problems, we incorporated EBG structure and closed ground structure in the proposed antenna model. The proposed model attained bandwidth more than 10.7 GHz with impedance bandwidth of 82.3%. In this design the HFSS electromagnetic simulator tool results are in good agreement with fabricated antenna measured results over ZNB 20 vector network analyzer.