In this paper A novel microstrip patch antenna with band width improvement and low cross polarization level is presented. The use of DGS on the ground plane of the substrate is easy and can simply be applied in many microwave designs. The proposed design for the low cross polarization level and band width improved patch antenna consist of elliptical-slots on ground and Creation of Modifications and Defects in the Ground Plane of Microstrip Antenna. These practices reduce the strength of unwanted radiated fields of microstrip patch antenna that results low cross polarization level and improve band width of antenna. To validate the result a reference patch antenna with conventional ground plane is designed and compared with proposed antenna. The designed antenna cross polarization level and band width are improved about 20dB and 15% respectively compared with microstrip patch antenna with conventional ground plane. The purposed antenna XP (cross-polarized) ratio has remarkable improvement in impedance bandwidth that is from 3.7GHz to 4.5GHz.