Abstract:A novel quasi-Yagi antenna was proposed with broad-band and broad-angle characteristics. CST microwave studio, high frequency structure simulation software based on Finite Integration Method(FIM)，were used to analyze the antenna performances. Two methods to extend beam width were simulated，and the method of adding rectangle microstrip patches as radiating element was selected at last. After being optimized with simulation software，the results of the modified quasi-Yagi show more than 120°beam width both in E-and H-plane and a relative bandwidth about 40% for Voltage Standing Wave Ratio(VSWR) of less than 2.