It has been known that a good broad band antenna could be obtained by adding two parasitic elements at a small distance from and parallel to a monopole antenna. In this paper, the monopole antenna with the two parasitic elements was analyzed. The effect on the monopole antenna with the two parasitic elements was examined for broadband performance of the impedance characteristic. As a result, it is found that the monopole antenna with the two parasitic elements has 42% band width.
