Abstract: Vivaldi antenna is a kind of the non-variable-frequency antenna. Taking full advantage of the wide-band, directive radiation, input impedance stability, high efficiency, simple structure, low cost and easy integration features, a high-power new structure antenna is developed. A problem to be solved for high-power devices is the discharge problem among its parts. The reported opposed structure solves that problem effectively. Besides, up to 196 percent bandwidth is also achieved. In order to resolve the feeding problem of the new structure , the input impedance is reduced to 40 ohm and a parallel waveguide-fed is used. This fed method can get the relative bandwidth about 180 percent.