PURPOSE: To improve the accuracy of dimensions and to miniaturize and simplify the structure by letting dipoles and connection feeders consisting of a ceramic compound of an oxide superconductor to both faces of a dielectric plate with desired shapes and dimensions.

CONSTITUTION: All of dipoles 1a, 1b, 2a and 2b, connection feeders 3a and 3b, and a feeder 4 consist of a ceramic compound of an oxide superconductor and are set to both faces of a dielectric plate 6. Since parts of dipoles 1a and 1b and parts of dipoles 2a and 2b are constituted on opposite faces of the dielectric plate and connection feeders 3a and 3b cross each other with the dielectric plate 6 between them, dipoles 1a and 1b and dipoles 2a and 2b are fed with phases opposite to each other. The feeder 4 consists of two parallel lines formed on both faces of the dielectric plate 6. Thus, the length of dipoles and intervals of dipoles are set with a high precision, and the structure of the whole of this device is miniaturized and simplified.