To adjust the strength/weakness of a signal source by providing a main line in the center part of a substrate and sub lines on both sides and feeding back a part of signals from the signal source through the main line toward an antenna through the sub lines.

The main line 4 made of silver palladium is provided in the center part in a longitudinal direction of the substrate 3 made of alumina and the sub lines 5 made of the silver palladium are provided on both sides with a prescribed interval. Also, the electrodes 4a and 4b of the main line 4 are provided on both ends in the longitudinal direction of the substrate 3 and the electrodes 5a and 5b for the sub lines 5 are provided in a lateral direction. Further, the two electrodes 5a and 5b are short-circuited on a back surface by the line. Thus, a part of the signals from the signal source through the electrode 4a, the main line 4 and the electrode 4b toward the antenna is fed back to the signal source through the sub lines 5 on both ends and the electrode 5a. Thus, the strength/weakness of the signal source are adjusted. Also, by providing the sub lines on both sides of the main line, the coupling degree of both is improved.