Abstract: An impedance matching device 2A connected between one or more plasma generating electrodes 51, 52 and a RF power supply 1 that selectively supplies RF power of multiple frequencies includes multiple matching devices 31, 32 each of which corresponds to each frequency of the multiple frequencies of the RF power, and matches an impedance of the RF power supply 1 to an impedance of a plasma load, and a demultiplexer 20 that demultiplexes the RF power of multiple frequencies output by the RF power supply 1 and feeds each of the demultiplexed RF power to a corresponding matching device in the multiple matching devices 31, 32.

Abstract: A power combiner includes a 90 degree hybrid circuit including first to fourth transmission lines, and first to fourth ports. The first transmission line, the second transmission line, the third transmission line and the fourth transmission line are connected to each other in this order to form a ring shape. The first port is connected at a connection portion between the first transmission line and the second transmission line; the second port is connected at a connection portion between the second transmission line and the third transmission line; the third port is connected at a connection portion between the third transmission line and the fourth transmission line; and the fourth port is connected at a connection portion between the fourth transmission line and the first transmission line. The 90 degree hybrid circuit has a thickness of 0.4 mm or greater.

Abstract: This invention relates to a microwave radiator for warming therapy inserted into a human body to cure focuses of the body such as tumors. It has a first and second high-frequency coaxial cable. The second high-frequency coaxial cable has an inner conductor and a plurality of ring conductors disposed at the outer periphery of the inner conductor via a dielectric. The second high-frequency coaxial cable is inserted into the focuses of the body, and warming therapy can be conducted using radiated electromagnetic waves.