Patent ID: 8773223

Claim:
A variable resonator, comprising: a line part that comprises one or more lines and has an annular shape; at least two parallel resonant circuits configured to permit a change of a characteristic; and at least three variable reactance blocks configured to permit a change of a reactance value, wherein said at least two parallel resonant circuits are electrically connected to said line part at one end thereof at different positions on the line part, only one parallel resonant circuit of said at least two parallel resonant circuits is selected as a circuit to operate as a switch in an ON state, each remaining parallel resonant circuit of said at least two parallel resonant circuits, which is not selected as the circuit to operate as the switch in the ON state, is selected as a circuit to operate as a switch in an open state, and said at least three variable reactance blocks are electrically connected to said line part at predetermined intervals based on an electrical length at a resonance frequency of the variable resonator.