| 摘要 |
PROBLEM TO BE SOLVED: To provide a high frequency filter of which the transfer characteristics are made variable. SOLUTION: The high frequency filter has: a capacitor and a switching element, connected in series to the capacitor formed in an identical semiconductor substrate and includes a first variable capacitance circuit 10 and a third variable capacitance circuit 30, connected in series between an input end and an output end; a second variable capacitance circuit 20 connected between the connection point of the first variable capacitance 10 and the third variable capacitance 30 and the ground; a first inductor 71 and a second inductor 72 connected in series to the input end and the output end; and further, a third inductor 73, connected between the connection point of the second variable capacitance circuit 20 and the third variable capacitance circuit 30 and the ground, with the frequency characteristics are made variable by controlling the switching element. COPYRIGHT: (C)2010,JPO&INPIT
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