| 摘要 |
The invention relates to a variable capacitance circuit which achieves reduction in both of distortion and current consumption and furthermore achieves requirements of high power handling capability, cost reduction, and downsizing of the circuit. The variable capacitance circuit includes a first variable capacitance element unit having n pieces (where n is a natural number of two or more) of variable capacitance capacitors connected in series with respect to high frequency and in parallel with respect to direct current, each of the variable capacitance capacitors including one or more variable capacitance elements, each of which includes a dielectric layer with dielectric constant varying according to an applied direct-current voltage and a pair of electrodes sandwiching the dielectric layer therebetween, and a second variable capacitance element unit which has an applied voltage amplitude smaller than a voltage amplitude of high frequency signal applied to the first variable capacitance element unit, the second variable capacitance element unit including one piece of the variable capacitance elements or having m pieces (where m is a natural number smaller than n) of the variable capacitance elements connected in series.
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