Patent ID: 7369394

Claim:
A variable capacitor comprising: a supporting substrate; a variable capacitance element array composed of a plurality of variable capacitance elements which are formed on the supporting substrate, each of the variable capacitance elements being composed of a first electrode layer and a second electrode layer facing each other, and a dielectric layer sandwiched therebetween whose dielectric constant is changeable through application of a direct current bias voltage, the second electrode layer being located farther from the supporting substrate than the first electrode layer in each of the variable capacitance elements, and the variable capacitance elements being electrically connected in series in such a manner that in each of pairs of the variable capacitance elements adjacent to each other, the first electrode layer of a first variable capacitance element of the pair and the second electrode layer of a second variable capacitance element of the pair are connected; and bias lines each connected to the variable capacitance elements, each of which includes at least one of resistance component and inductor component for applying the direct current bias voltage.