When using an element which incorporates two variable capacity diodes which shares the cathode in one package in an LC resonant circuit, a point which becomes H level in the DC analysis and a point which becomes H level in the AC analysis are different, and therefore a capacitor for cutting DC and a bias resistor having a high impedance are required, which hinders the reduction in substrate mounting area and hence hinders the reduction in cost of a set. A resistance having a high impedance is connected between anode terminals of two variable capacitance diodes sharing a cathode, and the components described above are sealed in one package. The resistance can be formed of a diffusion region between p-regions of the variable capacitance diodes or can be formed of polysilicon and disposed on a chip. Thus, the resistance can be mounted while a chip size of the variable capacitance diode is maintained. Accordingly, it is not required that a bias resistance having a high impedance is additionally provided, whereby achieving reduction in the substrate mounting area and reduction in costs of the set. |