| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage controlled oscillator that is configured by arranging C-coupling type variable capacitance circuits and a direct-coupling type variable capacitance circuit in a mixed manner and in which the linearity and the variable range of the oscillation frequency are well-balanced. SOLUTION: The voltage controlled oscillator includes an inductor circuit 110, C-coupling type variable capacitance circuits 120 and 140, a direct-coupling type variable capacitance circuit 130, and a negative resistance circuit 160, which are connected in parallel, and a reference voltage generating section 180 that generates reference voltages Vref1 and Vref2. A control voltage Vt for feedback control of an oscillation frequency is applied to back gate terminals of variable capacitance elements 121, 122, 131, 132, 141 and 142 of the variable capacitance circuits 120, 130 and 140. The reference voltages Vref1 and Vref2 are applied to gate terminals of the variable capacitance elements 121, 122, 141, and 142 of the C-coupling type variable capacitance circuits 120 and 140, respectively. COPYRIGHT: (C)2010,JPO&INPIT |
