| 摘要 |
PROBLEM TO BE SOLVED: To more easily provide a voltage controlled oscillator having high linearity of oscillation frequency over a wide control potential range. SOLUTION: The voltage controlled oscillator comprises an inductor circuit, n variable capacitance circuits and a negative resistance circuit that are connected in parallel, and a reference voltage generation section 114 for generating n reference voltages based on a power supply potential. One of the n reference voltages is input to one of the terminals of a variable capacitance element of each of the n variable capacitance circuits. A control voltage Vt for feedback-controlling an oscillation frequency is input to the other of the terminals of the variable capacitance element of each of the n variable capacitance circuits. A first to a third reference voltage Vref1, Vref2 and Vref3 are input to a first to a third variable capacitance circuit A, B and C, respectively. The first to third reference voltages Vref1, Vref2 and Vref3 each have a fixed value, and a difference between the first reference voltage Vref1 and the second reference voltage Vref2 and a difference between the second reference voltage Vref2 and the third reference voltage Vref3 are different from each other. COPYRIGHT: (C)2009,JPO&INPIT
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