Digital controlled oscillator, frequency synthesizer, radio communication apparatus using the same, and control method for the same

摘要

The digital controlled oscillator includes a variable capacitance section having a first capacitor array of a plurality of first variable capacitors and a second capacitor array of a plurality of second variable capacitors, and generates a signal having an oscillation frequency corresponding to the capacitance value of the variable capacitance section. The first capacitance change amount in the individual first variable capacitors is a value obtained by multiplying the second capacitance change amount in the individual second variable capacitors by an integer equal to or more than 2, and the number of second variable capacitors is equal to or more than a value obtained by subtracting 1 from the integer equal to or more than 2.