Patent ID: 9236872
Filing Date: 2016-01-12
CPC Classification: H03B,H03J,H03L

Claim Text:
1. A signal generation apparatus comprising: a voltage-controlled oscillator that includes an oscillation circuit for performing an oscillation operation at a frequency that corresponds to an inductance and a capacitance between a first node and a second node, a first group of capacitors that have a first terminal connected to the first node, a first group of transistors that are respectively connected between a reference potential and second terminals of the first group of capacitors and switch on and off in accordance with respective control signals, a first group of resistors that are respectively parallel-connected to the first group of transistors, a second group of capacitors that have a first terminal connected to the second node, a second group of transistors that are respectively connected between the reference potential and second terminals of the second group of capacitors and switch on and off in accordance with respective control signals, and a second group of resistors that are respectively parallel-connected to the second group of transistors; a frequency division circuit that divides an oscillation signal generated by the voltage-controlled oscillator and outputs a frequency division signal; an error signal generation circuit that compares at least the phase of the frequency division signal output from the frequency division circuit and at least the phase of a reference signal, and generates an error signal that corresponds to the difference therebetween; a first filter circuit that generates a control voltage for controlling the oscillation frequency of the voltage-controlled oscillator by subjecting the error signal to low-pass filter processing; a first switch circuit that switches on and off a supply of the error signal to the first filter circuit; a second filter circuit that generates a control voltage for controlling the oscillation frequency of the voltage-controlled oscillator by subjecting a modulation signal to low-pass filter processing; a second switch circuit that switches on and off a supply of the modulation signal to the second filter circuit; and a control circuit that controls the first switch circuit and the second switch circuit.