Voltage controlled oscillator using variable capacitor and phase locked loop using the same
AssigneeSamsung Electronics Co., Ltd.
InventorJong-Woo Lee
Life of this patent
Estimating the term…
Abstract
A variable capacitor is provided. The variable capacitor includes a plurality of capacitor segments. The plurality of capacitor segments are connected in parallel within the variable capacitor. When a plurality of candidate capacitances allowable to the variable capacitor according to a connection state of the plurality of capacitor segments connected in parallel are sorted in a magnitude sequence, the plurality of candidate capacitances form a geometric series. The variable capacitor is used for a Voltage Controlled Oscillator (VCO), and the VCO is used for a Phase Locked Loop (PLL).
Claims20
A variable capacitor comprising:
- a capacitor bank comprising a plurality of capacitor segments;
- and
- a plurality of switch segments configured to control connection states of each of the plurality of capacitor segments,
- wherein the capacitor bank provides a capacitance from a set of candidate capacitances based on the connection states,
- wherein the connection states are controlled based on a control code,
- wherein the capacitance provided by the capacitor bank is linearly changed on a log scale by linearly increasing a value of the control code,
- wherein the candidate capacitances form a geometric series with a constant ratio between successive candidate capacitances, and
- wherein the constant ratio is related to a quantity of the switch segments in the capacitor bank.
A voltage controlled oscillator (VCO) comprising:
- a resonance circuit configured to generate a signal with a frequency;
- and
- an amplifier circuit configured to amplify the signal,
- wherein the resonance circuit comprises an inductor and a variable capacitor that are coupled in parallel,
- wherein the variable capacitor comprises a capacitor bank comprising a plurality of capacitor segments, and a plurality of switch segments configured to control connection states of each of the plurality of capacitor segments,
- wherein the capacitor bank provides a capacitance from a set of candidate capacitances based on connection states of the plurality of capacitor segments,
- wherein the connection states are controlled based on a control code,
- wherein the capacitance provided by the capacitor bank is linearly changed on a log scale by linearly increasing a value of the control code, and
- wherein the frequency of the signal is linearly changed on the log scale by linearly increasing the value of the control code.
A phase locked loop (PLL) comprising:
- a phase comparator configured to:
- measure a phase difference between a phase of an input signal and a phase of a signal fed back from a voltage controlled oscillator (VCO), and
- output a voltage signal proportional to the phase difference;
- and
- a low pass filter configured to:
- remove a high frequency component of the voltage signal, and
- output a control voltage,
- wherein the VCO is configured to generate an output signal with a frequency according to a control code corresponding to the control voltage,
- wherein the VCO comprises a variable capacitor configured to provide a capacitance from a set of candidate capacitances,
- wherein the variable capacitor comprises:
- a capacitor bank comprising a plurality of capacitor segments;
- and
- a plurality of switch segments configured to control connection states of each of the plurality of capacitor segments,
- wherein the capacitor bank provides the capacitance based on connection states of the plurality of capacitor segments,
- wherein the connection states are controlled based on the control code,
- wherein the capacitance provided by the capacitor bank is linearly changed on a log scale by linearly increasing a value of the control code, and
- wherein the frequency of the output signal is linearly changed on the log scale by linearly increasing the value of the control code.
Dependencies are inferred from the claim text.