Calibration techniques for frequency synthesizers
AssigneeQUALCOMM Incorporated
InventorsJeremy D. Dunworth, Brett C. Walker
Life of this patent
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Abstract
In one embodiment, this disclosure describes a frequency synthesizer for use in a wireless communication device, or similar device that requires precision frequency synthesis but small amounts of noise. In particular, the frequency synthesizer may include a phase locked loop (PLL) and an integrated voltage controlled oscillator (VCO). The frequency synthesizer may implement one or more calibration techniques to quickly and precisely calibrate the VCO. In this manner, the analog gain of the VCO can be significantly reduced, which may improve performance of the wireless communication device. Also, the initial state of the PLL may be improved to reduce lock time of the PLL, which may enhance performance of the wireless communication device.
Claims41
A method of calibrating an oscillator comprising:
- generating a first signal indicative of an initial frequency of the oscillator for an input parameter;
- generating a second signal indicative of a reference frequency, wherein generating the first and second signals comprises scaling the initial frequency of the oscillator and the reference frequency at approximately the same time so that the generated signals are substantially in phase;
- and
- adjusting the initial frequency of the oscillator based on a comparison of the first and second signals.
A frequency synthesizer comprising:
- an oscillator including configurable circuitry that defines an initial frequency of the oscillator for an initial input parameter;
- and
- a calibration unit that adjusts the configurable circuitry based on a comparison of a signal indicative of the oscillator and a signal indicative of a reference, wherein the calibration unit initializes the signals indicative of the oscillator and the reference so that the signals are substantially in phase.
An apparatus comprising:
- circuitry that generates a first signal indicative of an initial frequency of an oscillator for an input parameter;
- circuitry that generates a second signal indicative of a reference frequency, wherein the circuitry that generates the first and second signals scales the initial frequency of the oscillator and scales the reference frequency at approximately the same time so that the generated signals are substantially in phase;
- and
- circuitry that adjusts the initial frequency of the oscillator based on a comparison of the first and second signals.
A frequency synthesizer comprising:
- an oscillator including configurable circuitry that defines an initial frequency of the oscillator for an initial input parameter;
- and
- means for adjusting the configurable circuitry based on a comparison of a signal indicative of the oscillator and a signal indicative of a reference, wherein the means for adjusting initializes the signals indicative of the oscillator and the reference so that the signals are substantially in phase.
A wireless communication device comprising:
- frequency synthesizer that generates waveforms, wherein the frequency synthesizer comprises an oscillator including configurable circuitry that defines an initial frequency of the oscillator for an initial input parameter, and a calibration unit that adjusts the configurable circuitry based on a comparison of a signal indicative of the oscillator and a signal indicative of a reference, wherein the calibration unit initializes the signals indicative of the oscillator and the reference so that the frequencies are substantially in phase;
- and
- a mixer that mixes the waveforms.
A method comprising:
- selecting a calibration input parameter for an oscillator based on temperature;
- and
- calibrating the oscillator based on a frequency of the oscillator at the calibration input parameter.
An apparatus comprising:
- an oscillator including configurable circuitry that defines an initial frequency of the oscillator at a calibration parameter;
- and
- temperature compensation circuitry that generates the calibration parameter based on temperature.
Dependencies are inferred from the claim text.