Frequency synthesizer employing a continuously adaptive phase detector and method
AssigneeMotorola, Inc.
InventorYiu-Kwong Chan
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Abstract
A frequency synthesizer (51) arranged in a phase locked loop fashion to provide an output signal with a preselected frequency within a controlled lock time from a voltage controlled oscillator (51), having: a phase detector (55) with a controllable gain, that provides an error signal proportional to the controllable gain and corresponding to a phase difference between a reference signal and a feedback signal, an adapt circuit (121) for setting the controllable gain to an adapt value (205), and a tracking circuit (123) for setting the controllable gain to a tracking value (207) by adjusting the controllable gain in a predetermined and controlled fashion from the adapt value (205) to the tracking value (207).
Claims20
A frequency synthesizer arranged in a phase locked loop fashion to provide an output signal with a preselected frequency within a controlled lock time from a voltage controlled oscillator, comprising:
- phase detector means having a controllable gain, for providing an error signal that is proportional to said controllable gain and that corresponds to a phase difference between a reference signal and a feedback signal, said error signal as processed determining the preselected frequency of the voltage controlled oscillator, said feedback signal corresponding to the preselected frequency;
- adapt means, coupled to said phase detector means, for setting said controllable gain to an adapt value;
- and
- tracking means, coupled to said phase detector means, for setting said controllable gain to a tracking value by adjusting said controllable gain in a substantially continuous and monotonic fashion from said adapt value to said tracking value.
A frequency synthesizer arranged in a phase locked loop fashion to provide an output signal with a preselected frequency within a controlled lock time from a voltage controlled oscillator, comprising:
- phase detector means having a controllable gain, for providing an error signal that is proportional to said controllable gain and that corresponds to a phase difference between a reference signal and a feedback signal, said error signal as processed determining the preselected frequency of the voltage controlled oscillator, said feedback signal corresponding to the preselected frequency;
- adapt means, coupled to said phase detector means, for setting said controllable gain to an adapt value;
- and
- tracking means, coupled to said phase detector means, for setting said controllable gain to a tracking value by adjusting said controllable gain in a predetermined and controlled fashion from said adapt value to said tracking value.
In a frequency synthesizer arranged in a phase locked loop fashion to provide an output signal with a preselected frequency within a controlled lock time from a voltage controlled oscillator, a method including the steps of:
- providing an error signal that is proportional to a controllable gain and that corresponds to a phase difference between a reference signal and a feedback signal, said error signal as processed determining the preselected frequency of the voltage controlled oscillator, said feedback signal corresponding to the preselected frequency;
- setting said controllable gain to an adapt value;
- and
- setting said controllable gain to a tracking value by adjusting said controllable gain in a predetermined and controlled fashion from said adapt value to said tracking value.
A communications receiver arranged to receive radio signals within a controlled time, comprising:
- receiver means for mixing a radio signal and a local oscillator signal to provide a received signal when said local oscillator signal has a preselected frequency;
- synthesizer means, coupled to said receiver means and arranged in a phase locked loop fashion, for providing said local oscillator signal with said preselected frequency within a controlled lock time from a voltage controlled oscillator, said synthesizer means further including;
- phase detector means having a controllable gain, for providing an error signal that is proportional to said controllable gain and that corresponds to a phase difference between a reference signal and a feedback signal, said error signal as processed determining said preselected frequency of said voltage controlled oscillator, said feedback signal corresponding to said preselected frequency;
- adapt means, coupled to said phase detector means, for setting said controllable gain to an adapt value;
- and
- tracking means, coupled to said phase detector means, for setting said controllable gain to a tracking value by adjusting said controllable gain in a predetermined and controlled fashion from said adapt value to said tracking value.
Dependencies are inferred from the claim text.