Systems and methods for frequency modulation adjustment

• US 7,920,033 B1
• Filed: 09/28/2007
• Issued: 04/05/2011
• Est. Priority Date: 09/28/2006
• Status: Expired due to Fees

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Quintic Holdings (NXP Semiconductors NV)
• Inventors: Lo, Carrie, Austin, Joseph, Groe, John B.
• Primary Examiner(s): Pascal; Robert
• Assistant Examiner(s): Johnson; Ryan
• Application Number:
  US11/863,772
• Time in Patent Office: 1,285 Days
• Field of Search: 331/23, 331/16, 331/34, 331/44, 331/36.C, 332/103, 332/117, 332/118, 332/119, 332/127, 332/128, 332/136, 375/308
• US Class Current: 332/128
• CPC Class Codes: H03C 3/0925 applying frequency modulation at the divider in the feedback loop

Abstract

A system and method for providing, among other things, wideband phase modulation is described. Several embodiments include a scaling network for scaling an input modulation signal in accordance with a scaling parameter and thereby generating a scaled modulation signal that is applied to a voltage-controlled oscillator of a phase-locked loop. A sensing network may also be included for detecting changes in one or more parameters characterizing the voltage-controlled oscillator. A calibration adjustment network may additionally be included for adjusting the scaling parameter in accordance with the changes in the one or more parameters.

Claims

1. A compensation apparatus for use with a phase-locked loop, the compensation apparatus comprising:

a scaling network configured to scale an input modulation signal in accordance with a scaling parameter and thereby generate a scaled modulation signal, the scaled modulation signal being applied to a voltage-controlled oscillator of the phase-locked loop;

a sensing network configured to detect changes in one or more parameters characterizing the voltage-controlled oscillator; and

a calibration adjustment network configured to adjust the scaling parameter in accordance with the changes in the one or more parameters, wherein the calibration adjustment network comprises;

a peak detector circuit configured to measure an amplitude of an output signal of the voltage-controlled oscillator; and

a swept capacitance circuit configured to release a control signal for adjusting the scaling parameter.

2. The compensation apparatus of claim 1, wherein the scaling network includes a frequency modulation signal multiplier component having an output coupled to a frequency modulation port of the voltage-controlled oscillator, wherein the frequency modulation signal multiplier component multiplies a frequency modulation signal by the scaling parameter to achieve a modified frequency modulation signal, the modified frequency modulation signal being released by the output of the frequency modulation signal multiplier component and received by the frequency modulation port of the voltage-controlled oscillator.

3. The compensation apparatus of claim 1, wherein the one or more parameters include a product of the frequency gain and a frequency modulation signal received by a frequency modulation port of the voltage-controlled oscillator.

5. The compensation apparatus of claim 1, wherein the scaling network includes a frequency modulation signal multiplier component having an output coupled to a frequency modulation port of the voltage-controlled oscillator, wherein the frequency modulation signal multiplier component multiplies a frequency modulation signal by the scaling parameter to achieve a modified frequency modulation signal, the modified frequency modulation signal being released by the output of the frequency modulation signal multiplier component and received by the frequency modulation port of the voltage-controlled oscillator.

4. A compensation apparatus for use with a phase-locked loop, the compensation apparatus comprising:

a scaling network configured to scale an input modulation signal in accordance with a scaling parameter and thereby generate a scaled modulation signal, the scaled modulation signal being applied to a voltage-controlled oscillator of the phase-locked loop;

a sensing network configured to detect changes in one or more parameters characterizing the voltage-controlled oscillator; and

a calibration adjustment network configured to adjust the scaling parameter in accordance with the changes in the one or more parameters, wherein the calibration adjustment network comprises;

a switch configured to release a constant current;

a first transistor configured to receive the constant current, wherein the constant current charges the capacitance of the first transistor to a first series of capacitance levels that is related to a second series of capacitance levels associated with a second transistor belonging to the voltage-controlled oscillator; and

an output port configured to release a control signal for adjusting the scaling parameter.

6. The compensation apparatus of claim 4, wherein the one or more parameters include a product of the frequency gain and a frequency modulation signal received by a frequency modulation port of the voltage-controlled oscillator.

7. A compensation apparatus for use with a phase-locked loop, the compensation apparatus comprising:

a scaling network configured to scale an input modulation signal in accordance with a scaling parameter and thereby generate a scaled modulation signal, the scaled modulation signal being applied to a voltage-controlled oscillator of the phase-locked loop;

a sensing network configured to detect changes in one or more parameters characterizing the voltage-controlled oscillator; and

a calibration adjustment network configured to adjust the scaling parameter in accordance with the changes in the one or more parameters, wherein the calibration adjustment network comprises;

a detector component responsive to an input signal, the detector component including a transistor which rectifies the input signal so as to generate a detection signal;

a reference component configured to provide a temperature-compensated reference signal; and

an output port for providing a temperature-compensated output signal corresponding to a difference between the detection signal and the temperature compensated reference signal.

8. The compensation apparatus of claim 7, wherein the scaling network includes a frequency modulation signal multiplier component having an output coupled to a frequency modulation port of the voltage-controlled oscillator, wherein the frequency modulation signal multiplier component multiplies a frequency modulation signal by the scaling parameter to achieve a modified frequency modulation signal, the modified frequency modulation signal being released by the output of the frequency modulation signal multiplier component and received by the frequency modulation port of the voltage-controlled oscillator.

9. The compensation apparatus of claim 7, wherein the one or more parameters include a product of the frequency gain and a frequency modulation signal received by a frequency modulation port of the voltage-controlled oscillator.

10. A method for adjusting a frequency gain of a voltage-controlled oscillator of a phase-locked loop, the method comprising:

scaling an input modulation signal in accordance with a scaling parameter and thereby generating a scaled modulation signal;

applying the scaled modulation signal to the voltage-controlled oscillator;

detecting changes in one or more parameters characterizing the voltage-controlled oscillator;

adjusting the scaling parameter in accordance with the changes in the one or more parameters; and

releasing a constant current that charges a capacitance of a first transistor to a first series of capacitance levels related to a second series of capacitance levels associated with a second transistor of the voltage-controlled oscillator.

11. The method of claim 10, further comprising:

multiplying a frequency modulation signal by the scaling parameter to achieve a modified frequency modulation signal; and

inputting the modified frequency modulation signal to a frequency modulation port of the voltage-controlled oscillator.

12. The method of claim 10, wherein the one or more parameters include a product of the frequency gain and a frequency modulation signal associated with the voltage-controlled oscillator.

13. A method for adjusting a frequency gain of a voltage-controlled oscillator of a phase-locked loop, the method comprising:

scaling an input modulation signal in accordance with a scaling parameter and thereby generating a scaled modulation signal;

applying the scaled modulation signal to the voltage-controlled oscillator;

detecting changes in one or more parameters characterizing the voltage-controlled oscillator; and

adjusting the scaling parameter in accordance with the changes in the one or more parameters;

generating a detection signal by rectifying an input signal;

providing a temperature-compensated reference signal; and

providing a temperature-compensated output signal corresponding to a difference between the detection signal and the temperature-compensated reference signal.

14. The method of claim 13, further comprising:

multiplying a frequency modulation signal by the scaling parameter to achieve a modified frequency modulation signal; and

inputting the modified frequency modulation signal to a frequency modulation port of the voltage-controlled oscillator.

15. The method of claim 13, wherein the one or more parameters include a product of the frequency gain and a frequency modulation signal associated with the voltage-controlled oscillator.

16. A compensation apparatus for use with a phase-locked loop, the compensation apparatus comprising:

a scaling network configured to scale an input modulation signal in accordance with a scaling parameter and thereby generate a scaled modulation signal, the scaled modulation signal being applied to a voltage-controlled oscillator of the phase-locked loop;

a sensing network configured to detect changes in one or more parameters characterizing the voltage-controlled oscillator; and

a calibration adjustment network configured to adjust the scaling parameter in accordance with the changes in the one or more parameters

a peak detector circuit; and

a swept capacitance circuit.

17. A compensation apparatus for use with a phase-locked loop, the compensation apparatus comprising:

a scaling network configured to scale an input modulation signal in accordance with a scaling parameter and thereby generate a scaled modulation signal, the scaled modulation signal being applied to a voltage-controlled oscillator of the phase-locked loop;

a sensing network configured to detect changes in one or more parameters characterizing the voltage-controlled oscillator; and

a calibration adjustment network configured to adjust the scaling parameter in accordance with the changes in the one or more parameters, wherein the calibration adjustment network comprises

a first transistor configured to receive a constant current, wherein the constant current charges the capacitance of the first transistor to a first series of capacitance levels that is related to a second series of capacitance levels associated with a second transistor belonging to the voltage-controlled oscillator.

18. A compensation apparatus for use with a phase-locked loop, the compensation apparatus comprising:

a scaling network configured to scale an input modulation signal in accordance with a scaling parameter and thereby generate a scaled modulation signal, the scaled modulation signal being applied to a voltage-controlled oscillator of the phase-locked loop;

a sensing network configured to detect changes in one or more parameters characterizing the voltage-controlled oscillator; and

a calibration adjustment network configured to adjust the scaling parameter in accordance with the changes in the one or more parameters, wherein the calibration adjustment network comprises

a detector component responsive to an input signal, the detector component including a transistor which rectifies the input signal so as to generate a detection signal.