METHOD AND APPARATUS FOR GENERATING OSCILLATING SIGNALS

• US 20080246548A1
• Filed: 04/05/2007
• Published: 10/09/2008
• Est. Priority Date: 04/05/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Fagg, Russell John, Wheatley, Charles E.
• Granted Patent: US 7,592,878 B2
• Time in Patent Office: Days
• US Class Current: 331/132
• CPC Class Codes: H03B 2200/0066 Amplitude or AM detection
• CPC Class Codes: H03B 2200/0094 Measures to ensure starting of oscillations
• CPC Class Codes: H03B 5/06 Modifications of generator to ensure starting of oscillations
• CPC Class Codes: H03B 5/1265 switched capacitors
• CPC Class Codes: H03L 1/022 by indirect stabilisation, i.e. by generating an electrical correction signal which is a function of the temperature H03L1/021 takes precedence
• CPC Class Codes: H03L 3/00 Starting of generators
• CPC Class Codes: H04B 2001/6908 using time hopping

Abstract

An apparatus for generating an oscillating signal that includes a circuit to accelerate the time in which an oscillating signal reaches a defined steady-state condition from a cold start. The apparatus includes an oscillating circuit to generate an oscillating signal; a first circuit to supply a first current to the oscillating circuit; and a second circuit to supply a second current to the oscillating circuit, wherein the first and second currents are adapted to reduce the time duration for the oscillating signal to reach a defined steady-state condition. The apparatus may be useful in communication systems that use low duty cycle pulse modulation to establish one or more communications channels, whereby the apparatus begins generating an oscillating signal at approximately the beginning of the pulse and terminates the oscillating signal at approximately the end of the pulse.

Claims

1. An apparatus for generating an oscillating signal, comprising:

a first circuit to generate an oscillating signal;

a second circuit to supply a first current to the first circuit; and

a third circuit to supply a second current to the first circuit, wherein the first and second currents are adapted to reduce a time duration for the oscillating signal to reach a defined steady-state condition.

2. The apparatus of claim 1, wherein the first circuit comprises:

a tank circuit; and

a negative resistance generator coupled to the tank circuit.

3. The apparatus of claim 2, wherein the tank circuit comprises:

an inductive device; and

a capacitive device coupled in parallel with the inductive device.

4. The apparatus of claim 3, wherein the capacitive device comprises a programmable switched capacitor bank.

5. The apparatus of claim 1, further comprising a steady-state detector adapted to disable the third circuit from supplying the second current to the first circuit in response to detecting the defined steady-state condition of the oscillating signal.

6. The apparatus of claim 1, wherein the defined steady-state condition is based on an amplitude stability of the oscillating signal.

7. The apparatus of claim 6, wherein the defined steady-state condition is based on the amplitude of the oscillating signal not varying more than 15 percent.

8. The apparatus of claim 1, wherein the defined steady-state condition is based on a frequency stability of the oscillating signal.

9. The apparatus of claim 8, wherein the defined steady-state condition is based on the frequency of the oscillating signal not varying more than one (1) percent.

10. The apparatus of claim 1, further comprising a frequency calibration unit adapted to tune the first circuit so that the oscillating signal cycles within a defined frequency range.

11. The apparatus of claim 10, wherein the defined frequency range is equal to one (1) percent of a defined center frequency.

12. The apparatus of claim 10, wherein the frequency calibration unit is adapted to tune the first circuit upon power up of the apparatus, upon detecting an ambient temperature change above a defined threshold, or upon receiving a new frequency word for the first circuit.

13. The apparatus of claim 1, further comprises a transceiver responsive to the oscillating signal to establish at least one ultra-wide band communications channel with another apparatus.

14. The apparatus of claim 13, wherein each ultra-wide band channel has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

15. A method of generating an oscillating signal, comprising:

generating a first current;

generating a second current; and

generating an oscillating signal in response to the first and second current, wherein the second current reduces a time duration for the oscillating signal to reach a defined steady-state condition.

16. The method of claim 15, wherein generating the oscillating signal is accomplished by:

a tank circuit; and

a negative resistance generator coupled to the tank circuit.

17. The method of claim 16, wherein the tank circuit comprises:

an inductive device; and

a capacitive device coupled in parallel with the inductive device.

18. The method of claim 17, wherein the capacitive device comprises a programmable switched capacitor bank.

19. The method of claim 15, further comprising disabling the generating of the second current in response to detecting the defined steady-state condition of the oscillating signal.

20. The method of claim 15, wherein the defined steady-state condition is based on an amplitude stability of the oscillating signal.

21. The method of claim 20, wherein the defined steady-state condition is based on the amplitude of the oscillating signal not varying more than 15 percent.

22. The method of claim 15, wherein the defined steady-state condition is based on a frequency stability of the oscillating signal.

23. The method of claim 22, wherein the defined steady-state condition is based on the frequency of the oscillating signal not varying more than one (1) percent.

24. The method of claim 15, further comprising calibrating the oscillating signal so that it cycles within a defined frequency range.

25. The method of claim 24, wherein the defined frequency range is equal to one (1) percent of a defined center frequency.

26. The method of claim 24, wherein calibrating the oscillating signal is performed in response to detecting power up, to detecting an ambient temperature change above a defined threshold, or to receiving a new frequency word.

27. The method of claim 15, further comprising establishing at least one ultra-wide band communications channel using the oscillating signal.

28. The method of claim 27, wherein each ultra-wide band channel has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

29. An apparatus for generating an oscillating signal, comprising:

means for generating an oscillating signal;

means for supplying a first current to the oscillating signal generating means; and

means for supplying a second current to the oscillating signal generating means, wherein the first and second currents are adapted to reduce a time duration for the oscillating signal to reach a defined steady-state condition.

30. The apparatus of claim 29, wherein the oscillating signal generating means comprises:

a tank circuit; and

a negative resistance generator coupled to the tank circuit.

31. The apparatus of claim 30, wherein the tank circuit comprises:

an inductive device; and

a capacitive device coupled in parallel with the inductive device.

32. The apparatus of claim 31, wherein the capacitive device comprises a programmable switched capacitor bank.

33. The apparatus of claim 29, further comprising means for disabling the second current supplying means from supplying the second current in response to detecting the defined steady-state condition of the oscillating signal.

34. The apparatus of claim 29, wherein the defined steady-state condition is based on an amplitude stability of the oscillating signal.

35. The apparatus of claim 34, wherein the defined steady-state condition is based on the amplitude of the oscillating signal not varying more than 15 percent.

36. The apparatus of claim 29, wherein the defined steady-state condition is based on a frequency stability of the oscillating signal.

37. The apparatus of claim 36, wherein the defined steady-state condition is based on the frequency of the oscillating signal not varying more than one (1) percent.

38. The apparatus of claim 29, further comprising means for calibrating the oscillating signal generating means so that the oscillating signal cycles within a defined frequency range.

39. The apparatus of claim 38, wherein the defined frequency range is equal to one percent of a defined center frequency.

40. The apparatus of claim 38, wherein the calibration means is adapted to calibrate the oscillating signal generating means upon power up of the apparatus, upon detecting an ambient temperature change above a defined threshold, or upon receiving a new frequency word for the oscillating signal generating means.

41. The apparatus of claim 29, further comprising means for establishing at least one ultra-wide band communications channel with another apparatus using the oscillating signal.

42. The apparatus of claim 41, wherein each ultra-wide band channel has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

43. A computer program product for generating an oscillating signal comprising:

a computer readable medium comprising codes executable by at least one computer to;

generate an oscillating signal;

supply a first current to produce the generation of the oscillating signal; and

supply a second current to reduce a time duration for the oscillating signal to reach a defined steady-state condition.

44. A headset for performing an operation based on distance, comprising:

a first circuit to generate an oscillating signal;

a second circuit to supply a first current to the first circuit;

a third circuit to supply a second current to the first circuit, wherein the first and second currents are adapted to reduce a time duration for the oscillating signal to reach a defined steady-state condition;

a transducer adapted to generate at least one audio signal; and

a transmitter adapted to combine the at least one audio signal with the oscillating signal, and transmit the combined signal.

45. A watch for performing an operation based on distance, comprising:

a first circuit to generate an oscillating signal;

a second circuit to supply a first current to the first circuit;

a third circuit to supply a second current to the first circuit, wherein the first and second currents are adapted to reduce a time duration for the oscillating signal to reach a defined steady-state condition;

a receiver adapted to combine an incoming signal with the oscillating signal; and

a display adapted to provide a visual output based on the combined signal.

46. A medical device for performing an operation based on distance, comprising:

a first circuit to generate an oscillating signal;

a second circuit to supply a first current to the first circuit;

a third circuit to supply a second current to the first circuit, wherein the first and second currents are adapted to reduce a time duration for the oscillating signal to reach a defined steady-state condition;

a sensor adapted to generate at least one sensed signal; and

a transmitter adapted to combine the at least one sensed signal and the oscillating signal and transmit the combined signal over a wireless communication link.