Frequency scalable, low self-generated noise frequency source

• US 6,782,248 B2
• Filed: 01/11/2002
• Issued: 08/24/2004
• Est. Priority Date: 01/11/2002
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: DiCamillo, Nicholas F., Franzen, Daniel R., Mooney, Dale W., Paxton, Allen W., Kintis, Mark, Lane, Daniel R., Martin, Bridget M.
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Jackson, Blane J.
• Application Number:
  US10/044,149
• Publication Number:
  US 20030134610A1
• Time in Patent Office: 956 Days
• Field of Search: 455/258, 455/259, 455/20, 455/22, 455/183.1, 455/314, 455/315, 455/76, 455/12.1, 455/13.1, 455/13.2, 455/318, 370/315, 370/316, 375/214, 375/215
• US Class Current: 455/318
• CPC Class Codes: H03B 29/00 Generation of noise currents and voltages gasfilled discharge tubes with solid cathode specially adapted as noise generators H01J17/005
• CPC Class Codes: H03L 7/22 using more than one loop

Abstract

A frequency scalable, low self-generated noise frequency source generates coherent or mostly-coherent local oscillator signals and includes a common reference, a coherent set of high frequency references and specific local oscillators which may be non-coherent for each specific output frequency. Delay lines may be included in the paths to ensure time delay alignment. The use of these elements with this modular design allows the generation of multiple coherent local oscillators via replication of the modular design elements.

Claims

1. A frequency source comprising:

a reference frequency source to generate a first signal of a specified first frequency;

a first frequency multiplier to receive the first signal from the reference frequency source and to generate a second signal of a specified second frequency, the second frequency being an integral multiple of the first frequency; and

;

at least two channels, each channel selected from the following group of channels;

a first channel comprising;

a second frequency multiplier to receive the second signal from the first multiplier and to generate a third signal of a specified third frequency as an output of the frequency source, the third frequency being a harmonic of the second frequency;

a second channel comprising;

a frequency synthesizer to receive the first signal from the reference frequency source and to generate a fourth signal of a specified fourth frequency, the fourth frequency bearing a specific relationship to the first frequency;

a third frequency multiplier to receive the second signal from the first frequency multiplier and to generate a fifth signal of a specified fifth frequency, the fifth frequency being a harmonic of the second frequency;

a first mixer to receive the fourth signal from the frequency synthesizer and the fifth signal from the third frequency multiplier and to generate a sixth signal, the sixth signal including a first signal component having a frequency equal to the sum of the fourth frequency and the fifth frequency and including a second signal component having a frequency equal to the difference between the fourth frequency and the fifth frequency; and

a first filter to receive the sixth signal from the first mixer and to output only one of the first signal component thereof and the second signal component thereof as an output of the frequency source;

a third channel comprising;

a second mixer to receive the fourth signal from the frequency synthesizer and the second signal from the first frequency multiplier and to generate a seventh signal, the seventh signal including a first signal component having a frequency equal to the sum of the fourth frequency and the second frequency and including a second signal component having a frequency equal to the difference between the fourth frequency and the second frequency;

a second filter to receive the seventh signal from the second mixer and to output only one of the first signal component thereof and the second signal component thereof as an eighth signal;

a third mixer to receive the eighth signal from the second filter and the fifth signal from the third frequency multiplier and to generate a ninth signal including a first signal component having a frequency equal to the sum of the eighth frequency and the fifth frequency and including a second signal component having a frequency equal to the difference between the eighth frequency and the fifth frequency; and

a third filter to receive the ninth signal from the third mixer and to output only one of the first signal component thereof and the second signal component thereof as an output of the frequency source.

2. The frequency source of claim 1, wherein the first frequency multiplier comprises:

a times N frequency multiplier to multiply a frequency of a signal inputted thereto by a multiplication factor N and to provide an output corresponding thereto, wherein N is an integer;

a bandpass filter to receive the output of the times N frequency multiplier and to provide a band limited portion thereof as an output; and

a PLL (Phase Locked Loop) to receive the output of the bandpass filter and to provide a signal output of a specified waveform having a frequency bearing a relationship to the frequency of the output of the times N frequency multiplier.

3. The frequency source of claim 2, wherein the second frequency multiplier comprises:

a delay unit to receive a signal inputted thereto and to output a delayed version thereof as an output thereof;

a comb generator to receive the output of the delay unit and to generate an output signal having a plurality of frequency components corresponding to harmonics of the signal inputted thereto; and

a sixth filter to receive an output of the comb generator and to output a selected one of the plurality of frequency components as an output signal thereof.

4. The frequency source of claim 1, wherein the first frequency multiplier comprises:

a fourth filter to receive a signal inputted thereto and to output a band limited portion thereof as an output thereof;

a times N1 frequency multiplier to receive the output of the fourth filter and to multiply its frequency by a multiplication factor N1 and to provide an output corresponding thereto, wherein N1 is an integer;

a fifth filter to receive the output of the times N1 frequency multiplier and to output a band limited portion thereof as an output thereof;

a times N2 frequency multiplier to receive an output of the fifth filter and to multiply its frequency by multiplication factor N2 and to provide an output corresponding thereto, wherein N2 is an integer; and

another filter to receive an output of the times N2 frequency multiplier and to provide a signal output of a specified waveform having a frequency bearing a relationship to the frequency of the output of the times N2 frequency multiplier.

5. The frequency source of claim 4, wherein the second frequency multiplier comprises:

a delay unit to receive a signal inputted thereto and to output a delayed version thereof as an output thereof;

a comb generator to receive the output of the delay unit and to generate an output signal having a plurality of frequency components corresponding to harmonics of the signal inputted thereto; and

a sixth filter to receive an output of the comb generator and to output a selected one of the plurality of frequency components as an output signal thereof.

6. The frequency source of claim 1, wherein the second frequency multiplier comprises:

a delay unit to receive a signal inputted thereto and to output a delayed version thereof as an output thereof;

a comb generator to receive the output of the delay unit and to generate an output signal having a plurality of frequency components corresponding to harmonics of the signal inputted thereto; and

a sixth filter to receive an output of the comb generator and to output a selected one of the plurality of frequency components as an output signal thereof.

7. The frequency source of claim 1, wherein the frequency synthesizer comprises:

a phase locked loop to receive a signal inputted thereto and to output a signal of a predetermined waveform of a frequency which bears a relationship to a frequency of the signal inputted thereto.

8. The frequency source of claim 1, wherein the frequency synthesizer comprises:

a second harmonic PLL to receive a signal inputted thereto and to output a signal of a frequency which bears a relationship to a frequency of the signal inputted thereto; and

a seventh filter to receive the output of the second harmonic PLL and to output a band limited portion thereof as an output said thereof.

9. The frequency source of claim 1, wherein the third frequency multiplier comprises:

a delay unit to receive a signal inputted thereto and to output a delayed version thereof as an output thereof;

a comb generator to receive the output of the delay unit and to generate an output signal having a plurality of frequency components corresponding to harmonics of the signal inputted thereto; and

a eighth filter to receive an output of the comb generator and to output a selected one of the plurality of frequency components as an output signal thereof.

10. A method of operating a frequency source, the method comprising:

generating a first signal of a specified first frequency with a reference frequency source;

receiving the first signal from the reference frequency source and generating a second signal of a specified second frequency with a first frequency multiplier, the second frequency being an integral multiple of the first frequency; and

providing an output of the frequency source from at least two channels, each channel selected from the following group of channels;

a first channel which operates by a method comprising;

receiving the second signal from the first multiplier and generating a third signal of a specified third frequency as an output of the frequency source with a second frequency multiplier, the third frequency being a harmonic of the second frequency;

a second channel which operates by a method comprising;

receiving the first signal from the reference frequency source and generating a fourth signal of a specified fourth frequency with a frequency synthesizer, the fourth frequency bearing a specific relationship to the first frequency;

receiving the second signal from the first frequency multiplier and generating a fifth signal of a specified fifth frequency with a third frequency multiplier, the fifth frequency being a harmonic of the second frequency;

receiving the fourth signal from the frequency synthesizer and the fifth signal from the third frequency multiplier and generating a sixth signal with a first mixer, the sixth signal including a first signal component having a frequency equal to the sum of the fourth frequency and the fifth frequency and including a second signal component having a frequency equal to the difference between the fourth frequency and the fifth frequency; and

receiving the sixth signal from the first mixer and outputting only one of the first signal component thereof and the second signal component thereof as an output of the frequency source with a first filter;

a third channel which operates by a method comprising;

receiving the fourth signal from the frequency synthesizer and the second signal from the first frequency multiplier and generating a seventh signal with a second mixer, the seventh signal including a first signal component having a frequency equal to the sum of the fourth frequency and the second frequency and including a second signal component having a frequency equal to the difference between the fourth frequency and the second frequency;

receiving the seventh signal from the second mixer and outputting only one of the first signal component thereof and the second signal component thereof as an eighth signal with a second filter;

receiving the eighth signal from the second filter and the fifth signal from the third frequency multiplier and generating a ninth signal with a third mixer, the ninth signal including a first signal component having a frequency equal to the sum of the eighth frequency and the fifth frequency and including a second signal component having a frequency equal to the difference between the eighth frequency and the fifth frequency; and

receiving the ninth signal from the third mixer and outputting only one of the first signal component thereof and the second signal component thereof as an output of the frequency source with a third filter.

11. The method of operating a frequency source of claim 10, wherein the first frequency multiplier operates by a method which comprises:

multiplying a frequency of a signal inputted thereto by a multiplication factor N and providing an output corresponding thereto with a Times N frequency multiplier, wherein N is an integer;

receiving the output of the times N frequency multiplier and providing a band limited portion thereof as an output with a bandpass filter; and

receiving the output of the bandpass filter and providing a signal output of a specified waveform having a frequency bearing a relationship to the frequency of the output of the times N frequency multiplier with a PLL (Phase Locked Loop).

12. The method of operating a frequency source of claim 11, wherein the second frequency multiplier operates by a method which comprises:

receiving a signal inputted thereto and outputting a delayed version thereof as an output thereof with a delay unit;

receiving the output of the delay unit and generating an output signal having a plurality of frequency components corresponding to harmonics of the signal inputted thereto with a comb generator; and

receiving an output of the comb generator and outputting a selected one of the plurality of frequency components as an output signal thereof with a sixth filter.

13. The method of operating a frequency source of claim 10, wherein the first frequency multiplier operates by a method which comprises:

receiving a signal inputted thereto and outputting a band limited portion thereof as an output thereof with a fourth filter;

receiving the output of the fourth filter and multiplying its frequency by a multiplication factor N1 and providing an output corresponding thereto with a times N1 frequency multiplier, wherein N1 is an integer;

receiving the output of the times N1 frequency multiplier and outputting a band limited portion thereof as an output thereof with a fifth filter;

receiving an output of the fifth filter and multiplying its frequency by a multiplication factor N2 and providing an output corresponding thereto with a times N2 multiplier, wherein N2 is an integer; and

receiving an output of the times N2 multiplier and providing a signal output of a specified waveform having a frequency bearing a relationship to the frequency of the output of the times N2 frequency multiplier with a filter.

14. The method of operating a frequency source of claim 13, wherein the second frequency multiplier operates by a method which comprises:

receiving a signal inputted thereto and outputting a delayed version thereof as an output thereof with a delay unit;

receiving the output of the delay unit and generating an output signal having a plurality of frequency components corresponding to harmonics of the signal inputted thereto with a comb generator; and

receiving an output of the comb generator and outputting a selected one of the plurality of frequency components as an output signal thereof with a sixth filter.

15. The method of operating a frequency source of claim 10, wherein the second frequency multiplier operates by a method which comprises:

receiving a signal inputted thereto and outputting a delayed version thereof as an output thereof with a a delay unit;

receiving the output of the delay unit and generating an output signal having a plurality of frequency components corresponding to harmonics of the signal inputted thereto with a a comb generator; and

receiving an output of the comb generator and outputting a selected one of the plurality of frequency components as an output signal thereof with an sixth filter.

16. The method of operating a frequency source of claim 10, wherein the frequency synthesizer operates by a method which comprises:

receiving a signal inputted thereto and outputting a signal of a predetermined waveform of a frequency which bears a relationship to a frequency of the signal inputted thereto with a phase locked loop.

17. The method of operating a frequency source of claim 10, wherein the frequency synthesizer operates by a method which comprises:

receiving a signal inputted thereto and outputting a signal of a frequency which bears a relationship to a frequency of the signal inputted thereto with a second harmonic PLL; and

receiving the output of the second harmonic PLL and outputting a band limited portion thereof as an output said thereof with a seventh filter.

18. The method of operating a frequency source of claim 10, wherein the third frequency multiplier operates by a method which comprises:

receiving a signal inputted thereto and outputting a delayed version thereof as an output thereof with a delay unit;

receiving the output of the delay unit and generating an output signal having a plurality of frequency components corresponding to harmonics of the signal inputted thereto with a comb generator; and

receiving an output of the comb generator and outputting a selected one of the plurality of frequency components as an output signal thereof with an eighth filter.

19. A method of operating a frequency source, the method comprising:

generating a first signal of a specified first frequency;

generating a second signal of a specified second frequency, the second frequency being an integral multiple of the first frequency; and

providing an output of the frequency source from at least two channels, each channel selected from the following group of channels;

a first channel which operates by a method comprising generating a third signal of a specified third frequency which is a harmonic of the second frequency;

a second channel which operates by method comprising generating a fourth signal of a specified fourth frequency which is a harmonic of the second frequency and generating a fifth signal of a specified fifth frequency which bears a specific relationship to the first frequency and mixing them to produce a sixth signal of a sixth frequency corresponding to one of the sum or difference therebetween; and

a third channel which operates by method comprising generating a seventh signal of a specified seventh frequency which is a harmonic of the second frequency and generating an eighth signal of a specified eighth frequency which bears a specific relationship to the first frequency and mixing the second and eighth signals to produce a ninth signal of a ninth frequency corresponding to one of the sum or difference therebetween and then mixing the seventh and ninth signals to produce a tenth signal of a tenth frequency corresponding to one of the sum or difference therebetween.

20. The method of claim 19, wherein the first channel operates by a method further comprising delaying the second signal by a predetermined period of time prior to generating the third signal.

21. The method of claim 19, wherein the second channel operates by a method further comprising delaying the second signal by a predetermined period of time prior to generating the fourth signal.

22. The method of claim 19, wherein the third channel operates by a method further comprising delaying the second signal by a predetermined period of time prior to generating the seventh signal.

23. The method of claim 19, wherein the first channel operates by a method further comprising filtering the third signal to eliminate spurious components thereof.

24. The method of claim 19, wherein the second channel operates by a method further comprising filtering the fourth signal to eliminate spurious components thereof.

25. The method of claim 19, wherein the second channel operates by a method further comprising filtering the sixth signal to eliminate spurious components thereof.

26. The method of claim 19, wherein the third channel operates by a method further comprising filtering the seventh signal to eliminate spurious components thereof.

27. The method of claim 19, wherein the third channel operates by a method further comprising filtering the ninth signal to eliminate spurious components thereof.

28. The method of claim 19, wherein the third channel operates by a method further comprising filtering the tenth signal to eliminate spurious components thereof.

29. A frequency source comprising:

a reference frequency source to generate a first signal of a specified first frequency;

a first frequency multiplier to generate a second signal of a specified second frequency which is an integral multiple of the first frequency; and

at least two channels, each channel selected from the following groups of channels;

a first channel to generate a third signal of a specified third frequency which is a harmonic of the second frequency;

a second channel to generate a fourth signal of a specified fourth frequency which is a harmonic of the second frequency and to generate a fifth signal of a specified fifth frequency which bears a specific relationship to the first frequency and to mix them to produce a sixth signal of a sixth frequency corresponding to one of the sum or difference therebetween; and

a third channel to generate a seventh signal of a specified seventh frequency which is a harmonic of the second frequency and to generate an eighth signal of a specified eighth frequency which bears a specific relationship to the first frequency and to mix the second and eighth signals to produce a ninth signal of a ninth frequency corresponding to one of the sum or difference therebetween and to then mix the seventh and ninth signals to produce a tenth signal of a tenth frequency corresponding to one of the sum or difference therebetween.

30. The frequency source of claim 29, wherein the first channel further comprises a delay means to delay the second signal by a predetermined period of time prior to generating the third signal.

31. The frequency source of claim 29, wherein the second channel further comprises a delay means to delay the second signal by a predetermined period of time prior to generating the fourth signal.

32. The frequency source of claim 29, wherein the third channel further comprises a delay means to delay the second signal by a predetermined period of time prior to generating the seventh signal.

33. The frequency source of claim 29, wherein the first channel further comprises a filter to filter the third signal to eliminate spurious components thereof.

34. The frequency source of claim 29, wherein the second channel further comprises a filter to filter the fourth signal to eliminate spurious components thereof.

35. The frequency source of claim 29, wherein the third channel further comprises a filter to filter the seventh signal to eliminate spurious components thereof.

36. The frequency source of claim 29, wherein the third channel further comprises a filter to filter the ninth signal to eliminate spurious components thereof.

37. The frequency source of claim 29, wherein the third channel further comprises a filter to filter the tenth signal to eliminate spurious components thereof.

38. A method of operating a frequency source, the method comprising:

generating a first signal of a specified first frequency; and

providing an output of the frequency source from at least two channels, each channel selected from the following group of channels;

a first channel which operates by a method comprising generating a second signal of a specified second frequency which is a harmonic of the first frequency;

a second channel which operates by method comprising generating a third signal of a specified third frequency which is a harmonic of the first frequency and generating a fourth signal of a specified fourth frequency which bears a specific relationship to the first frequency and mixing them to produce a fifth signal of a fifth frequency corresponding to one of the sum or difference therebetween; and

a third channel which operates by method comprising generating a sixth signal of a specified sixth frequency which is a harmonic of the first frequency and generating an seventh signal of a specified seventh frequency which bears a specific relationship to the first frequency and mixing the first and seventh signals to produce an eighth signal of an eighth frequency corresponding to one of the sum or difference therebetween and then mixing the sixth and eighth signals to produce a ninth signal of a ninth frequency corresponding to one of the sum or difference therebetween.

39. The method of claim 38, wherein the first channel operates by a method further comprising delaying the first signal by a predetermined period of time prior to generating the second signal.

40. The method of claim 38, wherein the second channel operates by a method further comprising delaying the first signal by a predetermined period of time prior to generating the third signal.

41. The method of claim 38, wherein the third channel operates by a method further comprising delaying the first signal by a predetermined period of time prior to generating the sixth signal.

42. The method of claim 38, wherein at least one of the first, second, and third channels operates by a method further comprising providing filtering to eliminate spurious signal components.

43. A frequency source comprising:

a reference frequency source to generate a first signal of a specified first frequency; and

at least two channels, each channel selected from the following groups of channels;

a first channel to generate a second signal of a specified second frequency which is a harmonic of the first frequency;

a second channel to generate a third signal of a specified third frequency which is a harmonic of the second frequency and to generate a fourth signal of a specified fourth frequency which bears a specific relationship to the first frequency and to mix them to produce a fifth signal of a fifth frequency corresponding to one of the sum or difference therebetween; and

a third channel to generate a sixth signal of a specified sixth frequency which is a harmonic of the first frequency and to generate a seventh signal of a specified seventh frequency which bears a specific relationship to the first frequency and to mix the first and seventh signals to produce an eighth signal of an eighth frequency corresponding to one of the sum or difference therebetween and to then mix the sixth and eighth signals to produce a ninth signal of a ninth frequency corresponding to one of the sum or difference therebetween.

44. The frequency source of claim 43, wherein the first channel further comprises a delay means to delay the first signal by a predetermined period of time prior to generating the second signal.

45. The frequency source of claim 43, wherein the second channel further comprises a delay means to delay the first signal by a predetermined period of time prior to generating the third signal.

46. The frequency source of claim 43, wherein the third channel further comprises a delay means to delay the first signal by a predetermined period of time prior to generating the sixth signal.

47. The frequency source of claim 43, wherein at least one of the first, second, and third channels further comprises a filter to eliminate spurious signal components.