Method and apparatus for reducing re-radiation using techniques of universal frequency translation technology

• US 7,224,749 B2
• Filed: 12/13/2002
• Issued: 05/29/2007
• Est. Priority Date: 04/16/1999
• Status: Expired due to Term

• Current Assignee: ParkerVision, Inc.
• Original Assignee: ParkerVision, Inc.
• Inventors: Rawlins, Michael W, Rawlins, Gregory S, Sorrells, David F, Moses, Charley D Jr., Looke, Richard C, Bultman, Michael J, Cook, Robert W
• Primary Examiner(s): Bocure; Tesfaldet
• Assistant Examiner(s): PANWALKAR, VINEETA S
• Application Number:
  US10/318,207
• Publication Number:
  US 20040002321A1
• Time in Patent Office: 1,628 Days
• Field of Search: 375/371, 375/130, 375/316, 375/147, 375/219, 375/238, 375/339, 375/296, 375/136, 375/140, 375/148, 375/358, 375/377, 455/313, 455/318, 455/323, 455/296, 455/208, 455/205, 329/302, 329/323, 329/346, 329/358, 329/359
• US Class Current: 375/316
• CPC Class Codes: H03C 3/40 using two signal paths the outputs of which have a predetermined phase difference and at least one output being amplitude-modulated
• CPC Class Codes: H03D 3/006 by sampling the oscillations and further processing the samples, e.g. by computing techniques H03D3/007 takes precedence
• CPC Class Codes: H03D 7/00 Transference of modulation from one carrier to another, e.g. frequency-changing H03D9/00, H03D11/00 take precedence; dielectric amplifiers, magnetic amplifiers, parametric amplifiers used as a frequency-changers H03F
• CPC Class Codes: H04B 1/12 Neutralising, balancing, or compensation arrangements
• CPC Class Codes: H04B 1/123 using adaptive balancing or compensation means adaptive filter circuits and algorithms H03H
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04B 1/30 for homodyne or synchrodyne receivers demodulator circuits H03D1/22

Abstract

Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal, and applications thereof are described herein. Reducing or eliminating DC offset voltages and re-radiation generated when down-converting an electromagnetic (EM) signal is also described herein. Down-converting a signal and improving receiver dynamic range is also described herein.

Claims

1. An apparatus for down-converting an electromagnetic signal and reducing circuit re-radiation, comprising:

a frequency down-conversion module that receives an input signal, wherein said frequency down-conversion module down-converts said input signal according to a control signal to a down-converted signal, wherein said control signal comprises a train of pulses having pulse widths;

wherein a signal related to said control signal is re-radiated;

wherein an increase of said pulse widths decreases a frequency of said re-radiated signal.

2. The apparatus of claim 1, wherein said pulse widths are approximately equal to 180+360×

n degrees of a frequency of said input signal, wherein n is an integer.

3. The apparatus of claim 2, wherein as n increases, a frequency of said re-radiated signal decreases.

4. The apparatus of claim 1, wherein said frequency down-conversion module under-samples said input signal according to said control signal.

5. The apparatus of claim 1, wherein said frequency down-conversion module comprises a switch and a storage element, wherein a first node of said storage element is coupled to a node of said switch, and a second node of said storage element is coupled to a reference potential.

6. The apparatus of claim 1, wherein said frequency down-conversion module comprises a switch and a storage element, wherein a first node of said switch is coupled to a node of said storage element, and a second node of said switch is coupled to a reference potential.

7. The apparatus of claim 1, further comprising a control signal generator that outputs said control signal.

8. The apparatus of claim 1, wherein the control signal comprises a pseudo-random noise (PN) code to reduce DC offset due to said re-radiated signal.

9. The apparatus of claim 8, wherein the PN code is a maximal length code or a balanced code.

10. The apparatus of claim 1, wherein the control signal further comprises:

an I-phase control signal and a Q-phase control signal, wherein the I-phase control signal and the Q-phase control signal do not overlap.

11. The apparatus of claim 1 further comprising of:

a second control signal used as a placebo to move potentially harmful circuit noise and re-radiated components to a non-critical frequency band.

12. The apparatus of claim 1, wherein the control signal is split into a set of two components that are mutually shifted by π

-radians forming a series of adjacent apertures used to reduce circuit re-radiation.

13. A method of down-converting an electromagnetic signal and reducing circuit re-radiation, comprising the steps of:

(1) frequency down-converting an input signal according to a control signal comprising a train of pulses having pulse widths, wherein a signal related to the control signal is re-radiated; and

(2) increasing the pulse widths to decrease a frequency of the re-radiated signal.

14. The method of claim 13, wherein step (2) comprises the step of:

(A) selecting the pulse widths according to the equation;

pulse width=180+360×

n degrees;

wherein n is any integer≧

zero; and

wherein as n is increased, a frequency of said re-radiated signal is decreased.

15. The method of claim 13, wherein the step of frequency down- converting using the control signal comprises using a pseudo-random noise (PN) code to reduce DC offset due to said re-radiated signal.

16. An apparatus for down-converting an electromagnetic signal and altering the frequency spectrum of potential circuit re-radiation, comprising:

a first frequency down-conversion module;

a second frequency down-conversion module, wherein said first frequency down-conversion module and said second frequency down-conversion module receive an input signal;

a control signal generator that outputs a control signal, wherein said control signal is received by said first frequency down-conversion module; and

a first phase shifter that receives said control signal, and outputs a phase-shifted control signal, wherein said phase-shifted control signal is received by said second frequency down-conversion module;

wherein said first frequency down-conversion module outputs a first down-converted signal;

wherein said second frequency down-conversion module outputs a second down-converted signal; and

wherein a re-radiated signal is a function of at least said control signal and said phase-shifted control signal.

17. The apparatus of claim 16, wherein said first frequency down-conversion module under-samples said input signal according to said control signal, and wherein said second frequency down-conversion module under-samples said input signal according to said phase-shifted control signal.

18. The apparatus of claim 16, wherein said first and said second frequency down-conversion modules each comprise a switch and a storage element, wherein a first node of said switch is coupled to a node of said storage element, and a second node of said switch is coupled to a reference potential.

19. The apparatus of claim 16, wherein said first and second frequency down-conversion modules each comprise a switch and a storage element, wherein a first node of said storage element is coupled to a node of said switch, and a second node of said storage element is coupled to a reference potential.

20. The apparatus of claim 16, wherein pulses of said control signal occur every 360+360×

n degrees of a frequency of said input signal, wherein n is equal to any integer greater than or equal to 0.

21. The apparatus of claim 16, wherein pulses of said control signal are of width m degrees, wherein said first phase shifter shifts said phase-shifted control signal in a range between 0 degrees and 360+360×

n degrees relative to said control signal, where n is any integer greater or equal to 0.

22. The apparatus of claim 16, wherein pulses of said control signal are of width m degrees, wherein said first phase shifter shifts said phase-shifted control signal in a range between m degrees and 360−

m+360×

n degrees relative to said control signal, where m and n are integers greater or equal to 0.

23. The apparatus of claim 16, wherein said phase-shifted control signal is phase shifted relative to said control signal in order to adjust at least one frequency of said re-radiated signal.

24. The apparatus of claim 23, wherein said phase-shifted control signal is phase shifted relative to said control signal in order to adjust at least one frequency of said re-radiated signal to be above a frequency range of interest of said input signal.

25. The apparatus of claim 16, wherein pulses of said control signal and pulses of said phase-shifted control signal have widths less than or equal to 180+360+n degrees of a frequency of said input signal, wherein n is any integer greater than or equal to 0.

26. The apparatus of claim 24, wherein said first phase shifter shifts said phase-shifted control signal by 180+360×

n degrees of a frequency of said input signal relative to said control signal.

27. The apparatus of claim 26, wherein said pulses of said control signal are substantially adjacent to said pulses of said phase-shifted control signal.

28. The apparatus of claim 27, wherein said re-radiated signal is a function of said control signal and said phase-shifted control signal, and wherein a noise spike in said re-radiated signal exists at a transition of said adjacent pulses of said control signal and said phase-shifted control signal.

29. The apparatus of claim 22, wherein a voltage amplitude of said noise spike approaches zero as said pulses of said control signal and said pulses of said phase-shifted control signal approach 180+360×

n degrees of a frequency of said input signal in width.

30. The apparatus of claim 29, wherein at least one frequency of said noise spike is above a frequency range of interest of said input signal.

31. An apparatus for down-converting an electromagnetic signal and altering the frequency spectrum of potential circuit re-radiation, comprising:

at least one frequency down-conversion module; and

at least one phase shifter each corresponding to one of said at least one frequency down-conversion module;

wherein said at least one frequency down-conversion module receives an input signal;

wherein a first of said at least one phase shifter receives a control signal and outputs a phase shifted control signal;

wherein at least one further of said at least one phase shifter receives a phase-shifted control signal output by another of said at least one phase shifter and outputs a further phase-shifted control signal;

wherein a first of said at least one frequency down-conversion module receives said control signal and outputs a corresponding down-converted signal;

wherein at least one further of said at least one frequency down-conversion module receives one of said phase-shifted control signals and outputs a corresponding down-converted signal; and

wherein a re-radiated signal is a function of at least said control signal and said phase-shifted control signals.

32. The apparatus of claim 31, wherein pulses of said control signal and pulses of said phase-shifted control signals have widths less than or equal to 180+360×

n degrees of a frequency of said input signal, where n is any integer ≧

zero.

33. The apparatus of claim 31, wherein said at least one phase shifter shifts a corresponding control signal by 180+360×

n degrees of a frequency of said input signal, where n is any integer ≧

zero.

34. The apparatus of claim 31, wherein said re-radiated signal approximates a DC voltage level.

41. The method of claim 31, wherein the pulses have widths less than or equal to 180+360×

n degrees of a frequency of the input signal, wherein n is any integer greater than or equal to 0.

47. The method of claim 41, wherein as the pulse widths approach 180+360×

n degrees of a frequency of the input signal, the re-radiated signal approaches a DC level, where n is equal to any integer greater or equal 0.

35. A method of down-converting an electromagnetic signal and altering circuit re-radiation, comprising the steps of:

(1) frequency down-converting an input signal to generate a first down-converted signal according to a control signal;

(2) phase-shifting the control signal; and

(3) frequency down-converting the input signal to generate a second down-converted signal according to the phase-shifted control signal;

wherein a signal that is at least a function of the control signal and the phase-shifted control signal is re-radiated.

36. The method of claim 35, wherein step (1) comprises generating a train of pulses, wherein pulses of the control signal occur every 360+360×

n degrees of a frequency of the input signal, wherein n is equal to any integer greater or equal 0.

37. The method of claim 35, wherein step (2) comprises the step of:

phase shifting the control signal in a range between 0 degrees and 360+360×

n degrees of a frequency of the input signal, wherein n is equal to any integer greater or equal 0.

38. The method of claim 36, wherein the pulses are of width m degrees, and wherein step (2) comprises the step of:

phase shifting the control signal in a range between m degrees and 360−

m+360×

n degrees of a frequency of the input signal, where m and n are integers greater or equal to 0.

39. The method of claim 35, wherein step (2) comprises the step of:

phase shifting the control signal to a phase-shifted control signal in order to adjust at least one frequency of the re-radiated signal.

40. The method of claim 35, wherein step (2) comprises the step of:

phase shifting the control signal to a phase-shifted control signal in order to adjust at least one frequency of the re-radiated signal to be above a frequency range of interest of the input signal.

42. The method of claim 35, wherein step (2) comprises the step of:

phase shifting the control signal by 180+360×

n degrees of a frequency of the input signal, wherein n is equal to any integer greater or equal 0.

43. The method of claim 42, wherein pulses of the control signal are substantially adjacent to pulses of the phase-shifted control signal.

44. The method of claim 43, wherein step (3) comprises the step of:

(A) forming a spike in the re-radiated signal at a transition of the adjacent pulses of the control signal and the phase-shifted control signal.

45. The method of claim 44, wherein a voltage amplitude of the spike approaches zero as the pulses of the control signal and the pulses of the phase-shifted control signal approach 180+360×

n degrees in width, where n is equal to any integer greater or equal 0.

46. The method of claim 45, wherein step (3)(A) comprises the step of:

forming the spike in the re-radiated signal, wherein that at least one frequency of the spike is above a frequency range of interest of the input signal.

48. The method of claim 35, further comprising the steps of:

(4) phase-shifting the phase-shifted control signal to a further phase-shifted control signal; and

(5) frequency down-converting the input signal to a corresponding down-converted signal, wherein the input signal is down-converted according to the further phase-shifted control signal;

wherein a signal that is a function of at least the control signal and the phase-shifted control signals is re-radiated.

49. The method of claim 48, further comprising the step of:

(6) repeating steps (4) and (5) x times, wherein x is equal to any integer greater than or equal to 0.

50. The method of claim 48, wherein pulses of the control signal and pulses of each phase-shifted control signal have widths less than or equal to 180+360×

n degrees of a frequency of the input signal, wherein n is equal to any integer greater or equal 0.

51. The method of claim 48, wherein step (4) comprises the step of phase shifting the phase-shifted control signal by 180+360×

n degrees of a frequency of said input signal, wherein n is equal to any integer greater or equal 0.

52. The method of claim 49, wherein the re-radiated signal that is a function of at least the control signal and the phase-shifted control signals approximates a DC voltage level.