Continuous-time delta-sigma modulator with small distributed resonators

• US 7,928,877 B1
• Filed: 07/23/2008
• Issued: 04/19/2011
• Est. Priority Date: 07/23/2008
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Kaplan, Todd
• Primary Examiner(s): YOUNG, BRIAN K
• Application Number:
  US12/178,536
• Time in Patent Office: 1,000 Days
• Field of Search: 341/143, 341/144, 341/145
• US Class Current: 341/143
• CPC Class Codes: H03M 3/404 characterised by the type of bandpass filters used
• CPC Class Codes: H03M 3/43 the quantiser being a single bit one
• CPC Class Codes: H03M 3/454 with distributed feedback, i.e. with feedback paths from the quantiser output to more than one filter stage

Abstract

A continuous time delta-sigma modulator having a sampling frequency includes a distributed resonator having a length about equal to a reciprocal of an integer times a velocity of a signal in the distributed resonator divided by twice the sampling frequency of the continuous time delta-sigma modulator.

Claims

1. A continuous time delta-sigma modulator having a sampling frequency, the continuous time delta-sigma modulator comprising:

a distributed resonator having a length about equal to a reciprocal of an integer times a velocity of a signal in the distributed resonator divided by twice the sampling frequency of the continuous time delta-sigma modulator;

wherein the integer is greater than one.

2. The continuous time delta-sigma modulator of claim 1 wherein the distributed resonator is a transmission line.

3. The continuous time delta-sigma modulator of claim 2 wherein one end of the transmission line is open.

4. The continuous time delta-sigma modulator of claim 2 wherein one end of the transmission line is shorted or grounded.

5. The continuous time delta-sigma modulator of claim 1 wherein the distributed resonator is a transverse electromagnetic (TEM) resonator.

6. The continuous time delta-sigma modulator of claim 1 wherein the velocity of the signal in the distributed resonator is a function of a dielectric constant of the distributed resonator.

10. The method of claim 6 wherein one end of the transmission line is shorted or grounded.

7. A method for providing a continuous time delta-sigma modulator having a sampling frequency, the method comprising:

providing a distributed resonator in the continuous time delta-sigma modulator, the distributed resonator having a length about equal to a reciprocal of an integer times a velocity of a signal in the distributed resonator divided by twice the sampling frequency of the continuous time delta-sigma modulator;

wherein the integer is greater than one.

8. The method of claim 7 wherein the distributed resonator is a transmission line.

9. The method of claim 8 wherein one end of the transmission line is open.

11. The method of claim 7 wherein the distributed resonator is a transverse electromagnetic (TEM) resonator.

12. The method of claim 7 wherein the velocity of the signal in the distributed resonator is a function of a dielectric constant of the distributed resonator.

13. A continuous time delta-sigma modulator having a sampling frequency, the continuous time delta-sigma modulator comprising:

a transmission line having a length about equal to a reciprocal of an integer times a velocity of a signal in the transmission line divided by twice the sampling frequency of the continuous time delta-sigma modulator;

wherein the integer is greater than one.

14. The continuous time delta-sigma modulator of claim 13 wherein one end of the transmission line is open.

15. The continuous time delta-sigma modulator of claim 13 wherein one end of the transmission line is grounded.

16. The continuous time delta-sigma modulator of claim 13 wherein one end of the transmission line is shorted.

17. The continuous time delta-sigma modulator of claim 13 wherein the velocity of the signal in the transmission line is a function of a dielectric constant of the transmission line.

18. A continuous time delta-sigma modulator having a sampling frequency, the continuous time delta-sigma modulator comprising:

a transmission line having a length equal to a reciprocal of an integer times one-half a velocity of a signal in the transmission line divided by a desired resonance frequency;

wherein the integer is greater than one.

19. The continuous time delta-sigma modulator of claim 18 wherein one end of the transmission line is open.

20. The continuous time delta-sigma modulator of claim 18 wherein one end of the transmission line is grounded.

21. A resonator comprising:

a transmission line having a length equal to a reciprocal of an integer times one-half a velocity of a signal in the transmission line divided by a desired resonance frequency;

wherein the integer is greater than one; and

wherein a velocity of a signal in the transmission line is a function of a dielectric constant of the transmission line.

22. A continuous time delta-sigma modulator having a sampling frequency, the continuous time delta-sigma modulator comprising:

a distributed resonator having a length equal to a reciprocal of an integer times one-half a velocity of a signal in the distributed resonator divided by a desired resonance frequency;

wherein the integer is greater than one.

23. The continuous time delta-sigma modulator of claim 22 wherein one end of the distributed resonator is open.

24. The continuous time delta-sigma modulator of claim 22 wherein one end of the distributed resonator is grounded.