Methods and systems for continuous-time digital modulation

• US 20090096650A1
• Filed: 12/06/2005
• Published: 04/16/2009
• Est. Priority Date: 12/07/2004
• Status: Abandoned Application

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Tsividis, Yannis
• Application Number:
  US11/792,354
• Publication Number:
  US 20090096650A1
• Time in Patent Office: Days
• US Class Current: 341/155
• CPC Class Codes: H03C 1/36 by means of semiconductor device having at least three electrodes H03C1/34, H03C1/50, H03C1/52, H03C1/62 take precedence
• CPC Class Codes: H03M 1/361 having a separate comparator and reference value for each quantisation level, i.e. full flash converter type

Abstract

Methods and systems for modulating (508) a radio frequency signal by a continuous-time signal are presented. More particularly, techniques and systems for converting an analog signal (202) to a continuous-time digital signal and using this continuous-time digital signal (204) to modulate (508) a radio-frequency signal in continuous-time are provided. This may be accomplished through the use of a continuous-time analog-to-digital converter (204). When modulating the continuous-time digital signal (508), various kinds of modulation may be utilized such as amplitude, frequency, phase, and/or any combination of the three (508). In some embodiments, a digital signal processor may be added to the system to process the continuous-time digital signal (506).

Claims

1. An apparatus for modulating an input signal, comprising:

a continuous-time analog-to-digital converter that simultaneously produces two or more continuous-time digital signals; and

a digital input signal modulator coupled to the continuous-time analog-to-digital converter that produces a modulated output in response to the two or more continuous-time digital signals.

2. The apparatus of claim 1, wherein the continuous-time analog-to-digital converter further comprises an output logic device that encodes the two or more continuous-time digital signals.

3. The apparatus of claim 2, wherein the output logic device produces continuous-time binary digital signals.

4. The apparatus of claim 1, further comprising:

a power amplifier controlled by the two or more of continuous-time digital signals; and

a RF source coupled to the power amplifier.

5. The apparatus of claim 1, further comprising a digital signal processor coupled between the continuous-time analog-to-digital converter and the digital input signal modulator.

6. The apparatus of claim 1, wherein the continuous-time analog-to-digital converter includes two or more level detectors that each compare the input signal to two or more thresholds to simultaneously produce two or more continuous-time digital signals.

7. A method for modulating an input signal, comprising:

comparing in continuous-time the input signal to two or more thresholds;

producing simultaneously two or more intermediate signals based on the two or more thresholds;

encoding the two or more intermediate signals into a continuous-time digital output; and

producing a modulated signal based on the values of the continuous-time digital output.

8. The method of claim 7, wherein the continuous-time digital output is a binary based continuous-time digital signal.

9. The method of claim 7, wherein the two or more intermediate signals are produced using a comparator.

10. The method of claim 7, further comprising processing the continuous-time digital output.

11. The method of claim 10, wherein the processing is implemented through a digital signal processor.

12. The method of claim 7, wherein producing a modulated signal involves frequency-shift keying.

13. The method of claim 7, wherein comparing in continuous-time the input signal includes using two or more level detectors.

14. An apparatus for modulating an input signal, comprising:

a means for simultaneously producing two or more continuous-time digital signals in response to the input signal; and

a means for receiving and modulating the two or more of continuous-time digital signals and producing a modulated output.

15. The apparatus of claim 14, wherein the means for converting also encodes an intermediate signal to produce the two or more continuous-time digital signals.

16. The apparatus of claim 15, wherein the two or more continuous-time digital signals are continuous-time binary digital signals.

17. The apparatus of claim 14, wherein the means for modulating comprises:

a means for amplifying that is controlled by the two or more continuous-time digital signals; and

a means for producing an RF signal that is coupled to the means for amplifying.

18. The apparatus of claim 14, further comprising a means for digital signal processing coupled between the means for converting and the means for modulating.

19. The apparatus of claim 14, wherein the means for simultaneously producing includes two or more level detectors.