Optically interleaved photonic analog to digital converters

• US 9,197,471 B1
• Filed: 09/10/2013
• Issued: 11/24/2015
• Est. Priority Date: 08/05/2011
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Original Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Inventors: Zanoni, Raymond, Jepsen, Kim S., King, Oliver S., Laliberte, Mark A.
• Primary Examiner(s): Bello, Agustin
• Application Number:
  US14/023,338
• Time in Patent Office: 805 Days
• Field of Search: 398202-214
• US Class Current: 1/1
• CPC Class Codes: H04B 10/90 Non-optical transmission systems, e.g. transmission systems employing non-photonic corpuscular radiation
• CPC Class Codes: H04B 2210/006 Devices for generating or processing an RF signal by optical means
• CPC Class Codes: H04L 27/223 Demodulation in the optical domain optical demodulation H04B10/676

Abstract

A method of and system of processing a phase-modulated optical signal includes performing, by demodulators, demodulation of the phase-modulated optical signal and outputting optical demodulated signals. The processing further includes performing, by pairs of gated photo detectors respectively connected to the I/Q demodulators, photo detection of the demodulated signals. The processing further tracks and holds electronicversions of the demodulated signals with a track and hold amplifier.

Claims

1. A processor, comprising:

a phase modulator the photonic processor configured to receive a first electronic signal and an optical reference signal and provide a phase modulated optical pulse signal;

an array of signal optical switches for receiving the phase modulated optical pulse signal and providing a set of time deinterleaved sampled phase modulated optical pulse signals;

an array of reference optical switches for receiving a reference pulse signal and providing a set of reference time deinterleaved reference pulse signals;

an array of optical demodulators each configured to receive a respective time deinterleaved phase modulated optical pulse signal of the time deinterleaved sampled phase modulated optical pulse signals on a respective signal path and a respective time deinterleaved reference pulse signal of the time de-interleaved reference pulse signals on a respective reference path, wherein each of the demodulators is configured to perform demodulation and to provide a respective optical demodulated signal;

an array of photoconverters each configured to receive the respective optical demodulated signal and to provide a respective second electronic signal corresponding to the respective optical demodulated signal; and

an array of track and hold amplifiers each for receiving the second respective electric signal and providing a respective deinterleaved electronic signal.

2. The processor according to claim 1, further comprising:

a clock generator configured to provide timing signals to the track and hold amplifiers.

3. The processor according to claim 2, wherein each of the photo detectors is at least one pair of photo detectors configured to detect the optical demodulated signal, the optical demodulated signal being a respective I demodulated signal and a respective Q demodulated signal.

4. The processor according to claim 3, further comprising at least one set of quantizers respectively receiving the respective second electronic signal.

5. The processor according to claim 1, wherein the signal path and the reference path are separate paths that do not directly intersect or directly connect with each other.

6. The photonic processor according to claim 1, wherein optical switches are provided between phase modulator and the signal path and no optical switches are provided between the optical demodulator and the signal path.

7. A method of quantization, the method comprising:

performing phase modulation and providing a phase-modulated optical pulse signal;

performing inphase/quadrature demodulation of the phase-modulated optical signal to provide an optical demodulated signal using deinterleaved signals provided by an array of optical switches;

converting the optical demodulated signal to an electronic signal; and

tracking and holding the electronic signal for reception by an electronic quantizer.

8. The method according to claim 7, wherein the converting step uses pairs of gated photo detectors performing photo detection of a respective I demodulated signal and a respective Q demodulated signal of the demodulated signal.

9. The method according to claim 8, wherein the tracking and holding step uses pairs of track and hold amplifiers.

10. The method according to claim 9, wherein the method deinterleaves the phase-modulated optical pulse signal.

11. The method according to claim 7, wherein a signal path receives the phase modulated optical signal and a reference path receives an optical clock signal, the signal path and the reference paths are separate paths that do not directly intersect or directly connect with each other.

12. The method according to claim 7, wherein the phase modulation uses a radio frequency electronic signal and a reference optical clock signal.

13. A photonic processor, comprising:

a phase modulator configured to receive an electronic radio frequency signal and an optical clock signal and to provide a phase-modulated optical signal;

an array of signal optical switches for receiving the phase modulated optical pulse signal and proving a set of time deinterleaved sampled phase modulated optical pulse signals;

a set of demodulators each configured to receive a respective time deinterleaved sampled phase modulated optical pulse signal of the time deinterleaved sampled phase modulated optical pulse signals from respective signal optical switches, and to perform demodulation the phase-modulated optical signal in response to an optical clock signal received on a reference path, wherein the demodulators provide respective optical first demodulated signals and respective optical second demodulated signals; and

a set of first and second photodetectors configured to receive respectively the optical first demodulated signal and the optical second demodulated signal and to provide an electronic first demodulated signal and an electronic second demodulated signal; and

a set of track and hold amplifiers configured to receive respective electronic first demodulated signals and respective second demodulated signals.

14. The photonic processor according to claim 13, further comprising:

a set of first and second electronic quantizers coupled to the first and second track and hold amplifiers, respectively, and configured to perform electronic quantization of the electronic first demodulated signal and the electronic second demodulated signal from the track and hold amplifiers respectively as first and second digital signals.

15. The photonic processor according to claim 13, wherein the first and second photo detectors are balanced.

16. The photonic processor according to claim 15, wherein a number of sets is four.

17. The photonic processor according to claim 13, further comprising:

an optical clock configured to output the optical clock signal to the phase modulator and to the reference path, wherein the phase modulator performs phase modulation of the optical signal at timings corresponding to the optical clock signal.

18. The photonic processor according to claim 13, wherein a signal path for the phase-modulated optical signal is not optically switched on the signal path.

19. The photonic processor of according to claim 18 further comprising a set of eADCS coupled to respective track and hold amplifiers.

20. The photonic processor of according to claim 19 further comprising a timing circuit coupled to the track and hold amplifiers for deinterleaving the electronic first and second demodulated signals.

21. A method of processing an analog signal, the method comprising:

providing at least a first optical signal and an optical reference signal;

optically sampling the analog signal with the first optical signal using a phase modulator to produce a sampled optical signal;

receiving the sampled optical signal at one of a plurality of optical signal switches to time deinterleave the sampled optical signal into a first time deinterleaved optically sampled signal and a second time deinterleaved optically sampled signal;

receiving the optical reference signal at one of a plurality of optical reference switches to time deinterleave the optical reference signal into a first time deinterleaved optical reference signal and a second time deinterleaved optical reference signal; and

receiving at least one of the first time deinterleaved optically sampled signal and the second time deinterleaved optically sampled signal and at least one of the first time deinterleaved optical reference signal and the second time deinterleaved optical reference signal at a one of a plurality of signal processors, the signal processors performing optical demodulation.