Method and apparatus for microwave signal generation that uses polarization selective photonic mixing

• US 6,262,681 B1
• Filed: 09/09/1999
• Issued: 07/17/2001
• Est. Priority Date: 09/09/1999
• Status: Expired due to Term

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Persechini, David L.
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US09/393,106
• Time in Patent Office: 677 Days
• Field of Search: 359/142, 359/145, 359/154, 359/168, 359/173, 359/180, 359/188-195, 385/1-15, 385/39, 385/42, 385/88-94, 385/24, 372/9, 372/18, 372/19, 372/26, 372/27, 372/28, 331/184-187, 331/94.1, 342/52, 342/54, 342/104, 342/165, 342/169-175, 342/188, 342/361-377, 342/167
• US Class Current: 342/188
• CPC Class Codes: G02F 2/002 using optical mixing
• CPC Class Codes: H03D 9/06 Transference of modulation using distributed inductance and capacitance
• CPC Class Codes: H03L 7/07 using several loops, e.g. for redundant clock signal generation

Abstract

A method and apparatus for generating microwave signal frequencies. An incident reference signal is provided. A first stimulus signal is also provided, the first stimulus signal having a first polarization and having a first predetermined relationship with the incident reference signal. A second stimulus signal is also provided, the second stimulus signal having a second polarization and having a second predetermined relationship with the incident reference signal. The incident reference signal is split into a first polarization reference signal and into a second polarization reference signal. The first stimulus signal is coupled with the first polarization reference signal to provide first polarization mixed signals. The second stimulus signal is coupled with the second polarization reference signal to provide second polarization mixed signals. The first polarization mixed signals are combined with the second polarization mixed signals to provide output signals having only a first component signal at the first predetermined relationship with the incident reference signal and a second component signal at the second predetermined relationship with the incident reference signal. The first predetermined relationship with the incident reference signal is provided by a first phase lock loop and the second predetermined relationship with the incident reference signal is provided by a second phase lock loop.

Claims

1. A method of microwave frequency signal generation comprising the steps of:

providing an incident reference signal;

providing a first stimulus signal, the first stimulus signal having a first polarization and having a first predetermined relationship with the incident reference signal;

providing a second stimulus signal, the second stimulus signal having a second polarization and having a second predetermined relationship with the incident reference signal;

splitting the incident reference signal into a first polarization reference signal and into a second polarization reference signal;

coupling the first stimulus signal with the first polarization reference signal to provide first polarization mixed signals;

coupling the second stimulus signal with the second polarization reference signal to provide second polarization mixed signals; and

combining the first polarization mixed signals with the second polarization mixed signals to provide output signals having only;

a first component signal at the first predetermined relationship with the incident reference signal, and

a second component signal at the second predetermined relationship with the incident reference signal.

2. The method of microwave frequency signal generation of claim 1, wherein the first predetermined relationship with the incident reference signal is provided by a first phase lock loop and the second predetermined relationship with the incident reference signal is provided by a second phase lock loop.

3. The method of microwave frequency signal generation of claim 2, wherein the first phase lock loop:

couples a portion of the first stimulus signal and a portion of the first polarization reference signal to provide a first phase lock loop difference signal;

compares the first phase lock loop difference signal with a first predetermined difference reference signal to provide a first difference correction signal; and

tunes the first stimulus signal by the first difference correction signal to maintain the first predetermined relationship with the incident reference signal.

4. The method of microwave frequency signal generation of claim 2, wherein the second phase lock loop:

couples a portion of the second stimulus signal and a portion of the second polarization reference signal to provide a second phase lock loop difference signal;

compares the second phase lock loop difference signal with a second predetermined difference reference signal to provide a second difference correction signal; and

tunes the second stimulus signal by the second difference correction signal to maintain the second predetermined relationship with the incident reference signal.

5. The method of microwave frequency signal generation of claim 1, wherein the first polarization is horizontal and the second polarization is vertical.

6. A method of microwave frequency signal generation comprising the steps of:

providing an incident reference signal;

providing a first stimulus signal, the first stimulus signal having a first polarization and having a first predetermined relationship with the incident reference signal;

providing a second stimulus signal, the second stimulus signal having a second polarization and having a second predetermined relationship with the incident reference signal;

splitting the incident reference signal into a first reference signal and into a second reference signal;

coupling the first stimulus signal with the first reference signal to provide first polarization mixed signals; and

combining the first polarization mixed signals with the second stimulus signal to provide output signals having only;

a first component signal at the first predetermined relationship with the incident reference signal, and

a second component signal at the second predetermined relationship with the incident reference signal.

7. The method of microwave frequency signal generation of claim 6, wherein the first predetermined relationship with the incident reference signal is provided by a first phase lock loop and the second predetermined relationship with the incident reference signal is provided by a second phase lock loop.

8. The method of microwave frequency signal generation of claim 7, wherein the first phase lock loop:

couples a portion of the first stimulus signal and a portion of the first reference signal to provide a first phase lock loop difference signal;

compares the first phase lock loop difference signal with a first predetermined difference reference signal to provide a first difference correction signal; and

tunes the first stimulus signal by the first difference correction signal to maintain the first predetermined relationship with the incident reference signal.

9. The method of microwave frequency signal generation of claim 7, wherein the second phase lock loop:

couples a portion of the second stimulus signal and a portion of the second reference signal to provide a second phase lock loop difference signal;

compares the second phase lock loop difference signal with a second predetermined difference reference signal to provide a second difference correction signal; and

tunes the second stimulus signal by the second difference correction signal to maintain the second predetermined relationship with the incident reference signal.

10. The method of microwave frequency signal generation of claim 6, wherein:

the first polarization is horizontal;

the second polarization is vertical; and

the incident reference signal, the first reference signal, and the second reference signal are each at 45°

polarization.

11. A microwave frequency signal generation system comprising:

a reference source for providing an incident reference signal;

a first source for providing a first stimulus signal, the first stimulus signal having a first polarization and having a first predetermined relationship with an incident reference signal generated by the first source;

a second source for providing a second stimulus signal having a second polarization and having a second predetermined relationship with the incident reference signal;

a first splitter coupled to the reference source for receiving and splitting the incident reference signal into a first polarization reference signal and into a second polarization reference signal;

a second splitter coupled to the first splitter for coupling the first stimulus signal with the first polarization reference signal to provide first polarization mixed signals;

a third splitter coupled to the first splitter for coupling the second stimulus signal with the second polarization reference signal to provide second polarization mixed signals; and

a fourth splitter coupled to the second splitter and to the third splitter for combining the first polarization mixed frequency signals with the second polarization mixed frequency signals to provide output signals having only;

a first component signal at the first predetermined relationship with the incident reference signal, and

a second component signal at the second predetermined relationship with the incident reference signal.

12. The microwave frequency signal generation system of claim 11, wherein the first predetermined relationship with the incident reference signal is provided by a first phase lock loop coupled between the second splitter and the first source and the second predetermined relationship with the incident reference signal is provided by a second phase lock loop coupled between the third splitter and the second source.

13. The microwave frequency signal generation system of claim 12, wherein the first phase lock loop includes:

a first phase lock loop photodiode for coupling a portion of the first stimulus signal and a portion of the first polarization reference signal to provide a first phase lock loop difference signal;

a first phase lock loop mixer subsystem for comparing the first phase lock loop difference signal with a first predetermined difference reference signal to provide a first difference correction signal; and

a first phase lock loop tuner coupled to the first phase lock loop mixer subsystem for tuning the first stimulus signal generated by the first source in response to the first difference correction signal to maintain the first predetermined relationship with the incident reference signal.

14. The microwave frequency signal generation system of claim 12, wherein the second phase lock loop includes:

a second phase lock loop photodiode for coupling a portion of the second stimulus signal and a portion of the second polarization reference signal to provide a second phase lock loop difference signal;

a second phase lock loop mixer subsystem for comparing the second phase lock loop difference signal with a second predetermined difference reference signal to provide a second difference correction signal; and

a second phase lock loop tuner coupled to the second phase lock loop mixer subsystem for tuning the second stimulus signal generated by the second source in response to the second difference correction signal to maintain the second predetermined relationship

with the incident reference signal.

15. The microwave frequency signal generation system of claim 11, wherein the first polarization is horizontal and the second polarization is vertical.

16. A microwave frequency signal generation system comprising:

a reference source for providing an incident reference signal;

a first source for providing a first stimulus signal, the first stimulus signal having a first polarization and having a first predetermined relationship with the incident reference signal;

a second source for providing a second stimulus signal, the second stimulus signal having a second polarization and having a second predetermined relationship with the incident reference signal;

a first splitter for receiving and splitting the incident reference signal into a first reference signal and into a second reference signal;

a second splitter coupled to the first splitter for coupling the first stimulus signal with the first reference signal to provide first polarization mixed signals;

a third splitter coupled to the first splitter and to the second source for combining the first polarization mixed signals with the second stimulus signal to provide output signals having a first component signal at the first predetermined relationship with the incident reference signal and a second component signal at the second predetermined relationship with the incident reference signal.

17. The microwave frequency signal generation system of claim 16, wherein the first predetermined relationship with the incident reference signal is provided by a first phase lock loop coupled between the second splitter and the first source and the second predetermined relationship with the incident reference signal is provided by a second phase lock loop coupled between the reference source and the second source.

18. The microwave frequency signal generation system of claim 17, wherein the first phase lock loop includes:

a first phase lock loop photodiode for coupling a portion of the first stimulus signal and a portion of the first reference signal to provide a first phase lock loop difference signal;

a first phase lock loop mixer subsystem for comparing the first phase lock loop difference signal with a first predetermined difference reference signal to provide a first difference correction signal; and

a first phase lock loop tuner coupled to the first phase lock loop mixer subsystem for tuning the first stimulus signal in response to the first difference correction signal to maintain the first predetermined relationship with the incident reference signal.

19. The microwave signal generation system of claim 17, wherein the second phase lock loop includes:

a second phase lock loop diode for coupling a portion of the second stimulus signal and a portion of the second reference signal to provide a second phase lock loop difference signal;

a second phase lock loop mixer subsystem for comparing the second phase lock loop difference signal with a second predetermined difference reference signal to provide a second difference correction signal; and

a second phase lock loop tuner for tuning the second stimulus signal in response to the second difference correction signal to maintain the second predetermined relationship with the incident reference signal.

20. The microwave frequency signal generation system of claim 16, wherein:

the first polarization is horizontal;

the second polarization is vertical; and

the incident reference signal, the first reference signal, and the second reference signal are each at 45°

polarization.