Method and system for independent I and Q loop amplitude control for quadrature generators

• US 7,634,027 B2
• Filed: 12/29/2006
• Issued: 12/15/2009
• Est. Priority Date: 12/06/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Li, Qiang, Behzad, Arya, Roufoogaran, Razieh
• Primary Examiner(s): Luu; An T
• Application Number:
  US11/618,719
• Publication Number:
  US 20080137777A1
• Time in Patent Office: 1,082 Days
• Field of Search: None
• US Class Current: 375/319
• CPC Class Codes: H04L 27/362 Modulation using more than one carrier, e.g. with quadrature carriers, separately amplitude modulated H04L27/366 takes precedence
• CPC Class Codes: H04L 27/364 Arrangements for overcoming imperfections in the modulator, e.g. quadrature error or unbalanced I and Q levels

Abstract

Certain aspects of a method and system for independent in-phase (I) and quadrature (Q) loop amplitude control for quadrature generators may include determining an amplitude voltage associated with an in-phase (I) component and a quadrature (Q) component of a generated signal. A DC reference voltage associated with the I component and the Q component may be determined. The determined amplitude voltage may be compared with the determined reference voltage to generate a control signal. The amplitude mismatch between the I component and the Q component may be compensated by controlling a biasing current of one or more programmable buffers associated with one or both of the I component and the Q component, based on the generated control signal.

Claims

1. A method for processing signals, the method comprising:

determining an amplitude voltage associated with an in-phase (I) component and a quadrature (Q) component of a generated signal;

determining a DC reference voltage associated with said I component and said Q component; and

compensating for an amplitude mismatch between said I component and said Q component by adjusting said amplitude voltage associated with one or both of said I component and said Q component, based on a comparison of said determined amplitude voltage and said determined DC reference voltage.

2. The method according to claim 1, comprising controlling a biasing current of one or more programmable buffers to adjust said amplitude voltage associated with one or both of said I component and said Q component.

3. The method according to claim 2, comprising generating a control signal based on said comparison.

4. The method according to claim 3, comprising controlling a programmable current source based on said generated control signal.

5. The method according to claim 4, comprising generating via said programmable current source, said biasing current, which is supplied to said one or more programmable buffers.

6. The method according to claim 2, comprising individually controlling said biasing current of said one or more programmable buffers by adjusting a value of one or more bits.

7. The method according to claim 1, comprising generating said I component and said Q component of said generated signal utilizing a quadrature network.

8. The method according to claim 7, wherein said quadrature network comprises a plurality of resistors and capacitors.

9. The method according to claim 1, wherein said determined amplitude voltage is one of:

a peak amplitude voltage, a root mean square amplitude voltage, and an average amplitude voltage associated with said I component and said Q component of said generated signal.

10. A system for processing signals, the system comprising:

one or more circuits that enables determination of an amplitude voltage associated with an in-phase (I) component and a quadrature (Q) component of a generated signal;

said one or more circuits enables determination of a DC reference voltage associated with said I component and said Q component; and

said one or more circuits enables compensation for an amplitude mismatch between said I component and said Q component by adjusting said amplitude voltage associated with one or both of said I component and said Q component, based on a comparison of said determined amplitude voltage and said determined DC reference voltage.

11. The system according to claim 10, wherein said one or more circuits enables controlling of a biasing current of one or more programmable buffers to adjust said amplitude voltage associated with one or both of said I component and said Q component.

12. The system according to claim 11, wherein said one or more circuits enables generation of a control signal based on said comparison.

13. The system according to claim 12, wherein said one or more circuits enables controlling of a programmable current source based on said generated control signal.

14. The system according to claim 13, wherein said one or more circuits enables generation via said programmable current source, said biasing current, which is supplied to said one or more programmable buffers.

15. The system according to claim 11, wherein said one or more circuits enables individual control of said biasing current of said one or more programmable buffers by adjusting a value of one or more bits.

16. The system according to claim 10, wherein said one or more circuits enables generation of said I component and said Q component of said generated signal utilizing a quadrature network.

17. The system according to claim 16, wherein said quadrature network comprises a plurality of resistors and capacitors.

18. The system according to claim 10, wherein said determined amplitude voltage is one of:

a peak amplitude voltage, a root mean square amplitude voltage, and an average amplitude voltage associated with said I component and said Q component of said generated signal.

19. A machine-readable storage having stored thereon, a computer program having at least one code section for processing signals, the at least one code section being executable by a machine for causing the machine to perform steps comprising:

determining an amplitude voltage associated with an in-phase (I) component and a quadrature (Q) component of a generated signal;

determining a DC reference voltage associated with said I component and said Q component; and

compensating for an amplitude mismatch between said I component and said Q component by adjusting said amplitude voltage associated with one or both of said I component and said Q component, based on a comparison of said determined amplitude voltage and said determined DC reference voltage.

20. The machine-readable storage according to claim 19, wherein said at least one code section comprises code for controlling a biasing current of one or more programmable buffers to adjust said amplitude voltage associated with one or both of said I component and said Q component.

21. The machine-readable storage according to claim 20, wherein said at least one code section comprises code for generating a control signal based on said comparison.

22. The machine-readable storage according to claim 21, wherein said at least one code section comprises code for controlling a programmable current source based on said generated control signal.

23. The machine-readable storage according to claim 22, wherein said at least one code section comprises code for generating via said programmable current source, said biasing current, which is supplied to said one or more programmable buffers.

24. The machine-readable storage according to claim 20, wherein said at least one code section comprises code for individually controlling said biasing current of said one or more programmable buffers by adjusting a value of one or more bits.

25. The machine-readable storage according to claim 19, wherein said at least one code section comprises code for generating said I component and said Q component of said generated signal utilizing a quadrature network.

26. The machine-readable storage according to claim 25, wherein said quadrature network comprises a plurality of resistors and capacitors.

27. The machine-readable storage according to claim 19, wherein said determined amplitude voltage is one of:

a peak amplitude voltage, a root mean square amplitude voltage, and an average amplitude voltage associated with said I component and said Q component of said generated signal.