Method and system for RF front-end calibration scheme using fractional-N frequency synthesized signals and RSSI

• US 20070207759A1
• Filed: 05/11/2006
• Published: 09/06/2007
• Est. Priority Date: 03/02/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Vassiliou, Iason, Vavelidis, Konstantinos, Kapnistis, Charalampos
• Granted Patent: US 7,668,521 B2
• Time in Patent Office: Days
• US Class Current: 455/232.100
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 7/08 at the receiving station
• CPC Class Codes: H04H 60/91 Mobile communication networks for accessing the Internet H04H60/85

Abstract

Aspects of a method and system for an RF front-end calibration scheme using signals from a fractional-N frequency synthesized and received signal strength indicator (RSSI) are provided. A frequency synthesizer within a wireless receiver may generate a signal for dynamically modifying a gain in an integrated low-noise amplifier (LNA) for each selected receiver channel. The frequency-synthesized signals may be applied to at least one tunable load communicatively coupled to the LNA. The tunable load may be an input load or an output load. The signal generated by the frequency synthesizer may be sequentially applied to the input load and the output load. A logarithmic amplifier may generate an RSSI signal from the LNA output during the calibration process. The RSSI signal may be utilized for controlling a tunable load coupled to the LNA and optimize the tuning of the LNA in a desired channel by adjusting the tunable load.

Claims

1. A method for calibration in a wireless device, the method comprising:

generating a signal via an on-chip frequency synthesizer in a multi-band wireless receiver chip; and

dynamically modifying a gain in a low-noise amplifier (LNA) within said multi-band wireless receiver chip for each selected receiver channel by applying a control signal derived from said generated signal to at least one tunable load communicatively coupled to said LNA.

2. The method according to claim 1, further comprising applying said generated signal to a tunable input load communicatively coupled to said LNA.

3. The method according to claim 1, further comprising applying said generated signal to a tunable output load communicatively coupled to said LNA.

4. The method according to claim 1, further comprising sequentially applying said generated signal to a tunable output load and to a tunable input load communicatively coupled to said LNA.

5. The method according to claim 1, further comprising generating a received signal strength indicator (RSSI) signal from an output of said LNA generated after said application of said generated signal to said at least one tunable load communicatively coupled to said LNA.

6. The method according to claim 5, further comprising generating said control signal for controlling said at least one tunable load communicatively coupled to said LNA based on said generated RSSI signal.

7. The method according to claim 1, wherein said at least one tunable load communicatively coupled to said LNA is a capacitor bank.

8. A machine-readable storage having stored thereon, a computer program having at least one code section for calibration in a wireless device, the at least one code section being executable by a machine for causing the machine to perform steps comprising:

generating a signal via an on-chip frequency synthesizer in a multi-band wireless receiver chip; and

dynamically modifying a gain in a low-noise amplifier (LNA) within said multi-band wireless receiver chip for each selected receiver channel by applying a control signal derived from said generated signal to at least one tunable load communicatively coupled to said LNA.

9. The machine-readable storage according to claim 8, further comprising code for applying said generated signal to a tunable input load communicatively coupled to said LNA.

10. The machine-readable storage according to claim 8, further comprising code for applying said generated signal to a tunable output load communicatively coupled to said LNA.

11. The machine-readable storage according to claim 8, further comprising code for sequentially applying said generated signal to a tunable output load and to a tunable input load communicatively coupled to said LNA.

12. The machine-readable storage according to claim 8, further comprising code for generating a received signal strength indicator (RSSI) signal from an output of said LNA generated after said application of said generated signal to said at least one tunable load communicatively coupled to said LNA.

13. The machine-readable storage according to claim 12, further comprising code for generating said control signal for controlling said at least one tunable load communicatively coupled to said LNA based on said generated RSSI signal.

14. The machine-readable storage according to claim 8, wherein said at least one tunable load communicatively coupled to said LNA is a capacitor bank.

15. A system for calibration in a wireless device, the system comprising:

a multi-band wireless receiver chip comprising an on-chip frequency synthesizer;

said frequency synthesizer enables generating a signal; and

said multi-band wireless receiver enables dynamically modifying a gain in a low-noise amplifier (LNA) within said multi-band wireless receiver chip for each selected receiver channel by applying a control signal derived from said generated signal to at least one tunable load communicatively coupled to said LNA.

16. The system according to claim 15, further comprising circuitry that enables applying said generated signal to a tunable input load communicatively coupled to said LNA.

17. The system according to claim 15, further comprising circuitry that enables applying said generated signal to a tunable output load communicatively coupled to said LNA.

18. The system according to claim 15, further comprising circuitry that enables sequentially applying said generated signal to a tunable output load and to a tunable input load communicatively coupled to said LNA.

19. The system according to claim 15, further comprising circuitry that enables generating a received signal strength indicator (RSSI) signal from an output of said LNA generated after said application of said generated signal to said at least one tunable load communicatively coupled to said LNA.

20. The system according to claim 19, further comprising circuitry within said multi-band wireless receiver chip that enables generating said control signal for controlling said at least one tunable load communicatively coupled to said LNA based on said generated RSSI signal.

21. The system according to claim 19, further comprising circuitry external to said multi-band wireless receiver chip that enables generating said control signal for controlling said at least one tunable load communicatively coupled to said LNA based on said generated RSSI signal.

22. The system according to claim 15, wherein said at least one tunable load communicatively coupled to said LNA is a capacitor bank.