Method and system for processing signals in a high performance receive chain

• US 7,840,198 B2
• Filed: 04/09/2007
• Issued: 11/23/2010
• Est. Priority Date: 12/06/2006
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rama Rao, Kishore, Chien, Hung-Ming, Behzad, Arya, Ojo, Adedayo, Seetharam, Guruprasad, Chang, Yuyu
• Primary Examiner(s): LE, NHAN T
• Application Number:
  US11/733,047
• Publication Number:
  US 20080139119A1
• Time in Patent Office: 1,324 Days
• Field of Search: 455/127.1, 455/127.3, 455/253.1, 455/552.1, 330/51
• US Class Current: 455/127.3
• CPC Class Codes: H04B 1/0057 using diplexing or multiplexing filters for selecting the desired band
• CPC Class Codes: H04B 1/0082 with a common local oscillator for more than one band
• CPC Class Codes: H04B 1/06 Receivers
• CPC Class Codes: H04B 7/084 Equal gain combining, only phase adjustments antenna beam scanning or forming by phase or amplitude control H01Q3/26, e.g. phased arrays

Abstract

Aspects of a method and system for processing signals in a high performance receive chain may include amplifying radio frequency signals in amplifier chains in a multistandard radio frequency front-end, comprising one or more shared processing stages, and combining, with substantially equal gain, a number of phase-shifted radio frequency signals of the radio frequency signals into substantially equal-gain-combined radio frequency signals. The substantially equal-gain-combined radio frequency signals may be demodulated to obtain inphase channels and quadrature channels. A number of inphase channels and quadrature channels may be processed in I-channel processing blocks and Q-channel processing blocks to generate an output analog baseband signal. The multistandard radio frequency front-end may be capable of processing Bluetooth® signals and Wireless Local Area Network (WLAN) signals. The amplifier chains may comprise a first amplifier and a second amplifier, where the first amplifier may be shared between Bluetooth® signal processing paths and WLAN signal processing paths.

Claims

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

amplifying a plurality of radio frequency signals in one or more respective one or one of a plurality of amplifier chains in a multistandard radio frequency front-end comprising one or more shared processing stages, wherein;

said plurality of radio frequency signals are compliant with a plurality of radio frequency communication standards;

said one or more shared processing stages are shared between two or more of said plurality of amplifier chains;

each of said two or more of said plurality of amplifier chains are operable to amplify signals compliant with different ones of said plurality of radio frequency communication standards; and

combining, with substantially equal gain, a number of phase-shifted radio frequency signals of said amplified plurality of radio frequency signals into a plurality of substantially equal-gain-combined radio frequency signals.

2. The method according to claim 1, comprising demodulating said plurality of substantially equal-gain-combined radio frequency signals to obtain a plurality of inphase channels and a plurality of quadrature channels.

3. The method according to claim 2, comprising processing a number of said plurality of inphase channels and a number of said plurality of quadrature channels in a plurality of I-channel processing circuits and a plurality of Q-channel processing circuits to generate an output analog baseband signal.

4. The method according to claim 1, wherein said multistandard radio frequency front-end is operable to process Bluetooth®

signals and a plurality of Wireless Local Area Network (WLAN) signals.

5. The method according to claim 1, wherein each of said plurality of amplifier chains comprise at least a first amplifier and a second amplifier.

6. The method according to claim 5, comprising sharing said first amplifier between a plurality of Bluetooth®

signal processing paths and a plurality of WLAN signal processing paths.

7. The method according to claim 6, comprising isolating said plurality of Bluetooth®

signal processing paths from a plurality of WLAN local oscillator signals by said second amplifier.

8. The method according to claim 6, comprising isolating said plurality of WLAN signal processing paths from a plurality of Bluetooth®

local oscillator signals by said second amplifier.

9. The method according to claim 1, comprising demodulating said plurality of substantially equal-gain-combined signals by using a plurality of transconductance multipliers.

10. The method according to claim 3, comprising filtering said plurality of inphase channels and said plurality of quadrature channels using a plurality of transimpedance amplifiers with low-pass filtering characteristics in said plurality of I-channel processing circuits and said plurality of Q-channel processing circuits.

11. The method according to claim 3, comprising amplifying said plurality of inphase channels and said plurality of quadrature channels using a plurality of transimpedance amplifiers with low-pass filtering characteristics in said plurality of I-channel processing circuits and said plurality of Q-channel processing circuits.

12. The method according to claim 3, wherein said plurality of I-channel processing circuits and said plurality of Q-channel processing circuits comprise a plurality of filters that are switchable between a plurality of filtering characteristics.

13. The method according to claim 12, comprising compensating DC offset introduced by said plurality of filters using a plurality of DC loops.

14. The method according to claim 3, wherein said plurality of I-channel processing circuits and said plurality of Q-channel processing circuits comprise a plurality of variable gain filters.

15. The method according to claim 14, comprising offsetting DC offset introduced by said plurality of variable gain amplifiers using a plurality of DC loops.

31. The method according to claim 1, wherein said plurality of radio transmission standards comprise WLAN 802.11 and Bluetooth.

16. A system for processing communication signals, the system comprising:

one or more circuits comprising a plurality of amplifier chains in a multistandard radio frequency front-end comprising one or more shared processing stages;

said one or more circuits operable to;

amplify a plurality of radio frequency signals in one or more respective one or ones of said plurality of amplifier chains in said multistandard radio frequency frontend, wherein said plurality of radio frequency signals are compliant with a plurality of radio communication standards;

share said one or more shared processing stages between two or more of said plurality of amplifier chains;

amplify signals compliant with different ones of said plurality of radio frequency communication standards in each of said two or more of said plurality of amplifier chains; and

combine, with substantially equal gain, a number of phase-shifted radio frequency signals of said plurality of radio frequency signals into a plurality of substantially equal-gain-combined radio frequency signals.

17. The system according to claim 16, wherein said one or more circuits demodulate said plurality of substantially equal-gain-combined radio frequency signals to obtain a plurality of inphase channels and a plurality of quadrature channels.

18. The system according to claim 17, wherein said one or more circuits comprises a plurality of I-channel processing circuits and a plurality of Q-channel processing circuits, which processes a number of said plurality of inphase channels and a number of said plurality of quadrature channels to generate an output analog baseband signal.

19. The system according to claim 16, wherein said multistandard radio frequency front-end is operable to process Bluetooth®

signals and a plurality of Wireless Local Area Network (WLAN) signals.

20. The system according to claim 16, wherein said one or more circuits comprises at least a first amplifier and a second amplifier in each of said plurality of amplifier chains.

21. The system according to claim 20, wherein said one or more circuits share said first amplifier between a plurality of Bluetooth®

signal processing paths and a plurality of WLAN signal processing paths.

22. The system according to claim 21, wherein said one or more circuits isolate said plurality of Bluetooth®

signal processing paths from a plurality of WLAN local oscillator signals by said second amplifier.

23. The system according to claim 21, wherein said one or more circuits isolate said plurality of WLAN signal processing paths from a plurality of Bluetooth®

local oscillator signals by said second amplifier.

24. The system according to claim 16, wherein said one or more circuits comprises a plurality of transconductance multipliers, which demodulate said plurality of substantially equal-gain-combined signals.

25. The system according to claim 18, wherein said one or more circuits comprises a plurality of transimpedance amplifiers with low-pass filtering characteristics in said plurality of I-channel processing circuits and said plurality of Q-channel processing circuits, which filters said plurality of inphase channels and said plurality of quadrature channels.

26. The system according to claim 18, wherein said one or more circuits comprises a plurality of transimpedance amplifiers with low-pass filtering characteristics in said plurality of I-channel processing circuits and said plurality of Q-channel processing circuits, which amplifies said plurality of inphase channels and said plurality of quadrature channels.

27. The system according to claim 18, wherein said one or more circuits comprises a plurality of filters within said plurality of I-channel processing circuits and said plurality of Q-channel processing circuits, which are switchable between a plurality of filtering characteristics.

28. The system according to claim 27, wherein said one or more circuits comprising a plurality of DC loops, which compensates for DC offset introduced by said plurality of filters.

29. The system according to claim 18, wherein said one or more circuits comprise a plurality of variable gain filters within said plurality of I-channel processing circuits and said plurality of Q-channel processing circuits.

30. The system according to claim 29, wherein said one or more circuits comprise a plurality of DC loops, which compensates for DC offset introduced by said plurality of variable gain amplifiers.

32. The system according to claim 16, wherein said plurality of radio transmission standards comprise WLAN 802.11 and Bluetooth.