Method and system for a low power fully differential noise cancelling low noise amplifier

• US 7,671,685 B2
• Filed: 03/30/2007
• Issued: 03/02/2010
• 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: Chang, Yuyu
• Primary Examiner(s): Choe; Henry K
• Application Number:
  US11/694,266
• Publication Number:
  US 20080136521A1
• Time in Patent Office: 1,068 Days
• Field of Search: 330/301, 330/116, 330/117
• US Class Current: 330/301
• CPC Class Codes: H03F 1/223 with MOSFET's
• CPC Class Codes: H03F 1/26 Modifications of amplifiers to reduce influence of noise generated by amplifying elements
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/372 Noise reduction and elimination in amplifier
• CPC Class Codes: H03F 2203/45166 Only one input of the dif amp being used for an input signal
• CPC Class Codes: H03F 2203/45668 the LC comprising a level shifter circuit, which does not comprise diodes
• CPC Class Codes: H03F 2203/45704 the LC comprising one or more parallel resonance circuits
• CPC Class Codes: H03F 3/193 with field-effect devices H03F3/195 takes precedence
• CPC Class Codes: H03F 3/45179 using MOSFET transistors as the active amplifying circuit H03F3/45278 takes precedence

Abstract

Aspects of a method and system for a low power fully differential noise canceling low noise amplifier (NC LNA) are provided. The NC LNA may receive signals via a single ended input and may generate an amplified symmetric differential output from the received signals. The NC LNA may utilize capacitor dividers, such as a capacitor bank, in the single ended input in order to provide impedance transformation that enables low power operation and matching to an input port. The NC LNA may generate one portion of the amplified symmetric differential output via a voltage divider, which may comprise a plurality of capacitors, such as a capacitor bank. The NC LNA may be implemented utilizing one or more circuits.

Claims

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

receiving signals via a single ended input of a noise cancellation low noise amplifier (NC LNA); and

generating an amplified symmetric differential output via said NC LNA from said received signals, wherein a first differential portion of said amplified symmetric differential output is generated via a voltage divider.

2. The method according to claim 1, comprising voltage dividing said received signals in said single ended input via a plurality of capacitors.

3. The method according to claim 2, wherein said plurality of capacitors is a capacitor bank.

4. The method according to claim 1, wherein said voltage divider comprises a plurality of capacitors.

5. The method according to claim 4, wherein said plurality of capacitors is a capacitor bank.

6. The method according to claim 1, wherein said single ended input matches an input port impedance.

7. A system for signal processing, the system comprising:

a noise cancellation low noise amplifier (NC LNA) that receives signals via a single ended input; and

said NC LNA generates an amplified symmetric differential output from said received signals, wherein said NC LNA comprises a voltage divider and a first differential portion of said amplified symmetric differential output is generated via said voltage divider.

8. The system according to claim 7, wherein said NC LNA voltage divides said received signals in said single ended input via a plurality of capacitors.

9. The system according to claim 8, wherein said plurality of capacitors is a capacitor bank.

10. The system according to claim 7, wherein said voltage divider comprises a plurality of capacitors.

11. The system according to claim 10, wherein said plurality of capacitors is a capacitor bank.

12. The system according to claim 7, wherein said single ended input matches an input port impedance.

13. A system for signal processing, the system comprising:

one or more circuits that provide noise cancellation low noise amplification of signals received via a single ended input; and

said one or more circuits generate an amplified symmetric differential output from said received signals, wherein said one or more circuits comprise a voltage divider and a first differential portion of said amplified symmetric differential output is generated via said voltage divider.

14. The system according to claim 13, wherein said one or more circuits voltage divide said received signals in said single ended input via a plurality of capacitors.

15. The system according to claim 14, wherein said plurality of capacitors is a capacitor bank.

16. The system according to claim 13, wherein said voltage divider comprises a plurality of capacitors.

17. The system according to claim 16, wherein said plurality of capacitors is a capacitor bank.

18. The system according to claim 13, wherein said single ended input matches an input port impedance.