High-linearity low noise amplifier

• US 8,018,288 B2
• Filed: 04/13/2009
• Issued: 09/13/2011
• Est. Priority Date: 04/13/2009
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Duster, Jon S., Taylor, Stewart S.
• Primary Examiner(s): NGUYEN, PATRICIA T
• Application Number:
  US12/422,430
• Publication Number:
  US 20100259331A1
• Time in Patent Office: 883 Days
• Field of Search: 330/311, 330/306, 330/253
• US Class Current: 330/311
• CPC Class Codes: H03F 1/0255 by using a signal derived from the output signal
• CPC Class Codes: H03F 1/0261 with control of the polarisation voltage or current, e.g. gliding Class A
• CPC Class Codes: H03F 1/223 with MOSFET's
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/213 A variable capacitor being added in the input circuit, e.g. base, gate, of an amplifier stage
• CPC Class Codes: H03F 2200/216 A coil being added in the input circuit, e.g. base, gate, of an amplifier stage
• CPC Class Codes: H03F 2200/222 A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier
• CPC Class Codes: H03F 2200/225 the input circuit of an amplifying stage comprising an LC-network
• CPC Class Codes: H03F 2200/241 A parallel resonance being added in shunt in the input circuit, e.g. base, gate, of an amplifier stage
• CPC Class Codes: H03F 2200/243 A series resonance being added in series in the input circuit, e.g. base, gate, of an amplifier stage
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/378 A variable capacitor being added in the output circuit, e.g. collector, drain, of an amplifier stage
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/391 the output circuit of an amplifying stage comprising an LC-network
• CPC Class Codes: H03F 2200/399 A parallel resonance being added in shunt in the output circuit, e.g. base, gate, of an amplifier stage
• CPC Class Codes: H03F 2200/429 Two or more amplifiers or one amplifier with filters for different frequency bands are coupled in parallel at the input or output
• CPC Class Codes: H03F 2200/61 the cascode amplifier has more than one common gate stage
• CPC Class Codes: H03F 2203/45352 the AAC comprising a combination of a plurality of transistors, e.g. Darlington coupled transistors
• CPC Class Codes: H03F 2203/45544 the IC comprising one or more capacitors, e.g. coupling capacitors
• CPC Class Codes: H03F 2203/45548 the IC comprising one or more capacitors as shunts to earth or as short circuit between inputs
• CPC Class Codes: H03F 2203/45554 : the IC comprising one or more coils
• CPC Class Codes: H03F 2203/45606 : the IC comprising one or more parallel resonance circuits
• CPC Class Codes: H03F 2203/45608 : the IC comprising one or more series resonance circuits
• CPC Class Codes: H03F 2203/45631 : the LC comprising one or more capacitors, e.g. coupling capacitors
• CPC Class Codes: H03F 2203/45638 : the LC comprising one or more coils
• CPC Class Codes: H03F 2203/45704 : the LC comprising one or more parallel resonance circuits
• CPC Class Codes: H03F 2203/45714 : the LC comprising a coil as shunt
• CPC Class Codes: H03F 3/195 : in integrated circuits
• CPC Class Codes: H03F 3/45179 : using MOSFET transistors as the active amplifying circuit H03F3/45278 takes precedence

Abstract

Embodiments of a high-linearity low-noise amplifier (LNA) are generally described herein. Other embodiments may be described and claimed. In some embodiments, an RF input signal may be amplified with a cascode amplifier. The cascode amplifier may include integrated notch filters to attenuate undesired signals. The cascode amplifier may operate from a large power supply when blockers are present to avoid voltage swing compression at its output. The cascode amplifier may be biased and designed to operate in a class AB mode to produce linear output current to avoid current compression or excessive current expansion.

Claims

1. A low-noise amplifier (LNA) comprising:

a cascode amplifier;

an integrated notch filter to attenuate undesired signals; and

a power supply that operates at a high voltage when undesired signals are present, wherein the cascode amplifier comprises a common-source transistor coupled with a first common-gate transistor,

further comprising a second common-gate transistor coupled to an output of the cascode amplifier,

wherein the integrated notch filter comprises a first resonant trap at the output of the common-source transistor, and

further comprising a second resonant trap in a source of the common-source transistor.

2. The LNA of claim 1 wherein the common-source transistor, the first common-gate transistor, and the second common-gate transistor comprise N-MOS transistors.

3. The LNA of claim 1 wherein the first and second resonant traps comprise variable components controlled by a programmable memory.

4. The LNA of claim 1 wherein the common-source transistor is biased to operate the LNA in a class AB mode.

5. The LNA of claim 1 further comprising a second common-source transistor, the first common-source transistor to amplify a first band and the second common-source transistor to amplify a second band.

6. The LNA of claim 1 wherein the power supply operates at a lower voltage when undesired signals are not present, and

further comprising circuitry to detect undesired signals and adjust the power supply.

7. The LNA of claim 6 wherein the high voltage comprises about 2.5 Volts and the lower voltage comprises about 1.2 Volts.

8. A low-noise amplifier (LNA) comprising:

a CMOS cascode amplifier, wherein the CMOS cascode amplifier comprises a common-source transistor coupled with a common-gate transistor, wherein the common-source transistor is biased and designed to operate in a class AB mode to produce a linear output current;

an integrated notch filter to attenuate undesired signals;

a power supply that operates at a high voltage when undesired signals are present, the power supply to operate at a lower voltage when undesired signals are not present; and

circuitry to detect undesired signals and adjust the power supply voltage.

9. The LNA of claim 8 further comprising a second CMOS cascode amplifier, the first CMOS cascode amplifier to amplify a low-midband and the second CMOS cascode amplifier to amplify a high band.

10. The LNA of claim 8 wherein the CMOS cascode amplifier comprises N-MOS transistors.

11. The LNA of claim 8 wherein the integrated notch filter comprises a resonant trap.

12. The LNA of claim 8 wherein the integrated notch filter is coupled with an output of a common-source transistor.

13. A receiver comprising a low-noise amplifier (LNA) to amplify an RF signal received through an antenna, wherein the LNA comprises a CMOS cascode amplifier, the CMOS cascode amplifier integrating a notch filter to attenuate undesired signals, the CMOS cascode amplifier operating from a large power supply, the CMOS cascode amplifier biased and designed to operate in a class AB mode to produce linear output current, and wherein the LNA is coupled with the antenna without a pre-select filter between the LNA and the antenna.

14. The receiver of claim 13 wherein the CMOS cascode amplifier comprises a common-source transistor coupled with a first common-gate transistor, and

further comprising a second common-gate transistor coupled to an output of the CMOS cascode amplifier.

15. The receiver of claim 13 further comprising a second LNA to amplify a second RF signal received through a second antenna.

16. The receiver of claim 13 wherein the integrated notch filter comprises a resonant trap including variable components controlled by a programmable memory.

17. The receiver of claim 13 wherein the integrated notch filter is coupled with an output of the CMOS cascode amplifier.

18. The receiver of claim 13 wherein the large power supply operates at about 2.5 Volts when undesired signals are present, the large power supply operates at about 1.2 Volts when undesired signals are not present, and further comprising circuitry to detect undesired signals and adjust the large power supply.

19. The receiver of claim 13 further comprising a passive mixer terminated into a low impedance, wherein the LNA achieves a single tone out of channel compression point or about 0 dBm.