Multi-standard amplifier

• US 7,245,187 B2
• Filed: 07/24/2003
• Issued: 07/17/2007
• Est. Priority Date: 07/24/2002
• Status: Active Grant

• Current Assignee: Icera Canada ULC (NVIDIA Corporation)
• Original Assignee: Sirific Wireless Corp. (NVIDIA Corporation)
• Inventors: Khajehpour, Javad
• Primary Examiner(s): Choe; Henry
• Application Number:
  US10/522,654
• Publication Number:
  US 20060055445A1
• Time in Patent Office: 1,454 Days
• Field of Search: 330/305, 330/306, 330/307, 330/253, 330/261
• US Class Current: 330/305
• CPC Class Codes: H03F 1/3211 in differential amplifiers
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/111 the amplifier being a dual or triple band amplifier, e.g. 900 and 1800 MHz, e.g. switched or not switched, simultaneously or not
• 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 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 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2203/45371 the AAC comprising parallel coupled multiple transistors at their source and gate and drain or at their base and emitter and collector, e.g. in a cascode dif amp, only those forming the composite common source transistor or the composite common emitter transistor respectively
• CPC Class Codes: H03F 2203/45386 the AAC comprising one or more coils in the source circuit
• CPC Class Codes: H03F 2203/45481 the CSC comprising only a direct connection to the supply voltage, no other components being present
• CPC Class Codes: H03F 2203/45616 the IC comprising more than one switch, which are not cross coupled
• CPC Class Codes: H03F 2203/45704 the LC comprising one or more parallel resonance circuits
• CPC Class Codes: H03F 2203/45726 the LC comprising more than one switch, which are not cross coupled
• CPC Class Codes: H03F 2203/7239 the gated amplifier being switched on or off by putting into parallel or not, by choosing between amplifiers and shunting lines by one or more switch(es)
• CPC Class Codes: H03F 3/195 in integrated circuits
• CPC Class Codes: H03F 3/45188 Non-folded cascode stages
• CPC Class Codes: H03F 3/45475 using IC blocks as the active amplifying circuit
• CPC Class Codes: H03F 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
• CPC Class Codes: H03J 2200/10 Tuning of a resonator by means of digitally controlled capacitor bank

Abstract

The present invention relates generally to amplifiers, and more specifically to multi-band and/or multi-standard low noise amplifiers. There are currently no inexpensive, highperformance, fully-integrable, multi-standard low noise amplifiers (LNAs) available. The invention provides a suitable LNA for a multi-band and/or multi-standard receiver in wireless and other applications. This LNA comprises a positive signal amplifier having a first input for receiving a positive RF signal, and a first output for providing an amplified positive RF signal; a negative signal amplifier having a second input for receiving a negative RF signal, and a second output for providing an amplified negative RF signal; and a tunable differential filter having a tuning control input, a third input for said first output and a fourth input for said second output; the frequency response of said tunable differential filter varying with a control signal input to said tuning control input, whereby signal of undesired frequencies may be filtered from said first output and said second output.

Claims

1. A low noise amplifier for a multi-band receiver, comprising:

a positive signal amplifier having a first input for receiving a positive RF signal, and a first output for providing an amplified positive RF signal;

a negative signal amplifier having a second input for receiving a negative RF signal, and a second output for providing an amplified negative RF signal; and

a tunable differential filter having a tuning control input, a third input for said first output and a fourth input for said second output the tunable differential filter including a centre-tapped inductor connected between the first output and the second output;

the frequency response of said tunable differential filter varying with a control signal input to said tuning control input, whereby signal of undesired frequencies may be filtered from said first output and said second output.

2. The low noise amplifier of claim 1, wherein said tunable differential filter comprises a capacitor/inductor filter.

3. The low noise amplifier of claim 1, wherein said positive and negative signal amplifiers include source degeneracy.

4. The low noise amplifier of claim 1, further comprising a sleep circuit.

5. The low noise amplifier of claim 1, further comprising RF blocking transistors.

6. The low noise amplifier of claim 1, wherein said positive and negative signal amplifiers comprise single amplification stages comprising a single transistor.

7. The low noise amplifier of claim 1, wherein said tunable differential filter comprises two or more capacitor/inductor filters, switched in and out of said circuit using transistors.

8. The low noise amplifier of claim 1, wherein said tunable differential filter comprises:

two or more pairs of capacitors, each pair of capacitors being arranged in series, one end of said series connected to said third input and the other end of said series connected to said fourth input; and

a signal centre-tapped inductor, the centre tap connect to supply voltage potential, one end of said inductor connected to said third input and the other end of said conductor connected to said fourth input.

9. The low noise amplifier of claim 7, wherein said tunable differential filter comprises a transistor in series with each of said two or more pairs of capacitors, each transistor being positioned between its associated pair of capacitors, whereby each the circuit for each pair of capacitors can be opened or closed.

10. The low noise amplifier of claim 1 wherein each of said amplifiers comprises a transistor.

11. The low noise amplifier of claim 1 wherein each of said amplifiers comprises a field effect transistor (FET).

12. The low noise amplifier of claim 1 wherein said tunable differential filter is tuned for a transmit band of a cellular communication system.

13. The low noise amplifier of claim 1 wherein a separate amplifier is used for each band and/or standard, whereby each separate amplifier may be optimised for the particular band and/or standard that it is to amplify.

14. The low noise amplifier of claim 1, further including decoupling capacitors to reduce second order distortion.

15. The low noise amplifier of claim 1 wherein said low noise amplifier is fully integrated.

16. A low noise amplifier for a multi-band receiver, comprising:

a positive signal amplifier having a first input for receiving a positive RF signal, and a first output for providing an amplified positive RF signal;

a negative signal amplifier having a second input for receiving a negative RF signal, and a second output for providing an amplified negative RF signal; and

a tunable differential filter having a tuning control input, a third input for said first output and a fourth input for said second output, the tunable differential filter including two or more pairs of capacitors where each pair of capacitors are arranged in series, one end of said series being

connected to said third input and the other end of said series being connected to said fourth input, the tunable differential filter further including a signal centre-tapped inductor, the centre tap being connected to a supply voltage potential, one end of said inductor connected to said third input and the other end of said conductor connected to said fourth input;

the frequency response of said tunable differential filter varying with a control signal input to said tuning control input, whereby signal of undesired frequencies may be filtered from said first output and said second output.

17. A low noise amplifier for a multi-band receiver, comprising:

a positive signal amplifier having a first input for receiving a positive RF signal, and a first output for providing an amplified positive RF signal;

a negative signal amplifier having a second input for receiving a negative RF signal, and a second output for providing an amplified negative RF signal; and

a tunable differential filter having a tuning control input, a third input for said first output and a fourth input for said second output, the tunable differential filter including two or more capacitor/inductor filters switched in and out of said circuit using transistors, and a transistor in series with each of said two or more pairs of capacitors, each said transistor being positioned between its associated pair of capacitors, whereby each circuit for each pair of capacitors can be opened or closed;

the frequency response of said tunable differential filter varying with a control signal input to said tuning control input, whereby signal of undesired frequencies may be filtered from said first output and said second output.