Receiver Having Multi-Stage Low Noise Amplifier

• US 20100141341A1
• Filed: 12/05/2008
• Published: 06/10/2010
• Est. Priority Date: 12/05/2008
• Status: Active Grant

• Current Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Original Assignee: SIRF Technology Incorporated (Qualcomm, Inc.)
• Inventors: Zhang, Liping
• Granted Patent: US 8,242,841 B2
• Time in Patent Office: Days
• US Class Current: 330/253
• 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 2203/45316 the AAC comprising one or more discrete inductive elements or coils
• CPC Class Codes: H03F 2203/45394 the AAC of the dif amp comprising FETs whose sources are not coupled, i.e. the AAC being a pseudo-differential amplifier
• 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 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/45179 using MOSFET transistors as the active amplifying circuit H03F3/45278 takes precedence

Abstract

A receiver having multi-stage low noise amplifier are provided. In this regard, a representative receiver, among others, includes at least one antenna and a filter that receives and filters signals from the at least one antenna. The filtered signals include a first frequency band signal and a second frequency band signal. The receiver further includes a multi-stage low noise amplifier that receives the filtered signals from the filter. The multi-stage low noise amplifier includes a first stage low noise amplifier that receives and performs impedance matching for the first frequency band signal and second frequency band signal. The multi-stage low noise amplifier further includes a second stage low noise amplifier that receives the first frequency band signal and second frequency band signal. The second stage low noise amplifier includes load resistors that switch off for the first frequency band signal and switch on for the second frequency band signal based on receiving either the first frequency band signal or second frequency band signal.

Claims

1. A receiver having multi-stage low noise amplifier comprising:

at least one antenna;

a filter that receives and filters signals from the at least one antenna, the filtered signals including a first frequency band signal and a second frequency band signal; and

a multi-stage low noise amplifier that receives the filtered signals from the filter, the multi-stage low noise amplifier including a first stage low noise amplifier that receives and performs impedance matching for the first frequency band signal and second frequency band signal, the multi-stage low noise amplifier further including a second stage low noise amplifier that receives the first frequency band signal and second frequency band signal, the second stage low noise amplifier including load resistors that switch off for the first frequency band signal and switch on for the second frequency band signal based on receiving either the first frequency band signal or second frequency band signal.

2. The receiver as defined in claim 1, wherein the first stage low noise amplifier achieves impedance matching by way of matching networks, which send the matching signals to input transistors that individually shut down through bandgap current supply.

3. The receiver as defined in claim 1, further comprising inter-stage alternating current coupling capacitors between the first and second stage low noise amplifiers.

4. The receiver as defined in claim 1, wherein the first stage low noise amplifier reuses the current from the second stage low noise amplifier based on whether interferers are detected.

5. The receiver as defined in claim 4, wherein the first stage and second stage low noise amplifiers use separate power supply based on the detected interferers.

6. The receiver as defined in claim 1, wherein the multi-stage low noise amplifier further includes a third stage low noise amplifier that includes alternating current coupling capacitors at differential inputs that are electrically connected to transistors, respectively, the differential inputs receiving the first and second frequency band signals from the second stage low noise amplifier, the third stage low noise amplifier further including load resistors that switch off for the first frequency band signal and switch on for the second frequency band signal based on receiving either the first frequency band signal or second frequency band signal.

7. The receiver as defined in claim 6, wherein the third stage low noise amplifier further includes resistors that are electrically connected in series between the transistors and current sources that are electrically connected between the transistors and resistors, respectively.

8. The receiver as defined in claim 6, wherein the third stage low noise amplifier further includes resistors that are electrically connected in series between the transistors and a current source that is electrically connected between the resistors that are electrically connected in series between the transistors.

9. A method for providing a receiver having multi-stage low noise amplifier, the method comprising:

connecting at least one antenna to a filter that receives and filters signals from the at least one antenna, the filtered signals including a first frequency band signal and a second frequency band signal;

connecting the filter to a multi-stage low noise amplifier that receives the filtered signals from the filter;

performing impedance matching for the first frequency band signal and second frequency band signal by a first stage low noise amplifier of the multi-stage low noise amplifier;

sending the first frequency band signal and second frequency band signal to a second stage low noise amplifier, the second stage low noise amplifier including load resistors that switch off for the first frequency band signal and switch on for the second frequency band signal; and

switching on or off the load resistors based on receiving either the first frequency band signal or second frequency band signal.

10. The method as defined in claim 9, further comprising sending the matching signals to input transistors that individually shut down through bandgap current supply.

11. The method as defined in claim 9, further comprising connecting inter-stage alternating current coupling capacitors between the first and second stage low noise amplifiers.

12. The method as defined in claim 9, further comprising reusing the current from the second stage low noise amplifier based on whether interferers are detected.

13. The method as defined in claim 12, further comprising using separate power supply by the first stage and second stage low noise amplifiers based on the detected interferers.

14. The method as defined in claim 9, further comprising:

connecting a third stage low noise amplifier that includes alternating current coupling capacitors at differential inputs that are electrically connected to transistors, respectively, the differential inputs receiving the first and second frequency band signals from the second stage low noise amplifier, the third stage low noise amplifier further including load resistors that switch off for the first frequency band signal and switch on for the second frequency band signal based on receiving either the first frequency band signal or second frequency band signal; and

switching on or off the load resister of the third stage low noise amplifier based on receiving either the first frequency band signal or second frequency band signal

15. The method as defined in claim 14, further comprising:

connecting resistors in series between the transistors of the third stage low noise amplifier; and

connecting current sources between the transistors and resistors of the third stage low noise amplifier, respectively.

16. The method as defined in claim 14, further comprising:

connecting resistors in series between the transistors of the third stage low noise amplifier; and

connecting a current source between the resistors of the third stage low noise amplifier.

17. A multi-stage low noise amplifier comprising:

a first stage low noise amplifier that receives and performs impedance matching for the first frequency band signal and second frequency band signal; and

a second stage low noise amplifier that receives the first frequency band signal and second frequency band signal, the second stage low noise amplifier including load resistors that switch off for the first frequency band signal and switch on for the second frequency band signal based on receiving either the first frequency band signal or second frequency band signal.

18. The multi-stage low noise amplifier as defined in claim 17, further comprising a third stage low noise amplifier that includes alternating current coupling capacitors at differential inputs that are electrically connected to transistors, respectively, the differential inputs receiving the first and second frequency band signals from the second stage low noise amplifier, the third stage low noise amplifier further including load resistors that switch off for the first frequency band signal and switch on for the second frequency band signal based on receiving either the first frequency band signal or second frequency band signal.

19. The multi-stage low noise amplifier as defined in claim 17, wherein the third stage low noise amplifier further includes resistors that are electrically connected in series between the transistors and current sources that are electrically connected between the transistors and resistors, respectively.

20. The multi-stage low noise amplifier as defined in claim 17, wherein the third stage low noise amplifier further includes resistors that are electrically connected in series between the transistors and a current source that is electrically connected between the resistors that are electrically connected in series between the transistors.