Transmitter with improved power efficiency

• US 20080119214A1
• Filed: 11/16/2006
• Published: 05/22/2008
• Est. Priority Date: 11/16/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Liu, Lianjun, Uscola, Ricardo A.
• Granted Patent: US 7,630,693 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H03F 1/02 Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
• 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 3/24 of transmitter output stages
• 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: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04B 2001/045 with means for improving efficiency

Abstract

A power amplifier (PA) line-up (210) and a method (500) for more efficiently utilizing battery power are disclosed. PA line-up (210) includes a driver (220), a matching circuit (214), and a PA (230) coupled to a matching circuit (216), wherein matching circuit (216) is configured to be coupled to a filter (260). PA line-up (210) includes a transmission line (260) coupled to matching circuit (216) and a switch (262) configured to selectively couple driver (220) to either matching circuit (214) or matching circuit (216) such that signal (205) is capable of by-passing PA (230) when signal (205) does not need to be amplified by PA (230). Furthermore, PA line-up (210) may include a second transmission line (250) so that signal (205) is capable of by-passing a driver (220) and a PA (230) when signal (205) does not need to be amplified by driver (220) and PA (230).

Claims

1. A power amplifier (PA) line-up comprising:

a driver having a driver output;

a PA having a PA input and a PA output;

a first matching circuit having a first matching circuit output coupled to the PA input and having a first matching circuit input, the first matching circuit configured to receive a signal from the driver output and impedance match the signal to the PA input and the driver output;

a second matching circuit having a second matching circuit input coupled to the PA output, a third matching circuit input, and a second matching circuit output configured to be coupled to a filter input, the second matching circuit configured to impedance match the signal to the filter input and at least one of the PA output and the driver output;

a first transmission line coupled the third matching circuit input; and

a first switch having a first switch output configured to selectively couple the driver to one of the first matching circuit and the second matching circuit via the first transmission line based upon a pre-determined output power level for the signal.

2. The PA line-up of claim 1, wherein the second matching circuit comprises a fourth matching circuit input, the PA line-up further comprising:

a pre-driver having a pre-driver output;

a third matching circuit having a third matching circuit output coupled to the driver input and a fifth matching circuit input, the third matching circuit configured to impedance match the signal to the pre-driver output and the driver input;

a second transmission line coupled to the fourth matching circuit input; and

a second switch having a second switch input coupled to the pre-driver output and a second switch output configured to selectively couple the pre-driver to one of the third matching circuit and the second matching circuit via the second transmission line based upon a pre-determined output power level for the signal, wherein the second matching circuit configured to impedance match the signal to the filter input and at least one of the driver output, the PA output, and the pre-driver output.

3. The PA line-up of claim 2, further comprising a third switch configured to selectively couple the first transmission line to the third matching circuit input, wherein the third switch is configured to be open when the first switch selectively couples the driver output to the first matching circuit input and configured to be closed when the first switch selectively couples the driver output to the first transmission line.

4. The PA line-up of claim 3, further comprising a fourth switch configured to selectively couple the second transmission line to the fourth matching circuit input, wherein the fourth switch is configured to be open when the second switch selectively couples the pre-driver output to the fifth matching circuit input and configured to be closed when the fourth switch selectively couples the pre-driver output to the second transmission line.

5. The PA line-up of claim 2, wherein the second matching circuit is a variable matching circuit.

6. The PA line-up of claim 1, further comprising a second switch configured to selectively couple the first transmission line to the third matching circuit input, wherein the second switch is configured to be open when the first switch selectively couples the signal generator output to the first matching circuit input and configured to be closed when the first switch selectively couples the signal generator output to the first transmission line.

7. The PA line-up of claim 1, wherein the second matching circuit is a variable matching circuit.

8. The PA line-up of claim 7, wherein the second matching circuit further comprises at least one variable capacitor coupled in parallel with at least one inductor.

9. The PA line-up of claim 7, wherein the second matching circuit further comprises at least one capacitor coupled in parallel with at least one inductor, and a second switch configured to selectively short circuit the at least one capacitor.

10. The PA line-up of claim 7, wherein the second matching circuit is variable based upon whether the second matching circuit is impedance matching the one of the PA and the driver.

11. A power amplifier (PA) line-up comprising:

a pre-driver having a pre-driver output;

a driver having a driver input and a driver output;

a first matching circuit having a first matching circuit output coupled to the driver input and having a first matching circuit input, the first matching circuit configured to receive a signal from the pre-driver output and impedance match the signal to the first driver input and the pre-driver output;

a PA having a PA input and a PA output;

a second matching circuit having a second matching circuit input coupled to the driver output and having a second matching circuit output coupled to the PA output, the second matching circuit configured to receive the signal from the driver output and impedance match the signal to the driver output and the PA input;

a third matching circuit having a third matching circuit input coupled to the PA output, a fourth matching circuit input, and a third matching circuit output configured to be coupled to a filter input, the third matching circuit configured to impedance match the signal to the filter input and at least one of the PA output and the pre-driver output;

a transmission line coupled the fourth matching circuit input; and

a first switch having a first switch input coupled to the pre-driver output, wherein the first switch is configured to selectively couple the pre-driver to one of the first matching circuit and the third matching circuit via the transmission line based upon a pre-determined output power level for the signal.

12. The PA line-up of claim 11, further comprising a second switch configured to selectively couple the transmission line to the fourth matching circuit input, wherein the second switch is configured to be open when the first switch selectively couples the pre-driver to the first matching circuit and configured to be closed when the first switch selectively couples the pre-driver to the third matching circuit via the transmission line.

13. A method for operating a power amplifier (PA) line-up of a wireless device, comprising:

receiving a message from a base station instructing the wireless device to utilize a transmission power level when transmitting a signal to the base station;

determining whether the transmission power level is one of a first power level and a second power level;

utilizing a first configuration of a power amplifier line-up to transmit the signal to the base station when the first power level is determined; and

utilizing a second configuration of the power amplifier line-up to transmit the signal to the base station when the second power level is determined.

14. The method of claim 13, wherein utilizing the first configuration comprises by-passing at least one driver in the PA line-up when amplifying the signal.

15. The method of claim 14, wherein utilizing the first configuration further comprises impedance matching a filter input to one of a pre-driver output, a driver output, and a power amplifier output.

16. The method of claim 15, wherein impedance matching comprises utilizing a MEMS capacitor in a variable matching circuit to impedance match the filter input to the one of the pre-driver output, the driver output, and the power amplifier output.

17. The method of claim 15, wherein impedance matching comprises utilizing a switch coupled in series with capacitor in a variable matching circuit to impedance match the filter input to the one of the pre-driver output, the driver output, and the power amplifier output.

18. The method of claim 15, wherein impedance matching comprises impedance matching differing amounts of impedance based upon whether the filter input is being impedance matched to one of the pre-driver output, the driver output, and the power amplifier output.

19. The method of claim 13, wherein determining comprises determining whether the transmission power level is one of a first power level, a second power level, and a third power level, the method further comprising:

utilizing a third configuration of the power amplifier line-up to transmit the signal to the base station when the third power level is determined.

20. The method of claim 19, wherein utilizing the first configuration comprises the signal by-passing at least one driver in the PA line-up when amplifying the signal.

21. The method of claim 20, wherein utilizing the second configuration comprises the signal by-passing at least two drivers in the PA line-up when amplifying the signal.

22. The method of claim 19, wherein utilizing the third configuration comprises amplifying the signal utilizing at least two drivers in the PA line-up.