System and method for selecting amplifiers in a communications device

• US 6,615,028 B1
• Filed: 12/29/1998
• Issued: 09/02/2003
• Est. Priority Date: 12/29/1998
• Status: Expired due to Term

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: Abdelgany, Mohy F., Kamke, James F., Loke, Aravind
• Primary Examiner(s): Kincaid, Lester G.
• Assistant Examiner(s): Mehrpour, N.
• Application Number:
  US09/222,063
• Time in Patent Office: 1,708 Days
• Field of Search: 455/92, 455/114, 455/115, 455/102, 455/103, 455/126, 455/127, 330/124.R, 330/51
• US Class Current: 455/127.1
• CPC Class Codes: H03F 1/0277 Selecting one or more amplifiers from a plurality of amplifiers
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/0483 Transmitters with multiple parallel paths
• CPC Class Codes: H04B 2001/0408 with power amplifiers

Abstract

A communications device includes an amplifier module configured to amplify a signal. The amplifier module includes a parallel arrangement of amplifiers each designed to operate with increased efficiency for different power level ranges. A controllable switch selectively interconnects the power amplifiers. A controller in communication with the controllable switch selectively interconnects the power amplifiers to increase the efficiency of the amplifier module.

Claims

1. A wireless communication device comprising:

a modulator module configured to convert a baseband signal to a radio frequency signal;

an amplifier module which receives the radio signal and generates an amplified output signal, the amplifier module comprising;

a first amplifier in communication with the radio frequency signal, the first amplifier configured to generate a first amplified signal at increased power efficiency in a first operational power range, the first amplifier comprising a fourth amplifier and a fifth amplifier, the fifth amplifier arranged in series with the fourth amplifier;

a second amplifier in communication with the radio frequency signal, the second amplifier arranged in parallel with the first amplifier, the second amplifier configured to generate a second amplified signal at increased power efficiency in a second operational power range, wherein the second operational power range is different than the first operational power range, and wherein the first operational power range and the second operational power range overlap to provide a hysteresis;

a third amplifier in communication with the radio frequency signal, the third amplifier arranged in parallel with the first and second amplifiers, the third amplifier configured to generate a third amplified signal at increased power efficiency in a third operational power range, wherein the third operational power range is different than the first and second operational power ranges, and wherein the second operational power range and the third operational power range overlap to provide the hysteresis;

a switch in communication with the first, second, and third amplifiers, the switch configured to select the first, second or third amplified signal as the amplified output signal; and

a selector in communication with the first, second, and third amplifiers, the selector configured to selectively activate the first, second or third amplifier; and

a control module in communication with the switch and the selector, wherein the control module processes a signal to change an output power level, the control module comprising;

a threshold detector configured to detect a voltage applied to the amplifier module; and

a preset threshold voltage comprising an upper threshold and a lower threshold to provide the hysteresis, wherein the control module is configured to control the switch and the selector based on a comparison of the voltage and the preset threshold voltage, the hysteresis, and as a function of the signal to change the output power level so that a power efficiency of the amplifier module is improved over a predetermined range of output power.

2. The device of claim 1, wherein the first operational power range is between 29 dBm and 19 dBm.

3. The device of claim 1, wherein the second operational power range is between 20 dBm and 9 dBm.

4. The device of claim 1, wherein the third operational power range is between 10 dBm and −

1 dBm.

5. The device of claim 1 wherein the selector receives a digital control value.

6. The device of claim 5 wherein the control value identifies at least one of the first, second or third amplifiers.

7. An amplification module comprising:

an input for receiving an amplifier input signal;

at least a first amplifier in communication with the input, the first amplifier configured to amplify the input signal to generate a first amplified signal at increased output power efficiency within a first amplifier input range;

at least a second amplifier in communication with the input, the second amplifier arranged in parallel with the first amplifier, the second amplifier configured to amplify the input signal to generate a second amplified signal at increased output power efficiency within a second amplifier input range, wherein the second amplifier input range is different than the first amplifier input range, and wherein the first amplifier input range and the second amplifier input range overlap to provide a hysteresis; and

a switch in communication with the first and second amplifiers, the switch configured to output at least one of the first and second amplified signals as an amplified output signal, wherein the switch is controlled as a function of an output power level change, a voltage applied at the input of the amplification module, a predetermined threshold value comprising an upper threshold and a lower threshold to provide the hysteresis, and the hysteresis so that a power efficiency of the amplification module is improved over a range of output power.

8. The amplification module of claim 7 wherein the first and second amplifiers are configured to be selectively activated.

9. The amplification module of claim 7 wherein the first amplifier operates with increased power efficiency for an operational power range between 29 dBm and 19 dBm.

10. The amplification module of claim 7 wherein the second amplifier operates with increased power efficiency for an operational power range between 20 dBm and 9 dBm.

11. The amplification module of claim 7 wherein the switch selects either the first or second amplified signal.

12. The amplification module of claim 7 wherein the switch combines the first and second amplified signals.

13. The amplification module of claim 7 further comprising a selector, the selector configured to at least enable or disable at least one of the first or second amplifiers.

14. The amplification module of claim 7, further comprising at least a third amplifier in communication with the input, the third amplifier arranged in parallel with the first and second amplifiers, the third amplifier configured to amplify the input signal to generate a third amplified signal at increased output power efficiency within a third amplifier input range, wherein the third amplifier input range is different than the first and second amplifier input ranges and wherein the second amplifier input range and the third amplifier input range overlap to provide the hysteresis.

15. An amplifier circuit comprising:

an input for receiving an input signal;

at least a first amplifier in communication with the input, the first amplifier configured to amplify the input signal to generate a first amplified signal at increased power efficiency within a first operational power range;

at least a second amplifier in communication with the input, the second amplifier arranged in parallel with the first amplifier, the second amplifier configured to amplify the input signal to generate a second amplified signal at increased power efficiency within a second operational power range, wherein the second operational power range is different than the first operational power range, and wherein the first operational power range and the second operational power range overlap to provide a hysteresis; and

a selector in communication with the first and second amplifiers, the selector configured to enable at least one of the first and second amplifiers so as to generate an amplified output signal as a function of a signal to change an output power level, a voltage applied to the amplifier circuit, a preset threshold voltage comprising an upper threshold and a lower threshold to provide the hysteresis, and the hysteresis so that a power efficiency of the amplifier circuit is improved over a range of output power.

16. The amplifier circuit of claim 15 wherein the input signal is approximately 800 megahertz.

17. The amplifier circuit of claim 15 wherein the input signal is approximately 1900 megahertz.

18. The amplifier circuit of claim 15 wherein the amplified output signal is a wireless communications signal.

19. The amplifier circuit of claim 15 wherein the amplified output signal is a CDMA communications signal.

20. The amplifier circuit of claim 15 wherein the amplified output signal is a GSM communications signal.

21. The amplifier circuit of claim 15 wherein the amplified output signal is a PCS communications signal.

22. The amplifier circuit of claim 15 wherein the amplified output signal is an AMPS communications signal.

23. An amplifier circuit comprising:

a first means for amplifying an input signal to generate a first amplified signal at increased power efficiency within a first operational power range;

a second means arranged generally parallel with the first means, the second means for amplifying the input signal to generate a second amplified signal at increased power efficiency within a second operational power range, wherein the second operational power range is different than the first operational power range, and wherein the second operational power range overlaps the first operational power range to provide a hysteresis;

a third means for selectively enabling an output of at least one of the first or second amplified signals as a function of a voltage applied to the amplifier circuit, a preset threshold voltage comprising an upper threshold and a lower threshold to provide the hysteresis, the hysteresis, and a signal to change an output power level so that a power efficiency of the amplifier circuit is improved over a range of output power.

24. The amplifier circuit of claim 23 further comprising a fourth means for selectively enabling at least one of the first or second means for amplifying.

25. The amplifier circuit of claim 24 further comprising a fifth means for controlling the fourth means, the fifth means for controlling the enabling of at least one of the first and second means for amplifying based on a desired operational.

26. A method of operating a wireless communications device comprising the acts of:

converting a baseband signal to a radio frequency signal;

receiving the radio frequency signal as an amplifier input signal;

amplifying with a first amplifier, the amplifier input signal at increased power efficiency in a first operational power range to produce a first amplified signal;

amplifying with a second amplifier, the amplifier input signal at increased power efficiency in a second operational power range to produce a second amplified signal, the second amplifier arranged in parallel with the first amplifier, wherein the second operational power range is different than the first operational power range, and wherein the first operational power range and the second operational power range overlap to provide a hysteresis;

amplifying with a third amplifier, the amplifier input signal at increased power efficiency in a third operational power range to produce a third amplified signal, the third amplifier arranged in parallel with the first and second amplifiers, wherein the third operational power range is different than the first and second operational power ranges, and wherein the second operational power range and the third operational power range overlap to provide the hysteresis; and

selectively outputting at least one of the first, second and third amplified signals as an amplified output signal, wherein the selectively outputting is based on an output power level change, a voltage applied to the first, second, and third amplifier, a preset threshold voltage comprising an upper threshold and a lower threshold to provide the hysteresis, and the hysteresis so that a power efficiency of the wireless communication device is improved over a predetermined range of output power.

27. The method of claim 26 wherein the first operational power range is between 29 dBm and 19 dBm.

28. The method of claim 26 wherein the second operational power range is between 20 dBm and 9 dBm.

29. The method of claim 26 wherein the third operational power range is between 10 dBm and −

1 dBm.

30. The method of claim 26 further comprising the act of selectively activating the first, second or third amplifier.

31. The method of claim 26 further comprising the act of processing a digital control value to selectively activate the first, second or third amplifier.

32. The method of claim 26 further comprising the act of processing the first amplified signal with a fourth amplifier to generate a modified first amplified signal.

33. A method of amplifying an input signal over a range of output power comprising the acts of:

receiving an amplifier input signal;

amplifying the input signal with a first amplifier to generate a first amplified signal at increased output power efficiency within a first amplifier input range;

amplifying the input signal with a second amplifier to generate a second amplified signal at increased output power efficiency within a second amplifier input range, the second amplifier arranged in parallel with the first amplifier, wherein the second amplifier input range is different than the first amplifier input range; and

selectively enabling an output of at least one of the first and second amplified signals as a function of a change in an output power, a voltage applied to at least one of the first and second amplifiers, a preset threshold voltage comprising an upper threshold and a lower threshold to provide a hysteresis, and the hysteresis so that a power efficiency is improved over the range of output power.

34. The method of claim 33 further comprising the act of selectively activating at least one of the first and second amplifiers.

35. The method of claim 33 wherein a first operational power range is between 29 dBm and 19 dBm.

36. The method of claim 33 wherein a second operational power range is between 20 dBm and 9 dBm.

37. The method of claim 33 wherein the act of selectively enabling selects either the first or second amplified signal.

38. The method of claim 33 wherein the act of selectively enabling combines the first and second amplified signals.

39. A method of amplifying an input signal and generating an amplified output signal comprising the acts of:

receiving an input signal;

amplifying with a first amplifier, the input signal to generate a first amplified signal at increased power efficiency within a first operational power range;

amplifying with a second amplifier, the input signal to generate a second amplified signal at increased power efficiency within a second operational power range, the second amplifier arranged in parallel with the first amplifier, and wherein the first operational power range is different from the second operational power range, and wherein the first operational power range overlaps the second operational power range to provide a hysteresis;

receiving a signal to change an output power level;

comparing a voltage applied to at least one of the first and second amplifiers with a preset threshold voltage comprising an upper threshold and a lower threshold to provide the hysteresis, wherein the act of comparing produces a comparison; and

selecting at least one of the first and second amplified signals so as to generate the amplified output signal as a function of the signal to change the output power level, the comparison, and the hysteresis so that a power efficiency is improved over a range of output power.

40. The method of claim 39 wherein the input signal is approximately 800 megahertz.

41. The method of claim 39 wherein the input signal is approximately 1900 megahertz.

42. The method of claim 39 wherein the amplified output signal is a wireless communications signal.

43. The method of claim 39 wherein the amplified output signal is a CDMA communications signal.

44. The method of claim 39 wherein the amplified output signal is a GSM communications signal.

45. The method of claim 39 wherein the amplified output signal is a PCS communications signal.

46. The method of claim 39 wherein the amplified output signal is an AMPS communications signal.