Amplifying a transmit signal using a fractional power amplifier

• US 20070218849A1
• Filed: 11/03/2005
• Published: 09/20/2007
• Est. Priority Date: 11/03/2005
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Magnolia Broadband Incorporated
• Inventors: Karmi, Yair, Harel, Haim
• Granted Patent: US 7,965,987 B2
• Time in Patent Office: Days
• US Class Current: 455/127.300
• CPC Class Codes: H03F 2203/7215 the gated amplifier being switched on or off by a switch at the input of the amplifier
• CPC Class Codes: H03F 2203/7221 the gated amplifier being switched on or off by a switch at the output of the amplifier
• 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: H04B 1/0483 Transmitters with multiple parallel paths

Abstract

A transmit amplifier stage operable to amplify a transmit signal comprises power amplifiers and switches. The power amplifiers include at least one full power amplifier operable to provide full power to amplify the transmit signal and at least one fractional power amplifier operable to provide fractional power to amplify the transmit signal, where the fractional power is a fraction of the full power. A switch has a plurality of positions, where a position directs the transmit signal to a selected power amplifier.

Claims

1. A transmit amplifier stage operable to amplify a transmit signal, comprising:

a plurality of power amplifiers, a power amplifier operable to amplify a transmit signal, the plurality of power amplifiers comprising;

at least one full power amplifier operable to provide full power to amplify the transmit signal; and

at least one fractional power amplifier operable to provide fractional power to amplify the transmit signal, the fractional power being a fraction of the full power; and

one or more switches, a switch having a plurality of positions, a position operable to direct the transmit signal to a selected power amplifier of the plurality of power amplifiers.

2. The transmit amplifier stage of claim 1, wherein a substantially maximum efficiency of the at least one fractional power amplifier substantially coincides at the fractional power.

3. The transmit amplifier stage of claim 1, wherein the at least one fractional power amplifier further comprises:

a first fractional power amplifier operable to provide a first fractional power; and

a second fractional power amplifier operable to provide a second fractional power, the second fractional power different from the first fractional power.

4. The transmit amplifier stage of claim 1, further comprising a bypass path bypassing the plurality of power amplifiers, a bypass position of the plurality of positions operable to direct the transmit signal to the bypass path.

5. A transmit amplifier stage operable to amplify a signal, comprising:

a plurality of channels comprising;

a first channel comprising;

a plurality of first power amplifiers, a first power amplifier operable to amplify a first transmit signal for transmission by a first antenna, the plurality of first power amplifiers comprising;

at least one full first power amplifier operable to provide full power to amplify the first transmit signal; and

at least one fractional first power amplifier operable to provide fractional power to amplify the first transmit signal, the fractional power being a fraction of the full power; and

one or more first switches, a first switch having a plurality of positions, a position operable to direct the first transmit signal to a selected power amplifier of the plurality of first power amplifiers; and

a second channel comprising one or more second power amplifiers, a second power amplifier operable to amplify a second transmit signal for transmission by a second antenna.

6. The transmit amplifier stage of claim 5, wherein a substantially maximum efficiency of the at least one first fractional power amplifier substantially coincides at the fractional power.

7. The transmit amplifier stage of claim 5, wherein the one or more second power amplifiers further comprise one or more fractional second power amplifiers.

8. The transmit amplifier stage of claim 5, wherein the second channel further comprises:

one or more second switches, a second switch having a plurality of positions, a position operable to direct the second transmit signal to a selected power amplifier of the one or more second power amplifiers.

9. The transmit amplifier stage of claim 5, wherein the at least one first fractional power amplifier further comprises:

a first fractional first power amplifier operable to provide a first fractional power; and

a second fractional first power amplifier operable to provide a second fractional power, the second fractional power different from the first fractional power.

10. The transmit amplifier stage of claim 5, further comprising at least one of:

a first bypass path operable to bypass the plurality of first power amplifiers; and

a second bypass path operable to bypass the one or more second power amplifiers.

11. A method for amplifying a transmit signal for transmission, comprising:

receiving a control signal comprising an instruction for amplifying a transmit signal for transmission by an antenna;

selecting a position of a plurality of positions of a switch in accordance with the control signal, a position operable to direct the transmit signal to a corresponding power amplifier of a plurality of power amplifiers, the plurality of power amplifiers comprising;

at least one full power amplifier operable to provide full power to amplify the transmit signal; and

at least one fractional power amplifier operable to provide fractional power to amplify the transmit signal, the fractional power being a fraction of the full power;

directing the transmit signal to the selected position of the switch; and

amplifying the transmit signal using the power amplifier corresponding to the selected position.

12. The method of claim 11, wherein a substantially maximum efficiency of the at least one fractional power amplifier substantially coincides at the fractional power.

13. The method of claim 11, wherein the at least one fractional power amplifier further comprises:

a first fractional power amplifier operable to provide a first fractional power; and

a second fractional power amplifier operable to provide a second fractional power, the second fractional power different from the first fractional power.

14. The method of claim 11, further comprising:

bypassing the plurality of power amplifiers through a bypass path, a bypass position of the plurality of positions operable to direct the transmit signal to the bypass path.

15. A method for amplifying a transmit signal for transmission, comprising:

receiving one or more control signals comprising a first control signal, the first control signal comprising an instruction for amplifying a first transmit signal;

amplifying the first transmit signal for transmission by a first antenna by;

selecting a position of a plurality of positions of a first switch in accordance with the first control signal, a position operable to direct the first transmit signal to a corresponding first power amplifier of a plurality of first power amplifiers, the plurality of first power amplifiers comprising;

at least one full first power amplifier operable to provide full power to amplify the first transmit signal; and

at least one fractional first power amplifier operable to provide fractional power to amplify the first transmit signal, the fractional power being a fraction of the full power;

directing the first transmit signal to the selected position of the switch; and

amplifying the first transmit signal using the first power amplifier corresponding to the selected position; and

amplifying a second transmit signal using a second power amplifier of one or more second power amplifiers, the second transmit signal for transmission by a second antenna.

16. The method of claim 15, wherein a substantially maximum efficiency of the at least one first fractional power amplifier substantially coincides at the fractional power.

17. The method of claim 15, wherein the one or more second power amplifiers further comprise one or more fractional second power amplifiers.

18. The method of claim 15, further comprising:

directing the second transmit signal using a second switch having a plurality of positions, a position operable to direct the second transmit signal to a selected power amplifier of the one or more second power amplifiers.

19. The method of claim 15, wherein the at least one first fractional power amplifier further comprises:

a first fractional first power amplifier operable to provide a first fractional power; and

a second fractional first power amplifier operable to provide a second fractional power, the second fractional power different from the first fractional power.

20. The method of claim 15, further comprising at least one of:

bypassing the plurality of first power amplifiers using a first bypass path; and

bypassing the one or more second power amplifiers using a second bypass path.

21. A system for amplifying a transmit signal for transmission, comprising:

means for receiving a control signal comprising an instruction for amplifying a transmit signal for transmission by an antenna;

means for selecting a position of a plurality of positions of a switch in accordance with the control signal, a position operable to direct the transmit signal to a corresponding power amplifier of a plurality of power amplifiers, the plurality of power amplifiers comprising;

at least one full power amplifier operable to provide full power to amplify the transmit signal; and

at least one fractional power amplifier operable to provide fractional power to amplify the transmit signal, the fractional power being a fraction of the full power;

means for directing the transmit signal to the selected position of the switch; and

means for amplifying the transmit signal using the power amplifier corresponding to the selected position.

22. A system for amplifying a transmit signal for transmission, comprising:

means for receiving one or more control signals comprising a first control signal, the first control signal comprising an instruction for amplifying a first transmit signal;

means for amplifying the first transmit signal for transmission by a first antenna by;

selecting a position of a plurality of positions of a first switch in accordance with the first control signal, a position operable to direct the first transmit signal to a corresponding first power amplifier of a plurality of first power amplifiers, the plurality of first power amplifiers comprising;

at least one full first power amplifier operable to provide full power to amplify the first transmit signal; and

at least one fractional first power amplifier operable to provide fractional power to amplify the first transmit signal, the fractional power being a fraction of the full power;

directing the first transmit signal to the selected position of the switch; and

amplifying the first transmit signal using the first power amplifier corresponding to the selected position; and

means for amplifying a second transmit signal using a second power amplifier of one or more second power amplifiers, the second transmit signal for transmission by a second antenna.

23. A transmit amplifier stage operable to amplify a transmit signal, comprising:

a plurality of power amplifiers, a power amplifier operable to amplify a transmit signal, the plurality of power amplifiers comprising;

at least one full power amplifier operable to provide full power to amplify the transmit signal; and

at least one fractional power amplifier operable to provide fractional power to amplify the transmit signal, the fractional power being a fraction of the full power, a substantially maximum efficiency of the at least one fractional power amplifier substantially coinciding at the fractional power, the at least one fractional power amplifier further comprising;

a first fractional power amplifier operable to provide a first fractional power; and

a second fractional power amplifier operable to provide a second fractional power, the second fractional power different from the first fractional power;

one or more switches, a switch having a plurality of positions, a position operable to direct the transmit signal to a selected power amplifier of the plurality of power amplifiers; and

a bypass path bypassing the plurality of power amplifiers, a bypass position of the plurality of positions operable to direct the transmit signal to the bypass path.

24. A transmit amplifier stage operable to amplify a signal, comprising:

a plurality of channels comprising;

a first channel comprising;

a plurality of first power amplifiers, a first power amplifier operable to amplify a first transmit signal for transmission by a first antenna, the plurality of first power amplifiers comprising;

at least one full first power amplifier operable to provide full power to amplify the first transmit signal; and

at least one fractional first power amplifier operable to provide fractional power to amplify the first transmit signal, the fractional power being a fraction of the full power, a substantially maximum efficiency of the at least one first fractional power amplifier substantially coinciding at the fractional power, the at least one first fractional power amplifier further comprising;

a first fractional first power amplifier operable to provide a first fractional power; and

a second fractional first power amplifier operable to provide a second fractional power, the second fractional power different from the first fractional power; and

one or more first switches, a first switch having a plurality of positions, a position operable to direct the first transmit signal to a selected power amplifier of the plurality of first power amplifiers; and

a second channel comprising;

one or more second power amplifiers, a second power amplifier operable to amplify a second transmit signal for transmission by a second antenna, the one or more second power amplifiers further comprising one or more fractional second power amplifiers; and

one or more second switches, a second switch having a plurality of positions, a position operable to direct the second transmit signal to a selected power amplifier of the one or more second power amplifiers;

a first bypass path operable to bypass the plurality of first power amplifiers; and

a second bypass path operable to bypass the one or more second power amplifiers.