Cascaded converged power amplifier

• US 8,942,651 B2
• Filed: 10/22/2012
• Issued: 01/27/2015
• Est. Priority Date: 04/20/2010
• Status: Active Grant

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: RF Micro Devices Incorporated (Qorvo, Inc.)
• Inventors: Jones, David E.
• Primary Examiner(s): PHU, SANH D
• Application Number:
  US13/656,997
• Publication Number:
  US 20130043944A1
• Time in Patent Office: 827 Days
• Field of Search: 455/127.1, 455/126.1, 455/118, 455/69, 455/78, 455/180.3, 455/112
• US Class Current: 455/127.1
• CPC Class Codes: H03F 1/0227 using supply converters
• CPC Class Codes: H03F 1/0261 with control of the polarisation voltage or current, e.g. gliding Class A
• CPC Class Codes: H03F 1/0277 Selecting one or more amplifiers from a plurality of amplifiers
• CPC Class Codes: H03F 2200/171 A filter circuit coupled to the output of an amplifier
• CPC Class Codes: H03F 2200/222 A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier
• CPC Class Codes: H03F 2200/27 A biasing circuit node being switched in an amplifier circuit
• CPC Class Codes: H03F 2200/318 A matching circuit being used as coupling element between two amplifying stages
• CPC Class Codes: H03F 2200/336 A I/Q, i.e. phase quadrature, modulator or demodulator being used in an amplifying circuit
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/411 the output amplifying stage of an amplifier comprising two power stages
• CPC Class Codes: H03F 2200/414 A switch being coupled in the output circuit of an amplifier to switch the output on/off
• CPC Class Codes: H03F 2200/417 A switch coupled in the output circuit of an amplifier being controlled by a circuit
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/504 the supply voltage or current being continuously controlled by a controlling signal, e.g. the controlling signal of a transistor implemented as variable resistor in a supply path for, an IC-block showed amplifier
• CPC Class Codes: H03F 2200/534 Transformer coupled at the input of an amplifier
• CPC Class Codes: H03F 2200/537 A transformer being used as coupling element between two amplifying stages
• CPC Class Codes: H03F 2200/541 Transformer coupled at the output of an amplifier
• CPC Class Codes: H03F 2203/21106 An input signal being distributed in parallel over the inputs of a plurality of power amplifiers
• CPC Class Codes: H03F 2203/21142 Output signals of a plurality of power amplifiers are parallel combined to a common output
• CPC Class Codes: H03F 2203/21157 A filter circuit being added at the output of a power amplifier stage
• CPC Class Codes: H03F 3/195 : in integrated circuits
• CPC Class Codes: H03F 3/211 : using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/245 : with semiconductor devices only
• CPC Class Codes: H03F 3/602 : Combinations of several amplifiers
• CPC Class Codes: H03F 3/72 : Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal

Abstract

A first radio frequency (RF) power amplifier (PA) stage, a second RF PA stage, and an alpha RF switch are disclosed. The first RF PA stage provides a first RF output signal. During a first alpha mode, the alpha RF switch forwards the first RF output signal to the second RF PA stage, such that the first RF PA stage functions as a driver stage and the second RF PA stage functions as a final stage. However, during one of a group of alpha modes, the alpha RF switch forwards the first RF output signal to provide a corresponding one of a group of alpha transmit signals, such that the first RF PA stage functions as a final stage. Further, the first alpha mode is not one of the group of alpha modes.

Claims

1. Circuitry comprising:

a first radio frequency (RF) power amplifier (PA) stage adapted to provide a first RF output signal;

a second RF PA stage; and

an alpha RF switch adapted to;

during a first alpha mode, forward the first RF output signal to the second RF PA stage, such that the first RF PA stage is further adapted to function as a driver stage and the second RF PA stage is adapted to function as a final stage; and

during one of a plurality of alpha modes, forward the first RF output signal to provide a corresponding one of a group of alpha transmit signals, such that the first RF PA stage is further adapted to function as a final stage and the first alpha mode is not one of the plurality of alpha modes, wherein a load line of the first RF PA stage during the first alpha mode is not equal to any load line of the second RF PA stage during any of the plurality of alpha modes.

2. The circuitry of claim 1 further comprising a first alpha harmonic filter coupled to the second RF PA stage, such that during the first alpha mode, the second RF PA stage is further adapted to amplify the forwarded first RF output signal to provide a first alpha RF transmit signal via the first alpha harmonic filter.

3. The circuitry of claim 1 wherein the first alpha mode is a first alpha non-linear mode and the plurality of alpha modes is a plurality of linear modes.

4. The circuitry of claim 3 wherein the first alpha non-linear mode is a half-duplex mode and each of the plurality of linear modes is a full-duplex mode.

5. The circuitry of claim 3 wherein the first alpha non-linear mode is a saturated mode.

6. The circuitry of claim 1 further comprising control circuitry adapted to select one of a group consisting of the first alpha mode and the plurality of alpha modes.

7. The circuitry of claim 1 further comprising a first switching power supply adapted to provide an envelope power supply signal, such that the first RF PA stage is further adapted to receive and amplify an alpha driver stage output signal to provide the first RF output signal using the envelope power supply signal.

8. The circuitry of claim 7 wherein the first switching power supply is an envelope tracking power supply.

9. The circuitry of claim 8 wherein the envelope tracking power supply comprises switching circuitry and a parallel amplifier, wherein the switching circuitry is adapted to provide part of the envelope power supply signal and the parallel amplifier is adapted to provide part of the envelope power supply signal.

10. The circuitry of claim 7 further comprising a first DC power supply adapted to provide a first DC power supply signal, such that during the first alpha mode, the second RF PA stage is further adapted to amplify the forwarded first RF output signal to provide a first alpha RF transmit signal via a first alpha harmonic filter using the first DC power supply signal.

11. The circuitry of claim 10 wherein the first DC power supply is a low drop-out (LDO) regulator.

12. The circuitry of claim 10 wherein the first DC power supply is a switching power supply.

13. The circuitry of claim 10 further comprising an alpha driver stage adapted to receive and amplify a first RF input signal to provide the alpha driver stage output signal.

14. The circuitry of claim 13 wherein a DC power source is adapted to provide a DC source signal, such that the alpha driver stage is further adapted to receive and amplify the first RF input signal to provide the alpha driver stage output signal using the DC source signal.

15. The circuitry of claim 14 wherein the DC power source is a battery.

16. The circuitry of claim 13 further comprising a second DC power supply adapted to provide a second DC power supply signal, such that the alpha driver stage is further adapted to receive and amplify the first RF input signal to provide the alpha driver stage output signal using the second DC power supply signal.

17. The circuitry of claim 7 wherein a DC power source adapted to provide a DC source signal, such that during the first alpha mode, the second RF PA stage is further adapted to amplify the forwarded first RF output signal to provide a first alpha RF transmit signal via a first alpha harmonic filter using the DC source signal.

18. The circuitry of claim 7 further comprising an alpha driver stage adapted to receive and amplify a first RF input signal to provide the alpha driver stage output signal using the envelope power supply signal.

19. The circuitry of claim 7 further comprising an alpha driver stage and a n alpha programmable attenuator, such that the alpha programmable attenuator is adapted to receive and attenuate a first RF input signal to provide an alpha driver stage input signal based on a selected one of a group consisting of the first alpha mode and the plurality of alpha modes, and the alpha driver stage is adapted to receive and amplify the alpha driver stage input signal to provide the alpha driver stage output signal.

20. The circuitry of claim 1 further comprising:

a third RF PA stage adapted to provide a second RF output signal;

a fourth RF PA stage; and

a beta RF switch adapted to;

during a first beta mode, forward the second RF output signal to the fourth RF PA stage, such that the third RF PA stage is further adapted to function as a driver stage and the fourth RF PA stage is adapted to function as a final stage; and

during one of a plurality of beta modes, forward the second RF output signal to provide a corresponding one of a group of beta transmit signals, such that the third RF PA stage is further adapted to function as a final stage and the first beta mode is not one of the plurality of beta modes.

21. The circuitry of claim 20 adapted to operate in one of a first PA operating mode and a second PA operating mode, such that during the first PA operating mode, the first RF PA stage, the second RF PA stage, and the alpha RF switch are enabled, and the third RF PA stage, the fourth RF PA stage, and the beta RF switch are disabled, and during the second PA operating mode, the first RF PA stage, the second RF PA stage, and the alpha RF switch are disabled, and the third RF PA stage, the fourth RF PA stage, and the beta RF switch are enabled.

22. The circuitry of claim 20 wherein the first RF output signal is a highband RF output signal and the second RF output signal is a lowband RF output signal.

23. The circuitry of claim 1 further comprising:

a first RF PA comprising the first RF PA stage, which is a first final stage having a first final bias input, such that bias of the first final stage is via the first final bias input;

PA control circuitry;

a PA-digital communications interface (DCI) coupled between a digital communications bus and the PA control circuitry; and

a final stage current digital-to-analog converter (IDAC) coupled between the PA control circuitry and the first final bias input.

24. The circuitry of claim 1 further comprising:

a first RF PA having the first RF PA stage, which is a first final stage, and adapted to;

receive and amplify a first RF input signal to provide the first RF output signal; and

receive a first final bias signal to bias the first final stage;

PA bias circuitry adapted to receive a bias power supply signal and provide the first final bias signal based on the bias power supply signal; and

a direct current (DC)-DC converter adapted to receive a DC power supply signal from a DC power supply and provide the bias power supply signal based on the DC power supply signal, such that a voltage of the bias power supply signal is greater than a voltage of the DC power supply signal.

25. The circuitry of claim 1 further comprising:

a direct current (DC)-DC converter comprising;

a power amplifier (PA) envelope power supply comprising a charge pump buck converter coupled to radio frequency (RF) PA circuitry; and

a PA bias power supply comprising a charge pump coupled to the RF PA circuitry; and

the RF PA circuitry, which comprises the first RF PA stage, the second RF PA stage, and the alpha RF switch.

26. The circuitry of claim 1 further comprising:

multi-mode multi-band RF power amplification circuitry having at least a first RF input and a plurality of RF outputs, such that;

configuration of the multi-mode multi-band RF power amplification circuitry associates one of the at least the first RF input with one of the plurality of RF outputs;

the multi-mode multi-band RF power amplification circuitry comprises the first RF PA stage, the second RF PA stage, and the alpha RF switch; and

the configuration is associated with at least a first look-up table (LUT);

PA control circuitry coupled between the multi-mode multi-band RF power amplification circuitry and a PA-digital communications interface (DCI), such that the PA control circuitry has at least the first LUT, which is associated with at least a first defined parameter set; and

the PA-DCI, which is coupled to a digital communications bus.

27. A method comprising:

selecting one of a group consisting of a first alpha mode and a plurality of alpha modes;

providing a first RF output signal using a first radio frequency (RF) power amplifier (PA) stage;

during the first alpha mode, forwarding the first RF output signal to a second RF PA stage, such that the first RF PA stage functions as a driver stage and the second RF PA stage functions as a final stage; and

during one of the plurality of alpha modes, forwarding the first RF output signal to provide a corresponding one of a group of alpha transmit signals, such that the first RF PA stage functions as a final stage and the first alpha mode is not one of the plurality of alpha modes, wherein a load line of the first RF PA stage during the first alpha mode is not equal to any load line of the second RF PA stage during any of the plurality of alpha modes.