Envelope tracking circuit and related power amplifier system

• US 10,742,170 B2
• Filed: 06/26/2018
• Issued: 08/11/2020
• Est. Priority Date: 02/01/2018
• Status: Active Grant

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Inventors: Khlat, Nadim
• Primary Examiner(s): Nguyen, Hieu P
• Application Number:
  US16/018,426
• Publication Number:
  US 20190238095A1
• Time in Patent Office: 777 Days
• Field of Search: 330297, 330127, 330129, 330134, 330279
• CPC Class Codes: H03F 1/0222 by using a signal derived from the input signal
• CPC Class Codes: H03F 1/0233 by using a signal derived from the output signal, e.g. bootstrapping the voltage supply
• CPC Class Codes: H03F 2200/105 A non-specified detector of the power of a signal being used in an amplifying circuit
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/245 with semiconductor devices only
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602

Abstract

Envelope tracking circuit and related power amplifier system are provided. In one aspect, an ET circuit is configured to generate a first number of ET modulated voltages based on a second number of target voltages and output the first number of ET modulated voltages via a third number of voltage outputs. In another aspect, the ET circuit can be provided in a power amplifier system including a transceiver circuit(s) and a number of power amplifier circuits. In examples discussed herein, the ET circuit may receive the second number of target voltages from the transceiver circuit(s) and provide the first number of ET modulated voltages to the power amplifier circuits for amplifying a radio frequency (RF) signal(s). By providing the ET circuit in the power amplifier system, it is possible to flexibly enable ET power management based on any number of transceiver circuits and for any number of power amplifier circuits.

Claims

1. An envelope tracking (ET) circuit comprising:

an ET voltage circuit comprising;

a first number of tracker circuits configured to generate a first number of ET modulated voltages;

a second number of voltage inputs configured to receive a second number of target voltages, wherein the second number of voltage inputs does not equal the first number of tracker circuits; and

a third number of voltage outputs configured to output the first number of ET modulated voltages; and

a control circuit configured to;

couple a selected number of tracker circuits among the first number of tracker circuits to a selected number of voltage inputs among the second number of voltage inputs, wherein the selected number of tracker circuits is configured to;

receive a selected number of target voltages among the second number of target voltages via the selected number of voltage inputs; and

generate a selected number of ET modulated voltages among the first number of ET modulated voltages based on the selected number of target voltages; and

selectively provide the selected number of ET modulated voltages to the third number of voltage outputs.

2. The ET circuit of claim 1 wherein:

the ET voltage circuit further comprises an input switching circuit coupled between the first number of tracker circuits and the second number of voltage inputs; and

the control circuit is further configured to control the input switching circuit to couple the selected number of tracker circuits to the selected number of voltage inputs.

3. The ET circuit of claim 1 wherein:

the ET voltage circuit further comprises an output switching circuit coupled between the first number of tracker circuits and the third number of voltage outputs; and

the control circuit is further configured to control the output switching circuit to selectively provide the selected number of ET modulated voltages to the third number of voltage outputs.

4. The ET circuit of claim 1 wherein the control circuit is further configured to couple the first number of tracker circuits to a selected subset of the second number of voltage inputs in response to the first number of tracker circuits being less than the second number of voltage inputs.

5. The ET circuit of claim 1 wherein the control circuit is further configured to activate and couple a selected subset of the first number of tracker circuits to the second number of voltage inputs in response to the first number of tracker circuits being greater than the second number of voltage inputs.

6. The ET circuit of claim 1 wherein the control circuit is further configured to couple the first number of tracker circuits to the third number of voltage outputs, respectively, in response to the first number of tracker circuits being equal to the third number of voltage outputs.

7. The ET circuit of claim 1 wherein:

the third number of voltage outputs comprises a plurality of primary voltage outputs and a plurality of auxiliary voltage outputs; and

the control circuit is further configured to;

couple one or more of the first number of tracker circuits to one or more selected primary voltage outputs among the plurality of primary voltage outputs; and

couple one or more of the first number of tracker circuits to one or more selected auxiliary voltage outputs among the plurality of auxiliary voltage outputs.

8. The ET circuit of claim 1 wherein:

the ET voltage circuit further comprises;

an input switching circuit coupled between the first number of tracker circuits and the second number of voltage inputs; and

an output switching circuit coupled between the first number of tracker circuits and the third number of voltage outputs; and

the control circuit is further configured to;

control the input switching circuit to couple the selected number of tracker circuits to the selected number of voltage inputs; and

control the output switching circuit to selectively provide the selected number of ET modulated voltages to the third number of voltage outputs.

9. The ET circuit of claim 8 wherein the control circuit is further configured to control the input switching circuit to couple the first number of tracker circuits to a selected subset of the second number of voltage inputs in response to the first number of tracker circuits being lesser than the second number of voltage inputs.

10. The ET circuit of claim 8 wherein the control circuit is further configured to activate a selected subset of the first number of tracker circuits and control the input switching circuit to couple the selected subset of the first number of tracker circuits to the second number of voltage inputs in response to the first number of tracker circuits being greater than the second number of voltage inputs.

11. The ET circuit of claim 8 wherein the control circuit is further configured to control the output switching circuit to couple the first number of tracker circuits to the third number of voltage outputs, respectively, in response to the first number of tracker circuits being equal to the third number of voltage outputs.

12. The ET circuit of claim 8 wherein:

the third number of voltage outputs comprises a plurality of primary voltage outputs and a plurality of auxiliary voltage outputs; and

the control circuit is further configured to;

control the output switching circuit to couple one or more of the first number of tracker circuits to one or more selected primary voltage outputs among the plurality of primary voltage outputs; and

control the output switching circuit to couple one or more of the first number of tracker circuits to one or more selected auxiliary voltage outputs among the plurality of auxiliary voltage outputs.

13. A power amplifier system comprising:

an envelope tracking (ET) circuit comprising;

an ET voltage circuit comprising;

a first number of tracker circuits configured to generate a first number of ET modulated voltages;

a second number of voltage inputs configured to receive a second number of target voltages, wherein the second number of voltage inputs does not equal the first number of tracker circuits; and

a third number of voltage outputs configured to output the first number of ET modulated voltages; and

a control circuit configured to;

couple a selected number of tracker circuits among the first number of tracker circuits to a selected number of voltage inputs among the second number of voltage inputs, wherein the selected number of tracker circuits is configured to;

receive a selected number of target voltages among the second number of target voltages via the selected number of voltage inputs; and

generate a selected number of ET modulated voltages among the first number of ET modulated voltages based on the selected number of target voltages; and

selectively provide the selected number of ET modulated voltages to the third number of voltage outputs; and

a plurality of power amplifier circuits coupled to the third number of voltage outputs each configured to amplify a radio frequency (RF) signal based on an ET modulated voltage among the first number of ET modulated voltages.

14. The power amplifier system of claim 13 wherein each of the third number of voltage outputs is coupled to one or more of the plurality of power amplifier circuits.

15. The power amplifier system of claim 13 wherein:

the ET voltage circuit further comprises an input switching circuit coupled between the first number of tracker circuits and the second number of voltage inputs; and

the control circuit is further configured to control the input switching circuit to couple the selected number of tracker circuits to the selected number of voltage inputs.

16. The power amplifier system of claim 13 wherein:

the ET voltage circuit further comprises an output switching circuit coupled between the first number of tracker circuits and the third number of voltage outputs; and

the control circuit is further configured to control the output switching circuit to selectively provide the selected number of ET modulated voltages to the third number of voltage outputs.

17. The power amplifier system of claim 13 wherein the control circuit is further configured to couple the first number of tracker circuits to a selected subset of the second number of voltage inputs in response to the first number of tracker circuits being less than the second number of voltage inputs.

18. The power amplifier system of claim 13 wherein the control circuit is further configured to activate and couple a selected subset of the first number of tracker circuits to the second number of voltage inputs in response to the first number of tracker circuits being greater than the second number of voltage inputs.

19. The power amplifier system of claim 13 wherein the control circuit is further configured to couple the first number of tracker circuits to the third number of voltage outputs, respectively, in response to the first number of tracker circuits being equal to the third number of voltage outputs.

20. The power amplifier system of claim 13 wherein:

the third number of voltage outputs comprises a plurality of primary voltage outputs and a plurality of auxiliary voltage outputs; and

the control circuit is further configured to;

couple one or more of the first number of tracker circuits to one or more selected primary voltage outputs among the plurality of primary voltage outputs; and

couple one or more of the first number of tracker circuits to one or more selected auxiliary voltage outputs among the plurality of auxiliary voltage outputs.

21. The power amplifier system of claim 13 further comprising a transceiver circuit configured to provide the second number of target voltages to the second number of voltage inputs.

22. The power amplifier system of claim 21 further comprising a second ET circuit coupled to the transceiver circuit and configured to receive the second number of target voltages and output the first number of ET modulated voltages via the third number of voltage outputs.

23. The power amplifier system of claim 22 further comprising a plurality of second amplifier circuits coupled to the second ET circuit.

24. The power amplifier system of claim 13 further comprising a transceiver system comprising a plurality of transceiver circuits configured to collectively provide the second number of target voltages to the second number of voltage inputs.

25. The power amplifier system of claim 24 further comprising a second ET circuit coupled to the transceiver system and configured to receive the second number of target voltages and output the first number of ET modulated voltages via the third number of voltage outputs.