APPARATUS AND METHODS FOR ENVELOPE TRACKERS

• US 20150180421A1
• Filed: 03/06/2015
• Published: 06/25/2015
• Est. Priority Date: 02/09/2012
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: Balteanu, Florinel G., Ripley, David Steven, Khesbak, Sabah, Strahler, Jeffrey Gordon, Arkiszewski, Roman Zbigniew, Tkachenko, Yevgeniy A.
• Granted Patent: US 9,294,054 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 1/0222 by using a signal derived from the input signal
• CPC Class Codes: H03F 1/0227 using supply converters
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 2200/102 A non-specified detector of a signal envelope being used in an amplifying circuit
• CPC Class Codes: H03F 2200/171 A filter circuit coupled to the output of an amplifier
• 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 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2203/21193 the supply voltage of a power amplifier being continuously controlled, e.g. by an active potentiometer
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/193 with field-effect devices H03F3/195 takes precedence
• 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: H04B 1/40 Circuits
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Apparatus and methods for envelope trackers are disclosed herein. In certain configurations, a mobile device includes a power amplifier configured to amplify a radio frequency (RF) input signal to generate an RF output signal. The power amplifier is configured to receive power from a power amplifier supply voltage. The mobile device further includes a voltage converter configured to convert a battery voltage into a regulated voltage, and the voltage converter is configured to control a magnitude of the regulated voltage based on an error signal. The mobile device further includes an error amplifier configured to generate an output current based on an envelope of the RF input signal and to generate the power amplifier supply voltage by adjusting the magnitude of the regulated voltage using the output current. The error amplifier is further configured to control the error signal.

Claims

1. A mobile device comprising:

a power amplifier configured to amplify a radio frequency (RF) input signal to generate an RF output signal, wherein the power amplifier is configured to receive power from a power amplifier supply voltage;

a voltage converter configured to convert a battery voltage into a regulated voltage, the voltage converter configured to control a magnitude of the regulated voltage based on an error signal; and

an error amplifier configured to generate an output current based on an envelope of the RF input signal and to generate the power amplifier supply voltage by adjusting the magnitude of the regulated voltage using the output current, the error amplifier further configured to control the error signal.

2. The mobile device of claim 1 wherein the voltage converter includes a buck converter.

3. The mobile device of claim 1 wherein the error signal corresponds to an error current generated by the error amplifier.

4. The mobile device of claim 1 wherein the error amplifier includes a first input configured to receive an envelope signal that changes in relation to the envelope of the RF input signal.

5. The mobile device of claim 4 further comprising a transceiver configured to generate the envelope signal.

6. The mobile device of claim 4 wherein the error amplifier further includes a second input, the mobile device further comprising a feedback circuit electrically connected between the second input of the error amplifier and the power amplifier supply voltage.

7. The mobile device of claim 1 wherein the error amplifier includes an output configured to output the output current, the output of the error amplifier electrically connected to the power amplifier supply voltage through an AC coupling capacitor.

8. The mobile device of claim 1 further comprising a power management integrated circuit including the voltage converter.

9. The mobile device of claim 1 wherein the error signal corresponds to a control voltage of the voltage converter.

10. An envelope tracker for generating a power amplifier supply voltage for a power amplifier, the envelope tracker comprising:

a voltage converter configured to convert a battery voltage into a regulated voltage, the voltage converter configured to control a magnitude of the regulated voltage based on an error signal; and

an error amplifier configured to generate an output current based on an envelope signal that changes in relation to an envelope of a radio frequency (RF) signal amplified by the power amplifier, the error amplifier further configured to generate the power amplifier supply voltage by adjusting the magnitude of the regulated voltage using the output current, the error amplifier further configured to control the error signal.

11. The envelope tracker of claim 10 wherein the voltage converter includes a buck converter.

12. The envelope tracker of claim 10 wherein the error signal corresponds to an error current generated by the error amplifier.

13. The envelope tracker of claim 10 wherein the error amplifier includes a first input configured to receive the envelope signal.

14. The envelope tracker of claim 10 wherein the error amplifier includes an output configured to output the output current, the output of the error amplifier electrically connected to the power amplifier supply voltage through an AC coupling capacitor.

15. The envelope tracker of claim 10 wherein the error signal corresponds to a control voltage of the voltage converter.

16. The envelope tracker of claim 10 wherein the error amplifier is powered using the battery voltage.

17. The envelope tracker of claim 10 further comprising a boost converter configured to convert the battery voltage into a boost voltage, the boost voltage having a voltage magnitude greater than a voltage magnitude of the battery voltage, the error amplifier powered using the boost voltage.

18. A method of generating a power amplifier supply voltage, the method comprising:

amplifying a radio frequency (RF) input signal to generate an RF output signal using a power amplifier;

powering the power amplifier using a power amplifier supply voltage;

generating a regulated voltage from a battery voltage using a voltage converter;

controlling a magnitude of the regulated voltage based on an error signal using the voltage converter;

generating an output current based on an envelope of the RF input signal using an error amplifier;

controlling the error signal using the error amplifier; and

generating the power amplifier supply voltage by adjusting the magnitude of the regulated voltage using the output current.

19. The method of claim 18 further comprising receiving an envelope signal that changes in relation to the envelope of the RF input signal as an input to the error amplifier.

20. The method of claim 18 further comprising powering the error amplifier using the battery voltage.