Adaptive envelope tracking based on detected transmit signal bandwidth
AssigneeSkyworks Solutions, Inc.
InventorsSabah Khesbak, Roman Zbigniew Arkiszewski, Jeffrey Gordon Strahler, Florinel G. Balteanu
Life of this patent
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Abstract
Apparatus and methods for power amplifier envelope tracking systems with automatic control of a slew rate and a mode of an error amplifier of the envelope tracking system. The envelope tracker can include a signal bandwidth detection circuit that processes the envelope signal to generate a detected bandwidth signal, and a control circuit that controls the slew rate of the error amplifier based on the detected signal bandwidth.
Claims13
An envelope tracker for a power amplifier, the envelope tracker comprising:
- an input configured to receive an envelope signal corresponding to an envelope of a radio frequency signal;
- an error amplifier configured to generate a power amplifier supply voltage, the error amplifier including a biasing stage including a plurality of biasing stages and configured to adjust a slew rate of the error amplifier;
- a bandwidth detection circuit configured to generate a bandwidth signal indicating a bandwidth of the envelope signal;
- and
- a control circuit configured to adaptively adjust the biasing stage based on the bandwidth signal to increase the slew rate of the error amplifier for larger envelope bandwidths and decrease the slew rate of the error amplifier for smaller envelope bandwidths by using one or more slew rate switches to selectively activate one or more of the plurality of biasing stages.
A radio frequency front end module comprising:
- a power amplifier configured to amplify a radio frequency signal and to receive power from a power amplifier supply voltage;
- an envelope tracker including an error amplifier configured to generate the power amplifier supply voltage, the error amplifier including a plurality of biasing stages, one or more of the plurality of biasing stages configured to be selectively controlled to adjust a slew rate of the error amplifier, the envelope tracker further including a bandwidth detection circuit configured to generate a bandwidth signal indicating a bandwidth of an envelope signal, and a control circuit configured to selectively activate the one or more of the plurality of biasing stages based on the bandwidth signal to increase the slew rate of the error amplifier for larger envelope bandwidths and decrease the slew rate of the error amplifier for smaller envelope bandwidths by using one or more slew rate switches.
A mobile device comprising:
- a power amplifier system including a power amplifier configured to amplify a radio frequency signal and to receive power from a power amplifier supply voltage, an error amplifier configured to generate the power amplifier supply voltage, a bandwidth detection circuit, and a control circuit, the error amplifier including a plurality of biasing stages configured to bias an amplifying stage, one or more of the plurality of biasing stages configured to adjust a slew rate of the error amplifier, the bandwidth detection circuit configured to generate a bandwidth signal indicating the bandwidth of an envelope signal, the control circuit configured to control the error amplifier based on the bandwidth signal to increase the slew rate of the error amplifier for larger envelope bandwidths and decrease the slew rate of the error amplifier for smaller envelope bandwidths by using one or more slew rate switches to selectively activate the plurality of biasing stages;
- and
- an antenna configured to transmit the amplified radio frequency signal.
Dependencies are inferred from the claim text.