Apparatus and methods for wideband envelope tracking systems
First Claim
1. A method of envelope tracking in a power amplifier system, the method comprising:
- generating a regulated voltage from a battery voltage using a DC-to-DC converter;
generating a first envelope current based on a first digital envelope signal, including level-shifting a plurality of bits of the first digital envelope signal using a plurality of level-shifters, providing the plurality of level-shifted bits to a plurality of resistors, and generating the first envelope current based on a flow of current through the plurality of resistors;
providing the first envelope current as an input to a first error amplifier, the first error amplifier electrically connected with negative feedback; and
generating a first power amplifier supply voltage by combining the regulated voltage from the DC-to-DC converter and an output of the first error amplifier using a first AC combiner.
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Abstract
Apparatus and methods for wideband envelope tracking systems are disclosed herein. In certain implementations, an envelope tracker includes a DC-to-DC converter, a current digital-to-analog converter (DAC), an error amplifier, a feedback circuit, and an AC combiner. The current DAC receives a digital envelope signal, and uses the digital envelope signal to generate an envelope current. The feedback circuit is connected between an output and an inverting input of the error amplifier, and the envelope current is provided to the error amplifier'"'"'s inverting input. Additionally, the AC combiner generates a power amplifier supply voltage by combining an output of the DC-to-DC converter and an output of the error amplifier.
120 Citations
20 Claims
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1. A method of envelope tracking in a power amplifier system, the method comprising:
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generating a regulated voltage from a battery voltage using a DC-to-DC converter; generating a first envelope current based on a first digital envelope signal, including level-shifting a plurality of bits of the first digital envelope signal using a plurality of level-shifters, providing the plurality of level-shifted bits to a plurality of resistors, and generating the first envelope current based on a flow of current through the plurality of resistors; providing the first envelope current as an input to a first error amplifier, the first error amplifier electrically connected with negative feedback; and generating a first power amplifier supply voltage by combining the regulated voltage from the DC-to-DC converter and an output of the first error amplifier using a first AC combiner. - View Dependent Claims (2, 3)
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4. A method of envelope tracking in a power amplifier system, the method comprising:
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generating a regulated voltage from a battery voltage using a DC-to-DC converter; generating a first envelope current based on a first digital envelope signal; providing the first envelope current as an input to a first error amplifier, the first error amplifier electrically connected with negative feedback; generating a first power amplifier supply voltage by combining the regulated voltage from the DC-to-DC converter and an output of the first error amplifier using a first AC combiner; generating a second envelope current based on a second digital envelope signal; controlling an output of a second error amplifier based on the second envelope current, the second error amplifier electrically connected with negative feedback; and generating a second power amplifier supply voltage by combining the regulated voltage from the DC-to-DC converter and the output of the second error amplifier using a second AC combiner. - View Dependent Claims (5, 6, 7, 8)
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9. An envelope tracking system comprising:
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a DC-to-DC converter configured to generate a regulated voltage from a battery voltage, the DC-to-DC converter including an output that provides the regulated voltage; a first current digital-to-analog converter (DAC) configured to receive a first digital envelope signal, the first current DAC configured to generate a first envelope current based on the first digital envelope signal, the first current DAC including a plurality of level-shifters and a plurality of resistors, the plurality of level-shifters configured to generate a plurality of level-shifted bits by level-shifting a plurality of bits of the first digital envelope signal and to provide the plurality of level-shifted bits to the plurality of resistors; a first feedback circuit; a first error amplifier including an output and an inverting input electrically connected to one another via the first feedback circuit, the output of the first error amplifier configured to change based on the first envelope current; and a first AC combiner configured to generate a first power amplifier supply voltage based on combining the output of first error amplifier and the output of the DC-to-DC converter. - View Dependent Claims (10, 11, 12, 13)
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14. An envelope tracking system comprising:
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a DC-to-DC converter configured to generate a regulated voltage from a battery voltage, the DC-to-DC converter including an output that provides the regulated voltage; a first current digital-to-analog converter (DAC) configured to receive a first digital envelope signal, the first current DAC configured to generate a first envelope current based on the first digital envelope signal; a first feedback circuit; a first error amplifier including an output and an inverting input electrically connected to one another via the first feedback circuit, the output of the first error amplifier configured to change based on the first envelope current; a first AC combiner configured to generate a first power amplifier supply voltage based on combining the output of first error amplifier and the output of the DC-to-DC converter; a second current DAC configured to receive a second digital envelope signal and to generate a second envelope current based on the second digital envelope signal; a second error amplifier including an output and an inverting input electrically connected to one another via a second feedback circuit, the output of the second error amplifier configured to change based on the second envelope current; and a second AC combiner configured to generate a second power amplifier supply voltage based on combining the output of second error amplifier and the output of the DC-to-DC converter. - View Dependent Claims (15, 16, 17)
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18. A wireless device comprising:
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a transceiver configured to generate a first digital envelope signal and a first radio frequency signal; a first power amplifier configured to amplify the first radio frequency signal; an envelope tracker configured to receive the first digital envelope signal and to generate a first power amplifier supply voltage for the first power amplifier, the envelope tracker including a DC-to-DC converter, a first error amplifier, and a first AC combiner, the first AC combiner configured to generate the first power amplifier supply voltage based on combining an output of the DC-to-DC converter and an output of the first error amplifier; and a second power amplifier configured to amplify a second radio frequency signal from the transceiver, the envelope tracker further configured to receive a second digital envelope signal from the transceiver and to generate a second power amplifier supply voltage for the second power amplifier. - View Dependent Claims (19, 20)
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Specification