Fast envelope tracking systems for power amplifiers
First Claim
1. A mobile device comprising:
- a transceiver configured to generate a radio frequency transmit signal;
a front end circuit including a power amplifier configured to amplify the radio frequency transmit signal; and
a power management circuit including an envelope tracker configured to generate a power amplifier supply voltage of the power amplifier, the envelope tracker including a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to an envelope of the radio frequency transmit signal, and a differential error amplifier configured to generate an output current based on comparing the single-ended envelope signal to a reference signal, the output current operable to adjust a voltage level of the power amplifier supply voltage, the differential envelope amplifier including an amplification circuit configured to amplify the differential envelope signal, and a common mode feedback circuit operable to compensate the amplification circuit for a common mode error arising from a common mode voltage of the differential envelope signal.
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Accused Products
Abstract
Fast envelope tracking systems are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator and a differential error amplifier configured to operate in combination with one another to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The envelope tracking system further includes a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to the envelope of the RF signal. Additionally, the differential error amplifier generates an output current operable to adjust a voltage level of the power amplifier supply voltage based on comparing the single-ended envelope signal to a reference signal.
113 Citations
20 Claims
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1. A mobile device comprising:
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a transceiver configured to generate a radio frequency transmit signal; a front end circuit including a power amplifier configured to amplify the radio frequency transmit signal; and a power management circuit including an envelope tracker configured to generate a power amplifier supply voltage of the power amplifier, the envelope tracker including a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to an envelope of the radio frequency transmit signal, and a differential error amplifier configured to generate an output current based on comparing the single-ended envelope signal to a reference signal, the output current operable to adjust a voltage level of the power amplifier supply voltage, the differential envelope amplifier including an amplification circuit configured to amplify the differential envelope signal, and a common mode feedback circuit operable to compensate the amplification circuit for a common mode error arising from a common mode voltage of the differential envelope signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An envelope tracking system comprising:
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a power amplifier configured to amplify a radio frequency signal; and an envelope tracker configured to generate a power amplifier supply voltage of the power amplifier, the envelope tracker including a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to an envelope of the radio frequency signal, and a differential error amplifier configured to generate an output current based on comparing the single-ended envelope signal to a reference signal, the output current operable to adjust a voltage level of the power amplifier supply voltage, the differential envelope amplifier including an amplification circuit configured to amplify the differential envelope signal, and a common mode feedback circuit operable to compensate the amplification circuit for a common mode error arising from a common mode voltage of the differential envelope signal. - View Dependent Claims (10, 11, 12, 13)
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14. An envelope tracking system comprising:
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a power amplifier configured to amplify a radio frequency signal; and an envelope tracker configured to generate a power amplifier supply voltage of the power amplifier, the envelope tracker including a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to an envelope of the radio frequency signal, a differential error amplifier configured to generate an output current based on comparing the single-ended envelope signal to a reference signal and to generate a sense signal that tracks the output current, a switching regulator configured to generate a regulated voltage based on the sense signal, and a combiner configured to combine the regulated voltage and the output current to thereby generate the power amplifier supply voltage, the output current operable to adjust a voltage level of the power amplifier supply voltage. - View Dependent Claims (15, 16)
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17. A method of envelope tracking, the method comprising:
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amplifying a radio frequency signal having an envelope using a power amplifier; generating a power amplifier supply voltage of the power amplifier using an envelope tracker, including amplifying a differential envelope signal to generate a single-ended envelope signal that changes in relation to the envelope using a differential envelope amplifier, generating an output current by comparing the single-ended envelope signal to a reference signal using a differential error amplifier, and adjusting a voltage level of the power amplifier supply voltage using the output current; amplifying the differential envelope signal using an amplification circuit of the differential envelope amplifier; and compensating the amplification circuit for a common mode error arising from a common mode voltage of the differential envelope signal using a common mode feedback circuit. - View Dependent Claims (18, 19, 20)
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Specification