Wide bandwidth envelope trackers
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 amplifier including an output configured to provide an output current operable to adjust a voltage level of the power amplifier supply voltage, a first input configured to receive a reference voltage, and a second input configured to receive an envelope signal that changes in relation to an envelope of the radio frequency transmit signal, the second input having an input impedance that is lower than an input impedance of the first input.
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Accused Products
Abstract
High bandwidth envelope trackers are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator that operates in combination with a high bandwidth amplifier 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 high bandwidth amplifier includes an output that generates an output current for adjusting the power amplifier supply voltage, a first input that receives a reference signal, and a second input that receives an envelope signal indicating the envelope of the RF signal. The second input has lower input impedance than the first input to provide a rapid transient response and high envelope tracking bandwidth.
118 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 amplifier including an output configured to provide an output current operable to adjust a voltage level of the power amplifier supply voltage, a first input configured to receive a reference voltage, and a second input configured to receive an envelope signal that changes in relation to an envelope of the radio frequency transmit signal, the second input having an input impedance that is lower than an input impedance of the first input. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. 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 amplifier including an output configured to provide an output current operable to adjust a voltage level of the power amplifier supply voltage, a first input configured to receive a reference voltage, and a second input configured to receive an envelope signal that changes in relation to an envelope of the radio frequency signal, the second input having an input impedance that is lower than an input impedance of the first input. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method of envelope tracking, the method comprising:
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amplifying a radio frequency signal using a power amplifier; and generating a power amplifier supply voltage of the power amplifier using an envelope tracker that includes a differential amplifier having a first input of a first input impedance and a second input of a second input impedance less than the first input impedance, generating the power amplifier supply voltage including receiving a reference voltage at the first input, receiving an envelope signal that changes in relation to an envelope of the radio frequency signal at the second input, and adjusting a voltage level of the power amplifier supply voltage using an output current of the differential amplifier. - View Dependent Claims (18, 19, 20)
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Specification