CPC H03F 1/0227 (2013.01) [H03F 3/19 (2013.01); H03F 3/21 (2013.01); H04B 1/3838 (2013.01); H04B 1/40 (2013.01); H03F 2200/102 (2013.01)] | 20 Claims |
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
an envelope tracker configured to generate a power amplifier supply voltage that powers the power amplifier, the envelope tracker including a first series inductor, a DC-to-DC converter having an output connected to the power amplifier supply voltage through the first series inductor, a second series inductor, a series capacitor in series with the second series inductor, a modulator having a plurality of inputs configured to receive a plurality of regulated voltages and an output connected to the power amplifier supply voltage through the series capacitor and the second series inductor, and a control circuit configured to control the modulator based on an envelope signal indicating an envelope of the radio frequency transmit signal.
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