US Patent 9876471 Apparatus and methods for power amplifiers with phase compensation

Apparatus and methods for phase compensation in power amplifiers are disclosed herein. In certain implementations, a method of phase compensation in a power amplifier includes amplifying a radio frequency signal using a power amplifier that includes an input stage and an output stage, powering a bipolar transistor of the output stage using a power amplifier supply voltage, changing a voltage level of the power amplifier supply voltage, the bipolar transistor having an input reactance that changes in response to the change in the voltage level of the power amplifier supply voltage, and compensating for a variation in a phase delay of the power amplifier arising from the change in the input reactance of the bipolar transistor using a compensation circuit that is electrically connected to an output of the input stage.