摘要 |
There is disclosed an envelope tracking power supply arranged to generate a modulated supply voltage in dependence on a reference signal, comprising a first path for tracking low frequency variations in the reference signal and a second path for tracking high frequency variations in the reference signal, the second path including a linear amplifier, wherein the output of the linear amplifier comprises a current source and a current sink connected to the high frequency output, there further being provided a DC offset current at the high frequency output. |