Patent attributes
The present invention relates to a power amplifier being preferably applied in mobile communication devices andusing an envelope tracking technique. It is the object of the invention to improve a power amplifier with respect to its efficiency by simultaneously enabling an adaptation of the supply voltage for the unit 110 to fast variations of an envelope signal. This object is achieved by providing a second DC/DC converter 140 for generating a variety of n+1 voltage levels and n threshold values both in response to a received power control signal representing a required output power of the RF output signal and by a first DC/DC converter 130 to select one of said n+1 voltage levels as the supply voltage for said unit 110 in response to the result of a comparison between the envelope signaland said n threshold values.
