Patent ID: 8380147

Claim:
A power amplifier circuit intended to be linked to an antenna arrangement of a communication system for transmission of ASK RF data signals, the power amplifier circuit comprising: an amplifier core with at least one cascode amplifier cell, wherein the cascode amplifier cell includes (i) at least a first transistor and a second transistor (ii) an output terminal that connects the amplifier core to the antenna arrangement; and (iii) an earth terminal, wherein the first transistor and the second transistor are connected in series between the output terminal and the earth terminal; wherein the first transistor of the cascode amplifier cell is controlled by a carrier frequency signal, wherein the second transistor of the cascode amplifier cell is controlled by a smoothing control loop in order to modulate data to be transmitted on carrier frequency by amplitude shift keying, wherein the smoothing control loop generates a gate voltage for the second transistor on the basis of an increasing or decreasing current ramp from a first current value to a second current value during a data transition for shaping the envelope of ASK RF data signals to be transmitted.