Patent ID: 8487703

Claim:
An integrated radiofrequency amplifier having an operational frequency, the amplifier comprising first and second Doherty amplifiers each comprising a main device, and a peak device connected at respective inputs and outputs by respective phase shift elements configured to provide a 90 degree phase shift at the operational frequency, wherein an input of the amplifier is connected to the input of the main device of the first Doherty amplifier, an output of the amplifier is connected to the outputs of the peak devices of the first and second Doherty amplifiers and the input of the peak device of the first Doherty amplifier is connected to the input of the main device of the second Doherty amplifier by a phase shift element configured to provide a 90 degree phase shift at the operational frequency; wherein the phase shift element connecting the input of the peak device of the first Doherty amplifier with the input of the main device of the second Doherty amplifier comprises a high-pass filter comprising a pair of inductances connected between a ground connection of the amplifier and opposing terminals of a capacitance.