Patent attributes
An embodiment of a Doherty amplifier includes first and second amplifier paths with first and second amplifiers, respectively, a power divider, a series delay element, and a short-circuited stub. The power divider is configured to receive a radio frequency (RF) signal and to divide the RF signal into first and second input signals that are produced at first and second power divider outputs. The series delay element is coupled between the first power divider output and the first amplifier. The short-circuited stub is coupled between the first power divider output and the first amplifier or between the second power divider output and the second amplifier. The first amplifier path is characterized by a first frequency-dependent insertion phase, the second amplifier path is characterized by a second frequency-dependent insertion phase, and a slope of the first or second frequency-dependent insertion phase is altered by the short-circuited stub.
