Abstract: A radio frequency power amplifier including control electronics for providing control signals for timing of the power amplifier. A first group of the drivers are coupled to the control electronics and a second group of drivers are coupled to the control electronics. The first group of drivers operate in response to the control signals to generate first drive signals and the second group of drivers operate in response to the control signals to generate second drive signals with a phase difference of 180° relative to the first drive signals. A first group of switches energize a first group of primary windings in response to the first drive signals and a second group of switches energize a second group of primary windings in response to the second drive signals. An output summing transformer has a plurality of ferrite cores, the first group of primary windings and the second group of primary windings passing through the ferrite cores.