Patent ID: 8269555

Claim:
Method for setting up a RF power amplifier circuit arrangement for amplification of RF input signals with modulated amplitude and modulated phase, wherein the circuit includes first and second amplification branches each having an input and an output, for amplifying one of a first and a second component signal of which only the phase is modulated, and a combination of which corresponding to the RF input signal; wherein in each of the first and second amplification branches, respective first and second amplification devices are configured to operate in a switching-mode with a respective duty-cycle; and wherein a combination circuit is configured to combine the outputs of the first and second amplification branches such that the circuit arrangement is arranged for operating in an out-phasing configuration; the method comprising: setting values of first and second reactive inductive components of the combination circuit connected to respective first and second amplification device outputs of the respective first and second amplification devices, in accordance with a criteria of zero-voltage switching for each of the first and second amplification devices as a separate component; and adjusting the first and second duty-cycles for operating the first and second switching-mode amplification devices in accordance with a criteria of a constant phase of the output signal of the circuit arrangement with respect to an out-phasing angle of an out-phasing configuration by sweeping the out-phasing angle for different duty-cycles, and monitoring phase and efficiency as a function of the out-phasing angle.