| 摘要 |
The invention relates to a sequential broadband Doherty power amplifier with adjustable output power back-off The sequential broadband Doherty power amplifier has at least one input (I1, I2; RFin) for receiving at least one broadband HF signal, wherein the broadband HF signal or broadband HF signals (RFin) have at least an average power level (carrier/average) and a peak envelope power level (peak), with the average power level and the peak envelope power level defining a crest factor, and a first amplifier branch for amplifying the input signal, with the first amplifier branch providing the amplification substantially for the low and at least the average power level, at least one second amplifier branch for amplifying the input signal, wherein the second amplifier branch substantially provides the amplification for the peak envelope power level, wherein the output of the first amplifier branch is connected via an impedance inverter (ZT) to the output of the second amplifier branch, the junction (CN) being connected to the load (Z0) in a substantially directly impedance-matched manner, wherein the first and the second amplifier branch each have a supply voltage, with at least one of the supply voltages being variable as a function of the crest factor of the signal to be amplified, and wherein the signal propagation delay through the at least two amplifier branches is substantially identical in the operating range. |
