Abstract: A digitally operating switching amplifier for direct and alternating voltage that is suitable as a modulation amplifier for radio transmitters with anode modulation. The power portion of the amplifier consists of cascade-connected, controllable, peak current-limited partial voltage sources that are connected via a low-pass filter to a load resistor, which is the high-frequency output stage in a radio transmitter. The control of peak current-limited partial voltage sources, some of which present differing voltage values, is effected in such a manner that a high degree of efficiency is attained and that distortions of the modulation signal are small.

Abstract: A switching amplifier, in particular for generating a modulated anode voltage for a high-frequency, high-power AM transmitter, includes a number of switchable voltage sources. The switchable voltage sources in a first portion of the amplifier provide small-scale gradations, which can be combined in any sequence. The switchable voltage sources in a second portion of the amplifier provide large voltage leaps of constant magnitude, which are combined in sequence.