HFHPTA´s efficiency analysis using PSpice non-linear vacuum tube model

An HF High-Power Tuned Amplifier (HFHPTA) is the output stage of a radio transmitter. Vacuum tubes (e.g. high power triode or tetrode) are used as active elements of the high-power amplifier classes ´B´ and ´C´ into the radio broadcasting transmitter. A standard goal in the balance of power analysis of an HFHPTA is to find optimal operating conditions (maximum output power with high efficiency) causing long service life for active elements. The principle of the injection of one or two harmonic signals into the drive and/or output carrier signal was used in order to improve power balance. The balance of power analysis of HFHPTA with composite drive and output signal obtained by the injection of two harmonics (N and P) into the basic carrier signal (M=1) is presented in this paper. The paper will compare the results of balance of power analysis between two types of HFHPTA with Siemens high power tetrodes using new PSpice method.