Maximal efficiency versus the amplification factor in double-cavity klystrons

The dependence of the maximal efficiency on the amplification factor is studied for double-cavity klystrons simulated based on real electron-optical systems and real electrodynamic parameters of cavities. Simulation uses a mathematical model of electron beam transformation in a narrow tube and a KlypWin software suite. It is shown that the maximal efficiency of such klystrons, 46–47%, is achieved at an amplification factor of 16–18 dB.