UDC 621.385.623.2
DIODE GENERATOR OF PLANAR CONSTRUCTION
V. K. Fedyaev, Dr. in technical sciences, full professor, RSREU, Ryazan, Russia;
orcid.org/0000-0003-2452-5146, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
N. M. Marankin, master student, RSREU, Ryazan, Russia;
orcid.org/0000-0002-4236-0923, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
A brief review of publications on single-cavity microwave generators of straight-through type (diode, monotron, two-gap resonator in generation modes) is given. The aim of this work is to study interaction processes and electron efficiency of a diode generator (diotron) of planar construction in various modes including cathode current cut-off mode by numerical simulation. Based on the model of an electron beam consisting of large particles and the solving the equations of particle motion by the Runge-Kutta third order method, the ways to calculate the efficiency by energy method and calculate the shape of convection current pulses using charge conservation law are developed. The authors have shown that the result of speed modulation under the influence of alternating voltage are bunches of electrons being formed that at certain transit angles fall into negative half-waves of alternating voltage leading to the formation of generation zones. Without cutting-off cathode current in case of particle charge equality (electrons enter high-frequency gap from external cathode or diode cathode operates in saturation mode) efficiency values in the center of zones were 12 % for the first zone, 8,3 % for the second and 6,1 % for the third at transit angles, respectively, 4,8 rad, 9 rad and 13,3 rad. In case of particle charge dependence on AC voltage phase, maximum efficiency decreases to 2,4 % for the first zone, 5,3 % for the second and 4,3 % for the third. The decrease is mainly due to the fact that the center of initial bunch formed at cathode and the center of bunch formed by subsequent grouping are shifted in phase by 0,5∏. Cathode current cut-off mode did not give expected efficiency increase as in klystrod operating in this mode.
Key words: microwave generator, efficiency, diode, diotron, gap, generation zone, convection current, saturation mode, spatial charge mode, cathode current cut-off mode.