Pavel D. Shalaev

Modeling and characterization of a slow-wave structure for a sheet-beam sub-THz TWT amplifier

Microfabricated sheet-beam traveling-wave tubes for THz and sub-THz operation have attracted a considerable interest. In this paper we discuss design issues of a double-vane slow-wave structure (SWS) for a 0.2 THz amplifier. A fast and accurate code for calculation of electrodynamic characteristics of the SWS is developed.

Study of electrodynamic parameters of the planar meander slow-wave structures for THz band traveling wave tubes

Planar meander line slow-wave structure (SWS) for traveling wave tubes at THz frequency band is studied. The meander SWS circuit at 180-230 GHz frequency band is designed and fabricated. Basic electrodynamic parameters of the SWS are calculated. The simulation shows a rather high coupling impedance.

Development and modeling of a sheet-beam sub-THz traveling wave tube

Results of research aimed on development of miniaturized O-type medium power sheet beam amplifier in sub-THz band are presented. Dispersion characteristics and coupling impedances for planar grating slow-wave structures (SWS) are calculated. The double-grating half-period staggered SWS circuit is designed and fabricated.

Studying a multibeam microwave drift-tube K-band oscillator with an electrodynamic system of two slot-coupled resonators

The possibility is shown of creating a new low-voltage multibeam oscillator of monotron type operating in the K band of wavelengths. The operating principle of this device is based on autogeneration of electromagnetic oscillations during the interaction of a multibeam electron stream with a high-frequency electric field of π type in a two-gap slot resonator having high-frequency voltages across gaps with different amplitudes. The results of theoretical and experimental studies of a 19-beam prototype of the device are presented. For the first time, a microwave-emission power of more than 600 W was obtained experimentally with an electronic efficiency of 45% and a total efficiency of 30% at an accelerating voltage of 2.6 kV and a frequency of 18.14 GHz.

Experimental study of electron guns for TWT of terahertz range

This paper presents the results of experimental testing of diode electron guns with sheet and multiple electron beams based on thermionic minicathodes for TWT of terahertz frequency range. The results of study in pulse mode of impregnated thermionic blade cathode with linear dimensions 0.1×0.7 mm with a current density of 114 A/cm2 are presented. A version of the five-beam electron gun is proposed with cylindrical minicathode with diameter of 0.25 mm, placing under the cells of control grid, achieved a current density of 85.5 A/cm2 at grid voltage of 900-1000 V.

Modeling of eigenwaves in single- and double-vane slow-wave structures for sheet-beam sub-THz devices

A fast and accurate code for calculation of eigenwaves in single- and double-vane slow-wave structures (SWS) is developed. Such SWS are used in sheet-beam traveling wave tubes (TWTs) and backward-wave oscillators (BWOs) at sub-THz and THz frequencies. Results of numerical modeling of SWS for a G-band sheet-beam TWT are presented.

Development of electron-optical system with three elliptic electron beams for a THz-band vacuum-tube device

The results of design, simulation, and experimental testing of an electron-optical system with three elliptic electron beams are presented. Total beam current is 93 mA. The beams are focused by a PPM system with 0.55 T magnitude of the magnetic field. Beam transmission in a rectangular tunnel at over 25 mm distance is demonstrated. The developed electron optical system is assumed to be used in sub-THz-band vacuum-tube devices such as O-type traveling-wave tube or backward-wave oscillator. Electromagnetic parameters of a double-grating staggered slow-wave structure are calculated.

Formation of an electron beam in a matrix carbon field-emission cells

Results of research of an electron beam in field-emission Grigoryev-Shesterkina type cathode cells, intended for use are presented to the microwave oven devices. Possibility of development an electron optical system (EOS) with field-emission cathode matrixes for the O-type microwave devices with the beam emittance similar to an emittance in EOS with the thermo cathode is shown.

Theoretical and experimental study of X-band low-voltage vompact multibeam generator

Analytic theory, numerical simulations, and experiments describing the compact multi-beams microwave split-cavity oscillator (MBSO), which operates with electron efficiency 45% at a frequency 18 Ghz with 0.8 A electron beam and a beam energy of 2.6 keV for a total output power approximately of 0.6 kW.

Investigation of the low voltage multi-beam k-band monotron with the split-cavity resonator

Results of the theoretical analysis of the multi-beam monotron oscillator K-band with split-cavity resonator are considered. The analysis of conditions of self-excitation in the small signal approximation is carried out. Numerical simulation of the oscillation processes build-up is performed. The results show the possibility of achieving an output power exceeding 600 W and an efficiency 45%.