Tatiana A. Karetnikova

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.

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.

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.

Simulation and development of novel slow-wave structures for miniaturized THz-band vacuum-tube devices

Microfabricated vacuum-tube millimeter- and THz-band sources are of great interest for numerous applications such as communications, radar, sensors, imaging, etc. Recently, miniaturized sheet-beam traveling-wave tubes for sub-THz and THz operation have attracted a considerable interest. In this paper, we present the results of modeling and development of slow-wave structures (SWS) for medium power (10-100 W) traveling-wave tube (TWT) amplifiers and backwardwave oscillators (BWO) in near-THz frequency band. Different types of SWSs are considered, such as double-vane SWS for TWT with a sheet electron beam, a folded-waveguide SWS, and novel planar SWSs on dielectric substrates.

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.

Simulation of a 0.2 THz second-harmonic multiplier with sheet electron beam

Design of a sub-THz traveling-wave tube multiplier with a sheet electron and half-period staggered beam slow-wave structure (SWS) is presented. The device consists of two SWS sections separated by drift section. The input one operates in W band and serves for modulation of the electron beam. The output one serves for second-harmonic power extraction in G band.

Gain analisys of O-type THz devices with sheet electron beam

The paper is aimed at development of miniaturized THz O-type devices with sheet electron beam. A 0,2 THz traveling-wave tube amplifier with a staggered double-grating slow-wave structure (SWS) is designed. The results of calculation of small-signal and large-signal gain are presented. The calculations predict 15–20 dB small-signal gain and up to 100 W saturation power in the amplifier with 20 kV 0,1 A sheet electron beam. In addition, a cascaded amplifier with two short SWS sections separated by the drift space is considered.

Development and modeling of a G-band sheet-beam traveling wave tube amplifier with grating slow-wave structure

Sheet-beam traveling-wave tubes (TWTs) and backward-wave oscillators (BWOs) with grating slow-wave structures (SWS) have attracted a considerable interest as THz and sub-THz power amplifiers [1]. Such devices can find wide application as compact sources with relatively high power for communications, radar, sensors, imaging, etc. In this paper, we present the results of research aimed at development of the G-band (0.22 THz) TWT amplifier with double- and singlegrating SWS and a sheet electron beam. For 3D numerical modeling we developed a fast and accurate approach based on the integral equation method (IEM). Detailed description of the method is presented in [2]. Using the code, we optimized the dimensions of the SWS to achieve rather wide passband about 70 GHz and interaction impedance about 1 Ohm, which is sufficient to achieve 20 dB gain.

Modeling of planar vane slow wave structures for a travelig wave tube amplifier with sheet electron beam

A fast and accurate code for calculation of eigenwaves in grating 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. Electron gun producing an intensive sheet electron beam s developed. Beam focusing and transportation is discussed.