N. A. Akafyeva

Some results of investigation of power multi-beam monotron oscillator

A multi-beam monotron oscillator that has four-gap cavity and which is excited in-phase oscillation was numerically investigated. As a result of numerical calculations and optimization the capability obtaining in such device on a frequency 2450 MHz high electron efficiency (60%) was shown.

Research multi-frequency mode of the three-gap cavity with resonant elements on printed circuit boards

We have studied the multigap resonance system, which is a rectangular cavity resonator with two suspended ceramic substrates, on which the two sides is applied by lithography strip line. During modeling process the resonator structure was calculated on three main modes with a maximum characteristic impedance, antiphase oscillation mode (π), π / 2 oscillation mode and in-phase mode (2π) oscillation mode. It is found that the π and π / 2 modes have significant dependence on the length of adjustment element, while in-phase oscillation mode (2π) weakly depends on the length of adjustment element and the dielectric constant of the substrate. The results can be used in the development of new types of vacuum microdevices multibeam klystron type with matrix field emission cathodes working in the S, C, X range.

A study of a miniature dual-beam monotron oscillator with triple-gap resonator formed by integrated circuit technology

The paper presents the results of numerical simulation of a miniature dual bean monotron with three-gap resonator, made by technology of integrated circuits. Was studied the stability of this device to different oscillation modes. It is shown that when working on main mode output power of the device on the 2,2 GHz is in the range from 150 to 350 watts with the change cathode voltage from 2 to 3,5 kV. The maximum value of technical efficiency of the device was 22 % at minimum a single beam current of 0,15 A. The proposed scheme of the device when using the field emission cathodes can also be realized in the millimeter wavelengths.

Investigation of ring microstrip resonators for a microwave microplasma source

Microplasma microwave sources are widely used in a bio-microelectromechanical sterilization systems, in materials processing, in a microchemical analysis systems. The possibility of ignition of microwave low-power plasma using ring microstrip resonators tuned to the frequency of 900 to 1500 MHz was investigated. We have simulated the ring resonators with microstrip gap size of 100 to 500 microns. Prototyping model of the resonant systems on different frequencies was produced and investigated. The «cold» measurement of resonators to clarify the parameters and design optimization was carried out, the experimental equipment for investigating the microwave low-power plasma was adjusted.

A new dual-mode two-gap strip-line resonator for microwave devices with field-emission cathode

A two-gap resonator on the basis of spiral symmetric strip line for klystron type microwave tubes with field emitter arrays (FEA) cathodes was investigated. Presented resonator has the suspended substrate strip-line (SSS) that allowed designing a compact dual-mode two-gap resonant system for a multi-beam klystron type microwave tubes with the cold cathode (FEA).

A new type of the microsized resonator with the asymmetric high-Q strip line for microwave devices with field-emission cathodes

This article describes a new dual mode two gaps resonator with the suspended ceramic substrate and the asymmetric strip lines. Using the asymmetric helical strip lines in resonator we can tunes it to anti-phase oscillation and to in-phase oscillation at the doubled frequency at the same time. On the basis of the 3-D modeling we found that such oscillatory systems can achieve the excitation of these modes with multiplicity of frequencies K = 2 with a good efficiency of interaction of electron beam with microwave fields.

Investigation of processes in the retarding field oscillator with the virtual cathode

In this work an oscillator with the hot cathode executed on the basis of the two-gap resonator is investigated. The structure of the retarding field oscillator differs from the classical reflective klystron that the reflector is entered into interaction space of the resonator. It was experimentally confirmed that in the modified retarding field oscillator with the two-gap resonator excited at multiple resonant frequencies, the electronic efficiency can reach 30% that approximately in 10 times more, than in a usual reflective klystron.

Current state and prospects of development the micromachined electrovacuum devices in the short-range microwave

In this article prospects of creations of new miniature electro vacuum amplifiers and generators of the terahertz range on the basis of vacuum integrated schemes with a field emission cathodes are considered. Analogs of such devices are classical devices of vacuum electronics with average transit angle: Monotrons, reflex klystrons, klystrons with the distributed interaction. The ways to further increase efficiency and power output of such devices were defined.

The dual-mode double-gap resonator with asymmetrrical strip line on the suspended ceramic substrate

A new dual-mode double-gap resonator on the basis of asymmetrical suspended stripline for miniature klystron type microwave tubes with field emitter arrays (FEA) cathodes was investigated. The resonator has a smaller size and mass when a doublegap capacitive segment of each quasi-lumped resonator consists of two assimmetrical strip conductors on opposite sides of the substrate and both inductive segments are grounded. This resonance circuit has two oscillation modes (anti-phase and in-phase). On the basis of the 3-D modeling found that such oscillatory systems can achieve the excitation of these modes with multiplicity of frequencies to = 2 with a good efficiency of interaction of electrons with microwave fields.

Ways of improvement of microwave oscillators with medium transit angle over interaction area

Ways of improvement of microwave oscillators, such as monotron, low-voltage vircator, retarding-field oscillator are presented in this paper.