V.A. Senchurov – Ph. D. (Eng.), Associate Professor, Department «Electronic Instruments and Devices», Yuri Gagarin State Technical University of Saratov
V.Yu. Muchkaev – Ph. D. (Eng.), Associate Professor, Department «Electronic Instruments and Devices», Yuri Gagarin State Technical University of Saratov
In this article constructions of multipath four-gap resonators in which it is possible to achieve fn/f1 = 3 relation, with a frequency of first harmonic of f1 = 30−40 GHz and, therefore, fn = 90−120 GHz numerically are researched. For the solution of the set task, the design of the four-gap resonator in which floating-drift channels are carried on two bunches has been considered. Each bunch consisted of five floating-drift channels. Calculations of electromagnetic field distribution was performed using three-dimensional program REZON, which is based on the solution of Maxwell's equations by finite difference method in the time domain with a rectangular spatial grid of splitting. The analysis of numerical calculations showed that in the researched resonator, there are two modes – f36 = 106.86 GHz and f37 = 107.18 GHz which frequencies are close to 3f1 = 106.95 GHz (f1 = 35.65 GHz). However, they have various spatial distribution longitudinal components of electric field in the plane, cross to the movement of a bunch. The longitudinal component of the electric field for 36 of the oscillation modes in the gaps of the resonator changes sign, except the maximum values of longitudinal component of electric field offset relative to the floating-drift channels. Therefore, further the 36th mode wasn't investigated. The longitudinal component of the electric field in all 4 gaps for the 37th oscillation modes have the same sign and max values falls on the location of the floating-drift channels.
The distribution of the longitudinal component of electric field of the main and 37th mode in the floating-drift channel of the investigated resonator has been constructed. It was shown that the main mode of oscillation has an anti-phase voltage on the gaps (π – view), and the highest type of mode has inphase voltage on the 1 and 2 gaps and antiphase on the 3rd and 4th gaps. Distribution of the electromagnetic field obtained during numerical calculations, allowed us to calculate the electrodynamic characteristics of the researched resonator. Values of characteristic resistance of the basic and the 37th type of oscillation mode in 3 channels have been calculated. The value of the characteristic resistance in the 37 type of oscillation mode has a fairly high unevenness, the largest value is achieved in the extreme floating-drift channels, with the minimum value in the central, unlike the main type of oscillation mode.
The side cavities the representing short-circuited segments of a rectangular waveguide have been established for decrease in un-evenness of values of the characteristic field on floating-drift channels within one bunch.
Researches showed that installation of additional side cavities in the researched resonator allows to receive almost uniform distribution of the field along the bunch with floating-drift channels, at the same time it was succeeded to achieve f27/f1 ≈ 3 relation, with a frequency of f1 = 33.22 GHz and f27 = 99.61 GHz. It is necessary to note that for the main type of oscillation mode «pockets» represented an transcendent wave guide (in case of the selected sizes, critical frequency was ~42,86 GHz) and practically didn't influence on distributions of a longitudinal component of the electric field in the gap.
The calculation of the dependence of the coefficient of efficiency of interaction from the accelerating voltage was carried out. The coefficient of efficiency of interaction in 27 type of oscillation mode in the range of accelerating voltages of 1−20 kV does not exceed 0.34. It should be noted that in the range of accelerating voltages (approximately from 5.5 kV to 10.5 kV), where the coefficient of efficiency of interaction of main mode of oscillation has a maximum value, the coefficient of efficiency of interaction at 27 type of os-cillation mode, also has a local maximum (0.21 at an accelerating voltage of 9.5 kV). The calculated dependences of the relative elec-tronic conductivity of Ge/G0 from the acceleration voltage U0 on the main and the 27th oscillation modes show that for the regime of frequency multiplication are the most suitable ranges of an accelerating voltage of 6.1−6.9 kV, 13−14.3, 16.3 kV to 18.6 kV, i.e. areas where Ge/G0 > 0 on a main type of oscillations and Ge/G0 < 0- on the higher type of oscillations.
- Gittings J.F. Power Travelling Wave Tubes. NewYork: Amer. Elsevier Publ. Comp. 1965.
- Muchkaev V.Yu., Senchurov V.A., Czarev V.A. E'lektrodinamicheskie parametry' trexzazornogo rezonatora s dvumya raznesnny'mi puchkami // Materialy' Mezhdunar. naucho-texnicheskoj konf. «Aktual'ny'e problemy' e'lektronnogo priborostroeniya». Saratov. 2016 g. T. 1. S. 343−349.
- Lebedev I.V. Texnika i pribory' sverxvy'sokix chastot. T. 2. Izd.2-e. M.: Vy'sshaya shkola. 1972. 376 s.
- Czarev V.A., Korchagin A.I., Muchkaev V.Yu. Issledovanie mnogokanal'ny'x dvuxzazorny'x rezonatorov s dvumya kratny'mi rezonansny'mi chastotami // Materialy' Vseros. konf. «Mikroe'lektronika SVCh». Sankt-Peterburg. 2012. S. 286−291.
- Czarev V.A., Muchkaev V.Yu., Shalaev P.D. Issledovanie trexzazornogo mnogokanal'nogo klistronnogo rezonatora, nastroennogo na dve kratny'e rezonansny'e chastoty' // Materialy' Vseros. konf. «Mikroe'lektronika SVCh». Sankt-Peterburg. 2016. S. 56−59.
- Senchurov V.A., Muchkaev V.Yu. E'lektrodinamicheskie xarakteristiki mnogoluchevogo dvuxzazornogo rezonatora millimetrovogo diapazona // Radiotexnika. 2017. № 2. S. 99−103.
- Muchkaev V.Yu., Czarev V.A. Svidetel'stvo ob oficzial'noj registraczii programmy' dlya E'VM № 2011611748 ot 24.02.2011 g.
- Grigor'ev A.D., Yankevich V.B. Rezonatory' i rezonatorny'e zamedlyayushhie sistemy' SVCh. Chislenny'e metody' rascheta i proektirovaniya. M.: Radio i svyaz'. 1984.
- Grigor'ev A.D. Rezonatorny'e sistemy' dlya klistronov millimetrovogo i submillimetrovogo diapazonov dlin voln // Problemy' SVCh e'lektroniki. 2015. T. 2. № 1. S. 23−26.
- Caryotakis G. High Power Klystrons: Theory and Practice at the Stanford Linear Accelerator Center. 2005.
- Branch G.M. Jr. Electron Beam Coupling in Interaction Gaps of Cylindrical Symmetry // IRE Trans. On Elec. Dev. 1961. P. 193−206.