M. A. Kopot

Development of Ka-range magnetron for portable radar

An experimental prototype of a pulse magnetron has been developed, having the output power of 2.5 kW at a frequency of 35 GHz with the operation voltage of 6.5 kV. The interaction space of the magnetron has been extended due to the properly selected operation mode - it works at the first negative spatial harmonics. The magnetrons structural scheme includes the main secondary-emission cold cathode and an additional side thermoemission cathode. This design provides for a substantial prolongation of magnetrons service life, while the pulse duration and the duty factor increase.

Submillimetric-wave magnetron oscillator: Simulation of its specific features

The application of the drift-orbital theory and 3-D numerical simulation is shown to offer ample scope for constructing a small-sized pulse cold-cathode sub-millimetric-wave magnetron oscillator. As the analytical estimation and computer-aided experiments indicate, the output power of this type of magnetron varies between hundreds of milliWatts and hundreds Watts.

Simulation and experimental breadboarding of 35 GHz spatial harmonic magnetrons with cold cathode

An analytical estimation has been performed to determine the optimal parameters of pulsed magnetrons, operating at a spatial harmonic at a frequency of 35 GHz and an anode voltage of 6.5 kV in the drift-resonance mode, with the main cathode being the cold secondary-emission one. A 3D simulation experiment on a magnetron with the analytically determined characteristics has been conducted to check its adequacy in providing the required energy parameters. The breadboard magnetrons have the number of vane-type resonators in the anode unit N = 20 and N = 16, respectively. The both magnetrons have generated the electromagnetic radiation in the Ka range with the magnetic field being slightly above 0.4 T. It was proven that it is possible to create a full-functional Ka-range magnetron with a relatively low anode voltage and such parameters that enable its wide applicability.

3D simulation of magnetrons with secondary-emission cathode stimulated by electrons from a field emitter

Presented in this paper are the results of 3-D simulation of the secondary-electro multiplication process in a magnetron with cold secondary emission Pd-Ba alloy cathode in which the primary electron sources are the blade-shaped field emitters. The application of the anode voltage pulse tandem is conducive to improving the efficiency and reliability of triggering the electromagnetic self-oscillation excitation in magnetron oscillator, as the nanosecond radiation pulses are generated.

X-band coaxial magnetron with field and secondary emitters

The findings of experimental investigations into and the field fests of the X-band cold, secondary - emission cathode magnetron referred to as “Buton” are presented. The primary - electron producing source in this system are the field emitters (FE). In addition to this, the data on 3-D simulation of the secondary-electron multiplication (SEM) process in this type of magnetron are given. The batch-produced “Buton” magnetrons are shown to offer an actual working capacity with 50ns to 6μs - width of e.m. radiation pulses. One of the noticeable features of these magnetrons installed in the transmitters of the lot-produced “Burevestnik-1” radar facility was their trouble-free operation time that lasted for over 12000 hours.

Modeling of submillimetric magnetron on the first positive space harmonic of Π-mode oscilastions

The characteristics of a submillimetric-wave cold-cathode magnetron oscillator (SubMMO) operating on the first positive spatial π-mode oscillation harmonic are analytically modeled using the drift-orbital resonances and 3-D simulation. The results of this procedure are presented in the short report below. The distinguishing features of the nonlinear dynamics of electron-wave interaction between synchronous electrons and electromagnetic field. It is shown that using such a magnetron makes it possible generate pulses with HF-power magnitude varying from hundreds of mWs to tens of Watts.

On the influence of anode voltage pulse in cold-cathode magnetron triggering

In mm-wave space-harmonic magnetrons use is made both of the main cold secondary-electron emitter cathode to produce the operating current and of an ancillary cathode with a thermo-electron emitter, which is located at the end of the main cathode to ensure the triggering current. The paper presents the results of 3-D simulation of the magnetron triggering process. It is shown that there exists a relationship between the magnitude of the ancillary cathode current and the steepness of anode voltage pulse, at which the self-oscillations in a magnetron cannot be induced.

Electronic Shell Generation in the MM-Wave Secondary Emission Magnetron with Cold Cathode

Presented in this paper are the results of 3-D simulation of electron-shell generation in mm-wave secondary-emission magnetron with cold cathode. Here the secondary-electron multiplication is stimulated by primary electrons from additional side cathode with a thermoionic emitter. It is shown that at the given magnetic field value the time of electron-shell generation is the current value of primary electrons, secondary-emission coefficient of the main cold-cathode emitter and the values of anode-voltage pulse edge slope. In this case the secondary emission process is triggered in the cold-cathode end surfaces.

Surface-Wave Magnetrons: Electromagnetic Radiation Oscillators in THZ Range

The present paper is focused on the possibility of designing small-size pulsed cold-cathode SWMs for THz frequencies us ing 3D numerical simulation. Such sources with an output power varying between hundreds of mW and units of kW may be employed, for example, in the development of high-resolution radars, as well as in the desktop charged-particle accelerator technology, in communication links between ultraspeed computers, and in THz devices to detect chemical and biological agents

3-D simulation of cooker magnetron with cold secondary emission cathode

The results from a 3-D simulation of dynamics and formation of an electron cloud in an cooker SEC magnetron when it is triggered off at a sag of an anode voltage pulse having a special shape are presented.