M.V. Davidovich – Dr.Sc.(Phys.-Math.), Professor,
Department of Radiotechnique and Electrodynamics,
Saratov National Research State University named after N. G. Chernyshevsky
E-mail: davidovichmv@info.sgu.ru
A.K. Kobets – Post-graduate Student,
Department of Solid State Physics, Saratov National Research State University named after N. G. Chernyshevsky E-mail: cobets.alexander@yandex.ru
We consider the rejection filter for conveyor installations of microwave heating. Such installations of microwave heating for high performance are convenient to build on several sections of grooved waveguides (CW), included quasi-periodically, while there is a problem of radiation from the input and output windows for transferring of product. The latter is fed by a belt conveyor and passes through the active area of several sections of the GW, which receives power of the order of several kW. To prevent radiation into the open space in the company's installation “Etna-plus LLC” provides cutting filters designed to weaken radiation significantly below the permissible level of 10 mW/cm2. To do this, the cutting filter must have a power attenuation factor of more than 80 dB. The paper considers the problem of parametric optimization of such a filter in the form of a large-section waveguide segment and several capacitive diaphragms. For greater reliability of suppression, the diaphragms of the original design were covered with absorbing rubber. It is shown that the barrier is strongly affected by the distance between the diaphragms, and the maximum attenuation is achieved in the center of the band gap of the periodic diaphragmented waveguide. The specified zone for a large number of periods corresponds approximately to the half-wave length of a partially filled dielectric waveguide. Absorption on the barrier is weak, and strong absorption worsens the barrier. Increasing the height of the waveguide section (increasing the size of the diaphragm) allows you to significantly reduce the length of the filter at a given attenuation. The proposed optimal design allows to reduce the filter capacity and dimensions with an increased barrier that meets the requirements of sanitary standards and electromagnetic compatibility.
- Javchunovskij V.Ja. Mikrovolnovaja i kombinirovannaja sushka: fizicheskie osnovy, tehnologii i oborudovanie. Saratov: Izd-vo Sarat. un-ta. 1999. 217 s. (In Russian).
- Davidovich M.V. Zamedljajushhaja sistema «dvojnaja sdvinutaja impedansnaja grebenka». ZhTF. 2019. T. 89. Vyp. 2. S. 280–296. DOI: 10.1134/S1063784219020051 (In Russian).
- Davidovich M.V. Zamedljajushhaja sistema tipa diafragmirovannyj prjamougol'nyj volnovod. Radiotehnika i jelektronika. 2020. T. 65. № 2. S. 107-117. DOI:10.113/S1064226920020047 (In Russian).
- Levin L. Sovremennaja teorija volnovodov. M.: IL. 1954. 216 c. (In Russian).
- Davidovich M.V., Kornev I.A. Opticheskie, IK- i TGc-jekrany na osnove sloistyh struktur metall–dijelektrik–polu-provodnik. Komp'juternaja optika. 2019. T. 43. № 5. S. 765‒772. DOI: 10.18287/2412-6179-2019-43-5-765-772 (In Russian).