59 research outputs found
Research of a possibility of resonator diagnostics of thin filamentary objects in a low part of the terahertz frequency band
No full textThe method of excitement of the open resonator by the narrow slot on a reflector formed by the waveguide with the highest modes transmitted was experimentally approved. The spectra of such resonator in the range of the frequencies of 85 GHz - 110 GHz were received. It is shown that modes with azimuthal variations of the fleld were most effectively exited. Transformations of spectra by thin dielectric cylinders were researched. A number of parameters of the open resonator, effective in schemes of resonator diagnostics of fllamentary objects with small own losses were found
Research of a possibility of resonator diagnostics of thin filamentary objects in a low part of the terahertz frequency band
No full textThe method of excitement of the open resonator by the narrow slot on a reflector formed by the waveguide with the highest modes transmitted was experimentally approved. The spectra of such resonator in the range of the frequencies of 85 GHz - 110 GHz were received. It is shown that modes with azimuthal variations of the fleld were most effectively exited. Transformations of spectra by thin dielectric cylinders were researched. A number of parameters of the open resonator, effective in schemes of resonator diagnostics of fllamentary objects with small own losses were found
Electromagnetic characteristics of filaments for 3D printing with carbon fillers in the microwave range
No full textThe results of a study of the complex permittivity and electromagnetic response from polymer composite materials obtained by additive technology from 3D printing filaments containing various carbon fillers are presented. New radio filaments for 3D printing with MWCNTs have been created. Investigated PLA-Conductive plastics may be used to create a shielding coating or narrowband absorbers for microwave range
Influence of ultrasonic treatment on electromagnetic characteristics of composites based on multiwall carbon nanotubes at wide range of frequencies (100 Hz - 258 GHz)
No full textIn the present paper, we investigated microwave properties of polymer composites based on multiwall carbon nanotubes. The multiwall carbon nanotubes used in the composite were about 9.4 nm and 18.4 nm in diameter. The results show that the ultrasonic treatment modifies the dielectric properties of the composite. The dependence of the real and imaginary parts of the permittivity of sonication time is non linear. The results showed that composite material based on nanotubes with a diameter of 9.4 nm has a dispersive region of dielectric permittivity at the range about 10 GHz
Structure and electromagnetic properties of Z-type barium ferrite composite exposed to external magnetic field
No full textThe paper presents the analysis of the structure and electromagnetic properties of magnetodielectric composite material polymerized under the influence of the external magnetic field. The structure, phase composition and magnetic properties are determined for Z-type barium ferrite employed as a filling material in the production of test specimens. It is shown that the external magnetic field has an effect on the structure of this composite material. The proposed treatment technique allows fabricating test specimens with both magnetic and dielectric anisotropy parameters
Quasi-optical 2D system for non-contact non-destructive testing of defects in natural and artificial crystals
No full textThe results of development the automated system of two-dimensional diagnostics of defects of crystalline materials are presented. Used technology imaging. The structural scheme of the system is given, its main blocks are indicated, the approbation process is described, the software of the system is described
Selective EHF absorber based on BaFe
No full textThe results of the study of the electromagnetic response of the hexagonal ferrite composite BaFe12O19 in the frequency range 34–250 GHz at room temperature are presented. At a frequency of 46.5 GHz a region of natural ferromagnetic resonance was found. The possibility of creating a selective EHF absorber based on the developed material is shown
The foam-glass material for a radio frequency echoless chambers
No full textThe conducted experiment of foam glass modification by carbon nanotubes shows increased radio absorbing properties in comparison with a foam glass without additives. Addition of carbon nanodimensional tubes in number of 1,5 wt.% increases a tangent of dielectric losses angle by 2,5 times. The coefficient of electromagnetic radiation absorption in the range of frequencies of 120 - 260 GHz increases for a foam glass with carbon nanotubes (1,5 wt. %) twice in comparison with a foam glass without additives. The foam glass modified by carbon nanotubes is recommended as the effective radio absorbing material for the device of anechoic cameras. This material is fire safety, nonflammable, environmentally friendly, rather light-weight
The foam-glass material for a radio frequency echoless chambers
No full textThe conducted experiment of foam glass modification by carbon nanotubes shows increased radio absorbing properties in comparison with a foam glass without additives. Addition of carbon nanodimensional tubes in number of 1,5 wt.% increases a tangent of dielectric losses angle by 2,5 times. The coefficient of electromagnetic radiation absorption in the range of frequencies of 120 - 260 GHz increases for a foam glass with carbon nanotubes (1,5 wt. %) twice in comparison with a foam glass without additives. The foam glass modified by carbon nanotubes is recommended as the effective radio absorbing material for the device of anechoic cameras. This material is fire safety, nonflammable, environmentally friendly, rather light-weight
Microwave absorption properties of foam qlass material modified by adding ilmenite concentrate
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