| 1. |
- Ivanchenko, Igor, et al.
(author)
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A novel resonance method for determining the complex permittivity of local inclusions in a rectangular waveguide
- 2020
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In: Measurement science and technology. - : Institute of Physics (IOP). - 0957-0233 .- 1361-6501. ; 31:9
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Journal article (peer-reviewed)abstract
- A novel resonance method for determining the complex permittivity of materials in the X-band is proposed. A distinctive feature of this method is that the sample under test, located in a radio-transparent isotropic and homogeneous dielectric matrix, is both a local inclusion and the excitation element of the resonance in the microwave module 'waveguide–dielectric matrix–inclusion'. The complex permittivity of an inclusion is determined by comparing the measured resonance frequency and quality factor with the computed database value. The permittivity and loss factor of microwave ceramics, natural granite and ferrite are investigated, as well as crystals of lead fluoride PbF2 doped with holmium trifluoride HoF3 and erbium fluoride ErF3 of different concentrations. The method allows the permittivity and loss tangent to be determined with uncertainties of 0.1% and 5%, respectively.
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| 2. |
- Ivanchenko, Igor, et al.
(author)
-
Combined L–S-bands antenna module
- 2019
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In: IET Microwaves, Antennas & Propagation. - : IET. - 1751-8725 .- 1751-8733. ; 13:5, s. 541-545
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Journal article (peer-reviewed)abstract
- A combined L-S-band antenna module consists of four rectangular patch antennas, two of which operate at the frequencies of the first harmonics (L-band), and two others at the frequencies of the second harmonics (S-band). The module is intended for use in super heterodyne signal reception circuits, for example in studying the various non-linear phenomena. The results of this study are presented in terms of improving the performance of each antenna and minimising their mutual influence. The resonance frequencies of the L-band antenna differ by 50MHz. All the antennas radiate close to the zenith and their beamwidths in two principal planes are virtually the same. At the resonance frequencies, the reflection coefficient is S-11<-30dB for the transmitting antenna, and S-11<-20dB for the receiving antenna. The minimum allowable distance between the antennas is determined, at which their mutual influence can be neglected (S-12<-50dB).
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| 3. |
- Ivanchenko, Igor, et al.
(author)
-
Determination of effective permittivity of metamaterial antenna cells
- 2016
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In: 2016 10th European Conference on Antennas and Propagation. - : Institute of Electrical and Electronics Engineers (IEEE). - 9788890701863
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Conference paper (peer-reviewed)abstract
- A numerical-analytical method of reconstructing complex frequency-dependent permittivities is proposed. Measurements of the transmission coefficient for three typical metamaterial antenna units are performed and the frequency-dependent effective complex permittivity of the units is reconstructed in a wide frequency range.
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| 4. |
- Ivanchenko, Igor, et al.
(author)
-
X-band aperture antenna with hybrid dielectric inserts
- 2016
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In: Progress In Electromagnetics Research C. - 1937-8718. ; 61, s. 27-35
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Journal article (peer-reviewed)abstract
- An X-band radiator as an open-ended waveguide with a hybrid dielectric insert is proposed. The insert is in the form of a parallelepiped, which fills the entire cross section of the waveguide and constitutes a Teflon matrix with local inhomogeneities in the form of dielectric cylinders with a different permittivity. The design allows for forming various near-field distributions and, hence, the radiator performance by means of definite combinations of the local inhomogeneities can be modified. A number of configurations in the location of air and quartz cylinders are investigated. The calculated and experimental results are in good agreement. The proposed approach to the near-field formation of the aperture antenna is promising, because the variety of possible configurations in the location of local inhomogeneities with different permittivity provides new opportunities in terms of designing both single radiators and antenna arrays.
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