Katkons in transformer schemes

Macromodels of transformers with different types of relationships (not only inductance but also capacitance) on the basis of circuits with quasi-distributed parameters simulation were proposed. The analysis of resonant modes and frequency characteristics of transformers on the basis of katkons with identical parameters at the open and closed secondary circuit were obtained. Results of the study will help to evaluate the effectiveness of the practical application of these transformers to improve power factor and efficiency of the transmission, distribution and conversion of electric energy. Using the correct transformers macromodels on the bases of katkons with strong and weak coupling makes possible to realize polyfunctional filter-compensative devices and current-limiting devices with reduced weight and dimensions.

Using of ltcc-technology to obtain hexagonal ferrites for substrates microstrip devices microwave electronics mm-range of wavelengths

In the work by the method low temperature co-fired ceramics (LTCC) obtained samples of isotropic and anisotropic polycrystalline hexaferrite BaFe12O19 and SrFe12O19. Using in the LTCC-technology the pressing operation for samples (tablets) in a magnetic field produces anisotropic hexaferrites, pressing without a magnetic field - isotropic hexaferrites. Application in the LTCC-technology molding process tape produces exclusively isotropic samples.

Features of crystal structure and phase composition of the anisotropic hexagonal ferrites bafe12o19 and bafe9,5al2,5o19, obtained by radiation-thermal sintering

The method of radiation-thermal sintering (RTS) in the fast electron beam by accelerator ILU-6 obtained samples of barium hexaferrite BaFe12O19 and substituted barium hexaferrite BaFe9,5Al2,5O19 (with additions of Ni, Ti, Mn). The research synthesized samples was carried out by X-ray structural analysis and X-ray phase analysis. It is found that both compounds besides the main phase samples (BaFe12O19 and BaFe9,5Al2,5O19, respectively), is also present phase BaFe2O4. With increasing sintering temperature from 1100°C to 1300°C phase barium monoferrite intensity decreases or disappears completely, and at a temperature of 1400°C this phase is fixed again (its intensity continues to increase). The possibility of practical use of the results.

Obtaining anisotropic hexagonal ferrites for substrates microstrip microwave devices of mm-range of radiation thermal sintering

We obtain polycrystalline hexagonal ferrite substrate of subminiature devices microstrip ferrite decoupling short-wave part of the centimeter and millimeter wavelength radiation and thermal sintering. A feature of the manufacture of anisotropic hexagonal ferrite technology radiation-thermal sintering is pressing in a strong magnetic field applied in the direction of compression, which allows target particles and to obtain a material with a high degree of texture, and the use of various compounds and dopants in the manufacturing process, allows you to control electromagnetic and magnetic hexagonal ferrites.

Ferrite resonators for mm-wave range devices

Currently on the way are R&D works targeted to expand operational frequencies of microwave devices, including frequency selective ones. The expansion occurs both at low and at high end of the frequency range. Due to the microwave communication systems trend of increasing transmitted data flow rate and volume, as well as for precise object resolution by the vision systems, one needs to shift microwave device operational frequencies to the mm-wave range. Operational frequencies of mm-wave range microwave devices are defined by crystallographic magnetic anisotropy field and magnetic activity of the ferrite material (4πМS/ΔH), related with saturation magnetization and ferromagnetic resonance (FMR) line width. For creation of mm-wave range frequency selective devices are needed the ferrite resonators made of materials with high crystallographic magnetic anisotropy field values, as well as high saturation magnetization and narrow FMR line width. R&D works undertaken in the institute show that such materials can be created on the basis of ferrites with hexagonal structure. As a starting point for the development of the material was taken barium hexaferrite with M-type structure (BaFe12O19). Single crystals with composition BaFe12-xAlxO19 and BaFe12-xScxO19 were received from a solution in melt. By this way one may create materials with anisotropy field values from 5 to 50 kÖe, saturation magnetization from 3900 to 4700 Gauss, narrow FMR line width, and Curie temperature from 370° to 445° С. The dependencies of crystallographic magnetic anisotropy field and saturation magnetization vs diamagnetic dilution and temperature are investigated, as well as FMR line width vs temperature, density and orientation of the growing grains.

Microstructure of magnetic field on permanent magnet surface

In this case we investigate the NdFeB permanent magnet by the atomic force microscopy. Obtained phase diagrams in the center and on the edge of the sample. We investigate the uniformity of the magnetic structure.

Composite radioabsorbing materials on a basis of ferroelectric and w-type hexagonal ferrites

It is investigated complex permeability and permittivity of composite radio absorbing materials at frequencies up to 3 GHz. W-type hexaferrite and a ferroelectric material – barium titanate are the basic components of composition. It is shown that the change of components ratio influence the real and imaginary parts of μ and ε of composition.

Special aspects of electric charge distribution on conductor surface with shape transformation

Few analytical solutions of the electrostatic problem for charge distribution on a conducting body surface are known nowadays. In the paper several new non-trivial forms of conducting bodies that afford an exact analytical solutions were derived. 2D and 3D graphics were plotted as a result of analysis of the solutions. It was also shown that the method in the paper allows to derive infinite solution sets of the problem for charge distribution on a conductor surface within four classes.