Radiotehnika i èlektronika

A model for calculating the radiation parameters of a flat aperture in the far zone of free space is described. The electromagnetic field on the aperture is specified by the field of the primary polarized wave emanating from the excitation point. The radiating system is represented by Huygens elements. Verification of the reliability of the calculation result is carried out at the level of agreement with fundamental physical principles, with analytical calculations, and with the experimental results. When the antenna is excited by an arbitrary electric pulse, the calculation time of the radiation parameters in the time, space, and frequency domains is a few minutes. The calculation model is equipped with an interface in the style of MS Windows.

Two methods for synthesizing Luneburg lenses based on an inhomogeneous anisotropic dielectric are proposed: using an iterative procedure and a gradient medium model, as well as using a recurrent procedure and a layered medium model. As an example of the application of the proposed methods, a synthesis of two variants of a cylindrical Luneburg lens based on a ring dielectric structure was carried out. It is shown that the method based on the iterative procedure is unstable at small values of the radius. Using numerical modeling by the finite element method, an analysis of two versions of lens antennas based on cylindrical Luneburg lens synthesized using a layered dielectric model and a recurrent procedure is carried out.

A non-linear electric circuit in a cube-like form is studied. Similar Child–Langmuir diodes are connected in its edges. The procedure of the circuit decomposition by the method of equivalent nodes is carried out. As a result, an exact formula of the general circuit purveyance was derived. The formula can be used to estimate volt-ampere characteristic (VAC) of tetragonal networks with cubic elementary cells containing Child–Langmuir diodes.

The precession of the magnetization equilibrium position in a medium with uniaxial anisotropy of the second and fourth orders is considered. In the geometry of the normally magnetized ferrite plate the conditions of orientational transition necessary for excitation of precession of equilibrium are found. Time dependences of the fluctuations of the transverse components of the magnetization are obtained. Precession portraits for the cases of anisotropy of the second and fourth orders are constructed. It is shown that both of them have the form of a large ring filled along the formation by small rings. It is shown that at sufficiently large magnitude of the fourth-order anisotropy in the distribution of small rings, thickenings corresponding to fractures of the time dependences of the transverse magnetization components are observed.

The paper discusses methods for encoding and decoding large amounts of data using a neuromorphic model based on known neuromechanisms for the perception of visual information. Known mechanisms of the visual system, such as aggregation of counts by receptive fields, central-lateral inhibition, etc., have been studied. A decoding model has been developed that implements the function of simple cells of the primary visual cortex responsible for spatial perception of stimulus contrasts. The proposed decoding model makes it possible to restore local boundaries of objects in an image, while improving the visual quality of images in comparison with the quality of restoration with classical bilinear interpolation.

In this paper, the similarity of glass systems with pinning in compounds with a charge density wave (CDW) TmTe₃ and HoTe₃ was investigated. For this purpose, the differential IVs in micro-bridge structures oriented along the sliding direction of the CDW, with a multi-stage temperature change, were studied. In such a system with a sliding CDW, the changing behavior of the threshold field during isothermal exposure was shown, with characteristic relaxation on a logarithmic time scale. A property characteristic of glass systems has been found – the memory effect, which allows us to assert the unusual glass nature of the system of pinning centers in this system.

This work presents the experience of designing and manufacturing of fractal elements (FE) based on resistance capacitance media, in particular, based on a one-dimensional structurally uniform resistance-capacitance element with distributed parameters (RC-EDP) with R-C-NR (R-C-NR ЭРП) kind of a layer structure. It also presents the results of designing and manufacturing of thick film FE samples having constant phase of impedance –10°, –20°, –30° and –40° in the frequences range of 1.5 decade order. It gives the results of the comparative analysis of phase-frequency characteristics of the input impedance of the synthesized model and the manufactured sample.