Quantization and soliton-like solutions for the $$\Phi \Psi $$-model in an optic fiber

In the framework of a mesoscopical model for dielectric media we provide an analytical description for the electromagnetic field confined in a cylindrical cavity containing a finite dielectric sample. This system is apted to simulate the electromagnetic field in a optic fiber, in which two different regions, a vacuum region and a dielectric one, appear. A complete description for the scattering basis is introduced, together with field quantization and the two-point function. Furthermore, we also determine soliton-like solutions in the dielectric, propagating in the sample of nonlinear dielectric medium.

Determination of the loss tangent for solid dielectrics at high frequencies

Cells with a micrometer screw are still used for testing solid dielectrics at frequencies from units to hundreds of megahertz despite the development of dielectric measurement technology. We present the results regarding elimination of the negative impact of successive stray inductances (Ln) and active resistance (rn) of such a cell on the accuracy of the dielectric loss tangent (tanδ) determination with allowance for the final value of the Q-factor (Qk) of the circuit inductor in resonant measurements. Tests with and without a dielectric sample were carried out under the condition of maintaining the cell capacity value. No information is available in the regulatory documents and technical literature about taking the aforementioned parameters into consideration. It is shown that the impact of Ln consists in the overestimation of measured tanδ values. To eliminate this effect, we proposed to introduce an additional factor which depends on Ln, frequency and capacity of the sample into existing formulas used for tanδ calculation. It is also shown that the tanδ error increases significantly with a decrease in the ratio of the dielectric loss characteristics of the measuring circuit with and without a sample which can be attributed to rn and Qk. The requirements for rn and circuit damping without a sample are formulated to ensure the desired accuracy. Conditions providing the possibility of assessing the suitability of a particular equipment for tanδ measurements are specified on basis of the developed requirements. The results experimentally proved in resonance measurements with a Q-meter can be used in high-frequency tanδ measurements to provide the required accuracy.

Quality control of substances by electromagnetic sensing in a waveguide

Relevance. The problems of remote non-destructive determination and control of quality indicators of a wide variety of material environments, in particular, household and food products, are relevant practically for all areas of the national economy, science and technology. The relevance of scientific research in the field of dielectrometry in the microwave range is also due to the needs for the development of high technologies in medicine and health care, the national economy in real time. The aim of this work is to develop the method of microwave waveguide dielectrometry based on the application of the theory of multilayer plane-layered dielectric structures to the determination of the complex dielectric constant of a substance from the values ​​of the standing wave ratio of the samples under study in a waveguide at two close frequencies. Materials and methods. The research is based on well-studied phenomena of interference of electromagnetic waves on multilayer plane-layered dielectric structures. By using a mathematical model of the phenomenon of interference of a plane electromagnetic wave on a three-layer dielectric structure, the ambiguity of determining the complex dielectric constant of a substance by the classical method of waveguide dielectrometry in the microwave range by measuring the standing wave ratio of a dielectric sample placed in the waveguide and the phase angle of the reflection coefficient is overcome. Results. A method is proposed for ensuring the unambiguity of determining the complex dielectric constant of a substance in waveguide dielectrometry on the basis of the theory of multilayer plane-layered dielectric structures. The method leads to an explicit expression for the complex reflection coefficient of an electromagnetic wave from the investigated dielectric sample placed in a rectangular waveguide. The complex dielectric constant of a substance is determined from the values ​​of the standing wave ratio at two close frequencies in the microwave range. By the found value of the dielectric constant and the tangent of the dielectric loss angle, the quality parameter of the substance is determined by comparing and optimizing two objective functions, including the arrays of reference values ​​of the complex dielectric constant obtained in the course of measurements and compiled in advance, and by comparing and optimizing the third objective function, previous functions. As an example of an indicator of the quality of a substance, the specific heat of combustion of coal was determined. Conclusions. The proposed method for determining the complex dielectric constant and quality indicators of dielectric materials in the microwave frequency range has been tested in the case of various types of coals, its efficiency has been proven and the reliability of the results has been proven. The method and the devices and software implemented on its basis are promising for non-destructive express control of dielectric materials and media.

Applicability of Measurements of Local Electrical Parameters in the Modeling of Technological Texture of Ceramic Blanks

The paper deals with the modeling of the technological texture of the pressed ceramic materials in the radial and axial direction, which consists in the graphical representation and subsequent analysis of the distribution of the electrostatic field potential differences on the surface of the dielectric sample with the diameter d and the thickness h located between the electrodes. In occasion of observing radial texture the electrodes have the cylindrical configuration and in occasion of observing the axial texture in the sample the electrodes have the axial configuration. The theoretical relationship in the paper is derived for the calculation of the voltage values measured at any position between the center electrode and the peripheral electrode, at a constant voltage U applied to the outer and inner electrodes of the dielectric sample of thickness h of the raw ceramic sample material (radial texture). Measurements have demonstrated the suitability of identifying the technological texture by measuring the potential differences on the sample surface which is located between the electrodes in the relation to the technology preparation and to the quality of the fired ceramic production.

Possibility of Evaluating a Depth of Defects as a Hole in a Composite Dielectric Sample by the Parameters of Electric Response to Pulse Mechanical Excitation

The applicability of the method mechanoelectrical transformations (MET) to determine the depth of the macrodefects location in the sample on parameters of the electromagnetic response is evaluated. As the response parameter it was used the phase characteristic of the signal analytical representation.On the one-dimensional mathematical model it was shown the possibility to detect phase response changes when reflected from defect acoustic wave is mixed with the signal spurious component generated by a distributed MET sources. Experimental verification of mathematical model on a sample of concrete was conducted. It has been shown that the sensitivity of the method MET to evaluation of the macrodefect locate depth depends on the wavelength of the excitation pulse and the area of the macrodefect border closest to the emitter-receiver system.

Hybrid Types of Waves Propagating in Double Ridged Waveguide with Piecewise-Layer Dielectric Filling

The algorithm for calculating electrodynamic characteristics of hybrid types of waves propagating in double ridged waveguide with piecewise-layered dielectric filling is presented. The double ridged waveguide structure with dielectric plates installed between the ridges, and with dielectric sample sandwiched between the dielectric substrates is consid-ered. The calculations are carried out using the method of partial regions. The presented algorithm takes into account the electromagnetic field components singularities near the dielectric and metal edges of the waveguide. The technique for calculating the electromagnetic energy losses in the double ridged waveguide with a piecewise layered dielectric filling is provided. The classification of hybrid waves is given. The spatial structures of electromagnetic fields and their planar projections (front view, top view, side view) for the first two HEwaves and the first EH-wave are demonstrated. Cutoff fre-quencies and propagation constants of HEand EH-waves are calculated. The results obtained using the described meth-od and numerical approach are compared. Then the results are analyzed.