Alexander V. Skripal

Resonance features of the allowed and forbidden bands of the microwave photonic crystal with periodicity defects

The resonance features of the allowed and forbidden bands of the microwave waveguide photonic crystals with periodicity defects are theoretically and experimentally analyzed. It is demonstrated that the number of resonances in the allowed band is determined by the number of identical elements whose periodic sequence determines the photonic crystal and the maximum Q factor is reached in the vicinity of the lower and upper boundaries of the allowed band. An increase in the size of the forbidden bands and a decrease in the size of the allowed bands of the microwave photonic crystal due to a decrease in the number of resonances in the allowed band are caused by violations of periodicity of the photonic crystal related to nonidentity of a single element.

Microstrip Photonic Crystals and their Application for Measurement Parameters of Materials

The computer simulation and experimental investigation of frequency dependencies of the reflectance and the transmittance of photonic crystals based on the microstrip structures in the frequency band 0-20 GHz have been performed. The investigations were performed for the photonic crystal with irregularity introduced as changed geometry size of the stripline conductor or changed substrate permittivity of one of the sequence microstrip sections. Good quantitative fit between the calculations and experimental results have been obtained. The possibility of application of open microwave transmission lines - microstrip photonic crystals - for measurement parameters of a material which acts as irregularity in the photonic crystal has been demonstrated.

Wideband Waveguide Matched Loads Based on Photonic Crystals with Nanometer Metal Layers

The possibility of creation of wideband matched loads based on waveguide photonic crystals consisted of alternating layers of dielectrics with different values of thickness and permittivity and nanometer-thin metals with different values of thickness and conductivity has been shown theoretically and proven experimentally.

Technologies of quantitative, color, and dynamic image analysis

Methods of analysis of objects characterized by wide variety of sizes, shapes, color and type of dynamics are described. Application of automatic video control systems for granulometric analysis of various metal powders and grinded materials used in dispenser elements of electrovacuum devices is illustrated. The results of color analysis of millet seeds images having different color shade are given. The features of optoelectronic detection and computer diagnostics of complex movements of the freshwater crayfish Daphnia eye are considered.

Photonic band gap structures and their application for measuring parameters of semiconductor layers

The possibility to simultaneously determine the thickness and the conductivity of thin semiconductor layer and the mobility of its free charge carriers by use of microwave photonic crystal with small number of its constituent elements has been shown. The results of the determination of semiconductor epitaxial layer parameters by the inverse problem solving using reflection and transmission spectra in microwave band are presented.

Determination of parameters of thin semiconductor layers by means of one-dimensional microwave photonic crystals

The possibility to simultaneously determine the thickness and the electrical conductivity of thin semiconductor layer, which play a role of the irregularity in one-dimensional waveguide photonic crystals, using the results of measurement of reflection and transmission spectra in microwave band has been shown. The results of computer modeling and the inverse problem solving are presented.

Application of one-dimensional microwave photonic crystals for measurements of parameters of structures based on thin semiconductor layers

The possibility to simultaneously determine the thickness and the electrical conductivity of structures based on thin semiconductor layers, which play a role of the irregularity in one-dimensional waveguide photonic crystals, using the results of measurement of reflection and transmission spectra in microwave band has been shown. The results of computer modeling and the inverse problem solving are presented.

Electrophysical properties of composites with carbon nanotubes, fine graphite, and feritte microparticles as inclusions

The electrophysical properties of composites based on epoxy adhesive with inclusions in the form of carbon nanotubes, particles of fine-dispersed graphite, and ferrite microparticles have been investigated in the frequency range from 0.1 up to 6 GHz. The effect of the spatial arrangement of ferrite inclusions in the composite volume on the frequency of the transmission coefficient of microstrip photonic crystals has been shown. Magnitudes of transmittance and reflection in the window of transparency of a photonic crystal has been established to be determined by the spatial arrangement of the ordered ferrite inclusions (ferrite filaments) relative to the direction of an electric field vector of an electromagnetic wave and its direction of propagation the photonic crystal. It has been found that with an increase in the induction value of the orienting magnetic field acting during an epoxy cure, the distance between the regularly arranged inclusions of ferrite (ferrite filaments) decreases.

Microwave Measurements of Thickness of Nanometer Metal Layers and Conductivity of Semiconductor in Structures "Metal-Semiconductor"

Peculiarities of interaction of electromagnetic radiation with nanometer metal-semiconductor structures have been investigated theoretically and experimentally. Method for nondestructive multiparameter check of electrophysical parameters of nanometer metal-semiconductor structures using frequency dependence of reflectance and transmittance had been proposed and implemented experimentally.

A microwave method for measurement of free charge carriers mobility in semiconductor structures

The use of the scheme of coherent signals subtraction (the synchrosignal and the synchronized Gunn oscillator output signal) in the measurement of charge carriers mobility in semiconductor structures by means of the microwave magnetoresistance method has been proved theoretically and experimentally. In this paper, the possibility of increasing the sensitivity of the microwave magnetoresistance method in semiconductor structures is investigated.