Abstract A laser heterodyne system for recording of small shifts and vibrations of remote objects is presented. The use of additional compensation interferometer makes it possible to compensate the influence of environmental fluctuations on the measurement results. The registration results of seismic vibrations for various setup configuration are shown. The experiments indicate the reducing of perturbations

Abstract Radar surveillance of unmanned aerial vehicles (UAVs) is actively developing area of scientific research. This article provides a review and analysis of publications in recent years devoted to the methods and radar systems of detection and recognition of classes and types of UAVs. It is noted that the most difficult targets for radar detection are low-sized, low-speed small UAVs (drones) flying

Abstract It is developed a method of information transmission with application of amplitude Single Sideband Hartley modulation (SSBH) allowing to increase of radio channel length for optical and fiber optic signal transmission systems where single sideband amplitude modulation (SSB) is used. Increase of communication range is provided due to application a sum of two orthogonal oscillations of the same

Abstract We consider the integrated circuit design and the measurement results of test crystals for the 12-bit sigma-delta analog-to-digital converter (ADC) based on 180 nm silicon-on-insulator (SOI) technology from X-FAB. The ADC processes input signals in the frequency range up to 100 kHz in the temperature range of –40…+175 °C with the supply voltage equal to 3.3 V and the modulator clock frequency

Abstract One of the possible physical mechanisms of so-called “angel” echoes, not visually observed radar discrete reflections from objects, is considered. The vortex flows can be the cause of “angel” echoes. They take out some volume of air with certain radiophysical parameters into the region of space with other radiophysical parameters of the air. Toroidal vortices (vortex rings) have a fairly long

Abstract This study proposes an approach for building high quality cheap emitters in mid-wave (MW) and long-wave (LW) infrared spectrum bands. A photonic infrared-wave emitter based on light down conversion from the region of fundamental absorption by semiconductor to infrared region has been proposed. The efficiency of such conversion does not depend on quantum yield of interband recombination. It

Abstract In this paper electromagnetic field energy balance equation for linear homogeneous dispersive stationary medium is deduced in general form. No dispersive limitations on ε′, ε″, μ′, and μ″ are used. Thus the following question is answered: why do existing equations not provide correct values for accumulated energy and dissipated energy in dispersive media? An electromagnetic field energy balance

Abstract The review of algorithms of estimation of stochastic processes with random structure and Markov switch obtained on a basis of mathematic tool of mixed Markov processes in discrete time is represented. It is shown that Markov property including continuous valued process with random structure in discrete time and Markov chain controlling its structure modification. There are considered recurrent

Abstract Conventional narrowband beamforming methods are not effective for wideband antenna arrays. Radiation pattern of such array has various beam width over the frequency. Existing frequency-invariant beamforming methods using finite impulse response filters (FIR-filters) can solve this problem. FIR-filters provide frequency response required for frequency-independent properties of the array radiation

Abstract The phenomenon of the voice signal acoustic variability in automatic speech recognition systems is considered. There are two varieties—intra- and inter-speaker speech variability. The probabilistic cluster model of minimal speech units in the Kullback–Leibler information metric is used for their mathematical description and comparison in magnitude. On its basis, theoretical estimates of the

Abstract Mostly random and adjacent error correcting codes are used to protect stored data in SRAMs against multiple bit upsets (MBUs). These MBUs caused by radiation are an important issue related to the reliability of static random access memories (SRAMs). As a result, multiple adjacent bits of a memory are distorted and valuable information is lost. To mitigate these problems, multi-bit adjacent

Abstract Discrete cosine transforms are widely used in smart radioelectronic systems for processing and analysis of incoming information. The popularity of using these transform is explained by the presence of fast algorithms that minimize the computational and hardware complexity of their implementation. Type-IV discrete cosine transform occupies a special place in the list of the specified transformations

Abstract The research approach on the investigation of recombination parameters of nonequilibrium charge carriers in Si technological plates by thermal imaging method is offered in this paper. The lifetime, diffusion length and surface recombination velocity of charge carriers are taken into account. The method is based on a study of the spatial distribution of Si samples thermal radiation beyond the

Abstract There is represented an information about phase inverters with split load. It is noted the problem of provision of identity of different polar signals at split loads. There are mentioned the specificities of Bragg’s diffraction in context of shaping of two different polar signals. It is shown that in case of modification of the frequency of electric signal at the input of acousto-optic modulator

Abstract The paper presents the results for estimating the potential coding efficiency of spectrum envelope waveform (SEW) of speech signals (SS) by using the linear prediction (LP) method and using different sets of alternative equivalent parameters (AEP) that include line spectral pairs/projections (LSP), line spectral frequencies (LSF), and alternative line spectral parameters of highest splitting

Abstract Mathematical expectations and variances of estimates of skewness and kurtosis coefficients of the noise signal model have been derived in this study. The specified noise signals represent the Bunimovich–Rice processes with exponentially power waveform of pulses expressed in terms of cumulant coefficients of the specified processes. It is shown that the distribution of instantaneous values

Abstract Image processing algorithms for compensation of the scattered radiation influence in X-ray imaging are proposed, studied and optimized by numerical simulation. These algorithms include the scattering estimation by convolution (superposition) technique, estimation of kernel functions by Monte Carlo (MC) simulation, the determination of the optimal number and shape of kernel functions and image

Abstract The independence estimation results of synchronously recorded pulse signals in distal parts of human radial arteries are presented in this paper. The study is carried out by the methods of structural-functional and simulation modeling in approximation of an equivalent planar movement of the biological object structural elements. Their elastic characteristics are taken into account using by

Abstract The ambiguity diagram of rectangular chirp RF pulse has been analyzed. The characteristic point of ambiguity diagram was identified. It was proposed to identify the signal on the basis of correlation level at the characteristic point of ellipsoidal ambiguity diagram built in a special coordinate system. The quasi-optimal autocorrelation algorithm with quadrature processing is proposed. This

Abstract The optimal and quasi-optimal algorithms of two-stage joint estimation of information symbols and frequency response (FR) of multibeam channels in OFDM-based communication systems have been synthesized. They involve the calculation of a posteriori probability density of estimated processes. At the first stage, the recurrent calculation of joint a posteriori distributions of information symbols

Abstract In this paper, three time-varying channel equalization schemes are studied in the underwater acoustic (UWA) Orthogonal Frequency Division Multiplexing (OFDM) communication system. The equalization algorithms are the zero-forcing (ZF) equalization algorithm, and the minimum mean square error equalization (MMSE) algorithm and the serial interference cancellation (SIC) equalization algorithm

Abstract The paper presents a method for calculating the radiation patterns (RP) of dual-reflector antenna systems taking into account the electrodynamic interaction between reflectors. This method is suitable for use in the resonance range of wavelengths with respect to the main dimensions of reflectors. The method is based on the iteration procedure proposed by the authors. Each iteration involves

Abstract A compact quad-band circularly polarized (CP) G-shaped printed antenna with square slot is proposed in this paper. Two semicircular notches have been etched from lower periphery of the ground to increase the impedance bandwidth (IBW). In order to increase significantly the axial ratio bandwidth (ARBW), a spring-shaped notch is etched from the upper periphery of the ground. For further increase

Abstract Changes in the geometric parameters of ring coils, which are an essential element of transducer design used for non-destructive testing of ferromagnetic metals, entail a change in the self-induction coefficient (inductance) of alternating magnetic field source. In the article, on the basis of proposed approach [1], the equations for determining the ring coils inductance are obtained, allowing

Abstract Two symmetrical third-order microstrip bandpass filters (BPF) with all mixed coupling coefficients are proposed and analyzed. The first filter is a combline filter with stepped impedance resonators (SIR) closely spaced to each other. This leads to mixed couplings between adjacent resonators. The cross coupling of the end resonators is also mixed K13 = Km13 + Ke13 (MCC). Its magnetic component

Abstract The possibility of sensitivity increasing of magnetic field sensors by combining different types of sensitive elements in one sensor circuit is experimentally investigated. For this purpose, four new sensor constructions are proposed: based on bridge circuit, based on magnetotransistor in combination with magnetodiode or with second magnetotransistor and with frequency output. More thermostable

AbstractThe use of bio-medical applications and bio-inspired computing facilitates the diagnosis of human health. The main work of bio-medical applications relies mostly over the biosensors. Biosensor construction are based on piezoelectric, chemical, optical or electronic principles. Field Effect Transistor (FET) based biosensors gain popularity because of some distinct advantages like compact, fast

AbstractIn order to accurately analyze the most vulnerable fracture points of normal human lumbar vertebrae under upright position, walking and left-right rotation, the spiral computer tomography (CT) was used to scan the segment from the upper edge of lumbar vertebra L1 to the lower edge of lumbar vertebra L5. After reading CT images with Mimics software, the threshold analysis, area segmentation

AbstractAn analysis of complex dielectric permittivity and characteristic impedance of micromechanically tunable coplanar line is presented. The coplanar line parameters tuning is achieved by signal line electrode movement above the substrate or the dielectric plate above the surface of line electrodes. A reconfiguration of electromagnetic field with complex nature occurs as a result of such movement

AbstractInterpretations of large electromagnetic parameters and giant effects in electronic materials are presented. Conductivity, permittivity and permeability of certain materials can be hundred times higher than normal values. Physical phenomena of magnetoresistivity, nonlinear resistivity, electrostriction, magnetostriction, magnetocaloric and thermistor effects in some materials appear to be giant

AbstractSince ancient times, human beings began to understand the periodicity of their own activities. In modern times, people gradually found that the movement of living matter followed a specific space-time law and put forward the concept of biological rhythm. The biological rhythm of human body is a cycle theory that takes the body of each person as a research object and reveals the laws of physical

AbstractIn this paper by means of physical modeling method we obtain the algorithms for calculation of magnetic permittivity in ferrite in case of arbitrary values of magnetic intensity of electromagnetic wave and force of standing electromagnetic wave impact on ferrite cylinder of arbitrary diameter which is placed into constant magnetic field. A value of constant magnetic field intensity provides

AbstractThe noise immunity of radars is essentially reduced under the simultaneous exposure to active noise and passive interferences. This is stipulated by the passive interference decorrelating the active noise and also by the disruption of interperiod correlation of passive interference during the adaptation of weight coefficients of spatial filter. This paper proposes and investigates a new method

AbstractThe paper presents the substantiation of algorithm for forming the structure and technique for message transmission in unidirectional radio communication systems. The proposed algorithm is intended for use before the beginning of signal transmission for implementing the single-use reliable transmission technique with delayed acknowledgement, but with the possibility of forecasting the interference

AbstractThe main aim of massive multiuser multiple-input multiple-output (MU-MIMO) system is to improve the throughput and spectral efficiency in 5G wireless networks. The performance of MU-MIMO system is severely influenced by inter-antenna interference (IAI) and multiuser interference (MUI). The IAI occurs due to space limitations at each user terminal (UT) and the MUI is added when one UT is in

AbstractA method of synthesis of odd-order I/Q demodulators based on replacing the multistage demodulation schemes with equivalent single-stage ones is proposed. The calculation of coefficients of single-stage odd-order I/Q demodulator, which is equivalent to multistage scheme in terms of the waveform of its amplitude-frequency characteristic (AFC), is based on the sample-wise analysis of the process

AbstractElectro-acoustic transducers of electromagnetic type are mainly use in modern non-destructive monitoring and technical diagnostics devices of metal products. The influence of a measuring device on parameters of recorded signals, i.e. on the measurement results, can be eliminated if the influence of dimensions of emitters and receivers of alternating magnetic field on the efficiency of generation

AbstractIt is considered a technique of mutual application of multi-antenna MIMO systems and multiplexing with orthogonal frequency division of OFDM channels for current-technology systems of wireless communication of special application. There are defined areas of prior application of time and frequency variant of diverse signals transmission according Alamouti principle for wireless channels with

AbstractThe paper proposes a new numerical measure for filtering quality assessment of additive white Gaussian noise in digital images based on the analysis of closeness of the difference image to white noise. Such analysis is often conducted visually that leads to undesirable subjectivism. The numerical analysis of difference image using the properties of nonparametric BDS statistic was performed

AbstractA circularly polarized (CP) CPW-fed (CoPlanar Waveguide) with two asymmetric U-shaped strips, patch antenna is described in this paper. The antenna consists of a radiating patch composed of a hexagonal-ring connected with two annular rings on the two corners, which provide wide CP. The CPW-fed antenna was constructed by etching out two L-shaped slots and adding two asymmetric U-shaped strips

AbstractThe ruggedness of emerging single adaptive approach that performs well in all types of operating conditions has led to the development of composite adaptive strategy. In this regard, the fusion of particular decisions of single adaptive schemes through suitable fusion rules can provide a better final detection. Particularly, the fusion of cell-averaging (CA), ordered statistics (OS) and trimmed-mean

AbstractApplication of multi-frequency radiolocation allows to expand essentially received signals spectrum that increases amount of a target (object) classification identifiers including thermal portraits for radiometric measurements. In this paper it is represented a prototype of measuring radiometric unit allowing to carry out simultaneously contactless radiometric research of liquids in two wavelength

AbstractThe digital compensation process for nonlinearly inertial characteristic of the transmit path of dual-band communication system with concurrent data transmission in the presence of unbalance of modulator quadratures has been considered. Analytical relationships enabling us to identify adaptively or change the parameters of dual-band polynomial model of corrector with due regard for the modulator

AbstractAnalysis of discrete estimates of bi-periodically correlated random processes (BPCRP)—mathematical models of signals with double stochastic periodicity was performed using least squares (LS) technique. It is shown that LS utilization allows to avoid systematic errors related to leakage effect. Expressions for estimate bias and dispersion were obtained, allowing determination systematic and

AbstractA new statement of the problem on the calculation of kinematic and dynamic characteristics of surface acoustic waves in piezoelectric monocrystals is proposed. A procedure for solving the above problem is also proposed with due regard for the existence of electric field scattering on the crystal surface not covered with electrodes and the vortex component of electric field in the general case

AbstractSpatial correlation is a crucial impairment for practical Multiple Input Multiple Output (MIMO) wireless communication systems. It is important to consider spatial correlation between antennas in actual communication scenario at both sides, i.e. transmit and receive side. Furthermore, we have considered nonorthogonal full rate STBC in MIMO systems equipped with four transmit antennas and four

AbstractThis paper describes the development of embedded software for the implementation and testing of the artificial multistable neuron model’s basic behavior with the help of the hardware architecture of programmable logic integrated circuits (FPGA). The real behavior and function of the biological neuron with linearized activation characteristics are investigated and implemented in the programming

AbstractSpace-time-frequency (STF) coding can obtain the diversity gain from three dimensions (space, time and frequency) to effectively improve the transmission performance of the multi-input multi-output (MIMO) relay system. In this study, a MIMO one-way two-hop amplify-and-forward (AF) relay communication system is presented by means of triple Khatri–Rao space-time-frequency (KRSTF) coding, which

AbstractThe quality of reception of radio signals at the destination is greatly influenced by the type of signaling schemes used and the use of multiple antennas at the output of transmitter and the input of receiver. However, this configuration usually causes InterCarrier Interference (ICI), which leads to distortions. In this paper, the performance of 6×6 multiple antenna beamforming in offset 16

AbstractIn this paper, two digitally-controlled ring oscillators (DROs) with similar structure but different constructive cells have been proposed. These proposed DROs include of 5 stages, and each stage contains 10 parallel delay cells. In addition, each stage has fine and coarse parts for adjusting the output frequency. The proposed designs have a wide frequency range and high frequency. The frequency

AbstractIn this paper, we present the radiated mode indoor radio coverage performance study of a co-existing dual technology, dual 4×4 Multiple Input Multiple Output (MIMO) antenna platform. The antenna platform is targeted to be used for low power wireless radio Base Station (BS) applications. One of the 4×4 MIMO antenna pairs operates in the 2.5–2.7 GHz licensed Long Term Evolution (LTE) band while

The numerical optimization results of constant thickness septum polarizer’s performances for various operating fractional bandwidths (FBW) are presented in the paper. The polarizer’s structure includes a common input square waveguide, a constant thickness septum with several steps, and two output rectangular waveguides. The polarizer design of 2-, 3-, 4-, and 5-step septums is optimized for different

The exact knowledge of the clutter properties is of great importance for modern radar systems due to the role that they are directly play mainly through the CFAR processor design in the optimization of the detection process. Owing to the central limit theorem, the most used models are of Gaussian distribution that has the feature of simple processing architectures. Actually, these models are expected

This paper describes the algorithm of antenna array (AA) calibration, which estimates and compensates phase lags, caused by non-identical electrical characteristics of array channels. The algorithm does not require the access to the channel signals or the channels disabling. It uses only the array output power measurements under the specific channel phase perturbations. The algorithm accuracy equals

It is considered a problem of automatic speech recognition at basic, phonetic level of speech signal processing. It is researched a problem of noise-immunity increase. For its solution it is proposed a criterion of minimum information divergence of the signals with tuning to a speaker voice and automatic scaling of speech template to thin structure of observed (current) speech frame. An example of

Two methods have been proposed for enhancing the accuracy in determining the coordinates of radio emission sources by using phase systems based on reducing the dynamic and random errors in terms of the curvature of electromagnetic wave phase front during processing the signals at inputs of linear antenna array. The reduction of dynamic errors stipulated by the limited number of terms of the Maclaurin

In this paper it is represented an efficient method for calculation of periodic stationery states of non-linear electronic circuits at time domain. The method is based on application of Kotelnikov-Shannon series for approximation of derivatives of mathematic models of the circuit. Cyclic approximation form with application of Shannon kernel allows to obtain simple matrix relation for the derivatives

The paper considers the problem of determining the eigenfrequencies of biconical cavity making it possible to simplify the eigenfrequency-based design of devices. We used the solving of the excitation problem for biconical cavity using the method of partial intersecting regions in combination with the collocation method. Based on the concept of the search of quasisolution for determining eigenfrequencies

A compact ultra-wideband circular monopole antennas with single, dual, triple and quad-band rejection characteristics are proposed in this paper. The antenna units are designed using RT/DUROID substrate with permittivity 2.2 and all are fed through a coplanar waveguide (CPW). In the proposed antennas splitted concentric rings (SCR) are used to achieve band rejection characteristics. The proposed antennas

In this paper, we consider Mt×M system (Mt > M), where Mt and M are the numbers of antennas at the transmitter and receiver, respectively. We select M out of Mt transmit antennas using two different antenna selection schemes. In scheme 1, we select the subset of M antennas out of total \((\begin{array}{l}{M_{t}} \\{M}\end{array})\) subsets. In the selected subset, the minimum SNR is maximum compared