http://radap.kpi.ua/en/radiotechnique/issue/feedVisnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia2018-01-11T15:55:41+02:00Oleg Sharpanradap@rtf.kpi.uaOpen Journal Systems<p>RADAP is a refereed non-profit both paper and electronic journal operated by the following people (all from the Radioengineering Faculty of Igor Sikorskiy Kyiv Politechnic Institute).</p>http://radap.kpi.ua/en/radiotechnique/article/view/1417Scattering of Electromagnetic Waves on Different Dielectric Resonators of the Microwave Filters2017-12-30T13:14:08+02:00A. A. Trubinatrubin9@gmail.comThe theory of scattering of electromagnetic waves by systems of various coupled the different shape and variant permittivity dielectric resonators is expanded. A new definition of the coupling coefficients of different dielectric resonators is given. The analytical expressions of coupling coefficient of different cylindrical and spherical dielectric resonators made from different dielectrics are obtained. The main regularities of the change in the coupling with the variation of the structure's parameters are considered. The results of calculation of the transmission and the reflection coefficients for bandpass and bandstop filters on various dielectric resonators in the rectangular and circular waveguides are presented. Most optimal configurations, allowing to achieve the best scattering characteristics are determined.2017-12-30T13:14:08+02:00Copyright (c) 2017 Trubin A. A.http://radap.kpi.ua/en/radiotechnique/article/view/1439Near-field open coaxial sensor. Measurement aperture spatial resolution ability evaluation2017-12-30T13:14:09+02:00Liu Changolha.zaichenko@nure.uaO. B. Zaichenkoolha.zaichenko@nure.uaA. Yu. Panchenkopanchenko-a-yu@yandex.ruN. I. Slipchenkomykola.slipchenko@nure.uaMicrowave sensors find wider and wider application in the different domain. The sensors design became more complicated, the methods of their description became more exact.The paper presents a simplified model for describing the near field of a coaxial sensor. There was given grounding of analytical solution simplification, considered fields components in the working area and analyzed field in the working area distribution. The results of a comparison of the distributions of the electromagnetic field components near the aperture are shown, obtained on the basis of a rigorous and simplified model. The field intrusion into the sample at first approximation corresponds to radial distribution. The spatial resolving ability of the sensor, both along the radius and the depth of the sample, is determined by the diameter of the central conductor or by the size of the slit. By varying the shape of the aperture, it is possible to change the characteristics of the sensor, optimally selecting them for a priori known properties of the sample.2017-12-30T13:14:09+02:00Copyright (c) 2017 Liu Chang, Zaichenko O. B., Panchenko A. Yu., Slipchenko N. I.http://radap.kpi.ua/en/radiotechnique/article/view/1438Model of the managment and control device for mobile radio systems2017-12-30T13:14:10+02:00V. N. Pochernyaevkkz@ukr.netV. S. Povhlibpovviktoriya@gmail.comV. V. Zaichenkobig-valtan@bigmir.netThe article presents a mathematical model of a common panel for control and monitoring (PCM) of combined mobile radio engineering systems and its physical interpretation. The model describes management as a ramified process, the functions of which are entrusted on the PCM, the actual model of the PCM containing objects of different importance, among which the generator of orthogonal piecewise-continuous functions is distinguished, process of monitoring the state of objects. The physical interpretation of the above components of the model is determined. It involves the management of a mobile radio engineering system carried out from a remote control, which has in its composition a generator of orthogonal piecewise-continuous functions. The obtained results can be used for telecommunication platforms, which combined various types of communication, devices for monitoring objects and the state of data transmission paths, radar systems of detection, recognition, tracking and guidance. An example of a combined telecommunication platform is shown mobile digital troposcatter-radiorelay station.2017-12-30T13:14:10+02:00Copyright (c) 2017 Pochernyaev V. N., Povhlib V. S., Zaichenko V. V.http://radap.kpi.ua/en/radiotechnique/article/view/1432Performance Analysis of OFDMA and SC-FDMA2017-12-30T13:14:10+02:00Muhanned AL-Rawimuhrawi@yahoo.comThe main challenge in any high-speed digital communication system is how to maximize the data rate with minimizing the bit error rate. Several techniques have been developed to achieve this point. Some of these techniques are orthogonal frequency division multiplexing (OFDM), single-carrier frequency domain equalization (SC-FDE), orthogonal frequency division multiple access (OFDMA), and single-carrier frequency division multiple access (SC-FDMA). These four techniques are described briefly in this paper. Also, the paper measures the performances of OFDMA and SC-FDMA systems over international telecommunication union (ITU) vehicular-A channel using minimum mean square error (MMSE) equalization. Simulation results show that the performances with interleaved mapping outperform that with localized mapping. Also, the performances with quadrature phase shift keying(QPSK) are better than that with 16-ary quadrature amplitude modulation (16QAM). In addition, the performance of SC-FDMA is better than that of OFDMA, when QPSK is used, but the latter is little bit better than that of SC-FDMA when 16QAM is used2017-12-30T13:14:10+02:00Copyright (c) 2017 AL-Rawi, Muhannedhttp://radap.kpi.ua/en/radiotechnique/article/view/1434Signals Features from Distributed Targets of Autodyne SRR with Simultaneous Pulse Amplitude and Linear Frequency Modulations2017-12-30T13:14:10+02:00V. Ya. Noskovnoskov@oko-ek.ruK. A. Ignatkovk.a.ignatkov@gmail.comA. P. Chupahinccaapp1992@gmail.comA. S. Vasilievvasilev@ire.kharkov.uaA. V. Fateevfateev@ire.kharkov.uaS. M. Smolskiysmolskiysm@mail.ruA mathematical model for signals description of the autodyne short-range radar (ASRR) with the simultaneous pulse amplitude modulation (PAM) and the linear frequency modulation (FM) is considered. The peculiarities of signal formation are described, which are obtained from the radar distributed object in the form of an ensemble of an arbitrary number of point-type reflectors. Signal calculations are carried out by the offered approach of the step method for the case of two point reflectors on the radar object located at various distances from ASRR. The distinctive signal properties formed at reception of the first and further emissions reflected form the radar object are established. After sending of the probe emission, the reception of the first reflected emission from the set of shining points is accompanied by linear signal superposition formation from separate reflectors. The reception of further reflections causes an appearance of combinational signal interaction from separate reflectors. The character and degree of such an interaction is defined by the feedback parameter of ASRR, which depends on the autodyne frequency deviation and delay time of reflected emission. Results of ASRR experimental investigations with simultaneous PAM and the linear FM are obtained using the oscillating module made on the Gunn diode of 8mm-range.2017-12-30T13:14:10+02:00Copyright (c) 2017 Noskov V. Ya., Ignatkov K. A., Chupahin A. P., Vasiliev A. S., Fateev A. V., Smolskiy S. M.http://radap.kpi.ua/en/radiotechnique/article/view/1440The use of optimal spatial filtering by the method of common spatial pattern for the classification of EEG signals according to the type of brain activity2017-12-30T13:14:11+02:00P. H. Kytsunkytsun.petro@gmail.comDuring EEG due to the volume conduction the signal from each individual source appears simultaneously in a number of channels registered from different leads. Therefore, the recorded EEG signal gives a blurred picture of human brain activity, which makes the task of classifying such signals rather complicated. One of the effective methods to obtain an informative signal from the EEG record is to use the optimal spatial filtering (some kind of deblurring), when the maximum content of the signal from the particular region of the brain (which corresponds to a certain type of brain activity) is achived in the output signal. An algorithm for classifying EEG signals using optimal spatial filtering by the method of common spatial pattern is proposed to identify two classes of brain activity -- imaginary left and right hand movements. To evaluate the quality of the algorithm, an EEG record, known as BCI Competition IV dataset 2b, was used. To determine the efficacy of the algorithm, the result of its operation was compared with the result of the algorithm without using optimal spatial filtering. The use of optimal spatial filtering improved the accuracy of classification from 0.74 to 0.79, which has shown its efficacy.2017-12-30T13:14:11+02:00Copyright (c) 2017 Kytsun P. H.http://radap.kpi.ua/en/radiotechnique/article/view/1412The Effect of Gamma Rays on the Main Static Characteristics of SiGe Transistors2017-12-30T13:14:11+02:00O. V. Dvornikovoleg_dvornikov@tut.byV. L. Dziatlaunitnelaff@gmail.comN. N. Prokopenkoprokopnik1949@gmail.comV. A. Tchekhovskivtchek@hep.byThe article considers the effect of <sup>60</sup>Co gamma rays on the characteristics (the major ones for the analog ICs) of SiGe n-p-n transistors of SGB25V technology: the voltage across the forward-biased base-emitter junction, the dependence of the static base current gain in the common-emitter (CE) configuration on emitter current, the output characteristic in the CE configuration.2017-12-30T13:14:11+02:00Copyright (c) 2017 Dvornikov О. V., Dziatlau V. L., Prokopenko N. N., Tchekhovski V. А.http://radap.kpi.ua/en/radiotechnique/article/view/1402Combined Electromagnetocrystalline Inhomogeneities2018-01-11T15:55:41+02:00E. A. Nelinye.nelin@gmail.comYa. L. Zinhersinger.yana@gmail.comV. I. Popsuipopsui@kivra.kpi.uaA major expansion of the range of wave impedances provide 3D electromagnetocrystalline heterogeneities (ECIs), combining heterogeneities in metallized surface, dielectric and the signal surface of microstrip line. As consequence 3D ECIs as quasi-lumped reactive elements ensure a significant reactivity increasing compared with the conventional structures. The inductor and capacitor may be combined in the construction of ECI, named combined.<br /> The constructions of combined ECIs are proposed. As a model of the first approximation for combined ECI a 1D model based on transmission line is considered. With the help of 1D model analytical results for combined ECI are obtained. A comparison between the efficiency of single and combined ECI using 1D and 3D models is made. 3D modeling is performed in the program package CST Microwave Studio.<br /> Experimental and calculated transfer characteristics of electromagnetic crystalls (ECs) on the basis of single and combined ECIs are presented. Experimental and calculated values of the forbidden zone minimums for ECs on the basis of single and combined ECIs are equal -36, -38, -64 and -75 dB, respectively.2017-12-30T13:14:11+02:00Copyright (c) 2017 Nelin E. A., Zinher Ya. L., Popsui V. I.http://radap.kpi.ua/en/radiotechnique/article/view/1437Homomorphic Two-Stage Image Sequence Filtering Algorithm in the Presence of Correlated Speckle Noise2017-12-30T13:14:12+02:00O. M. Liashukoleksii.liashuk@gmail.comS. V. VishnevyyVishnevyy@kpi.uaS. Ya. Zhuksyadom@freenet.com.ua<strong>Introduction</strong>. An images received from synthetic-aperture radar and ultrasonic medical coherent systems are distorted by speckle noise which can be spatially correlated. Sequence frame processing is applied due to poor quality of source images. The large number of filters for processing the images distorted by a multiplicative speckle noise were developed at the present time. Most of existing filters don’t take into account spatial correlation in the speckle noise which leads to lower efficiency of noise suppression. Image sequence processing leads to processed data volume increase. Thus, a problem of computing complexity and practical implementability of the filtering algorithms used for speckle noise suppression is even more relevant.<br /> <strong>Theoretical results</strong>. The task of filtering the sequence of images in the presence of correlated speckle noise becomes the task of filtering a signal component in the presence of the additive correlated noise as a result of homomorphic transformation. An expression for posteriori probability density of signal component pixel and the correlated noise pixel in each point of the sequence of images was created using property of the conditional independence. It’s used for combining received posterior distributions at the first stage as a result of executing one-dimensional non-linear filtering. The algorithm of computation of mathematical expectation and correlation matrix of joint posteriori probability density of a signal and correlated noise pixels in each point for a case of gaussian posterior distributions for non-causal intraframe and causal interframe processing is synthesized.<br /> <strong>Experimental results</strong>. The developed algorithm allows to receive a gain in signal-to-noise ratio in 5.8-1 dB for a model example by processing from one to five frames compared to interframe averaging algorithm. The number of segmentation errors for the images filtered by Otsu algorithm using three frames is 2 % for the developed algorithm and 18 % for interframe averaging. <br /> <strong>Conclusion</strong>. The homomorphic two-stage filtering algorithm of the sequence of images in the presence of correlated speckle noise was developed. It uses two-stage joint filtering of a signal component and the additive correlated noise with intraframe not causal and interframe causal processing after homomorphic transformation.2017-12-30T13:14:12+02:00Copyright (c) 2017 Liashuk O. M., Vishnevyy S.V., Zhuk S. Ya.http://radap.kpi.ua/en/radiotechnique/article/view/1435Evaluation of the quality characteristics of the radio electronic systems in the operation critical modes2017-12-30T13:14:12+02:00V. O. Bychkovskyimarina060709@gmail.comYu. Yu. Reutskareutska_rtf@ukr.net<strong>Introduction.</strong> Feature of the modern radio electronic systems is the need to ensure their effective functioning in conditions of the changing working conditions and the uncertainty regarding the internal factors and the external random factors. In such more and more often situations there are critical events of a diverse nature, when a number of target indicators of the system or functional characteristics of the environment go beyond the permissible limits. From the point of view of information analysis the critical situation arises under the condition of insufficient information support of processes in the radio electronic systems, the information loss and the restrictions on the operation time of radio electronic systems. The use of existing methods of information analysis for evaluating the qualitative characteristics of radio electronic systems in critical operating modes is not possible. This is due to several circumstances. Firstly, generally known methods are based on a static approach. Consequently, time limits for the work of radio electronic systems cannot be taken into account. Secondly, the dynamics of entering the critical regime remains hidden, this does not allow to evaluate the threat of an accident or disaster in the event of further deployment of critical events. In addition, it is impossible to predict the consequences of the information loss or the effect of deliberate interference on the radio systems characteristics. Thus, the task of evaluating the qualitative characteristics of radio electronic systems in critical operating modes is relevant and practically oriented. <br /> <strong>Results.</strong> For solve the problem use the analogy method, which involves the reduction of predictive models and models of technical systems to the level of multi-elemental physical systems. The effectiveness of the radio electronic systems depends on the amount and value of incoming information in the functioning process. We will consider useful information and misleading or lost information taking into account the peculiarities of the radio electronic systems work in critical operating modes. On the basis of the partial quantitiesmethod the qualitative characteristics evaluating task of the radio electronic systems in the critical operating modes is solved. The need to use automated systems is due to the fact that the human operator can give way to technical means for the speed, timing of tasks and the amount of perceived information but it is the most flexible, versatile and active link. Thanks to the human operator, the intra-system interaction is combined into a single, purposeful process of functioning. Taken into account that in conditions of deliberate interferences with an unknown distribution of probabilities the main burden lies on the human operator. He uses a priori knowledge about the nature of useful signals and interferences, experience and intuition. A critical situation arises when disorientation and overloading of the operator is achieved. The classical results of the application of the partial-value method were supplemented by information components enabled to take into account the information capabilities of typical dynamic links and relative errors of the transition process. For automatic systems the dependence of the error on time, the initial values of the partial values and the constant time of the dynamic units is established. The essential factor was that the dynamic properties of the human-operator, which follows the object in the conditions of interference is taken into account, and the requirements for the time of its operation is established.<br /> <strong>Conclusions.</strong> The obtained results allow us to proceed to a qualitatively new level of macroscopic analysis of radio electronic systems, give an opportunity to evaluate their characteristics in critical operating modes and to predict these characteristics at the initial stage of the design of radio electronic systems.2017-12-30T13:14:12+02:00Copyright (c) 2017 Bychkovskyi V. O., Reutska Yu. Yu.