Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia
http://radap.kpi.ua/en/radiotechnique
<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>en-USAuthors who publish with this journal agree to the following terms:<ol type="a"><li>Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a <a href="http://creativecommons.org/licenses/by/3.0/" target="_new">Creative Commons Attribution License</a> that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.</li><li>Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.</li><li>Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See <a href="http://opcit.eprints.org/oacitation-biblio.html" target="_new">The Effect of Open Access</a>).</li></ol>radap@rtf.kpi.ua (Oleg Sharpan)mosichuk@ua.fm (Vitaliy Mosiychuk)Sat, 30 Sep 2017 22:55:37 +0300OJS 2.4.7.1http://blogs.law.harvard.edu/tech/rss60Adaptive signal detection on the background clutter
http://radap.kpi.ua/en/radiotechnique/article/view/1409
<strong>Introduction</strong>. The article poses the problem of optimal detection of coherent-pulsed signals of moving targets against a background of clutter with a priori uncertainty of the signals and clutter parameters. The aim of the article is the synthesis and analysis of adaptive signal detection systems.<br /> <strong>Synthesis of adaptive detection algorithm</strong>. The algorithm for optimal detection of signals against a background of clutter is determined by calculating the likelihood ratio. The implementation of the obtained algorithm for optimal linear filtering is assumed on the basis of the adaptive matrix filter and the non-adaptive multichannel filter.<br /> Evaluation of the signal phase. A quasi-optimal algorithm for estimating the Doppler phase of the signal from the output samples of the adaptive matrix filter is synthesized. Modeling on a PC has established that the asymptotic properties of the obtained estimates are acceptable for their use in adaptive signal accumulation.<br /> <strong>Synthesis of the adaptive detection system</strong>. A detection algorithm with adaptive signal accumulation is proposed. This algorithm combines adaptation to the clutter parameters and to the Doppler phase of the signal. A block diagram of the adaptive signal detection system is given. Analysis of the adaptive detection system. The optimal size of the detuning of Doppler channels of adaptive signal accumulation is determined by PC simulation. It is established that with an allowable loss level of up to 2 dB, the number of Doppler channels can be reduced by a factor of four.<br /> <strong>Conclusion</strong>. The use of Doppler signal estimation in detection systems with adaptive signal accumulation allows reducing the number of Doppler channels or, with the same number of Doppler channels, detuning between channels, eliminating interchannel losses.Popov, D. I.
Copyright (c) 2017 Попов, Дмитрий
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http://radap.kpi.ua/en/radiotechnique/article/view/1409Sat, 30 Sep 2017 22:55:33 +0300Study of the spectral characteristics of the Scattering of MOM-structures in non-linear locations
http://radap.kpi.ua/en/radiotechnique/article/view/1379
The reliability of non-linear junction detectors (NLJD) at detection of radio-electronic devices (RD) and scatterers of corrosion origin of the type “metal-oxide-metal” (MOM-structures) is investigayed. It is revealed that the presence of MOM-structures in the study space substantially impair the reliability of NLJD at revealing RD with the “small” non-linear effective area of dispersion (NEAD) of the probing signal. In this case determination of threshold levels of multiple harmonics and their ratios will not improve the efficiency of the NLJD use, which is associated with the peculiarities of MOM-structures current-voltage characteristics (CVC). The contacts between the metals Al, Cr, Ni have CVC with asymmetry, which are determined by the thickness and area of the oxide. The asymmetry can be of two types – positive and negative, have a clear and quasi-clear manifestation. It is shown that the choice of the optimal threshold ratio ensures the reliability of NLJD only upon detection of MOM-structures with quasi-clear CVC asymmetries of two types. In the case of MOM-structures with a clear CVC asymmetry of two types, the efficiency of the use of NLJD initially requires a significant decrease of levels of spurious emissions of the transmitting antenna.Zinchenko, M. V., Vo Duy, Phuc, Zinkovskiy, Yu. F.
Copyright (c) 2017 Zinchenko M. V., Vo Duy Phuc, Zinkovskii Y. F.
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http://radap.kpi.ua/en/radiotechnique/article/view/1379Sat, 30 Sep 2017 22:55:34 +0300Mathematical model of instantaneous frequency measuring process of radioemission phasemeasuring sources by interference type devices
http://radap.kpi.ua/en/radiotechnique/article/view/1428
<strong>Formulation of the problem in general</strong>. The question of determination of the instantaneous significance of the radio emission sources’ carrier frequency in the conditions of high aprior uncertainty of signal parameters and the limited resource potential of radiomonitoring forces and means is an actual scientific and practical task.<br /> Analysis of recent researches and publications. An analysis of existing mathematical models describing the processes of determining the carrier frequency of radio emission sources has shown that they take into account only linear results of measurements. In modern conditions, the task of creating a new generation of informational-measuring technologies, methods, algorithms and procedures becomes a special urgency.<br /> <strong>Presenting the main material</strong>. For the mathematical formalization of the process and the development of a general procedure for determination of the instantaneous significance of the radio emission sources’ carrier frequency, it is advisable to use the method of maximum likelihood.<br /> <strong>Conclusion</strong>. The analytical approach, that is a mathematical formalization of physical processes which take place at determination of estimations of bearing frequency of radioemission sources during the radiomonitoring, is shown in the article. The got analytical expressions can be used for development of new and improvement of existent methods of instantaneous determination of bearing frequency of radioemission sources with further development of devices of their realization.<br /> <strong>The perspectives of future researches</strong>. Solving the problem of obtaining new analytical dependencies during the simulation of processes occurring in devices that carry out mono-pulse bearing of radioemission sources will become the research in the nearest future.Voitko, V. V., Ilnytskyi, A. I.
Copyright (c) 2017 Voitko V. V.
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http://radap.kpi.ua/en/radiotechnique/article/view/1428Sat, 30 Sep 2017 22:55:35 +0300Frequency Determination Method of the Sweep-Generator of the Panoramic Frequency Characteristics Meter
http://radap.kpi.ua/en/radiotechnique/article/view/1425
Usage of the panoramic meters of frequency-response characteristics or frequency-response characteristic tracers significantly increases work productivity of adjusters and operators of radioelectronic and telecommunication systems. <br /> One of the main functions of the frequency-response characteristic tracer is formation of frequency-response scale, that is determining sweep generator frequency, which is a part of it. High-quality frequency-response characteristic tracers must have little error of scale bars formation in the broad frequency range, automatically and independently define their frequency of the swing band of the sweep generator.<br /> There is a basic structural scheme of the sweep generator frequency meter with a single-channel frequency-time converter, the main units of which include two reference-frequency generators and stroboscopic mixer. It is proved that usage of reference-frequency generators on quartz-crystal resonators reduces to zero the error component of frequency defining, provided by frequency instability of the generator.<br /> To compensate the deflection non-linearity influence of the sweep generator on frequency determination accuracy, the basic scheme of the meter was added with the third reference-frequency generators, as well as the operating procedure of the control and evaluation unit was changed. The evaluating formulas were received for the sweep generator frequency, on their basis the mathematical models for deflection non-linearity cases were created. As a result of the analysis it was found that in the new meter in comparison with the basic one the error component of frequency determination of the sweep generator caused by deflection non-linearity is decreased by times.<br /> Interrelation between the multiplication factor and deflection non-linearity coefficient was found, it can be used by designing of the sweep generator frequency meter and formation of the requirements to frequencies of reference-frequency generators.<br /> The developed meter with a single-channel frequency-time converter can be used in high-frequency characteristic tracers of 20 GHz and higher range. Its advantages include: simplicity, absence of fast-speed units, except for the stroboscopic mixer, transfer of measurements to great time range, that is to low frequencies.Kononov, S. P., Nehur, A. A.
Copyright (c) 2017 Kononov S. P., Nehur A. A.
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http://radap.kpi.ua/en/radiotechnique/article/view/1425Sat, 30 Sep 2017 22:55:35 +0300Technique of increasing the impedance measuring transducers accuracy at inharmoniousness signals
http://radap.kpi.ua/en/radiotechnique/article/view/1422
<strong>Introduction</strong>. Nowadays, one of the most relevant classes of sensor electronics for the Internet of Things is based on the methods of impedance spectroscopy. In general, the informative signals of impedance spectroscopy, namely, an active component or resistance which forms the real part and a reactive component or reactance which forms the imaginary part of complex impedance of the investigated two-terminal network, are formed by specialized analog front-end or measuring transducers. The defining requirements for measuring converters of sensor devices of the Internet Things are their versatility, minimal power consumption, the ability to work at low supply voltages, stability of operation with changing external factors and so on. In this paper, the problem of improving the accuracy of electrical impedance measuring transducers is considered, taking into account the non-harmonic of the driving signals.<br /> <strong>SPICE model and research technique</strong>. The implementation of impedance spectroscopy assumes a transition from frequency plots to plots on the complex plane, called as Nyquist plots. In a number of modern versions of circuit simulation programs the method of impedance analysis is already provided with the use of mathematical functions of Real (Re) and Imagine (Im) components of the signal. Using these functions, it is possible to calculate the corresponding values of the active (Re Z) and the reactive (Im Z) impedance of the object under investigation. As a result of his usage a Nyquist plot is plotted. However, this approach is not universal, and in particular, imposes significant restrictions taking into account the parameters of real signals, namely, their amplitude, shape, non-harmonics, etc. The results obtained in this paper are based on the new SPICE (Simulation Program with Integrated Circuit Emphasis) model studding methodology, which compares small signal Alternative Current Analysis with large signal Transient Analysis. During the Alternative Current Analysis, Nyquist impedance plot are obtained in the idealized case, and during the Transient Analysis the active Re Z value and reactive Im Z impedance components are calculated for the actual parameters of the measuring transducers and the form of the activating signals. The implementation of the above mentioned methodology involves the use of synchronous quadrature detection of the output signals of the measuring circuit.<br /> <strong>Analysis and correction of results</strong>. In accordance with the task of increasing the impedance measuring transducers accuracy at inharmoniousness signals we consider the method of calculating the coefficients KRE and KIM, allowing correcting the measurement results of the active Re Z and the reactive Im Z impedance components. A few analysis and correction results are presented. The obtained regularities can be widely used in correcting the results of impedance spectroscopy upon activation by pulse signals for the vast majority of research options.<br /> <strong>Conclusion</strong>. A new approach is proposed, according to which three arrays of informative signals of active Re Z and reactive Im Z impedance are formed and compared. The first M(AC) array is obtained using small signal Alternative Current Analysis, which corresponds to an idealized version of the measurement transformation and is subsequently used as a reference. The next two arrays M(H1) and M(HN) are obtained by the method of large signal Transient Analysis using the results of integrating the quadrature detector output voltages of the impedance transducer. The array M(H1) is formed when the input source triggers a harmonic oscillation (the first H1 harmonic), and the M(HN) array when activated by a functionally controlled source synthesizes a non-harmonic signal in the form of harmonics HN. The increase in the accuracy of the measurement conversion is provided by coefficients $K_{RE}$ and $K_{IM}$, which allow the correction of the measurement results of the active and reactive components of the impedance. A method for calculating such coefficients and examples of their use are presented.Barylo, G. I., Holyaka, R. L., Prudyus, I. N., Fabirovskyy, S. E.
Copyright (c) 2017 Barylo G. I., Holyaka R. L., Prudyus I. N., Fabirovskyy S. E.
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http://radap.kpi.ua/en/radiotechnique/article/view/1422Sat, 30 Sep 2017 22:55:36 +0300IC Discrete-Analog Correlators Accuraccy Improvements
http://radap.kpi.ua/en/radiotechnique/article/view/1388
Some variants to improve accuracy of the integrated circuits of asynchronous digital-analog correlators with a binary impulse response are discussed. Possibility of signal processing with an arbitrary impulse response in binary form is presented. Each variant of the asynchronous programmable correlators structure have been constructed upon parallell channels. Each channel consists of two quadrature parts. It has SIN-code register, COS-code register and selector register for sample-hold input signal operations to load signal samples into static parallel analog cells. Each correlator channel has weight. Master channel has weight 1. Next has weight ½ etc. according to pulse function binary code.. In the first correlator case the input voltage was been scaled from channel to channel, in the second – output signals has been divided according to bit pulse function. The third case have been realized when each channel scaled supply parallel analog memory current. It have supplied maximum signal/noise ratio in signal processing. The main meaning is the output resistance analog parallel memory is low. All three variants of realization have tested. The best result was obtained in case when current of the parallel analog memory have been scaled. The output response have been discovered when input signal was equal 20 mV with input noise 1 V. The master clock was equal 80 MHz. The reference code had long of 1024 points for four parallel channels analog memory. It is noted the modern design must be done to increase the master clock up to 800 MHz. It is noted as well the new correlator can be build with scaled IC topological components for currents weighting. This way the MOS-transistor is in a steep area of CVC.Pavlov, L. M.
Copyright (c) 2017 Pavlov L. M.
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http://radap.kpi.ua/en/radiotechnique/article/view/1388Sat, 30 Sep 2017 22:55:36 +0300Dynamics of frequency dependences of parameters of electric impedance of a person during dry fasting
http://radap.kpi.ua/en/radiotechnique/article/view/1159
<strong>Introduction</strong> The article considers the possibility of further development of the method of analysis of the parameters of electrical impedance to determine the current functional state of a person in various conditions of his life, in particular during the "dry" fasting.<br /> <strong>The aim of the study</strong> was the dispersion properties investigation of the amplitude and phase parameters of human body impedance in the extended frequency band during the weekly one and half day "dry" fasting.<br /> <strong>Methods</strong>. Measurement of electrical impedance parameters was performed weekly during half a year on one person before, during and after a day and a half fasting . Broadband three-frequency measurement technique is used. The possibility of analyzing the dispersion characteristics of a human body using the Cole hologram is considered.<br /> <strong>Results and discussion</strong>. It is established that in the process of "dry" fasting there is a change of all parameters of impedance. The most pronounced changes in the parameters of electrical impedance are observed by the definition of the module and the active component at a frequency of 100 kHz, the phase at frequencies 20 and 500 kHz, the reactive component at a frequency of 20 kHz.<br /> <strong>Conclusion</strong>. Changes in the dispersion properties of the human body impedance are noticeable in all parameters especially in phase and reactive resistance. According to the research results an interpretation of changes in the functional state of a person during fasting was made.Sharpan, O. B., Mosiychuk, V. S.
Copyright (c) 2017 Mosiychuk Vitaliy, Sharpan Oleg
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http://radap.kpi.ua/en/radiotechnique/article/view/1159Sat, 30 Sep 2017 22:55:36 +0300Two-part electrodes of the physical phantom for EIT
http://radap.kpi.ua/en/radiotechnique/article/view/1418
In this article explored methods for increasing of the accuracy of measurement in the hardware part of the electrical impedance tomograph, in particular, in its electrode system, which contains two-parts (combined) electrodes and are installed directly in a physical phantom. The principles of construction of the measuring part of the EITomograph using simple and combined electric drives are considered.<br /> Justified the choice of material for the producing of electrodes. Presented the construction of combined electrodes and the parameters of different materials for their producing.<br /> In the article describe the influence of non-identity for physical sizes of combined electrodes. Shown possible variants for the compensation of inaccuracy in the producing of electrodes and the inaccuracy of their installation. Increased ease of use and maintainability signal transmission lines by using these electrodes.<br /> Compared to simple electrodes, combined have several advantages: maintainability; rapid replacement of the electrode in a physical phantom (even in the presence of an electrolyte); manufacturability of producing; higher mechanical resistance and reliability; absolute decoupling of the measuring circle and power circle in the hardware part of the EITomograph; significantly lower amount of occurrence of artifacts during the image reconstruction.<br /> That's why application of combined electrodes leads not only to facilitate the physical construction and setting of the EITomograph. It also increases the quality of the solution of the inverse problem.Hamanenko, O. I., Guseva, E. V.
Copyright (c) 2017 Hamanenko, O. I., Guseva, Е. V.
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http://radap.kpi.ua/en/radiotechnique/article/view/1418Sat, 30 Sep 2017 22:55:36 +0300Results comparison of microwave lowpass filters three- and one-dimensional modeling
http://radap.kpi.ua/en/radiotechnique/article/view/1411
In the research and design of microwave devices it is a standard three-dimensional electromagnetic modeling. Three-dimensional modeling greatly enhances the possibilities, but due to the complexity of the model, the connection between construction and its characteristics is largely implicit. As the result the synthesis of construction based on the visibility of the said connection is complicated or even becomes impossible. In this paper it is examined the using of simple one-dimensional model for microstrip lowpass filters by comparing the results of three- and one- dimensional modeling.<br /><br /> The results of three- and one-dimensional modeling of the lowpass filters based on traditional microstrip technology and microstrip three-dimensional electromagnetocrystalline inhomogeneities are compared. Two designs of filters are examined: filters based on high and low impedance sections of microstrip line and with capacitive stub. One-dimensional model is a heterogeneous transmission line with equivalent parameters. One-dimensional model allows obtaining analytical expressions for the transmission characteristics of such filters. Three-dimensional modeling is performed in the program package CST Microwave Studio. Calculated transmission characteristics are presented. Features of stubs characteristics are analyzed.<br /><br /> The proposed one-dimensional model can be used as a model of the first approximation. One-dimensional model allows separate filter elements (even such complicated as three-dimensional electromagnetocrystalline) characterized by equivalent wave impedance and relative dielectric constant. It is interesting to investigate the possibility of one-dimensional model using for filters with other transmission characteristics.Zinher, Ya. L., Adamenko, Yu. F., Adamenko, V. O., Nelin, E. A.
Copyright (c) 2017 Zinher Ya. L., Adamenko Yu. F., Adamenko V. O., Nelin E. A.
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http://radap.kpi.ua/en/radiotechnique/article/view/1411Sat, 30 Sep 2017 22:55:37 +0300Engineering of nanostructured plasmonic substrates for use as SERS sensors
http://radap.kpi.ua/en/radiotechnique/article/view/1431
Plasmonic nanostructures strongly localize electric fields on their surfaces via the collective oscillations of conducting electrons under stimulation by incident light at certain wavelength. Molecules adsorbed onto such surfaces experiences a strongly enhanced electric field due to the localized surface plasmon resonance (LSPR), which amplifies the Raman scattering signal from these molecules. This phenomenon is referred to as surface enhanced Raman scattering (SERS). Further enhancements in the Raman intensity have been achieved by designing plasmonic nanostructures with a controlled size, shape, composition, and arrangement. This review paper focuses on the theory and analyses the influence of protective coating with oxide materials an isolated plasmonic metal nanostructures. Starting with a brief description of the basic principles underlying LSPR and SERS, we compare two plasmonic metals, two dielectric materials and the effect of changing individual parameters of the nanostructure on output enhanced Raman signal.Bandeliuk, O. V., Kolobrodov, V. H.
Copyright (c) 2017 Bandeliuk O., Kolobrodov V.
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http://radap.kpi.ua/en/radiotechnique/article/view/1431Sat, 30 Sep 2017 22:55:37 +0300