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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">vdgtu</journal-id><journal-title-group><journal-title xml:lang="ru">Вестник Дагестанского государственного технического университета. Технические науки</journal-title><trans-title-group xml:lang="en"><trans-title>Herald of Dagestan State Technical University. Technical Sciences</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2073-6185</issn><issn pub-type="epub">2542-095X</issn><publisher><publisher-name>Daghestan State Technical University</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.21822/2073-6185-2017-44-3-126-135</article-id><article-id custom-type="elpub" pub-id-type="custom">vdgtu-437</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>ТЕХНИЧЕСКИЕ НАУКИ. ИНФОРМАТИКА, ВЫЧИСЛИТЕЛЬНАЯ ТЕХНИКА И УПРАВЛЕНИЕ</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>TECHNICAL SCIENCE. COMPUTER SCIENCE, COMPUTER ENGINEERING AND MANAGEMENT</subject></subj-group></article-categories><title-group><article-title>ПРОГРАММНЫЙ КОМПЛЕКС ДЛЯ РАСЧЕТА И ПРОЕКТИРОВАНИЯ АКТИВНЫХ ФИЛЬТРОВ НА ОСНОВЕ МОДЕЛИ Ε-СЛОЯ</article-title><trans-title-group xml:lang="en"><trans-title>PROGRAM COMPLEX FOR THE CALCULATION AND DESIGN OF ACTIVE FILTERS BASED ON THE E-LAYER MODEL</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Пыльский</surname><given-names>В. А.</given-names></name><name name-style="western" xml:lang="en"><surname>Pylsky</surname><given-names>V. A.</given-names></name></name-alternatives><bio xml:lang="ru"><p>656038, Алтайский край, г. Барнаул, пр. Ленина, 46, Россия</p><p>магистрант</p></bio><bio xml:lang="en"><p>46 Lenina Ave., Barnaul 656038, Russia</p><p>Post-graduate student</p></bio><email xlink:type="simple">almpas@list.ru</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Якунин</surname><given-names>А. Г.</given-names></name><name name-style="western" xml:lang="en"><surname>Yakunin</surname><given-names>A. G.</given-names></name></name-alternatives><bio xml:lang="ru"><p>656038, Алтайский край, г. Барнаул, пр. Ленина, 46, Россия</p><p>доктор технических наук, профессор, заведующий кафедрой информатики, вычислительной техники и информационной безопасности</p></bio><bio xml:lang="en"><p>46 Lenina Ave., Barnaul 656038, Russia</p><p>Dr. Sci. (Technical), Prof., Head of the Department of Informatics, Computer Science and Information Security</p></bio><email xlink:type="simple">yakunin@agtu.secna.ru</email><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>Алтайский государственный технический университет</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Polzunov Altai State Technical University</institution><country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2017</year></pub-date><pub-date pub-type="epub"><day>21</day><month>12</month><year>2017</year></pub-date><volume>44</volume><issue>3</issue><fpage>126</fpage><lpage>135</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Пыльский В.А., Якунин А.Г., 2017</copyright-statement><copyright-year>2017</copyright-year><copyright-holder xml:lang="ru">Пыльский В.А., Якунин А.Г.</copyright-holder><copyright-holder xml:lang="en">Pylsky V.A., Yakunin A.G.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://vestnik.dgtu.ru/jour/article/view/437">https://vestnik.dgtu.ru/jour/article/view/437</self-uri><abstract><sec><title>Цель</title><p>Цель. Статья посвящена разработке метода проектирования аналоговых, в том числе активных фильтров, отличающегося от известных методов использованием принципиально иного подхода к выбору критериев оптимизации.</p></sec><sec><title>Метод</title><p>Метод. Большинство современных методов рассчитывают параметры образующих фильтр  электронных компонентов исходя лишь из обеспечения требуемых значений коэффициентов полинома передаточной функции. При этом обеспечение требуемой стабильности и  воспроизводимости характеристик фильтра достигается преимущественно технологическими приемами, например, за счет использования прецизионных элементов. В то же время  достичь аналогичного эффекта можно и иным способом, а именно рациональным выбором  значений параметров компонентов схемы. Такой подход возможен в силу того, что при  расчете имеется возможность выбирать значения отдельных компонентов схемы  произвольным образом, а необходимые значения коэффициентов полинома передаточной  функции получать подбором значений оставшихся элементов. Таким образом, решая оптимизационную задачу, можно добиваться наилучших результатов проектирования в соответствии с выбранным критерием качества.</p></sec><sec><title>Результат</title><p>Результат. В работе предлагается за основу такого критерия выбрать модель ε-слоя, в  соответствии с которой отклонения передаточной функции, либо пропускаемого через  фильтр сигнала должны минимально отличаться от заданного вида и лежать в пределах  заданного слоя либо во всей области определения функции или сигнала, либо в заданном наиболее важном диапазоне.</p></sec><sec><title>Вывод</title><p>Вывод. В соответствии с предложенным подходом был разработан программный комплекс для расчета активных фильтров. Выполненные с его применением расчеты и  экспериментальные исследования подтвердили продуктивность применения.</p></sec></abstract><trans-abstract xml:lang="en"><sec><title>Objectives</title><p>Objectives. The article is devoted to the development of a method for designing analogue filters, including active, which differs from  known methods due to the fundamentally different approach taken to the selection of optimisation criteria.</p></sec><sec><title>Methods</title><p>Methods. Most contemporary methods, as a rule, calculate the  parameters of filter forming electronic components based solely on  the required values of the transfer function polynomial coefficients.  At the same time, the maintenance of the required stability and  reproducibility of filter characteristics is achieved primarily by  technological methods; for example, by using precision elements.  Nevertheless, it is possible to achieve a similar effect in a different  way, namely, by appropriate choice of the circuit component  parameter values. This approach is possible by selecting the individual circuit component values in an arbitrary manner, while the  necessary transfer function polynomial coefficients are obtained by  selecting the values of the remaining elements. Thus, having solved  the optimisation task, it is possible to achieve optimal design results in accordance with the chosen quality criterion.</p></sec><sec><title>Results</title><p>Results. In this paper, the ε-layer model is proposed as the basis for this criterion, according to which either the deviations of the transfer function or the signal passed through the filter should be  minimally different from the given type and be located within the  given layer, either in the entire domain of the function or signal  definition, or in the most significant defined range.</p></sec><sec><title>Conclusion</title><p>Conclusion. The software package for the calculation of active filters is developed according to the proposed approach. The  productivity of its application is confirmed by experimental studies and the calculations performed using this application.</p></sec></trans-abstract><kwd-group xml:lang="ru"><kwd>аналоговые фильтры</kwd><kwd>допустимые отклонения параметров электронных компонентов фильтра</kwd><kwd>оптимизация параметров электронных компонентов фильтра</kwd><kwd>критерии оптимизации</kwd><kwd>модель ε-слоя</kwd></kwd-group><kwd-group xml:lang="en"><kwd>analogue filters</kwd><kwd>permissible deviations of the parameters of the filter electronic components</kwd><kwd>optimisation of electronic filter component parameters</kwd><kwd>optimisation criteria</kwd><kwd>ε-layer model</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Тушев А.Н. Методы расчета активных фильтров в медицинских диагностических системах: Дис. /Алт.гос.технолог. ун-т им. И.И. Ползунова. – Брн.,1997. URL: http://tekhnosfera.com/metody-raschetaaktivnyh-filtrov-v-meditsinskih-diagnosticheskih-sistemah.</mixed-citation><mixed-citation xml:lang="en">Tushev A.N. Metody rascheta aktivnykh fil'trov v meditsinskikh diagnosticheskikh sistemakh: Dissertatsiya. Altai gos. tekhnolog. un-t im. I.I. Polzunova. Barnaul,  1997. URL: http://tekhnosfera.com/metody-rascheta-aktivnyhfiltrov-v-meditsinskih- diagnosticheskih-sistemah. [Tushev A.N. Methods of calculation of active filters in  medical diagnostic systems: Dissertation. 2Polzunov Altai State Technical  University. Barnaul, 1997. URL: http://tekhnosfera.com/metody-rascheta-aktivnyh- filtrov-v-meditsinskih-diagnosticheskih-sistemah. (In Russ.)]</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Wang Yu (王彧), Liu Jing (刘静), Yan Na (闫娜), Min Hao (闵昊) A low-noise widely tunable Gm-C filter with frequency calibration// J. Semicond. 2016.- Vol 37.- №9 095002 doi:10.1088/1674-4926/37/9/095002.- URL: http://iopscience.iop.org/article/10.1088/1674-4926/37/9/095002/pdf -</mixed-citation><mixed-citation xml:lang="en">Wang Yu (王彧), Liu Jing (刘静), Yan Na (闫娜), Min Hao (闵昊). A low-noise widely tunable Gm-C filter with frequency calibration. J. Semicond. 2016;37(9):095002  doi:10.1088/1674-4926/37/9/095002. URL: http://iopscience.iop.org/article/10.1088/1674-4926/37/9/095002/pdf.</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Wakamatsu T, Yamanashi Yu, Yoshikawa N. High-Speed Superconductive Decimation Filter for Sigma-Delta Analog to Digital Converter // Journal of Physics: Conference Series, 2017 1742-6596 Vol 87, confrence 1, 012068 doi:10.1088/1742-6596/871/1/012068.- URL: http://iopscience.iop.org/article/10.1088/1742-6596/871/1/012068/pdf</mixed-citation><mixed-citation xml:lang="en">Wakamatsu T., Yamanashi Yu., Yoshikawa N. High-Speed Superconductive Decimation Filter for Sigma-Delta Analog to Digital Converter. Journal of Physics: Conference  Series. 2017; 87:1742-6596.Confrence 1, 012068 doi:10.1088/1742-6596/871/1/012068.  URL: http://iopscience.iop.org/article/10.1088/1742-6596/871/1/012068/pdf.</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">Boustani B., Torabi S., Javaherian A., Mortazavi S.A. Ground roll attenuation using a curvelet-SVD filter: a case study from the west of Iran / J. Geophys. Eng. 2013,10 055006 doi:10.1088/1742-2132/10/5/055006 URL: http://iopscience.iop.org/article/10.1088/1742-2132/10/5/055006/pdf</mixed-citation><mixed-citation xml:lang="en">Boustani B., Torabi S., Javaherian A., Mortazavi S.A. Ground roll attenuation using a curvelet-SVD filter: a case study from the west of Iran. J. Geophys. Eng.  2013;10:055006 doi:10.1088/1742-2132/10/5/055006.URL: http://iopscience.iop.org/article/10.1088/1742-2132/10/5/055006/pdf.</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">Filters. URL: https://www.allaboutcircuits.com/textbook/alternating-current/chpt-8/what-is-a-filter/</mixed-citation><mixed-citation xml:lang="en">Filters. URL: https://www.allaboutcircuits.com/textbook/alternating-current/chpt-8/what-is-a-filter.</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Расчет аналогового фильтра. Постановка задачи и способы аппроксимации АЧХ идеального нормированного ФНЧ. URL: http://www.dsplib.ru/content/filters/ch2/ch2.html</mixed-citation><mixed-citation xml:lang="en">Raschet analogovogo fil'tra. Postanovka zadachi i sposoby approksimatsii AChKh ideal'nogo normirovannogo FNCh. URL:  http://www.dsplib.ru/content/filters/ch2/ch2.html[Calculation of the analog filter.  Statement of the problem and methods for approximating the AFC of an ideal normalized LFF (in Russ.)]</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Second Order Filters. URL: http://www.electronics-tutorials.ws/filter/second-order-filters.html</mixed-citation><mixed-citation xml:lang="en">Second Order Filters. URL: http://www.electronics-tutorials.ws/filter/second-order-filters.html</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Vizmuller, P. RF Design Guide: Systems, Circuits, and Equations. – Artech House, 1995. – С. 81-84.</mixed-citation><mixed-citation xml:lang="en">Vizmuller P. RF Design Guide: Systems, Circuits, and Equations. Artech House; 1995. P. 81-84.</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Miroslav D. Lutovac. Filter Design for Signal Processing using MATLAB© and Mathematica©. – New Jersey, USA.: Prentice Hall, 2001</mixed-citation><mixed-citation xml:lang="en">Lutovac M.D. Filter Design for Signal Processing using MATLAB© and Mathematica©. New Jersey, USA: Prentice Hall; 2001.</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Williams Artur B. Analog Filter and Circuit Design Handbook. – NY.: Mc Graw Hill, 2006.-619 с.</mixed-citation><mixed-citation xml:lang="en">Williams A.B. Analog Filter and Circuit Design Handbook. NY: Mc Graw Hill; 2006. 619 p.</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">M.E. Van Valkenburg. Analog Filter Design. – NY.: Oxford University Press, 1982. – 607с.</mixed-citation><mixed-citation xml:lang="en">Van Valkenburg M.E. Analog Filter Design. NY: Oxford University Press; 1982. 607 p.</mixed-citation></citation-alternatives></ref><ref id="cit12"><label>12</label><citation-alternatives><mixed-citation xml:lang="ru">Bowick C. RFCircuit Design. - .UK: Newnes, 2008. – 242 с.</mixed-citation><mixed-citation xml:lang="en">Bowick C. RFCircuit Design. UK: Newnes; 2008. 242 p.</mixed-citation></citation-alternatives></ref><ref id="cit13"><label>13</label><citation-alternatives><mixed-citation xml:lang="ru">Palmer R. An Introduction To RF Circuit Design For Communication Systems. – Canada.: VE7AP, 2016. – 335с.</mixed-citation><mixed-citation xml:lang="en">Palmer R. An Introduction to RF Circuit Design For Communication Systems. Canada: VE7AP; 2016. 335 p.</mixed-citation></citation-alternatives></ref><ref id="cit14"><label>14</label><citation-alternatives><mixed-citation xml:lang="ru">Лэм Г. Аналоговые и цифровые фильтры. Расчет и реализация. Пер. с англ. Г. Лэм. -М.: Мир, 1982. - 592 с.</mixed-citation><mixed-citation xml:lang="en">Lem G. Analogovye i tsifrovye fil'try. Raschet i realizatsiya. M.: Mir; 1982. 592 s. [Lem G. Analog and digital filters. Calculation and implementation. M.: Mir; 1982. 592 p. (In Russ.)]</mixed-citation></citation-alternatives></ref><ref id="cit15"><label>15</label><citation-alternatives><mixed-citation xml:lang="ru">Мошиц Г., Хорн П. Проектирование активных фильтров. Пер. с англ. -М.: Мир, 1984. -320 с.</mixed-citation><mixed-citation xml:lang="en">Moshits G., Khorn P. Design of active filters. M.: Mir; 1984. 320 s. [Moshits G., Khorn P. Proektirovanie aktivnykh fil'trov. M.: Mir; 1984. 320 p. (In Russ.)]</mixed-citation></citation-alternatives></ref><ref id="cit16"><label>16</label><citation-alternatives><mixed-citation xml:lang="ru">Karki J. Active Low-Pass Filter Design //Application Report SLOA049A – Texas Instument, October 2000. 24pp. -URL: http://www.science.unitn.it/~bassi/ Signal/TInotes/ sloa049.pdf</mixed-citation><mixed-citation xml:lang="en">Karki J. Active Low-Pass Filter Design. Application Report SLOA049A – Texas Instument, October 2000. 24p. URL: http://www.science.unitn.it/~bassi/ Signal/TInotes/ sloa049.pdf.</mixed-citation></citation-alternatives></ref><ref id="cit17"><label>17</label><citation-alternatives><mixed-citation xml:lang="ru">Lacanette K. A Basic Introduction to Filters - Active, Passive, and Switched-Capacitor//National Semiconductor Application Note 779, April1991.-22pp. URL: http://www.science.unitn.it/~bassi/Signal/TInotes/sloa049.pdf</mixed-citation><mixed-citation xml:lang="en">Lacanette K. A Basic Introduction to Filters - Active, Passive, and Switched-Capacitor. National Semiconductor Application Note 779, April 1991. 22p. URL: http://www.science.unitn.it/~bassi/Signal/TInotes/sloa049.pdf.</mixed-citation></citation-alternatives></ref><ref id="cit18"><label>18</label><citation-alternatives><mixed-citation xml:lang="ru">Сучкова Л.И., Якунин А.Г. Нахождение интервальных оценок параметров квазидетерминированных процессов с применением модели слоя//Материалы Всероссийской научной конференции «Актуальные проблемы математики и механики»- Самара, 2013. – С. 151-153.</mixed-citation><mixed-citation xml:lang="en">Suchkova L.I., Yakunin A.G. Nakhozhdenie interval'nykh otsenok parametrov kvazideterminirovannykh protsessov s primeneniem modeli sloya. Materialy Vserossiyskoy nauchnoy konferentsii ―Aktual'nye problemy matematiki i mekhaniki‖.  Samara; 2013. S. 151-153. [Suchkova L.I., Yakunin A.G. Finding interval estimates  for parameters of quasidetermined processes using the layer model. Materials of  the All-Russian scientific conference ―Relevantissues of mathematics and mechanics‖; 2013. P. 151-153. (In Russ.)]</mixed-citation></citation-alternatives></ref><ref id="cit19"><label>19</label><citation-alternatives><mixed-citation xml:lang="ru">Сучкова Л.И., Якунин А.Г. Прогнозирование нештатных ситуаций в системах контроля и управления на основе модели слоя Л.И.//Материалы 10 Международной конференции «Измерение, контроль, информатизация». - Барнаул: АлтГТУ, 2009.- С. 103-105.</mixed-citation><mixed-citation xml:lang="en">Suchkova L.I., Yakunin A.G. Prognozirovanie neshtatnykh situatsiy v sistemakh kontrolya i upravleniya na osnove modeli sloya. Materialy 10 Mezhdunarodnoy  konferentsii ―Izmerenie, kontrol', informatizatsiya‖. Barnaul: AltGTU; 2009. S. 103-105. [Suchkova L.I., YakuninA.G. Predictionofabnormalsituationsincontrolandmanagementsystemsbasedonthe layermodel. Materials of the 10th International Conference "Measurement, Control, Informatization". Barnaul: AltSTU; 2009. P. 103-105. (In Russ.)]</mixed-citation></citation-alternatives></ref><ref id="cit20"><label>20</label><citation-alternatives><mixed-citation xml:lang="ru">Сучкова Л.И., Якунин А.Г. Оценка параметров квазидетерминированных информативных сигналов методом слоя Л.И.//Вестник Дагестанского государственного технического университета. Технические науки. № 4 -2011. - С.11-22.</mixed-citation><mixed-citation xml:lang="en">Suchkova L.I., Yakunin A.G. Otsenka parametrov kvazideterminirovannykh informativnykh signalov metodom sloya. Vestnik Dagestanskogo gosudarstvennogo  tekhnicheskogo universiteta. Tekhnicheskie nauki.2011;4:11-22.[Suchkova L.I.,  Yakunin A.G. Estimation of parameters of quasideterministic informative signals by  the layer method. Herald of Daghestan State Technical University. Technical  Sciences. 2011;4:11-22. (In Russ.)]</mixed-citation></citation-alternatives></ref><ref id="cit21"><label>21</label><citation-alternatives><mixed-citation xml:lang="ru">Якунин А.Г. Тищенко А.Н. Применение моделей ε-слоев для моделирования сигналов ОЭПП. // Измерения и контроль при автоматизации производственных процессов. Барнаул, АлтГТУ, 1994.</mixed-citation><mixed-citation xml:lang="en">Yakunin A.G. Tishchenko A.N. Primenenie modeley ε-sloev dlya modelirovaniya signalov OEPP. Izmereniya i kontrol' pri avtomatizatsii proizvodstvennykh  protsessov. Barnaul: AltGTU;1994. [Yakunin A.G. Tishchenko A.N. The use of ε-layer  models for modeling the signals of the OEBP. Measurement and control in the  automation of production processes. Barnaul: AltSTU; 1994. (In Russ.)]</mixed-citation></citation-alternatives></ref><ref id="cit22"><label>22</label><citation-alternatives><mixed-citation xml:lang="ru">Ханзел Г. Е. Справочник по расчету фильтров. Пер. с англ. В.А. Старостина - М.: Советское радио, 1974. - 286 с.</mixed-citation><mixed-citation xml:lang="en">Khanzel G.E. Spravochnik po raschetu fil'trov. M.: Sovetskoe radio; 1974. 286 s. [Khanzel G.E. Handbook on the calculation of filters. Moscow: Sovetskoe radio; 1974.  286 p. (In Russ.)]</mixed-citation></citation-alternatives></ref><ref id="cit23"><label>23</label><citation-alternatives><mixed-citation xml:lang="ru">Джонсон Д. Справочник по активным фильтрам. Пер с англ. Д. Джонсон. – М. 1983. -128 c.</mixed-citation><mixed-citation xml:lang="en">Dzhonson D. Spravochnik po aktivnym fil'tram. M.: 1983; 128 s. [Dzhonson D. Reference book on active filters.</mixed-citation></citation-alternatives></ref><ref id="cit24"><label>24</label><citation-alternatives><mixed-citation xml:lang="ru">M.: 1983; 128 p. (In Russ.)]</mixed-citation><mixed-citation xml:lang="en">M.: 1983; 128 p. (In Russ.)]</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
