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UDC 621.372.8.01
Siberian Journal of Science and Technology. 2018, Vol. 19, No. 1, P. 44-48 MODAL FILTER SIMULATION WITH LOSSES R. R. Khazhibekov*, A. M. Zabolotsky, T. R. Gazizov
Tomsk State University of Control Systems and Radioelectronics 40, Lenina Av., Tomsk, 634050, Russian Federation E-mail: r300994@mail.ru
Protection of spacecraft on-board equipment against electromagnetic interferences is an actual problem. Much attention is paid to the susceptibility to the excitation of powerful ultra short impulses (nanosecond and subnanosecond impulses). The use of known protection devices to solve this problem is hampered by a number of conflicting requirements. For example, low mass, high reliability, long life. In addition, ultrashort pulses are able to penetrate into various radio-electronic equipment by passing the instrument shields. Protection potential using the devices based on modal filtering is well known. To simulate these devices, rigorous electro-dynamic approach is applied, which requires high computational costs. Approximate quasi-static approach allows to significantly reduce computational costs. The quasi-static simulation was used in this paper, loss record in conductors was realized by means of exact calculation of the matrix of per-unit-length resistances through a change in the matrix of the per-unit-length coefficients of electromagnetic induction when scaling the cross section of conductors. The effect of losses on the shape and amplitude of the pulses at the output of the modal filter is shown. A comparison of simulation results with electrodynamic and quasi-static approaches taking into account losses is presented. Good consistency is obtained. Quasi-static simulation with losses took much less time than the electrodynamic simulation. Analysis of the results suggests that software-based approaches can be used for modal filter simulation.
Keywords: microstrip line, linear delay, wave impedance, modal filtering, quasi-static simulation, protection device
Сибирский журнал науки и технологий. 2018. Т. 19, № 1. С. 44-48 МОДЕЛИРОВАНИЕ МОДАЛЬНОГО ФИЛЬТРА С УЧЕТОМ ПОТЕРЬ Р. Р. Хажибеков*, А. М. Заболоцкий, Т. Р. Газизов
Томский государственный университет систем управления и радиоэлектроники Российская Федерация, 634050, г. Томск, просп. Ленина, 40 E-mail: r300994@mail.ru
Защита бортовой аппаратуры космического аппарата от электромагнитных помех является актуальной проблемой. Большое внимание уделяется восприимчивости к воздействию мощных сверхкоротких импульсов (импульсов наносекундного и субнаносекундного диапазонов). Использование известных устройств защиты для решения данной задачи затруднено рядом противоречивых требований, например, малой массы, высокой надежности, длительного срока активного существования. Кроме того, сверхкороткие импульсы способны проникать в различную радиоэлектронную аппаратуру, минуя экраны приборов. Известна возможность защиты с помощью устройств, основанных на использовании модальной фильтрации. Для моделирования таких устройств применяют строгий электродинамический подход, который требует больших вычислительных затрат. Приближенный квазистатический подход позволяет значительно уменьшить вычислительные затраты. Использован учет потерь в проводниках при квазистатическом моделировании, реализованный с помощью точного вычисления матрицы погонных сопротивлений через изменение матрицы погонных коэффициентов электромагнитной индукции при масштабировании поперечного сечения проводников. Показано влияние потерь на форму и амплитуду импульсов на выходе модального фильтра. Представлено сравнение результатов моделирования электродинамическим и квазистатическим подходами с учетом потерь. Получена хорошая согласованность. Квазистатическое моделирование заняло значительно меньше времени, чем электродинамическое. Анализ результатов показал, что программно-реализованные подходы можно использовать для моделирования модального фильтра.
Ключевые слова: микрополосковая линия, погонная задержка, волновое сопротивление, модальная фильтрация, квазистатическое моделирование, устройство защиты.
Introduction. As long-term practice of start and maintenance of the spacecrafts (SC) showed, reliability of the elements, devices of airborne computers and control modules functioning is one of the key factors defining success of the mission in general. Reliability assurance in special conditions of harmful space factors impact is connected with specific difficulties. One of such factors is interfering super short impulse (ISI). Its dangers are extensively researched [1-5]. However, the increase in SC effective performance period (up to 15 years) leads to considerable degradation of the used materials' properties and also makes it problematic to predict the new materials' properties mutation in the future SCs. This will inevitably create conditions for harmful effects of ISI, causing improvements of protection against it. The use of the known protection devices is complicated by a number of contradictory requirements, for example, protection of a bigger number of circuits, law mass of the safety device, ability to function effectively for 15 years in space. Therefore creation of new elements and protection devices of airborne computers and control modules from SIS proves to be relevant. Protection against short impulses based on modal filtering [6-11] is suggested. The physical principle of such protection is based on the effect of splitting of interfering impulse in the segment of line into modes, each of which extends with the time delay. In case of un-homogeneous dielectric filling in the cross-section of the connected line segment, the difference of these time delays can exceed duration of interfering impulse, so that one impulse given between the active and reference conductors at the beginning of the segment will split into two impulses at the end of the segment.
Often for the analysis of strip structures quasi static simulation is used. For exact simulation of such structures it is necessary to consider losses both in conductors, and in dielectrics. Meanwhile, accurate loss record is especially important in certain cases. Thus, in modal filters (MF) output amplitude depends on losses.
The purpose of this paper is to compare results of quasi static and electro-dynamic simulations of MF taking into account loss record.
Calculation of resistance per-unit-length matrix. The algorithm of Calculation of resistance per unit length matrix of N-wire transmission line in which (N + 1) reference conductor, in quasi static simulation environment TALGAT [12] looks as follows [13]:
1. Input of conductor parameters: p - conductor specific resistance, ^ - magnetic conductivity.
2. Input of frequency.
3. Input of the initial geometrical parameters.
4. Calculation of value of conductor boundaries extension dn (value 0.1 from the lowest parameter is used by default).
5. Calculation of the conductor's surface resistance using formula
Rs цр.
(1)
6. Geometrical modeling of cross-section structure under initial parameters.
7. Calculation of per-unit-length initial matrix coefficients of electromagnetic induction L1.
8. Extension of all boundaries of cross-section of the reference conductor on An.
9. Calculation of inductance matrix L2 for the changed structure.
10. Calculation of AL,;k = L2,;k- L1jk.
11. Calculation of non-diagonal matrix elements Reusing formula:
Rs
R j ,k\
j ф k
Ц0
An
Om/m.
(2)
12. Extension of all boundaries of the cross-section of the 1st from N conductors.
13. Calculation of L2,-.
14. Calculation of AL, = Ll, - L2,
R,
15. Calculation of diagonal components of the matrix using formula:
R
Цо
An
Om/m.
(3)
16. Serial repetition of points 12-15 for each of the remained conductors, successively expanding boundaries of this conductor.
The calculation algorithm of matrix R has been implemented. In cases where it is required to calculate L matrix, functions of the TALGAT system are used. In the algorithm extension of conductor boundaries by value An is applied. It is realized programmatically. The user value An is set for this purpose, or default value An equal to 0.1 from the lowest parameter of structure is used. For calculation of default value of boundary with the lowest length whose value is equated to value of the lowest parameter is found.
In order to expend the conductor i, where i = 1, 2, ..., N, N - number of conductors multi-wire transmission line, applying scaling against the centre of the conductor, which transforms conductor coordinatespu; p2i; ...; pMi, where M - the number of conductor angles i, into coordinates pi,/; p2i'; ...; pNJ so to obtain the conductor, increased by An from all sides. For this purpose scaling coefficients are calculated:
IX + 2 An _y iy + 2 An
fX =-
f? - ~
(4)
I- i
where iix , iiy - the width and thickness of conductor i. Further conductor center coordinates are calculated pci and transformation matrix is built:
f-0
i (1 - fr )
0
fry & (1 - fï )
(5)
pjj - f?ph+pc
(6)
where j = 1, 2,
y = fypy, r + pc
where pxci and pyci - components x and y coordinate pc i. Transformation matrix can be applied in the following way:
(1 -. fx); I1 - f" )•
M. For the conductor boundaries extension transformation matrix should be applied (2) to every conductor angle. Extension of the infinite earth is done via displacement of all structure boundaries towards the line of the infinite earth on An.
Simulation. The approaches described above are software realised and built-in in the TALGAT system. However, the use of this program for quasi-static simulation of real strip structures and comparing the received results with the results of electro-dynamic simulation was not shown earlier. For simulation MF structure, researched in [14], will be used.
Quasi-static simulation is executed in TALGAT system, electro-dynamic - in CST MWS [15]. The cross-section and the diagram of MF switch are provided in fig. 1, where width and thickness of conductors w = 500 micron and t = 85 micron; conductor spacing - 5 = 200, distance
between edge of the conductor and dielectric edge d = 1000 micron, substrate thickness h = 400 micron, FR-4 substrate material, line length l = 2.5. MF contains three copper conductors: A - the active, O - reference and p - passive. The impulse oscillator is connected to the active conductor with the following parameters: amplitude - 10 V and duration of peak td = 100 picoseconds, duration of the front and recession of tr = tf = 100 picoseconds. Resistance values are R\ = R2 = R3 = R4 = = 100 Ohms. Results of simulation taking into account losses and dispersion are provided in fig. 2.
w
w
О
w
П
Fig. 1. MF cross-section (a) and connection scheme (b) Рис. 1. Поперечное сечение (а) и схема включения (b) МФ
Г, !1 — VI V2 — V3 ... V4
А ч Л
I, ......\j„
V, в —-— VI —Si— V2 ---V3
\ ! V -
г' i 1 1 t, С
Fig. 2. Voltage waveforms obtained in CST MWS (a) and TALGAT (b) Рис. 2. Формы напряжения, полученные в CST MWS (а) и TALGAT (б)
а
b
а
b
Table
Comparative results of amplitudes and impulses time delays
Parameter CST TALGAT (CST - TALGAT)/(CST + TALGAT), %
Amplitude of 1st impulse V3, В 1.1 0.88 11
Amplitude of 2nd impulse V3, В 0.73 0.71 1.4
Amplitude of 1st impulse V4, В -1.1 -0.88 11
Amplitude of 2nd impulse V3, В 0.73 0.71 1.4
Time delay of 1st impulse in nodes V3 and V4, ps 11.6 12.2 2.5
Time delay of 2nd impulse in nodes V3 и V4, ps 14.9 15 0.3
The results proved that with reference to losses in conductors and dielectrics, wavefront time and impulse drop on the MF output increase. Thus the voltage amplitude of output impulses (V3) is much less than a half of amplitude of an input impulse (V1). Impulse amplitude of the even mode appeared to be less than impulse amplitude of the odd mode. This results from the fact that currents of the even mode extend mostly in dielectric, while currents of the odd mode - in the air. Fig. 2 shows that voltage waveforms, calculated in TALGAT and CST MWS, coincide. Values of amplitudes and time delays of impulses are given in the table.
Conclusion. Simulation results showed that the maximum deviation under impulses delays makes 2.5 % under amplitudes - 11 %. It proves consistency of results received by means of the approaches described in the present paper. Besides. calculation time in TALGAT was about 1 h, in CST MWS - about 50 h. Therefore. the software realized approaches can be used for MF simulation.
Acknowledgments. This work was carried out as a result of the project 8.9562.2017/8.9 of the Ministry of Education and Science of the Russian Federation.
Благодарности. Работа выполнена за счет проекта 8.9562.2017/8.9 Минобрнауки Российской Федерации.
References
1. Mora N., Vega F., Lugrin G., Rachidi F., Rubinstein M. Study and classification of potential IEMI sources. System and assessment notes. 2014. Note 41.
2. Gazizov A. T., Zabolotsky A. M., Gazizov T. R. UWB pulse decomposition in simple printed structures. IEEE Transactions on Electromagnetic Compatibility. 2016, Vol. 58, No. 4, P. 1136-1142.
3. Orlov P., Gazizov T., Zabolotsky A. Short pulse propagation along microstrip meander delay lines with design constraints: comparative analysis of the quasi-static and electromagnetic approaches. Applied computational electro-magnetics society journal. 2016, Vol. 31, No. 3, P. 238-243.
4. Gazizov R. R., Gazizov T. T. [A study of the localization of peak signal values in a printed circuit board of an autonomous navigation system]. Infokommuni-katsionnye tekhnologii. 2017, Vol. 15, No. 2, P. 170-178 (In Russ.).
5. Surovtsev R. S., Nosov A. V., Zabolotsky A. M., Gazizov T. R. Possibility of protection against UWB pulses based on a turn of a meander microstrip line. IEEE
Transactions on Electromagnetic Compatibility. 2017, Vol. 59, No. 6, P. 1864-1871.
6. Zabolotsky A. M., Gazizov A. T. Simulation of ul-trawide band pulse propagation in asymmetrical modal filter for power network protection. International Journal of Circuits. Systems and Signal Processing. 2015, Vol. 9, P. 68-74.
7. Gazizov A. T. [Comparison of measurement results and simulation of the temporal response of the modal filter to the excitation of an ultrashort pulse]. Doklady TUSUR. 2015, No. 4(38), P. 149-152 (In Russ.).
8. Zabolotsky A. M. [Using mirror symmetry to improve modal filtering]. Doklady TUSUR. 2015, No. 2(36), P. 41-44 (In Russ.).
9. Belousov A. O. [Multi-wire microstrip line as a modal filter for protection against ultrashort pulses]. Doklady TUSUR. 2015, No. 3(37), P. 124-128 (In Russ.).
10. Orlov P. Y., Gazizov T. R., Zabolotsky A. M. The impact of coupled conductors in a dielectric material above an ideally conducting plane on the difference of board delay per unit length of even and odd modes. International Journal of Advanced And Applied Sciences. 2017, Vol. 4, No. 2, P. 68-71.
11. Dmitrienko I. V. [Analysis of the frequency response of the modal filter to suppress the emitted emissions of the on-board apparatus of the spacecraft]. Doklady TUSUR. 2015, No. 4(38), P. 157-160 (In Russ.).
12. Kuksenko S. P., Zabolotsky A. M., Melkoserov A. O., Gazizov ^ R. [New features of the TALGAT electromagnetic compatibility simulation system]. Doklady TUSUR. 2015, No. 2, P. 45-50 (In Russ.).
13. Mussabaev R. R. [Algorithm for calculating the impedance matrix of a multi-wire transmission line]. Materialy Mezhdunarodnoy nauchno-tekhnicheskoy konferentsii studentov. aspirantov i molodykh uchenykh "Nauchnaya sessiya TUSUR-2017", posvyashchennoy 55-letiyu TUSURa [Materials of the International scientific and technical conference of students. graduate students and young scientists "Scientific session of TUSUR-2017". dedicated to the 55th anniversary of TUSUR]. Tomsk, 2017, P. 68-71 (In Russ.).
14. Zabolotsky A. M., Gazizov T. R., Kalimulin I. F. Novye resheniya dlya obespecheniya elektromagnitnoy sovmestimosti bortovoy radioelektronnoy apparatury kosmicheskogo apparata [New solutions for ensuring electromagnetic compatibility of on-board radio-electronic apparatus of the spacecraft]. Tomsk, TUSUR Publ., 2016, 288 p.
15. CST STUDIO SUITE [Advertisement]. IEEE Antennas and Propagation Magazine. 2013, Vol. 55, Iss. 4, P. c2-c2.
Библиографические ссылки
1. Study and classification of potential IEMI sources / N. Mora [et al.] // System and assessment notes 2014. Note 41.
2. Gazizov A. T., Zabolotsky A. M., Gazizov T. R. UWB pulse decomposition in simple printed structures // IEEE Transactions on Electromagnetic Compatibility.
2016. Vol. 58, No. 4. P. 1136-1142.
3. Orlov P., Gazizov T., Zabolotsky A. Short pulse propagation along microstrip meander delay lines with design constraints: comparative analysis of the quasi-static and electromagnetic approaches // Applied computational electromagnetics society journal. 2016. Vol. 31. no. 3. P. 238-243.
4. Газизов Р. Р., Газизов Т. Т. Исследование локализации пиковых значений сигнала в печатной плате системы автономной навигации // Инфокоммуника-ционные технологии. 2017. Т. 15. № 2. С. 170-178.
5. Surovtsev R. S., Nosov A. V., Zabolotsky A. M., Gazizov T. R. Possibility of protection against UWB pulses based on a turn of a meander microstrip line // IEEE Transactions on Electromagnetic Compatibility.
2017. Vol. 59. no. 6. P. 1864-1871.
6. Zabolotsky A. M., Gazizov A. T. Simulation of ultrawide band pulse propagation in asymmetrical modal filter for power network protection // International Journal of Circuits. Systems and Signal Processing. 2015. Vol. 9. P. 68-74.
7. Газизов A. T. Сравнение результатов измерения и моделирования временного отклика модального фильтра на воздействие сверхкороткого импульса // Доклады ТУСУР. 2015. № 4(38). C. 149-152.
8. Заболоцкий А. М. Использование зеркальной симметрии для совершенствования модальной фильтрации // Доклады ТУСУР. 2015. № 2(36). C. 41-44.
9. Белоусов А. О. Многопроводная микрополоско-вая линия как модальный фильтр для защиты от сверхкоротких импульсов // Доклады ТУСУР. 2015. № 3(37). C. 124-128.
10. Orlov P. Y., Gazizov T. R., Zabolotsky A. M. The impact of coupled conductors in a dielectric material above an ideally conducting plane on the difference of board delay per unit length of even and odd modes // International Journal of Advanced And Applied Sciences. 2017. Vol. 4. no. 2. P. 68-71.
11. Дмитренко И. В. Анализ частотного отклика модального фильтра для подавления излучаемых эмиссий бортовой аппаратуры космического аппарата // Доклады ТУСУР. 2015. № 4(38). C. 157-160.
12. Новые возможности системы моделирования электромагнитной совместимости TALGAT / С. П. Кук-сенко [и др.] // Доклады ТУСУР. 2015. № 2(36). C. 45-50.
13. Мусабаев Р. Р. Алгоритм вычисления матрицы погонных сопротивлений многопроводной линии передачи // Научная сессия ТУСУР-2017 : материалы Междунар. науч.-технич. конф. студентов, аспирантов и молодых ученых, посвященной 55-летию ТУСУРа. 2017. Ч. 3. С. 68-71.
14. Заболоцкий А. М., Газизов Т. Р. Калимулин И. Ф. Новые решения для обеспечения электромагнитной совместимости бортовой радиоэлектронной аппаратуры космического аппарата. Томск : Изд-во Томск. гос. ун-та систем управления и радиоэлектроники, 2016. 288 с.
15. CST STUDIO SUITE [Advertisement] // IEEE Antennas and Propagation Magazine. 2013. Vol. 55,. iss. 4. P. c2-c2.
© Khazhibekov R. R., Zabolotsky A. M., Gazizov T. R., 2018
