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Труды Международного симпозиума «Надежность и качество», 2017, том 2
Содержание примесей
Таблица 5
Название химического элемента примеси Массовая доля ионной примеси, не более % по номерам образцов Среднее значение
1 2 3
Натрий (Na) 7,2*10-4 5,2*10-4 6,5*10-4 7,3*10-4
Исследования показали, что образцы лака АД 9103 содержат только примесь натрия.
ВЫВОД
В результате проведенных исследований лака АД 9103 обнаружено наличие гидрофильной ионной примеси, что увеличивает значение равновесного влагопоглощения, коэффициента влагопроницаемо-сти и делает такое защитное покрытие потенциально ненадежными для защиты алюминиевой металлизации. Примесные ионы защитных покрытий влияют
на электрические параметры активных элементов микросхем. Миграция подвижных ионов по поверхности активных областей кристалла микросхем вызывает деградацию их электрических параметров. Одна из главных проблем в этом случае связана с ростом токов поверхностной утечки, вызывающих нестабильность работы как биполярных, так и полевых элементов микросхем.
ЛИТЕРАТУРА
1. Исследование и испытание защитных покрытий (компаундов), применяемых в ИС. Отчет о НИР Шифр: «Оборона» (II этап) // ФГУП «22 ЦНИИИ Минобороны России».- Мытищи.- 2003.- 157 с.
2. ОСТ 11 0044-84 «Материалы полимерные для защиты и герметизации полупроводниковых приборов и интегральных схем»
3. Никитин А.В. Исследование реакционной способности мономерных аминосодержащих кремнийоргани-ческих соединений.- М.: Химия, 2004.-127 с.
4. Потоцкая И.В. Синтез полииминов в сверхкритическом диоксиде углерода: автореферат к.х.н., М., 2006.- 24 с
5. Зелякова Т.И. Влияние кремнийорганических покрытий на коррозионную стойкость интегральных микросхем: дис.к.т.н., М., 2007.- 144 с
6. Зелякова Т.И., Крутов Л.Н., Баринов П.Е. Комплекс средств для контроля характеристик компаундов // Экономика и производство.—2005. №3.-72 с.
7. Рейтлингер С.А. Проницаемость полимерных материалов.- М.: Химия, 1974, с.104.
УДК 621.396.67
Chernova1 N.B., Kulikov2 A.A.
1Samara National Research University, Samara, Russia
2Almaty University of Power Engineering & Telecommunications, Almaty, Kazakhstan
CPW-FED FRACTAL SLOT ANTENNA DESIGN FOR ULTRA WIDE BAND APPLICATIONS
In this paper, CPW-fed circular fractal slot antennas are studied for broadband and multiband applications, such as Global Navigation Satellite Systems (GNSS). In practice, the experimental results with broadband responses (68.33% bandwidth) in the range from 1100 MHz to 1700 MHz for antenna design that is represented by circular fractal patterns with all stages of the iterations are achieved firstly. Then, the other broadband responses (78.33% bandwidth) in the range from 1100 MHz to 1700 MHz for antenna design that is represented by circular fractal patterns with just two first stages of the iterations are described herein.
Keywords: Circular fractal slot antenna, Descartes circle theorem, self-similar iteration, CPW-fed, GNSS, GPS.
I. Introduction
With the deployment of several GNSS such as GPS, GLONASS and GALILEO, and with the growing need to develop systems capable of receiving signals from any GNSS, it is necessary to design a compact antenna operating in all frequency bands for at least the three major systems: GPS, GALILEO and GLONASS [1]-[2].
1) GPS (Global Positioning System). As shown in Fig.1, its satellites transmit signals using three different bands, centred on the frequencies:
L2: 1 227.60 MHz
L5:
L1: 1 575.42 MHz. 1 176.45 MHz
2) European-lead GALILEO development. As shown in Fig.1, its satellites transmit signals using three different bands, centred on the frequencies:
E1: 1 575.42 MHz, E6: 1 278.75 MHz, E5a: 1 176.45 MHz, E5b: 1 207.14 MHz
3) The Russian GLONASS. As shown in Fig.1, its satellites transmit signals using two different bands, centred on the frequencies:
G1: 1 602 MHz, G2: 1 246 MHz, G3: 1 207.14
MHz
ARNS : Aviation Radio Navigation Service RNSS ; Radio Navigation Satellite Service
Figure1 - The frequencies bands used for the GNSS systems
Twàbi Мeмдvнаvoднoгo cwnno3uvMa «Haàewnocmb u xauecmeo», 2017, moM 2
For designing multi-bands and Ultra Wide Band (UWB) antennas, several techniques are used such as adding slots to the radiating elements or using fractal geometries. Due to the typical Sierpinski gasket configuration, a triangle generator with a scale fractal ratio of 0.5 was slotted in the triangle patch to form the multiband antenna, thus optimum design techniques using a genetic algorithm (GA) were developed for multiband, broadband, and UWB antennas [6]. On the other hand, a circular generator with a non-constant fractal ratio dependent on the Descartes circle theorem in the CPW-fed circular aperture has been proposed to present alternative broadband antennas [8]-[10].
The main structure of the CPW-fed slot antenna includes the aperture, inner conductor, and feed-line couplings. The last component is one of the most crucial moments of this proposed antenna design. So, there are many configurations that can be used to feed a patch antenna. But compared to typical microstrip antennas [3], coplanar waveguide (CPW) structures in which
both the conductor and ground plane are on one side of the PCB have several useful properties including wider bandwidth, better impedance matching and lower radiation loss.
II. Antenna configuration synthesis
A. Antenna Configuration
Based on the coplanar configuration, the proposed antenna has a circular inner conductor, circular aperture, feed-line, and ground plane on one side of the PCB, while the other side is completely etched. As illustrated in Fig. 2, the dimension of the circular aperture is D with enough ground of areas W1*W2. For feeding, the width of CPW feed-line is given by w, the spacing is given by s, and the impedance matching of the circular aperture can be improved by adjusting w and s.
The CPW-fed circular fractal slot antenna with dimensions W1 = 130 mm, W2 = 130 mm, D = 126 mm, w = 2.5 mm, s = 0.5 mm is printed on a FR4 dielectric substrate of relative permittivity Sr = 4.4, thickness h = 1.5 mm, loss tangent = 0.025 and fed by a 50 Q SMA connector.
Figure 2
CPW-fed slot antenna
B. Iterative Design
Firstly, a circular aperture is slotted inside the ground plane for CPW structure. Then four mutually tangent configurations to construct the circular fractal pattern in addition to original inner conductor are used. Based on the iterative processes and the following rela-
tions (1-3), theorem, the synthesized, rbi = rci = 1
according to the Descartes circle circular fractal structures are
3
3+2V3
re2-1 :
1+2V3
3
7+4V3 1
"f3-1 3 + 14V3 ' "f3-2 17 + 10V3
It means that for normalization, the circular aperture D (D = rai) is expressed as a unit. Thus,
at the first stage of iteration, i = 1, rai = -1, the radii of each three identical inner circles are rbi = rci = rdi = 3/(3 + 2V3).
Once the first stage configuration of the four circles is obtained, the Descartes circle equation can be applied in the next stage to specify the size of a smaller circle from any set of three original circles. Using the processes with stage to stage, it is designated as the self-similar iteration design.
In this way, both re2-1 and re2-2 denote the radii of the obtained circles in the second stage. Further, the radii of the obtained circles in the third stage are rf3-1 and rf3-2. These radii of the circles are represented by relations 2 and 3 respectively.
Figure 3 - CPW-fed circular fractal slot antenna
re2-2
III. Experimental procedure
The experiment is based on a comparative analysis of the radiating properties and characteristics of two prototypes of the antenna design. One of them consists of a complete set of iterations (ra1, rb1, rc1, rd1, re2-1, re2-2, rf3-1, rf3-2), and the second - just of the first two iteration stages (ra1, rb1, rc1, rd1, re2-1, re2-2).
When they are compared, the general behavior and the trend of VSWR variation over the entire length of the frequency axis is identical for both prototypes, but with the following remarks:
1) As the iteration progresses, the reactive component of the impedance increases due to the
space-filling of the area of dielectric with radiating circles of small diameters that introduce corresponding changes in the HF region;
2) With the addition of iterations two distinct frequency responses (blue curve in Fig. 4), which denote the phenomenon of dual band, on the S11 plot are observed. While the S11 plot of the prototype with a smaller number of iterations is more smooth (green curve in Fig. 4).
Thus, it is clear that the choice of the necessary stages of self-similar iteration design is completely dependent on the optimizing factor, which, in its turn, is dictated by the field of application of the antenna system.
Figure 4 - Compared S11 characteristics of two antenna prototypes
A. Antenna prototype with a complete set of iterations
Using the design map in Fig. 3 the 1164 MHz resonated frequency, which is the lower limit of the operating frequency range for Global Satellite Navigation Systems (GNSS), is preset to determine the D = 126 mm with half-wavelength characteristics for a shorter monopole.
The whole S11 spectrum is broadband frequency responses (68.33% bandwidth) in the range from 1100 MHz to 1700 MHz are shown in the Fig. 5. Fig. 6 and 7 illustrate S11 spectra measured with a small step in the frequency domain in the upper and lower operating ranges.
Figure 5 - General form of the S11 spectrum for the antenna prototype with a complete set of
iterations
Figure 6 - The S11 spectrum for the antenna prototype with a complete set of iterations in the
lower frequency range
Figure 7 - The S11 spectrum for the antenna prototype with a complete set of iterations in the
higher frequency range
Responses that meet the specified limitations at -10 dB are present at 1190 MHz, 1200 MHz and 1210 MHz. A stable reception starts at 1290 MHz. It follows that this antenna prototype can be used for G1 and G3 bands of GLONASS, E1 and E5b bands of the GALILEO system, as well as for the L1 band of GPS.
B. Antenna prototype with the first two stages of iterations
As noted earlier, the process of configuring the antenna design and selecting the desired dimensions is identical to the calculation already done in the previous paragraph.
The whole S11 spectrum is broadband frequency responses (78.33% bandwidth) in the range from 1100 MHz to 1700 MHz are shown in the Fig. 8.
Figure 8 - General form of the S11 spectrum for the antenna prototype with the first two stages
of iterations
Responses that meet the specified limitations at -10 dB are present on the whole frequency axis. It follows that this antenna prototype covers all bands, on which GNSS operates. With the exception of L2 band of GPS, in which the quality of reception cannot be guaranteed.
C. Radiation Patterns
Fig. 9 illustrates the results of normalized two-cut patterns, measured at the 1164 MHz lower resonated frequency, for antenna prototype with the first two stages of iterations. It is seen that in both cases, this antenna design has directional patterns.
So, in the horizontal plane (blue curve in Fig. 9), we are dealing with an orientation in four main directions, separated by 90 degrees from each other. The peak value of emitted energy falls on the first quadrant of the diagram (i.e. 45 degrees), further responses are observed at angles of 135 degrees, 225 degrees and 315 degrees.
In the case of a vertical plane (red curve in Fig. 9), the directional patterns are more unpredictable. Thus, the peak value of emitted energy falls on the third quadrant of the diagram
(205-210 degrees). And the second significant lobe lies in the direction of zero.
These features processing gain for GNSS transceiver equipment are given. For example, by controlling the main lobe of radiation pattern with a rather narrow bandwidth (16.7% for vertical plane and 11.1% for horizontal plane), it is possible to achieve good quality performance of the received signal.
When considering the radiation pattern in the horizontal plane of the antenna prototype with a complete set of iterations (Fig. 10), the radiation pattern suffers strong change in comparison with the previous antenna prototype. Thus, significant narrow-band side lobes appear near the peak of emitted energy (120 degrees) and a wide-band response that covers the whole third and the whole fourth quadrant (range from 180 degrees to 360 degrees). In addition, the value of emitted energy slightly fluctuates at the level of 0.9, judging by the normalized radiation pattern, throughout the whole side lobe band. It can be considered as the bidirectional patterns.
Twàbi Мeмдvнаvoднoгo cwnno3uvMa «Haàewnocmb u xauecmeo», 2017, moM 2
Figure 9 - Radiation patterns for the antenna prototype with the first two stages of iterations
Figure 10 - Radiation patterns for the antenna prototype with a complete set of iterations
IV. Conclusion
This paper proposes an alternative feeding method using by coplanar waveguide to obtain a UWB slot antenna with circular fractal patterns. For accurate design and better performance, a synthesis with the Descartes circle theorem is presented here. A comparative analysis of the radiating properties and characteristics of two prototypes of the antenna design was carried out. One of them consists of a complete set of iterations, and the second - just of the first two iteration stages.
For antenna design with a complete set of iterations S11 results with broadband responses (68.33% bandwidth) in the range from 1100 MHz to 1700 MHz were achieved. And also it was concluded that this antenna is applicable for such working bands of GNSS as G1 and G3, E1 and E5b, L1. The bidirectional patterns are exhibited in the horizontal plane.
For antenna design with the first two stages of iterations S11 results with broadband responses (78.33% bandwidth) in the range from
1100 MHz to 17 00 MHz were achieved. From the results of the comparative analysis it follows that the antenna prototype with the first two stages of iterations has an extended bandwidth and, correspondingly, extended to a full GNSS bands list. The radiation patterns at a frequency of 1164 MHz in two planes were measured. Their analysis is given here.
In the end, the choice between broadband and selectivity is determined by the stages of iterations. As the iteration progresses, the reactive component of the impedance increases, that introduces corresponding changes in the HF region. For example, at the 1470 MHz frequency, the impedance of the antenna design with 2 stages of iteration is 0.22 Q and is capacitive in nature. While on the same frequency the impedance of the antenna design with 3 stages of iterations is 8.89 Ohm and is inductive in nature. On the S11 spectrums, this manifests itself as an upward shift along the frequency axis and two distinct frequency responses while the iteration progressed.
Труды Международного симпозиума «Надежность и качество», 2017, том 2
REFERENCES
1. P.MisraandP.Enge, Global Positioning System: Signals, Measurements, and Performance. Lincoln, MA, USA: Ganga-Jamuna Press, 2010.
2. N. Samama, Global Positioning: Technologies and Performance. New York, NY, USA: Wiley, 2 008.
3. J. W. Greiser, "Coplanar stripline antenna," Microw. J., vol. 19, no. 10, pp. 47-49, Oct. 1976.
4. J. Yeo, L. Lee, and R. Mittra, "Wideband slot antennas for wireless communications," Inst. Elect. Eng. Proc. Microw. Antennas Proprag., vol. 151, no. 4, pp. 351-355, Aug. 2004.
5. J. Y. Sze, K. L. Wong, and C. C. Huang, "Coplanar waveguide-fed square slot antenna for broadband circularly polarized radiation," IEEE Trans. Antennas Propag., vol. 51, no. 8, pp. 21412144, Aug. 2003.
6. T. Hori, "Broadband/multiband printed antennas," IEICE Trans. Commun., vol. E88-B, no. 5, pp. 1809-1817, May 2005.
7. D. H. Werner and S. Ganguly, "An overview of fractal antenna engineering research," IEEE Antennas Propag. Mag., vol. 45, no. 1, pp. 38-57, Feb. 2003.
8. J. C. Liu, D. C. Chang, D. Soong, C. H. Chen, C. Y. Wu, and L. Yao, "Circular fractal antenna approaches with Descartes circle theorem for multi-band/wide-band applications," Microw. Opt. Technol. Lett., vol. 44, no. 5, pp. 404-408, Mar. 2005.
9. J.C. Liu, D. C. Lou, C. Y. Liu, C. Y. Wu, and T. W. Soong, "Precise determinations of the CPW-fed circular fractal slot antenna," Microw. Opt. Technol. Lett., vol. 48, no. 8, pp. 1586-1592, Aug. 2006.
10. J.C. Liu, C. Y.Wu, D. C. Chang, and C. Y. Liu, "Relationship between Sierpinski gasket and Apollonian packing monopole antennas," Electron. Lett., vol. 42, no. 15, pp. 847-848, Jul. 2006.
УДК 661.728.86
Шипина1 О.Т., Трескова1 В.И., Никитина2 Л.Е.
1ФГБОУ ВО «Казанский национальный исследовательский технологический университет», Казань, Россия 2ФГБОУ ВО «Казанский государственный медицинский университет», Казань, Россия
СИНТЕЗ АМИНОПРОИЗВОДНЫХ СЛОЖНЫХ ЭФИРОВ ЦЕЛЛЮЛОЗЫ
Изучено химическое взаимодействие натриевой соли карбоксиметилцеллюлозы с аллиламином. Установлено наиболее вероятное направление протекания химической реакции: замещение карбоксильных групп на фрагмент аллиламина по мономолекулярному нуклео-фильному механизму. Синтезирован новый смешанный эфир целлюлозы — аллиламинакарбоксиметилцеллюлозы Ключевые слова:
натриевая соль карбоксиметилцеллюлозы (Na-КМЦ); аллиламин; замещение карбоксиметильных групп; аллиламинакарбоксиметилцеллюлозы
ВВЕДЕНИЕ
Одним из ведущих направлений в исследованиях химии природных полимеров последних лет является физическая и химическая модификация производных целлюлозы. Обзор научной и патентной литературы последних лет, посвященной вопросам химии целлюлозы и её производных, позволяет сделать вывод, что её эфиры являются полупродуктами, на основе которых возможно целенаправленное образование новых производных целлюлозы [1-5]. В этом смысле актуальным становится химическая модификация карбоксиметилцеллюлозы низкомолекулярными соединениями, позволяющая изменять в заданном направлении молекулярный состав, физические и химические свойства.
Обычно при действии на натриевую соль карбок-симетилцеллюлозы (Na-КМЦ) химических реагентов в той или иной степени одновременно протекают несколько процессов, среди которых можно выделить преимущественные: реакции по карбоксильным и гидроксильным группам и реакции по в-гликозидной связи, всегда приводящие к деструкции полимерной цепи [8]. Детальное изучение реакции помогает понять, какое из направлений будет доминирующим и, как следствие, каким будет строение и свойства конечных продуктов. А возможность управления протекания реакции повышает выход конечного продукта [9].
Целью данного исследования является изучение химического взаимодействия натриевой соли кар-боксиметилцеллюлозы с аллиламином, строения и свойств синтезированных продуктов реакции. Согласно анализу опубликованных работ, подобные модификаты имеющие в своем составе карбоксиме-тильные и аминогруппы рекомендуются к применению в качестве сорбентов по отношению к ионам тяжелых металлов, водоудерживающих добавок в составе строительных материалов [10, 11]. Варьируя количество карбоксильных и аминогрупп в макроцепях производных целлюлозы, а также степень их ионизации, можно целенаправленно изменять сорбцион-ную способность сорбентов, получаемых на основе целлюлозы по отношению к ионам поливалентных металлов, а также изменять растворимость исходной КМЦ [10].
ЭКСПЕРИМЕНТАЛЬНАЯ ЧАСТЬ
Методы физико-химических исследований:
Элементный анализ производился на автоматизированном элементном анализаторе Euro EA-3000, который представляет новый стандарт анализа CHNS (углерода, водорода, азота и серы) методом сжигания и анализа кислорода методом пиролиза.
ИК-спектры записывались на спектрометре Фурье «Avatar-360» с математическим обеспечением «OMNIC» в интервале частот 4 00 - 4 000 см-1.
Микроскопическое исследование оптически анизотропных элементов, фазовых элементов и фазовых переходов (плавление и кристаллизации) изучали на поляризационном микроскопе МИН-8.
Динамическую вязкость определяли на вискозиметре ВПЖ-3 (растворитель - раствор едкого натра).
Для исследования рентгено-структурных характеристик применяли дифрактометр RigakuUltimaIV с рентгеновской трубкой Cu/40 kV/4 0 mA, детектор - сцинцилляционный. Сканирование производилось в диапазоне углов 5-48 оС, с шагом измерения 0.02 градуса, скоростью съемки 2 градуса в минуту.
ОБСУЖДЕНИЕ РЕЗУЛЬТАТОВ
Методика проведения синтеза аллиламинакарбок-симетилцеллюлозы: к раствору 1 г карбоксиметил-целлюлозы в 40 мл воды в трехгорлой колбе объемом 100 мл, добавляли аллиламин из расчета 2 моль на каждую карбоксильную группу, а именно 0,5 г и перемешивали в течение заданного времени от 2 до 8 часов при температуре 50 °С. По окончании выдержки раствор высаживали в изопропиловый спирт, выпавший твердый продукт отфильтровывали и промывали на воронке Шотта, далее сушили сначала на воздухе, затем в вакуум эксикаторе над хлористым кальцием до постоянной массы.
В качестве исходной Na-КМЦ был взят технический образец «Полицелл КМЦ-9 Н» (табл. 1) [12] . Технический продукт Na-КМЦ может содержать до 50 % гликолята натрия и хлорида натрия. Поэтому перед химической модификацией проводили очистку КМЦ в приборе Сокслета (растворитель изопропа-нол).
