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Vestnik SibGAU Vol. 16, No. 4, P. 868-874
ANTENNA MODULES OF GNSS USER EQUIPMENT: INNOVATIVE APPROACHES
S. N. Boyko, A. V. Isaev, S. V. Kosyakin, A. S. Kukharenko, Y. S. Yaskin
Branch of United Rocket and Space Corporation Institute of Space Device Engineering 53, Aviamotornaya Str., Moscow, 111250, Russian Federation E-mail: npk6@mail.ru
An original engineering conception of the navigation antenna module design, involving the idea that a dielectric substrate of the antenna element is made of a ceramic in the form of a turned cup provided with the patch on its top and metalized cavity, in which all active elements are placed, is suggested. The cup-shaped antenna element has additional advantages against the patch antenna of a traditional form: it has a wider matching band, higher radiation efficiency, a wider radiation pattern, and a wider (up to 1.5 times) meridian angle range, with circular field polarization. Metamaterial, used in the antenna element of an all-ceramic type antenna module, allows obtaining a circular field polarization even at low elevation angles, which only a quadrifilar antenna has. To work with all operating GNSS systems (in the extended bandwidth), an antenna element, which has two planar axial elements placed on the common substrate, is proposed. The antenna element can also be designed to work in 2 bands, for example, in L1 and L2 GLONASS/GPS or in L1 and L2 GPS/GALILEO. A multi frequency stacked antenna design method with opposite feeding of the antenna elements, which provides the antenna element isolation of more than 25 dB and identical radiation patterns is suggested. It is proposed to use for multipath mitigating a special type of the EBG-metamaterial and, as well, a special method of multipath mitigating ground plane mounting, which doesn't narrow antenna element radiation pattern and doesn't spoil phase center stability.
Keywords: antenna modules, GNSS antennas, patch antennas, active antennas.
Вестник СибГАУ Т. 16, № 4. С. 868-874
АНТЕННЫЕ МОДУЛИ АППАРАТУРЫ ПОТРЕБИТЕЛЕЙ ГНСС: ИННОВАЦИОННЫЕ РЕШЕНИЯ
С. Н. Бойко, А. В. Исаев, С. В. Косякин, А. С. Кухаренко, Ю. С. Яскин
Филиал ОАО «Объединенная ракетно-космическая корпорация» -
Научно-исследовательский институт космического приборостроения Российская Федерация, 111250, г. Москва, ул. Авиамотрная, 53 E-mail: npk6@mail.ru
Представлена оригинальная концепция проектирования навигационных антенных модулей, основанная на том, что подложка антенного элемента выполняется из керамики в форме перевернутой чаши, с топологией антенны на своей внешней стороне и металлизированной внутренней полостью, в которой размещаются все активные элементы. Антенный элемент в форме перевернутой чаши имеет также дополнительные преимущества пред антеннами традиционного типа: более широкую полосу по согласованию, большую эффективность излучения, расширенную диаграмму направленности и более широкий (до полутора раз) диапазон углов диаграммы направленности, в котором сохраняется круговая поляризация. Применение метаматериала в конструкции антенного элемента цельнокерамического антенного модуля позволяет получить круговую поляризацию даже на низких углах места, что является свойством только лишь квадрифилярных антенн. Для обеспечения работы со всеми спутниковыми навигационными системами (в расширенной полосе частот) предложена конструкция антенны с двумя аксиально-симметричными элементами, расположенными на общей подложке. Конструкция этого антенного элемента также может быть адаптирована для работы в двух диапазонах, например, в L1 и L2 GLONASS/GPS или в L1 и L2 GPS/GALILEO. Представлен метод проектирования многочастотных антенн этажерочного типа с кроссзапиткой антенных элементов, обеспечивающий развязку между антенными элементами более 25 дБ и идентичность их диаграмм направленности. Для отсечки многолучевости предложено использовать специальную полосно-заграждающую структуру метаматериала. Также представлен специальный метод применения такой структуры, который позволяет избежать обуже-ния диаграммы направленности и не портит стабильность фазового центра антенного элемента.
Ключевые слова: антенные модули, антенны GNSS, печатные антенны, активные антенны.
Introduction. In our days in the world practice standard antenna module design approaches and methods are formed. In the paper our methods and solutions, which differ from the conventional ones, are presented.
During the navigation antennas design a trend of integrating of antenna element, filters, low noise amplifier (LNA) and also a receiver chipset into a union device, named active navigation antenna or navigation antenna module (NAM) is seen.
Usually a microstrip (or patch) antenna (MSA) acts as an antenna element of a NAM, as a mostly compact [1-3].
Navigation antenna modules design innovative approaches. An original conception of the NAM was suggested by our company, according which a dielectric substrate of the antenna element is made of a ceramic in the form of turned cup provided with the patch on its top and metalized inner hollow, in which all active elements are placed [4; 5]. This technology of NAM production was named "uncased" or "full-ceramic".
A cup-shape antenna element and navigation natenna module, made basing on it and using uncased technology, are presented on fig. 1.
As a result of this way of NAM design, their strength was significantly increased and size was optimized, as well the production cost was reduced for a module because of its high manufacturability. Also, turned-cup shape antenna has additional advantages comparing with traditional patch antenna. It has 1.5-2 times wider working band, its radiation efficiency is about 6 % higher, wider radiation pattern and wider (up to 1.5 times) meridian angle range in which circle field polarization persists (fig. 2). These advantages give an opportunity of the total NAM miniaturization.
Besides, parameters of cup-shaped antenna elements depend much less on the additional shield size, on which they can be placed [2; 5]. Consequently, NAM, made using uncased technology, can be used even without additional shield.
Usage of metamaterials in antenna element and total full-ceramic antenna module construction gives additional advantages. Basically, usage of metamaterials in the elements of antenna technique improve such parameters as coupled bandwidth, gain, selectivity, back radiation reductions and others.
a b
Fig. 1. A cup-shape antenna element construction (a) and navigation natenna module ASNK-1, based on it (b), having dimentions 48x44x19 mm
G I (IB]
Ar I (IB]
1
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J k
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!
0
Fig. 2. Amplitude (a) and polarization (b) radiation patterns of traditional (1) and uncased (2) antenna modules
b
a
a b
Fig. 3. A metamaterial-based antenna element construction (a) and navigation natenna module ASNK-3, based on it (b), having dimentions 30x30x12 mm
On fig. 3 a construction of a metamaterial-made antenna element and an uncased type antenna module, based on it are presented. This antenna element construction allows using substrates with the lower value of permittivity, what provides higher radiation efficiency. Also presented metamaterial-made antenna element has a meridian angle range with the axial ratio of less than 5 dB up to -80°...+80° (fig. 4), which only quadrifillar antennas also have [6]. Due to usage of low permittivity materials for the substrate, the presented antenna module has a lower weight and cost value. The antenna module has a flat and compact planar construction and due to this fact it can be implemented into any compact onboard or even on-body devices.
On fig. 5 an embedded receiving antenna module with a receiver chipset, made using uncased technology (fig. 5, a) and an analog of the module made using traditional technologies (fig. 5, b) are presented. Advantages of the uncased module are its complete tightness, simultaneous operation in L1 GLONASS/GPS, E1 GALILEO and B1 BEYDOU bands and better navigation signal reception, what is caused by the cup-shaped antenna element.
In our days the number of GNSS systems increases because of GALILEO and BEYDOU operation start, and also number of GNSS operating bands increases. Thus appears a necessity of creation of multifunctional devises, which simultaneously work with maximum number of GNSS in various (ideally in all) bands. It forces creation of patch antennas with extended operating band or multiband MSA. Usually the bandwidth of coupling with low noise amplifier is achieved by using the so called proximity antenna feeding [7; 8]. But this method forces multilayer PCB design.
For operation in widened bend (with more number of operating GNSS) we have proposed an antenna element, which has two planar segments with symmetry around the center of MSA [9; 10]. The first segment is a patch located in the center of the ceramic surface, while the second one is a square frame surrounding the first segment. Two segments have a distributed mutual coupling, what
allows achieving antenna element matching with 50-Ohm feeding and invariable radiation pattern in L1 GLON-ASS/GPS, E1 GALILEO and B1 BEYDOU bands.
The proposed antenna element can be also designed to work in 2 bands, for example L1 and L2 GLONASS/GPS or L1 and L2 GPS/GALILEO.
The designed active GNSS module based on the proposed antenna element which also contains a low noise amplifier with filters and overload protection for operation in L1, GLONASS/GPS, E1 GALILEO and B1 BEI-DOU bands is presented on fig. 6. It can be seen, that the antenna element VSWR is lower than 3 in the band 15041631 MHz (fig. 6, b) and its axial ratio is not higher than 3 in the band 1540-1600 MHz (fig. 6, c).
The designed antenna module can be used as an independent embedded element of GLONASS/GPS/GALILEO navigation receivers, and also as a basic part of external antennas and antenna arrays.
During design of an antenna module, which is able to work simultaneously in all GLONASS/ GPS/ GALILEO/ BEYDOU GNSS operating bands it is possible to implement more complicated antenna element - a stacked MSA [11]. In the stacked antennas antenna elements for different bands are placed one above another in the way that antenna for higher frequencies are placed above antennas for lower frequencies. Each mentioned antenna serves as a ground plane for the antenna, placed above.
The main deficiency of multi frequency stacked MSA antennas is a high mutual influence of the antenna elements what causes radiation pattern distortion in each band and low mutual isolation of the antenna inputs. The mutual isolation of antenna inputs can be sometimes improved when using the special multi frequency MSA feeding nets, but the problem is not solved generally.
We have suggested a multi frequency stacked antenna design method with cross feeding of the antenna elements (fig. 7), which provides the antenna element isolation more than 25 dB and identical radiation patterns in separated bands (fig. 8).
Fig. 4. Measured amplitude (a) and polarization (b) radiation patterns of navigation antenna module ASNK-3
b
Fig. 5. Full-ceramic antenna module PAM-2 (30x30x10 mm) (a) and similar traditionally made ceaseless module (22x22x8) (b)
b
a
a
Fig. 6. Dual band navigation antenna module ASNP-8 (30x30x10 mm) (a), the antenna element VSWR (b) and axial ratio (c)
Fig. 7. Stacked patch antenna with cross feeding of antenna elements
G [dBJ
J 1
/
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-u
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i-
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-1,-
f
J
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4
-50
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a
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-60
-30
30
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b
Fig. 8. Radiation patterns of the module AA2-KKS, based on stacked antenna with antenna elements cross feeding on the frequencies 1600 (a) and 1247 (b) MHz
In especial GNSS antenna application it is very impotent not to receive multipath signals. Multipath signal is a signal from the satellite, which was received by the antenna not directly, but after some reflections from earth or any constructions, which surround the antenna. This is the cause of a phase noise, which increases the mistake in determining co-ordinates.
Usually choke ring ground planes are used for multi-path mitigating. But these constructions have a disadvantage of big size and weight. EBG metamaterials allow obtaining compact ground planes for GNSS antenna mul-tipath mitigating [12-14].
But all multipath mitigating ground planes have a common deficiency - they spoil the antenna element phase center stability. In our antenna module ASNG-3 a special type of a EBG metamaterial (fig. 9) and a special method of EBG metamaterial multipath mitigating ground plane mounting is used, which has no such a deficiency [15].
The antenna module radiation patterns, taken on the frequencies 1590 MHz and 1236 MHz are presented on fig. 10. Diagrams show the wide radiation pattern in the top hemisphere and the maximum down-up ratio value minus 40 dBi in L1 band and minus 35 dBi in L2 band.
Using two antenna modules, installed stationary with the base between them 0.538 m, measurements of router point coordinates within 24 hours were made. On fig. 11 router point latitude and longitude deviations are presented as well.
It is seen from the diagram that most part of deviations are within ±2 mm what means that antenna phase center stability is not greater than 2 mm.
Conclusion. Thus, navigation antenna module design innovative approaches, provided in the paper, allow with the use of their combination obtaining devises with almost any characteristics collection for implementation in various GNSS equipment.
Fig. 9. EBG metamaterial ground plane
G [dB] G [dB]
Fig. 10. Radiation patterns of the module ASNG-3 on the frequencies 1236 (a) and 1590 (b) MHz
■2 J U 1 2
LenjiLlDitt [mm]
Fig. 11. Router point latitude and longitude deviations
Acknowledgments. Practical results, presented in the paper were obtained in the Institute of Space Device Engineering, based in Moscow, during continued work of antenna design department of the Institute.
Благодарности. Результаты, представленные в статье, были получены в Научно-исследовательском институте космического приборостроения в Москве в ходе продолжительной работы коллектива отдела разработки антенных устройств.
References
1. Balanis C. A. Modern Antenna Handbook, John Wiley & Sons inc., 2008, 1680 p.
2. Panchenko B. A., Nefedov Y. I. Micropoloscoviye antenny [Microstrip antennas], Moscow, Radio y svias Pabl., 1986, 145 p.
3. Rama Rao B., Kunysz W., Fante R. еt al. GPS/GNSS Antennas, Artech House, 2012, 420 p.
4. Boyko S. N., Kukharenko A. S., Yaskin Y. S. Miniaturization of satellite navigation system navigation equipment antenna modules. 2013 Loughborougn Antennas & Propagation Conference, 2013, P. 102-105.
5. Boyko S. N., Kosiakin S. V., Kukharenko A. S. еt al. [Miniaturisation of antenna modules of satellite navigation system navigation equipment], Antenny, 2013, No. 12, P. 38-44 (In Russ.).
6. Boyko S. N., Kosiakin S. V., Kukharenko A. S. еt al. Metamaterial-made GNSS Antenna. 2014 Loughborougn Antennas & Propagation Conference, 2014, P. 410411.
7. Zhou Y., Chen C. C., Volakis J. L. Dual band proximity-feed patch antenna for tri-band GPS applications. IEEE Transactions on AP, 2007, Vol. 55, No. 1, P. 220223.
8. Jing-Ya Deng, Li-Xin Guo, Ying-Zeng Yin and others. Broadband Patch Antennas Fed by Novel Tuned Loop. IEEE Transactions on AP, 2013, Vol. 61, No. 4, P. 2290-2293.
9. Avdonin V. Y., Boyko S. N., Isaev A. V. еt al. A compact active dual-band GLONASS/GPS navigation antenna. Loughborougn Antennas & Propagation Conference, 2014, P. 683-684.
10. Avdonin V. Y., Boyko S. N., Isaev A. V. [Dual band active microstrip antenna with circular polarization]. Antenny, 2012, No. 8, P. 38-45 (In Russ.).
11. Li J., Shi H., Lim H. еt al. Quad-band probe-feed stacked annular patch antenna for GNSS application. IEEE Antennas and Wireless Propagation, 2014, Vol. 13, P. 372-375.
12. Baggen R., Martinez-Vazquez M., Leiss J. еt al. Low profile GALILEO antenna using EBG technology. IEEE Transactions on AP, 2008, Vol. 56, No. 3, P. 667-674.
13. Ruvio G., Amman M. J., Bao X. Radial EBG Cell Layout for GPS Patch Antennas. Dublin Institute of Technology, School of Electrical and Electronic Engineering, Articles, 2009-06-18.
14. Tranquilla J. M., Cam J. P., Al-Rizzo H. M. Analysis of a choke-ring ground plane for multipath control in Global Positioning System (GPS) application. IEEE Trans. on Antenna and Propagations, 1994, Vol. 42, No. 7, P. 905-911.
15. Boyko S. N., Kukharenko A. S., Yaskin Y. S. EBG Metamaterial Ground Plane Application for GNSS Antenna Multipath Mitigating. IEEE International Workshop on Antenna Technology, 2015, P. 178-181.
Библиографические ссылки
1. Balanis C. A. Modern Antenna Handbook. John Wiley & Sons inc., 2008, 1680 p.
2. Панченко Б. А., Нефёдов E. И. Микрополоско-вые антенны. М. : Радио и связь, 1986. 145 с.
3. GPS/GNSS Antennas / B. Rama Rao [et al.]. Artech House, 2012. 420 p.
4. Boyko S. N., Kukharenko A. S., Yaskin Y. S. Miniaturization of satellite navigation system navigation equipment antenna modules // Loughborougn Antennas & Propagation Conference. 2013. P. 102-105.
5. Миниатюризация антенных модулей навигационной аппаратуры спутниковых навигационных систем / С. Н. Бойко [и др.] //Антенны. 2013. № 12. C. 38-44.
6. Metamaterial-made GNSS Antenna / S. N. Boyko [et al.] // Loughborougn Antennas & Propagation Conference. 2014. P. 410-411.
7. Zhou Y., Chen C. C., Volakis J. L. Dual band proximity-feed patch antenna for tri-band GPS applications // IEEE Transactions on AP. 2007. Vol. 55, No. 1. P. 220-223.
8. Broadband Patch Antennas Fed by Novel Tuned Loop / Jing-Ya Deng [et al.] // IEEE Transactions on AP. 2013. Vol. 61, No. 4. P. 2290-2293.
9. A compact active dual-band GLONASS/GPS navigation antenna / V. Y. Avdonin [et al.] // Loughbor-ougn Antennas & Propagation Conference. 2014. P. 683684.
10. Авдонин В. Ю., Бойко С. Н., Исаев А. В. Двух-диапазонная активная микрополосковая антенна круговой поляризации // Антенны. 2012. № 8. C. 38-45.
11. Quad-band probe-feed stacked annular patch antenna for GNSS application / J. Li [et al.] // IEEE Antennas and Wireless Propagation. 2014. Vol. 13. P. 372-375.
12. Low profile GALILEO antenna using EBG technology / R. Baggen [et al.] // IEEE Transactions on AP. 2008. Vol. 56, No. 3. P. 667-674.
13. Ruvio G., Amman M. J., Bao X. Radial EBG Cell Layout for GPS Patch Antennas / Dublin Institute of Technology, School of Electrical and Electronic Engineering, Articles. 2009-06-18.
14. Tranquilla J. M., Cam J. P., Al-Rizzo H. M. Analysis of a choke-ring ground plane for multipath control in Global Positioning System (GPS) application // IEEE Trans. on Antenna and Propagations. 1994. Vol. 42, No. 7. P. 905-911.
15. Boyko S. N., Kukharenko A. S., Yaskin Y. S. EBG Metamaterial Ground Plane Application for GNSS Antenna Multipath Mitigating // IEEE International Workshop on Antenna Technology. 2015. P. 178-181.
© Boyko S. N., Isaev A. V., Kosyakin S. V., Kukharenko A. S., Yaskin Y. S., 2015
