Description of Analysis and Design of a Reconfigurable Antenna for CR Applications

1. Analysis and design of a reconfigurable antenna
for ISM and GSM bands for cognitive radio
applications.
Fernando López-Marcos1, Richard Torrealba-
Meléndez1, Edna Iliana Tamariz-Flores2.
1Electronic Science Faculty, Benemérita
Universidad Autónoma de Puebla, México.
2Computer Science Faculty, Benemérita
Universidad Autónoma de Puebla, México.

2. Purposes of this presentation
This presentation:
• Mentions the requirements for Cognitive
Radio (CR) communications systems.
• Describes the analysis and design of a
reconfigurable antenna that operates in 2400
MHz and 1850 MHz bands.
• Shows the designed antenna is in accordance
to required parameters for CR applications.
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3. Description of Cognitive Radio
(FCC, 2002)
CR is defined as:
“Real-time monitoring of a radio channel or
spectrum band and limiting transmissions in
terms of frequency, power, or timing in order
to avoid harmful interference to other
spectrum users”
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4. Requirements for CR systems
(Tawk, 2014)
Cognitive
Radio
1. Observing
the channel
activity.
2. Deciding which
part of the
spectrum is
suitable for
communication.
3. Acting
appropriately to
achieve the
required mode of
communication.
4. Learning from
previous
channel activity
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5. Steps that can be taken to improve
spectrum efficiency (FCC, 2002)
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6. Designed Antenna
• A square spiral monopole microstrip spiral antenna
was designed. It is composed by a microstrip λ/4
feedline and a microstrip λ/2 resonator.
• The substrate used is 0.702 mm Rogers 3003, with
a dielectric permittivity of 3.2.
• The feedline impedance is 50 ohms and the
resonant frequency is 2400 MHz.
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7. Designed Antenna Diagram
Dimension a b c d e f g h i j
Size (mm) 1.6 33.6 14.4 20 11.2 9.6 8 6.4 0.8 1.5
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8. Analysis for the reconfiguration
element value
The response for the antenna, operating
at 1850 MHz. is:
feedline
DC
BA






element
DC
BA






resonator
DC
BA






240024001850 resonatorelementfeedlineantenna
DC
BA
DC
BA
DC
BA
DC
BA






⋅





⋅





=





(1)
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9. Analysis for the reconfiguration
element value (2)
Using (1), the value for the reconfiguration element is:
The calculated value with (2), has the form:
Where is an imaginary positive value. This
indicates that an inductor is necessary to reconfigure
the antenna.
1
2400
1
24001850
−−


















=





resonatorfeedlineantennaelement
DC
BA
DC
BA
DC
BA
DC
BA
(2)






=





10
1 element
element
Z
DC
BA
(3)
elementZ
9

10. Resonance frequency change
for different inductor values
2400 MHz
ISM Band
3G
Mobile
Communications
1850 MHz
GSM Band
Satellite
Communications
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11. Frequency Response
for the antennas
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12. Radiation Patterns for the antennas
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13. Comparison With Other Works
AbuTarboush
et al
Li et al Nalarwar et al This Work
Short Size
√ √ √√ √√
Performance
√√√ √√ √ √√
Design
Simplicity
√ √ √√ √√
Analysis
Shown?
X X X √
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14. Conclusions
• We analyzed and designed a microstrip
spiral monopole antenna that can be
reconfigured with putting only a discrete
element.
• This methodology can be used to design
antennas for cognitive radio (CR)
applications and other bands and
technologies.
• The design let us reconfigure an antenna
into a lower frequency without increasing
the physical length.
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15. Future Works
• Get the antenna reconfigured with a
complementary switch.
• Design other reconfigurable antennas
using the methodology of this work.
• Improve the features for the designed
antennas with this methodology.
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16. References
[1] Bkassiny, M., Jayaweera, S.K., Avery, K.A. "Distributed Reinforcement
Learning based MAC protocols for autonomous cognitive secondary users,"
in Wireless and Optical Communications Conference (WOCC), 2011, pp. 1-6.
[2] FCC Spectrum Policy Task Force, “Report of the Spectrum Efficiency
Working Group,” Technical Report, Federal Communications Commission,
Washington DC, 2002.
[3] Y. Tawk, J. Constantine and C.G. Christodoulou. “Cognitive-Radio and
Antenna Functionalities: A Tutorial”, IEEE Antennas and Propagation
Magazine, vol. 56, no. 1, pp. 231-243, February 2014.
[4] K. A. Narayanankutty, Abhijith A. Nair, Dilip Soori, Deepak Pradeep, V. Ravi
Teja, Vishnu K. B. “Cognitive Radio Sensing Using Hilbert Huang Transform”
Wireless Engineering and Technology, vol. 1, no. 1, pp. 36-40, July 2010.
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17. References
• [5] M.S. Nalarwar and S.L. Badjate. “A Circular Monopole with a
Rectangular Microstrip Antenna for Cognitive Radio Applications”
International Journal of Innovative Research in Science & Engineering, vol.
2, no. 4, pp. 190-194, April 2014.
• [6] H.F. AbuTarboush, R. Nilavalan, K.M. Nasr, H.S. Al-Raweshidy and D.
Budimir. “A reconfigurable CPW antenna for GPS, GSM and WLAN
applications”, in European Conference on Antennas and Propagation,
Barcelona, 2010.
• [7] Yue Li, Zhijun Zhang, Jianfeng Zheng, Zhenghe Feng and Magdy F.
Iskander. “A Compact Hepta-Band Loop-Inverted F Reconfigurable
Antenna for Mobile Phone”, IEEE Transactions on Antennas and
Propagation, vol. 60, no. 1, pp. 389-392, January 2010.
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18. Acknownledgments
We want to thank to the Electronic Science
Faculty and the Vicerectory of Research and
Postgraduate Studies of the Benemérita
Universidad Autónoma de Puebla, for their
support in the realization of this work.
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19. Thanks for your attention!
Any questions?
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