on-body antenna design using carbon...

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On-body Antenna Design using Carbon

Nanotubes

Centre for Electromagnetic and Antenna Engineering (CELANE) Department of Engineering

Presenter: Syed Muzahir Abbas, Ph.D. Student

Supervisor: Prof. Karu Esselle

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Presentation Outline • Project Overview

• Background

– Antennas

– CNT

– CNT Yarns

– Body Centric Communication

– On-body Antennas

• Research Objectives

– On-body Antenna Design Requirements

– Design Constraints/Aims & Objective

– Expected Outcomes

• Task Plan

• Conclusion

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Project Overview

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• Background

– Antennas

– CNT

– CNT Yarns







• Task Plan

• Conclusion

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Antennas [1] • Antenna Definition

“Usually a metallic device (as a rod or wire) for radiating or receiving radio waves”. (Webster’s dictionary)

OR

“A means for radiating or receiving radio waves”. (IEEE Standard)

• Antenna Parameters

– Antenna Impendence

– Efficiency

– Radiation Pattern

– Antenna Gain

– Directivity

– Antenna Polarization

– Bandwidth

– Return Loss

[1] C. A. Balanis, Antenna Theory: Analysis and Design: John Wiley, 2005.

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Carbon Nanotube (CNT) • Potential candidates for replacement of

conventional metals – Density of CNT composites is about five time lower

than copper and around half that of aluminium.

– Thermal conductivity is about ten times that of copper

• Significant Advantages – Mechanical (high strength and load bearing)

– Electrical (conductivity and resistivity)

– Thermal (sustain at high temperatures)

– Non-oxidizing abilities

• Applications – Nanoantennas

– Nanoelectronics

• Allotropes of carbon with a cylindrical nanostructure

Fig. 1: Diamond *

Fig. 2: Graphite *

* http://chem-guide.blogspot.com.au/2010/04/covalent-solid.html

Graphene

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Carbon Nanotube (CNT) -- Continued

• CNT can be categorized as

– Single-Walled Carbon Nanotube (SWCNT)

A layer of graphite, a single atom thick, called graphene, which is rolled into a seamless cylinder

Diameter is close to 1nm

Length thousand times of diameter

– Multi-Walled Carbon Nanotube (MWCNT)

Consist of concentric tubes (i.e. multiple rolled layers) of graphene. OR

As a single sheet of graphite rolled into the shape of a scroll.

Diameter range is 5nm to 50nm

Length thousand times of diameter

Fig. 3: SWCNT *

Fig. 4: MWCNT *

*http://staff.aist.go.jp/h-kataura/Kogaku-kiji-forweb.htm

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Carbon Nanotube (CNT) -- Continued

Fig. 5: Carbon Nanotubes *

* http://explow.com/buckypaper http://www.phy.mtu.edu/yap/frontiercarbon.html

a b

c d

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CNTs in Antenna Applications -- Continued

– Polymer-carbon nanotube sheets for conformal load bearing antennas.

– Presented circuit model to calculate CNT sheet conductivity.

– Presented fabrication process.

• Load Bearing Antenna Applications [2]

Fig. 6: Circuit model for conductivity [2]

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CNTs in Antenna Applications -- Continued – Conducted mechanical tests for

• Stress,

• Strain

• Bending

Fig. 7: (a) Stress (b) Strain (c) Bend [2]

[2] Z. Yijun, Y. Bayram, D. Feng, D. Liming, and J. L. Volakis, "Polymer-Carbon Nanotube Sheets for Conformal Load Bearing Antennas," Antennas and Propagation, IEEE Transactions on, vol. 58, pp. 2169-2175, 2010.

– Proposed it suitable for conformal load bearing antennas and RF circuits.

(b)

(c)

(a)

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– Full-Composite Fractal Antenna Using Carbon Nanotubes for Multiband Wireless Applications.

– UHF-RFID (900MHz), Blutooth (2.4GHz) and WLAN (5.5GHz).

– Presented antenna design and fabrication process.

– Antenna gain and read range can be controlled by changing the conductivity of composite, which is not possible for materials with fixed conductivity such as copper.

• Multiband Wireless Applications [3]

Fig. 8: Fractal Antenna Design [3]

[3] A. Mehdipour, I. D. Rosca, A. R. Sebak, C. W. Trueman, and S. V. Hoa, "Full-Composite Fractal Antenna Using Carbon Nanotubes for Multiband Wireless Applications," Antennas and Wireless Propagation Letters, IEEE, vol. 9, pp. 891-894, 2010.

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– Comparison of copper and CNT antennas.

– Frequency range 24 - 34 GHz.

– Presented antenna design and fabrication process.

– Housing effect on the performance of CNT antenna is much lower than for the copper antenna

– Above 30GHz its significantly less resulting in stable gain and less distortion in radiation pattern.

• Wideband Millimeter-Wave Antenna Applications [4]

Fig. 9: (a) Antenna Design (b) Array [4]

[4] A. Mehdipour, I. D. Rosca, A. R. Sebak, C. W. Trueman, and S. V. Hoa, "Carbon Nanotube Composites for Wideband Millimeter-Wave Antenna Applications," Antennas and Propagation, IEEE Transactions on, vol. 59, pp. 3572-3578, 2011.

(a)

(b)

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Carbon Nanotube (CNT) Yarns • CNT yarns (fibers) are composed of individual CNTs

• Can be spun from CNT forest by spinning

• By passing CNT films through a drop of volatile liquid

Fig. 10: CNT yarns production by CSIRO*

* http://www.csiro.au/Outcomes/Materials-and-Manufacturing/ Innovation/Carbon-Nanotubes-2.aspx

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Body Centric Communication [5]

• Off-body communication

– Communications from off-body to an on-body device or system

• On-body communication

– Communications within on-body networks and wearable systems

• In-body communication

– Communications to medical implants and sensor networks

Fig. 11: Human body model

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• Background

– Antennas

– CNT

– CNT Yarns







• Task Plan

• Conclusion

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On-body Antenna Design Requirements

• Frequency Range

– UWB lower band (3 - 5 GHz)

– UWB (3.1 – 10.6 GHz)

– V-Band (7 GHz around 60 GHz)

TABLE: Unlicensed frequency bands around 60 GHz [6].

• Antenna Impedance

– 50 ohm

Country Japan USA Canada Korea Europe Australia

Frequency Band (GHz)

59-66 57.05-64 57-64 57-64 57-64 59.4-62

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Design Constraints/Aims & Objective

• Polarization

– Horizontal / Vertical

• Radiation Pattern [6]

– Omni-directional and along the body surface

• Full Ground Plane

– To prevent radiation towards body

• Bandwidth

– Larger bandwidth

• Size/Weight

– Small/Light

• Distance b/w antenna and body

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Expected Outcomes

• RF/Microwave characterization of CNT yarns

• Antenna prototype for on-body communication with desired parameters

• Which polarization is suitable and why?

• Desired radiation pattern over the required bandwidth

• How bandwidth can be enhanced in presence of full ground plane?

• Recommended distance between antenna and body?

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• Background

– Antennas

– CNT

– CNT Yarns







• Task Plan

• Conclusion

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Task Plan-First year (2012-2013) Months 1 - 6 7 - 8 9 - 11 12

Task-1, Literature Review Mar –Aug2012

Task-2, Software Learning Sep-Oct

Task-3, Test Structures Designing Nov-Jan2013

Task-4, Test Structures Fabrication Feb

Task-1, Literature Review (6-months)

– To strengthen the relevant knowledge and to gain detailed insight of existing work carried out so far in the field under investigation

– CNT, CNT yarns, Antennas, On-body communication/antennas, UWB, Human body properties

Deliverables

– Literature review report

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Task Plan-First year (2012-2013)

Task-2, Software Learning (2-months)

– High Frequency Structure Simulator (HFSS) Completed

– CST Microwave Studio In progress

– AWR Microwave Office In progress

Tasks To Do

– Task-3, Test Structures Designing

– Task-4, Test Structures Fabrication

Task-1, Achieved (March 2012 to date)

– CNT, CNT yarns, Antennas, On-body communication/antennas, UWB, Human body properties

Deliverables

– Test Structures

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Task Plan-Second year (2013-2014)

Months 13 - 15 16 - 18 19 - 21 22-24

Task-5, CNT Measurements Mar –May2013

Task-6, Antenna Designing Jun-Aug

Task-7, Antenna Simulations Sep-Nov

Task-8, Antenna Fabrication Dec

Task-9, Antenna Testing Jan-Feb2014

Deliverables

– Properties of CNT yarns

– Antenna prototype

– Publication of results in International conferences/journals

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Task Plan-Third year (2014-2015)

Months 25 - 26 27 - 36

Task-10, Results and Analysis Mar-Apr2014

Task-11, Write-up May2014 - Feb2015

Deliverables

– Publication of results in International conferences/journals

– Thesis write-up

– Completion of thesis in 3 years

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• Background

– Antennas

– CNT

– CNT Yarns







• Task Plan

• Conclusion

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Conclusion

• Overview of CNT, CNT yarns, body-centric communication, on-body antennas

• Use of CNTs in antenna applications and their advantages

• On-body antenna design requirements

• Design Constraints/Aims & Objective

• Expected outcomes

• Task plan (achieved & to do)

• Investigating RF/Microwave characterization of CNT yarns will open new dimensions for their usage in nanoantennas and nanoelectronics applications

• CNT based antennas for on-body communications will be compact, light weight, flexible and will have better performance characteristics

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References [1] C. A. Balanis, Antenna Theory: Analysis and Design: John Wiley, 2005.

[2] Z. Yijun, Y. Bayram, D. Feng, D. Liming, and J. L. Volakis, "Polymer-Carbon Nanotube Sheets for Conformal Load Bearing Antennas," Antennas and Propagation, IEEE Transactions on, vol. 58, pp. 2169-2175, 2010.

[3] A. Mehdipour, I. D. Rosca, A. R. Sebak, C. W. Trueman, and S. V. Hoa, "Full-Composite Fractal Antenna Using Carbon Nanotubes for Multiband Wireless Applications," Antennas and Wireless Propagation Letters, IEEE, vol. 9, pp. 891-894, 2010.

[4] A. Mehdipour, I. D. Rosca, A. R. Sebak, C. W. Trueman, and S. V. Hoa, "Carbon Nanotube Composites for Wideband Millimeter-Wave Antenna Applications," Antennas and Propagation, IEEE Transactions on, vol. 59, pp. 3572-3578, 2011.

[5] P. S. Hall and Y. Hao, Antennas and propagation for body-centric wireless communications: Artech House, 2006.

[6] A. Brizzi, A. Pellegrini, and Y. Hao, "Design of a cylindrical resonant cavity antenna for BAN applications at V band," in Antenna Technology (iWAT), 2012 IEEE International Workshop on, 2012, pp. 152-155.

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