On-body Antenna Design using Carbon Nanotubes

Transcription

1 On-body Antenna Design using Carbon Nanotubes Presenter: Syed Muzahir Abbas, Ph.D. Student Supervisor: Prof. Karu Esselle Centre for Electromagnetic and Antenna Engineering (CELANE) Department of Engineering 1/28

2 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 2/28

3 Project Overview 3/28

4 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 4/28

5 Antenna Definition Antennas [1] 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, /28

6 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 Graphene Fig. 1: Diamond * Fig. 2: Graphite * * 6/28

7 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 * * 7/28

8 Carbon Nanotube (CNT) -- Continued a c b d Fig. 5: Carbon Nanotubes * * 8/28

9 CNTs in Antenna Applications -- Continued Load Bearing Antenna Applications [2] Polymer-carbon nanotube sheets for conformal load bearing antennas. Presented circuit model to calculate CNT sheet conductivity. Presented fabrication process. Fig. 6: Circuit model for conductivity [2] 9/28

10 CNTs in Antenna Applications -- Continued Conducted mechanical tests for Stress, Strain Bending (a) Fig. 7: (a) Stress (b) Strain (c) Bend [2] (b) Proposed it suitable for conformal load bearing antennas and RF circuits. [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 , (c) 10/28

11 CNTs in Antenna Applications -- Continued Multiband Wireless Applications [3] 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. 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 , /28

12 CNTs in Antenna Applications -- Continued Wideband Millimeter-Wave Antenna Applications [4] Comparison of copper and CNT antennas. Frequency range 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. [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 , (a) (b) Fig. 9: (a) Antenna Design (b) Array [4] 12/28

13 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* * Innovation/Carbon-Nanotubes-2.aspx 13/28

14 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 14/28

15 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 15/28

16 On-body Antenna Design Requirements Frequency Range UWB lower band (3-5 GHz) UWB ( GHz) V-Band (7 GHz around 60 GHz) TABLE: Unlicensed frequency bands around 60 GHz [6]. Country Japan USA Canada Korea Europe Australia Frequency Band (GHz) Antenna Impedance 50 ohm 16/28

17 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 17/28

18 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? 18/28

19 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 19/28

20 Task Plan-First year ( ) Months 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 20/28

21 Task Plan-First year ( ) Task-1, Achieved (March 2012 to date) CNT, CNT yarns, Antennas, On-body communication/antennas, UWB, Human body properties 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 Deliverables Test Structures 21/28

22 Task Plan-Second year ( ) Months Task-5, CNT Measurements Task-6, Antenna Designing Task-7, Antenna Simulations Task-8, Antenna Fabrication Task-9, Antenna Testing Mar May2013 Jun-Aug Sep-Nov Dec Jan-Feb2014 Deliverables Properties of CNT yarns Antenna prototype Publication of results in International conferences/journals 22/28

23 Task Plan-Third year ( ) Months Task-10, Results and Analysis Task-11, Write-up Mar-Apr2014 May Feb2015 Deliverables Publication of results in International conferences/journals Thesis write-up Completion of thesis in 3 years 23/28

24 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 24/28

25 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 25/28

26 References [1] C. A. Balanis, Antenna Theory: Analysis and Design: John Wiley, [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 , [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 , [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 , [5] P. S. Hall and Y. Hao, Antennas and propagation for body-centric wireless communications: Artech House, [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 /28

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