BENDING STUDY OF MULTIBAND FRACTAL ANTENNA

PRESENTED BY – MURSHED ALI NASKAR – 15MCE0026 DEBAYAN DAS – 15MCE0025

GUIDED BY -PROF. POONKUZHALI R.

SET ID – 11SETMCE0948

The study proposes a flexible wideband wearable antenna for military applications. A Sierpenski Carpet Fractal antenna is designed and simulated with a flexible common jeans cotton for body centric application. For size reduction and multiband operation, the self-similarity property of fractal antenna has been utilized. The antenna performance has been analyzed for various bending conditions.

ABSTRACT

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FRACTAL ANTENNA

Fractal antennas are antennas that have the shape of fractal structures. The fractal antennas consist of geometrical shapes that are repeated. Each one of the shapes has unique attributes. By careful selection, a number of these fractal shaped antennas can be valuable in the field of telecommunications.

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SIERPENSKI CARPETDesign steps: 1. Design of a rectangular/square patch.2. Subdivision of patch into nine smaller congruent squares. 3. Etching process to remove the central square to obtain the first iteration.

This process can be continued infinitely to obtain the multiband.

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DESIGN PARAMETERS

Design Operating Frequency – 524 MHz Substrate Material – Common Jeans Cotton Dielectric Constant – 1.6 Substrate thickness – 3 mm Patch Material – Copper Patch thickness – 0.05 mm

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RECTANGULAR PATCHW=162 mm

L=146 mm

78 mm

352 mm

390 mm

380 mm

80 mm

12 mm

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RESULT OF THE RECTANGULAR PATCH

286 MHz

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1ST ITERATED ANTENNA

54 mm

49 mm

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REFLECTION COEFFICIENT PLOT 1ST ITERATED ANTENNA

532.7 MHz

789 MHz

Front View Back View

19 mm

16 mm

2ND ITERATED ANTENNA

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RESULT OF THE FINAL DESIGN

329.28 MHz 421 MHz 613.7 MHz 497.6 MHz

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(a) At 0.5199 GHz (b) At 2.5 GHz

(c) At 4.266 GHz (d) At 5.9626 GHz

RADIATION PATTERNS OF THE 2ND ITERATED ANTENNA

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(a) Bending radius of 70 mm (b) Bending radius of 80 mm

(c) Bending radius of 150 mm

BENT ANTENNA FOR DIFFERENT RADIUS

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FOR BENDING RADIUS OF 70 MM

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FOR BENDING RADIUS OF 80 MM

524.58 MHz 610.3 MHz 484.6 MHz 394.9 MHz

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(a) 0.495 GHz (b) 2.45 GHz

(c) 4.266 GHz (d) 5.99 GHz

RADIATION PATTERNS FOR 80 MM BENDING

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FOR BENDING RADIUS OF 150 MM

706 MHz

772 MHz 732 MHz

573.2 MHz

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RADIATION PATTERNS FOR 150 MM BENDING

(a) 1.82 GHz (b) 3.36 GHz

(c) 4.93 GHz (d) 6.44 GHz

CONCLUSION

We have designed a Sierpenski Carpet fractal antenna for UHF and VHF band. As this is designed for wearable application, we have studied the performance of our designed antenna under bending conditions. From the obtained result, we conclude if the bending radius is less the antenna doesn’t shows impressive result. But it shows good result as the bending radius increases. So this antenna can be wore only in the body parts where radius is more like legs or back or front of the body.

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[1’Design of Sierpenski Carpet Fractal Antenna For Body Worn Applications.’R Poonkuzhali, D. Thiripurasundari, S. Sameer, Z.C. Alex,VIT University, India, INTERNATIONAL JOURNAL OF MICROWAVE AND OPTICAL TECHNOLOGY,VOL.10, NO.1, JANUARY 2015

[2] P. S. Hall and Y. Hao, Antennas and Propagation for Body Centric Communications Systems. Norwood, MA, USA: Artech House, 2006, ISBN-10: 1-58053-493-7.

[3] C. Hertleer, A. Tronquo, H. Rogier, L. Vallozzi, and L. Van Langenhove, “Aperture-coupled patch antenna for integration into wearable textile systems,” IEEE Antennas Wireless Propag. Lett, vol. 6, pp. 392–395, 2007.

[4] D.H. Werner, “An Overview of Fractal Electrodynamics Research”, Proceedings of the 11th Annual Review of Progress in Applied Computational Electromagnetics (ACES), vol.2, pp.964-969, 1955

REFERENCES

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