This paper presents a theoretical approach to compare the performance of a directive and a quasi-omnidirectional on-body antennas.Two canonical antennas, namely, a dipole and a rectangular aperture, are considered in the 60 GHz band. We first demonstrate that for this on-body configuration, the classically-defined far-field antenna gain depends on the observation distance. Consequently, we derive results in terms of radiation efficiency and link budget. To do so, the antenna input impedance computation is a preliminary step to normalize the input power to allow a fair comparison between the two antennas. The impedance over a lossy half-plane of an aperture illuminated by a TE10 mode normally polarized is therefore derived into a convenient easy-to-compute formulation, which to authors' best knowledge, is not available in the literature. In terms of link budget, it is obtained that the received power due to an aperture is generally higher than the one due to the dipole in the main lobe direction. A constant difference is observed along the distance, and this difference increases with the aperture width for antennas touching the body. Besides, it is shown that the standard aperture waveguide WR15 exhibits a slightly higher efficiency than a vertical dipole with the same vertical size when being placed at a distance less than 3 mm (i.e., 0.6λ) from the body phantom surface. Above this distance, the dipole and the aperture exhibit similar efficiency in the order of 60%.
2. Yuce, M. R. and J. Khan, Wireless Body Area Networks: Technology, Implementation, and Applications, CRC Press, 2011.
3. Li, H.-B. and K. Y. Yazdandoost, Wireless Body Area Network, River Publishers, 2010.
4. Zhu, N., "Simulation and optimization of energy consumption on wireless sensor networks," Journal of the Institute of Polytechnics Osaka City University, Ser. A Mathematics, Ecole Centrale de Lyon, 2013.
5. Aoyagi, T., M. Kim, and J. Takada, "Characterization for a electrically small antenna in proximity to human body --- Towards Antenna de-embedding in body area network channel modeling," 7th European Conference on Antennas and Propagation, 3421-3422, 2013.
6. Grimm, M. and D. Manteuffel, "On-Body antenna parameters," IEEE Trans. Antennas Propag., Vol. 63, No. 12, 5812-5821, 2015.
7. Naganawa, J., J. Takada, T. Aoyagi, and M. Kim, "Antenna deembedding in WBAN channel modeling using spherical wave functions," IEEE Trans. Antennas Propag., Vol. 65, No. 3, 1289-1300, 2017.
8. Boyes, S. J., P. J. Soh, Y. Huang, G. A. E. Vandenbosch, and N. Khiabani, "On-body performance of dual-band textile antennas," IET Microwaves, Antennas Propag., Vol. 6, No. 15, 1696-1703, 2012.
9. Giddens, H., D. L. Paul, G. S. Hilton, and J. P. McGeehan, "Influence of body proximity on the efficiency of a wearable textile patch antenna," 6th European Conference on Antennas and Propagation (EuCAP), 1353-1357, 2012.
10. Klemm, M., I. Z. Kovacs, G. F. Pedersen, and G. Troster, "Comparison of directional and omni-directional UWB antennas for Wireless Body Area Network applications," 18th Internaitonal Conference on Applied Electromagnetics and Communications (ICECom), 1-4, 2005.
11. Sarrazin, J., et al., "Antenna radiation efficiency considerations in body area networks," 11th EAI International Conference on Body Area Networks, ICST (Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering), 10-11, 2016.
12. Razafimahatratra, S., J. Sarrazin, A. Benlarbi-delai, and P. De Doncker, "Horn antenna design for BAN millimeter wave on-body communication," IEEE APS, 204.2, 2014.
13. Chahat, N, G. Valerio, M. Zhadobov, and R. Sauleau, "On-body propagation at 60 GHz," IEEE Trans. Antennas Propag., Vol. 61, No. 4, 1876-1888, 2013.
14. Alipour, S., F. Parvaresh, H. Ghajari, and F. K. Donald, "Propagation characteristics for a 60 GHz Wireless Body Area Network (WBAN)," Military Communications Conference, 719-723, 2010.
15. Petrillo, L., T. Mavridis, J. Sarrazin, A. Benlarbi-Delai, and P. De Doncker, "Statistical on-body measurement results at 60 GHz," IEEE Trans. Antennas Propag., Vol. 63, No. 1, 400-403, 2015.
16. Shubair, R. M. and Y. L. Chow, "A closed-form solution of vertical dipole antennas above a dielectric halfspace," IEEE Trans. Antennas Propag., Vol. 41, No. 12, 1737-1741, 1993.
17. Hasgall, P. A., E. Neufeld, M. C. Gosselin, A. Klingenbock, and N. Kuster, "TIS database for thermal and electromagnetic, parameters of biological tissues,", Version 2.6, 2015, [Online], Available: www.itis.ethz.ch/database.
18. Balanis, C. A., Antenna Theory: Analysis and Design, 3rd Ed., John Wiley and Sons, 2005.
19. Grimm, M. and D. Manteuffel, "Norton surface waves in the scope of body area networks," IEEE Trans. Antennas Propag., Vol. 62, No. 5, 2616-2623, 2014.
20. King, R. W. P., G. J. Fikioris, and R. B. Mack, Cylindrical Antennas and Arrays, Cambridge University Press, 2002.
21. Lea, A., P. Hui, J. Ollikainen, and R. G. Vaughan, "Propagation between on-body antennas," IEEE Trans. Antennas Propag., Vol. 57, No. 11, 3619-3627, 2009.
22. Alexander, H. and D. L. Miller, "Determining skin thickness with pulsed ultra sound," Journal of Investigative Dermatology, Vol. 72, No. 1, 17-19, 1979.
23. Marks, R., P. J. Dykes, and E. Roberts, "The measurement of corticosteroid induced dermal atrophy by a radiological method," Archives of Dermatological Research, Vol. 253, No. 2, 93-96, Sep. 1975.
24. Shelkunoff, H. T. and S. A. Friis, Antennas: Theory and Practice, Wiley, New York, 1952.
25. Compton, R. T., "The admittance of aperture antennas radiating into lossy media,", Antenna Lab., The Ohio State University Research Foundation, Columbus, Rept. 1691-5, Mar. 15, 1964.
26. Yang, J. J., Y. L. Chow, and D. G. Fang, "Discrete complex images of a three-dimensional dipole above and within a lossy ground," IEE Proc. H (Microwaves, Antennas Propagation), IET Digit. Libr., Vol. 138, No. 4, 319-326, 1991.
27. Xu, X. and Y. F. Huang, "An efficient analysis of vertical dipole antennas above a lossy half-space," Progress In Electromagnetics Research, Vol. 74, 353-377, 2007.
28. Khalatpour, A., R. Sarraf Shirazi, and G. Moradi, "Analysis of vertical wire antennas above lossy half-space using matrix pencil method," AEU --- Int. J. Electron. Commun., Vol. 64, No. 8, 784-789, 2010.
29. Shubair, R. M. and Y. L. Chow, "A simple and accurate complex image interpretation of vertical antennas present in contiguous dielectric half-spaces," IEEE Trans. Antennas Propag., Vol. 41, No. 6, 1993.
30. Michalski, K. A. and J. R. Mosig, "The Sommerfeld half-space problem revisited: From radio frequencies and Zenneck waves to visible light and Fano modes," Journal of Electromagnetic Waves and Applications, Vol. 30, No. 1, 1-42, 2016.
31. Felsen, L. and N. Marcuvitz, Radiation and Scattering of Waves, Prentice-Hall, 1973.
32. Ur-Rehman, M., N. A. Malik, X. Yang, Q. H. Abbasi, Z. Zhang, and N. Zhao, "A low profile antenna for millimeter-wave body-centric applications," IEEE Trans. Antennas Propag., Vol. PP, No. 99, 1-1, 2017.
33. Puskely, J., M. Pokorny, J. Lacik, and Z. Raida, "Antenna implementable into button for on-body communications at 61 GHz," 8th European Conference on Antennas and Propagation (EuCAP), 1551-1555, 2014.