In this paper, a mounting method is proposed for antennas used in ultra wideband (UWB) body area network (BAN) channel sounding, which reduces the antenna’s electromagnetic coupling to the human body. Coupling with the body is shown to distort the free space characteristics of the antenna. An antenna mount modification is proposed to reduce this distortion, and decrease the variation in antenna characteristics when mounted. The antennas reflection coefficient from 4 to 9 GHz is used to assess the coupling of two UWB BAN antennas when they are mounted at different distances from the skin and at several locations on the body. The free space characteristics of the modified antennas are also tested, showing a reduction of up to 4.7 dB of radiated power into the body. The modified antennas are tested in BAN measurement campaigns showing the fading depth and coherency time of the channels.
|COST 2100 TD(10)11048
Additional information: A document presented to the 11th Management Committee Meeting of COST2010 (European Cooperation in the Field of Scientific and Technical Research), held in Aalborg, Denmark, June 2nd - 4th, 2010.
Sponsorship: The authors would like to thank COST2100 for funding a short term scientific mission, and Prof. Reiner Thom¨a, Dr. Rudolf Zetik and Ulrich Schwarz from Ilmenau University of Technology for their help with antenna measurement and channel sounder characterisation. The authors would also like to thank TREL (Toshiba Research Europe Limited) for their funding, support and allowing publication of this work. Funding was also attained from EPSRC (Engineering and physical research council) through the CASE (Cooperative Awards in Science and Engineering) scheme.
- channel measurements
- ultra wideband
- body area network