Search

The theory of propagating waves near a surface is reviewed with an eye to gain insight into the mechanisms involved, and to provide analytical-based models, for power-efficient on-body propagation. The Zenneck wave, and in particular the Norton wave, are appraised as candidate mechanisms for the propagation. For flush-mounted ("band aid") antennas, desired for on-body sensors, the Norton wave is the only direct propagation mechanism between the sensors. The Norton wave fits very well to simulation results presented here, and comparisons are also made with available published physical experiments, although these measurements typically feature the optical paths of elevated, or non-flush, antennas. [ABSTRACT FROM AUTHOR]

This paper considers the propagation model in which the amplitude of the direct wave is kept constant and that of the indirect wave exhibits Rayleigh fluctuations in the line-of-sight and non-line-of-sight channels. The instantaneous received signal level distribution is examined by computer simulation and a fading simululator, with the equivalent received bandwidth (product of received bandwidth 2Δf and maximum path length difference ΔLmax) as the propagation parameter. It is seen that the equivalent received bandwidth is suited as a parameter to represent the instantaneous received signal level distribution. The instantaneous received signal level distributions derived by the computer simulation and the fading simulator agree well. Conventional narrow-band transmission corresponds to the case in which 2ΔfΔLmax is less than 10 MHz-m. Then, the fading depth is determined by the power ratio a between the direct wave and the indirect wave. Wide-band transmission corresponds to the case in which 2ΔfΔLmax is larger than 10-MHz-m. Then, the fading depth is determined by a and 2ΔfΔLmax, becoming less when those quantities are increased. When 2ΔfΔLmax is very large, the fading depth also depends on the number of arriving waves. These properties are derived theoretically and are verified by the simulation and the fading simulator. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(2): 94–105, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1157 [ABSTRACT FROM AUTHOR]

Examines the influence of a diffraction coefficient and building corner shape on predicting the propagation of radio waves in urban environments. Formulation of the diffraction coefficient; Information on a vertical plane launch ray tracing algorithm used in predicting the propagation; Description of a wide-band measurement system.