ULTRAWIDEBAND PULSE PENETRATION IN A DEBYE MEDIUM WITHSTATIC CONDUCTIVITY

摘要

The high frequency, low power characteristics of ultra-wideband/short-pulse signals exhibit uniquely promisingfeatures with applications to remote sensing of terrestrialobjects from satellites, foliage-penetrating radar, as wellas the study of biological tissue exposed to ultrawidebandpulses. Indeed, previous studies of ultrawideband elec-tromagnetic pulse propagation through dispersive, noncon-ducting media has shown the existence of a so-called Bril-louin precursor whose peak amplitude only decays alge-braically with propagation distance. However, materialssuch as the ionosphere, foliage and biological tissue ex-hibit conductivity. In this paper, we show that a Debye-model material with static conductivity does indeed supporta Brillouin precursor, but that this precursor now attenu-ates exponentially with propagation distance and not justalgebraically. Nevertheless, we show that it is still advan-tageous to track the Brillouin precursor in remote sensingapplications because its attenuation is less than the attenu-ation of the main signal.