ABSTRACT
What distinguishes UWB? Its spectral density, the power emitted into any narrow-frequency interval, is very low. Figure 6.1 shows typical spectral magnitudes of electric fields, or E-fields, over a wide range of frequency. (This is a
frequency-domain
plot, as distinct from the better-known
time-domain
plot, which shows amplitude vs. time.) It gives perspective on the relation between the regions of HPM: the lower-frequency continuous spectra from natural lightning and high-altitude electromagnetic pulse (HEMP) together with higher-frequency narrowband HPM, including wideband spectra, the so-called ultrawideband.
