Time domain versus frequency domain in ultra wideband

When during the last years the regulating authorities worldwide made an ultra wide spectrum license free available for indoor applications, the only limitation was the spectral power density, limited at -41.3 dBm/MHz, R&D activities almost exploded everywhere. Two scientist fractions grew up, the time domain and the frequency domain enthusiasts. Each one claims up to now to be working and fighting for the better usage and options. In this paper the advantages and drawbacks of each technology are examined and compared in the RF domain, i.e. antennas, radiation and propagation channels. For the argumentation typical applications are cited, e.g. communications, radar and sensors. The outcome of this comparison is quite simple; each technology has its favorite applications, where it is more advantageous than the other one.