An evaluation method of the interference of ultrawideband signals to out-of-band systems

A method is proposed to evaluate the interference of ultrawideband (UWB) signals to other systems outside its frequency band, by introducing two critical parameters Wob and Pob. These two parameters represent the total bandwidth and total power of the UWB signal to be evaluated exceeding the frequency mask, respectively. Wob is the bandwidth out of the frequency mask limit and Pob is the signal power exceeding the frequency mask. At last, the derivatives of the Gaussian pulse are evaluated up to third order, i.e. monocycle, doublet and triplet, when the original Gaussian pulse width varies from 60 to 350 ps. The results show that the interference introduced to outside band by the UWB signal decreases at first and then increases and finally decreases again, when the original Gaussian pulse width increases. To evaluate an optical UWB signal, this evaluation method should be applied after a simple photoelectric conversion.