Free space link budget estimation scheme for ultra wideband impulse radio with imperfect antennas

The ultra wideband (UWB) radio has been a promising technology for the short range wireless systems. The frequencydependent behavior of the antennas are not negligible in UWB systems, especially in the impulse radio (IR). This letter presents the extension of the Friis’ transmission formula for the link budget estimation of UWB radio, considering the transmit signal waveform and the imperfect antennas. The results presented here give the upper bound of the transmission gain, irrespective of the waveform distortion due to the frequency response of the antenna.