Performance evaluation of Ultra Wideband printed antenna by system characterization

A lot of Ultra Wideband (UWB) antenna designs, especially printed antenna, have been proposed so far. However, among those proposed designs, only single unit antenna analysis i.e. return loss and radiation pattern at particular frequencies are usually observed. This paper reports a deeper transmission analysis by considering UWB antenna as a system; so called system characterization. For a specific case, a pair of UWB printed monopole antenna with known single unit antenna performance was used for this study. Two-identical-antenna system was measured with Vector Network Analyzer (VNA), then its system transfer function, group delay, and waveform distortion are investigated. The results show that even the single unit antenna performance looks good enough but not so that well when the antenna is considered as a system. Nonlinear transfer function and group delay at some frequency ranges inflicts distortion in the waveform transmission which is crucial for UWB impulse radio scheme. Antenna performance evaluation in this study is provided in the term of its distortion by showing pattern of correlation between the transmitted and the received waveform.