文献简单介绍了超宽带技术和超宽带天线的发展趋势，为了满足这种发展趋势，对超宽带天线性能的要求有了进一步的提高，从而引出了用特征模理论来研究设计超宽带天线的需求价值。-This paper simply introduces that, in the light of the development of the UWB technology and UWB antennas, the standard of UWB antennas performance has been improved g