中文摘要：

套筒天线的发现一定程度上拓展了线天线的带宽，但是传统的套筒天线在VSWR〈8的条件下带宽只有4：1。文献提出了一种新型的宽带套筒天线，在VSWR〈1．5的情况下可以达到1．81：1的阻抗带宽。本文对这种新型宽带套筒天线中特殊的结构进行讨论，主要讨论端部加载对该新型天线S11的影响，经研究发现端部加载可以很大程度上拓展天线带宽，在同样尺寸的情况下将传统套筒天线的阻抗带宽（VSWR〈1．5）由1．03：1拓展到1．81：1，即带宽拓展了75．7％。在s11〈-10dB的条件下由1．09：1拓展到2．05：1，即带宽拓宽了88．1％，在天线没有小型化处理时可以拓展N3．81：1。因此这为天线阻抗的良好匹配提供一种新的方法，同时也很好的弥补了传统套筒天线结构上不连续的不足。

英文摘要：

The invention of sleeve antenna expands the bandwidth of wire antenna to some extent, but the bandwidth of traditional sleeve antenna can only reach 4：1 on the condition of VSWR〈8. Literature proposed a new type of sleeve antenna, whose impedance bandwidth can reach up to 1.81：1 on the condition of VSWR〈1.5. This paper discusses the structure of this special antenna and mainly focuses on the impact of end-loading on the antenna＇s S 11. Some research reveals that the end-loading can notably expand the bandwidth of antenna. With the similar size, this new broadband sleeve antenna can expand the bandwidth of traditional sleeve antenna from 1.03：1 to 1.81：l（at VSWR〈I.5）, which means an expansion of 75.7% in bandwidth. And on the condition of Sll〈-10dB, the expansion from 1.09：1 to 2.05：1 is achieved, i.e. an improvement of 88.1%, and on the condition of antenna not being miniature processed the bandwidth can be expanded up to 3.81：1. Thus it provides a new method to improve antenna＇s impedance matching characteristics and broaden antenna＇s impedance bandwidth. This new structure also compensate for the deficiency of the traditional sleeve antenna＇s discontinuity in structure.