摘要
因為FCC開放超寬頻技術於民生商品，所以超寬頻相關的技術被立即注意，當然也包括超寬頻天線。超寬頻天線要包含的頻段為3.1GHz~10.6GHz，場形要盡量全向性的場形，而增益最好超過0dBi以上。如果實驗環境許可，功率頻譜的限制與脈衝信號的失真也是超寬頻天線需要量測的重點。 在超寬頻天線的文獻中，環形天線的資料非常少，本論文參考的超寬頻環形天線在特性的表現還不錯，加上其資料和數據上的完整，因此大大的增加了該天線的實用性。但該天線的尺寸似乎過大，所以進行縮小化該天線元件做為本論文的第一支天線，並從而了解其寬頻特性的工作原理。經由實驗與電磁模擬結果可知，該天線是結合漸進式槽孔天線與環形天線的工作原理來達到寬頻。因此，第二支天線就利用了此概念，將半環形天線結合漸進式槽孔天線，並利用接地面來增加諧振頻寬與平衡場型之對稱。由實驗與模擬結果顯示，確可達到超寬頻的效果，而場形也可接受。在天線增益方面，第一支縮小化的天線比原型天線約少1dBi，增益變動範圍從2到6dBi，而第二支半環形天線增益變動範圍約從2到8dBi，變動幅度較大。
並列摘要
Because FCC unfastened UWB technology in commodities, the UWB relating technologies were noticed immediately, certainly including UWB antenna. The band of UWB antenna include 3.1GHz~10.6GHz, the radiation patterns must be omni-directional, and the gains must be better than 0dbi. If the influence of environment is acceptable, the limit of power spectrum and the distortion of impulse signals are also measurement point. The papers and investigations of UWB about loop antenna are few, this thesis utilizes UWB loop antenna with good characteristics, and the document and data are adequate, so enhancing the implement. However, this antenna’s dimension is quite large, so this thesis bases this antenna to reduce its dimension, further, comprehending the theory of broadband characteristic. Through experiment and electromagnetics it is observed that this antenna mixes taper antenna and loop antenna to attain broadband. Furthermore, antenna two utilizes this concept, using half-loop antenna to combine a taper antenna and ground plane to increase bandwidth and symmetric radiation pattern. Experiment and simulation show that this method can obtain UWB operation and the radiation patterns are acceptable. In antenna gain, first miniature antenna is less 1dBi than original antenna.