本論文設計一種新型的漸變槽孔天線元件。首先，本論文針對微帶與slot line的transition結構進行設計，目標包括降低通帶(passband)的最低頻率fL，以及提供維持漸變槽孔天線所需的超寬頻阻抗頻寬；另外，針對天線元件，本論文不只考慮阻抗頻寬，還將考慮頻帶內的增益特性。 有關天線元件的尺寸考量，本論文提出幾種技巧來降低漸變槽孔天線的長度，但仍要能夠滿足低頻fL= 500MHz (或300MHz)要求；技巧之一是使用橢圓形(取代圓形)的slot line cavity，技巧之二是引進多段三次仿樣曲線(cubic spline)來建構漸變的輪廓形狀(tapered profile)。由於漸變輪廓形狀也會影響頻帶內的天線增益，因此，三次仿樣曲線同時也可用來調節通過頻帶內的增益特性。 This thesis conducts a design of an innovative tapered slot antenna element. At first, the transition of microstrip and slot line is designed, of which the goals include reducing the lowest frequency fL of the passband, and provide the required impedance bandwidth for the ultra-wideband slot antenna. In addition, for the antenna element, the thesis not only consider the impedance bandwidth, but also consider the gain characteristic in the passband. As the size of the antenna element is concerned, this thesis utilized several techniques to reduce the length of the tapered slot antenna, but with the requirement of low frequency fL = 500MHz (or 300MHz) being met; One technique is to use the oval slot line cavity, the second is the introduction of cubic splines to construct the tapered profile. Since the tapered profile also affects the antenna gain in the passband, and therefore, cubic splines also be used to adjust the gain characteristic of the passband.
