非均勻耦合微帶線之設計與合成

Abstract

在本論文中,我們提出了一個設計與合成非均勻雙重或三重耦合微帶 線的方法,此方法是源自一用於單一非均勻微帶線的電子長度匹配程序.因 為我們所考慮的系統性能是散射參數S11的頻寬和漣波波峰,所以柴比雪夫 響應被用作為設計時的初始響應.利用非均勻雙重或三重耦合微帶線的電 子匹配程序,可合成出較小的反射係數.反射係數的漣波波峰降低和頻寬增 加是不可能同時達成的,因此二者之間必然要有折衷存在.設計者可依據系 統的需求調整參數如各模態下的漣波波峰和截止角頻率使系統的性能達到 預期的要求. In the thesis, we present a method for the design and synthesis of double and triple coupled nonuniform microstrip lines. The method is originated from an electrical lengthmatched procedure for single nonuniform microstrip line. The system performances we considered are bandwidth and ripple peak of scattering parameter S11, so the Tchebtcheffresponse is adopted as the initial response for our design. Using the electrical lengthmatched procedure double or triple coupled nonuniform microstrip lines with smaller reflection can be synthesized. The reduction of ripple peak and the increase of bandwidthare impossible to obtain at the mean time and there must be a tradeoff between them.According to the system demands, the designer may adjust the parameters such as tolerable reflection coefficient and cutoff angular frequency for each mode so that desired performance can be achieved.