臺灣博碩士論文加值系統

本研究提出一個簡單的理論模型，來分析共面波導至槽線之Ｔ型接合。首
先由槽線傳播模態為準橫向電磁波的假設，可將原來包含介質基板的不均
勻結構，簡化為均勻介質的等效問題。其次將共面波導中心導體上的電流
，視為槽線的饋入電流，可列出電流處磁場的積分方程。最後使用海倫氏
法求解開槽上的電場分佈，並且由傳輸功率的定義，則得到共面波導的輸
入阻抗。本研究將求出槽線接負載後，共面波導端的反射損，此模型結果
與實驗結果相比，充份驗證此理論模型的可靠性。另外由研究結果顯示，
僅考慮兩種傳輸線的特徵阻抗，不足以描述Ｔ型接合的散射現象，必須要
考慮接合處的不連續效應，才能充分了解Ｔ型接合的各種特性。

A simple model is proposed for an analysis of the coplanar
waveguide to slotline T-junction. By the quasi-TEM assumption,
the original inhomogeneous slotline structure containing the
dielectric substrate can be replaced by an equivalent
homogeneous one. By regarding the strip current of the coplanar
waveguide as the fed current of the slotline, one may obtain
the governing integral equation for the aperture field over the
slot region of slotline. The Hallen's method is then be used to
determine the electric field distribution along the slotline
from which the input impedance to the T-junction is
established. This study carefully examines the return loss to
the T-junction where the sloline is terminated by a load
impedance. Good agreement between the experiment and the
simulation results is observed and ensures the reliability of
the model. In this study, the discontinuity effect of the T-
junction is investigated theorectically and experimentally.