臺灣博碩士論文加值系統

本論文以修正型邊界元素法( modified boundary ele- ment method )對
微帶藕合線 ( microstrip coupled lines )做準橫向電磁波模態分析 (
quasi-TEM analysis ), 此分析結供前向 ( forward ), 後向(
backward )藕合器設計之用o 再利用藕合模態公式, 將其視為四個埠 (
ports )的方向藕合電路, 即可獲得電路參數o基於非對稱藕合器 (
asymmetric coupler ) 之電感 ,電容藕合係數( coupling
coefficients ) 是決定藕合器指向性 ( directivity )的兩個重要參
數, 本論文提出一種新的架構以提高指向性, 其外圍封閉高度是介質厚度
的兩倍 ,只要它的四個輸出埠均匹配, 則可達到理想後向藕合器的效果o

A modified boundary element method in the application of quasi-
TEM analysis of microstrip coupled lines is The analytic
results are then used to design the forward and backward
directional coupler. Applying the coupled-mode lation of
microstrip coupled lines, the directional coupler be treated as
a four port network and the circuit parameters can easily be
obtained. In this thesis, investigation is mainly made on the
asymmetric coupled microstrip lines. The mutual inductance
capacitance coupling coefficients are the two main parameters
which determine the directivity of the coupler. Through our
study, a new structure is presented with an aim to provide
directivity. The structure is referred to an enclosed one,
height of the enclosure is equal to twice the dielectric ness.
It is investigated that this structure can compose an backward-
coupling directional coupler so long as all four are well
matched (characteristically terminated).