利用步階阻抗傳輸線段和微帶線至共平面波導寬邊耦合結構設計微小化鼠徑耦合器

Abstract

本論文提出週期性步階阻抗共振腔和微帶線至共平面波導結構設計微小化鼠徑耦合器之設計。週期性步階阻抗共振腔用來代替傳統鼠徑耦合器中的lamda/4傳輸線，以及7lamda/6鼠徑耦合器中的lamda/6傳輸線，微帶線至共平面波導結構用來代替傳統鼠徑耦合器的3lamda/4傳輸線。本論文中設計的微小化電路都沒有使用集總元件，其中最小的鼠徑耦合器電路只使用傳統鼠徑耦合器18.3%的面積，與已公開的發表文獻比較，這電路擁有最好的面積縮小效果，並且在設計頻率的功率損耗少於3.2%。在實做電路量測結果與模擬結果比較，證實所設計的電路是正確的。

Miniaturized rat race coupler is implemented by incorporating stepped-impedance line sections and broadside-coupled structure into the ring circuit. The former is for each lamda/4 line in the conventional design and lamda/6 line in the 7lamda/6 design. The latter is used to replace the 3lamda/4-section in the conventional rat race coupler. The miniaturized designs without any lumped-element are presented. One of the experimental circuits occupies only 18.3% of the area of a traditional rat race of 6lamda/4 circumference and total inband power loss of the circuit is better than 3.2%. It is believed that it has the best size reduction in comparison with those in open literature. Measurement results are shown to validate the design and theoretical prediction.