兩種微小化雙模雙頻環形共振器

Abstract

本論文提出兩種微小化雙模雙頻環型共振器濾波器的設計。第一種設計使用單一週期性步階阻抗環型共振器實現雙模雙頻濾波器。利用傳輸線理論，將輸出輸入端埠以不同的饋入角度畫出對應的傳輸零點與共振極點位置，稱之為傳輸零點圖。實際設計電路時，可以根據本圖很容易選擇饋入角度，得到通帶兩側均具有傳輸零點之準橢圓函數的雙模雙頻響應。這一部分，本文有四個實作雙模雙頻濾波器，電路的面積僅佔傳統環型電路的60%。 論文的第二部分利用串接許多微波C型段組成微小化雙模雙頻環型濾波器，每一微波C段均可等效為一段電氣長度給定的傳輸線，再經由選擇適當的饋入角度，則也可以達到準橢圓函數響應。本文分別使用四段C型段與六段C型段實做出環型共振器濾波器，其面積皆可以小於傳統環型電路的30%。量測數據與模擬結果相當一致。

The thesis presents two designs of miniaturized dual-mode dual-band ring resonator bandpass filter. The first design uses a single periodic stepped-impedance ring resonator. Based on the transmission line theory, a pole-zero design graph consisting of the transmission zeros together with the resonant frequencies of the resonator is plotted against the space separation angle between the input and output ports. Based on this graph, the space angle can be determined for the dual-mode dual-band design with designated zeros near the two passbands. Four dual-mode dual-band bandpass filters are realized for demonstration. All circuits occupy about 60% of the area of the conventional ring resonator at the first passband frequency. In the second part of this thesis, the ring resonator is implemented by a cascade of several microwave C-sections. Each C-section is used to substitute a transmission line section of designated electrical length. Through proper design of input/output coupling configuration, two transmission zeros can also be created on both sides of each passband. Two circuits with four and six microwave C-sections are fabricated for demonstration. They occupy less than 30% of the area of a traditional ring resonator filter. Measured results agree very well with their simulation counterparts.