利用基板合成波導共振腔設計帶通濾波器

Abstract

在本篇論文中，我們提出具有高選擇性之基板合成波導帶通濾波器。此種帶通濾波器是利用基板合成波導共振腔所形成，藉由等效封閉矩形波導和經驗公式，我們可轉換為基板合成波導尺寸。與傳統共振濾波器相比，新的濾波器提供較寬的截止帶，且值得注意的是，只要適當橫向位移共振腔或輸入輸出端和共振腔相差一個角度，就可達到抑制效果。在這裡我們使用CST電磁模擬軟體分析結構的不連續邊界值電磁問題，也有實際製作和量測濾波器的散色參數，由量測和模擬結果相比都非常一致，更可看出新濾波器的特性。

In this thesis, we present a substrate integrated waveguide-based band-pass filter with wide stop-band rejection property. This band-pass filter is made up of substrate integrated waveguide cavities. By using the empirical formula for obtaining the equivalent rectangular waveguide dimensions, the substrate integrated waveguide structure could then be properly approximated by a closed rectangular waveguide. In comparison with the conventional end-to-end coupled cavity filters, we found that our new side-wall-coupled cavity filter can provide a wide rejection band. It is interesting to note that a wide rejection band can be achieved by properly shifting the second cavity in lateral direction. We employed the CST electromagnetic simulation software to analyze the electromagnetic boundary-value problem of the structure containing multiple discontinuities. In addition to the simulation analysis, we have fabricated the filters and measured their scattering parameters. The good agreement between the theoretical and measured results validates the accuracy of numerical computation, and also shows the promising performance of the proposed filters