利用耦合矩陣合成法設計之廣義柴比雪夫型帶通濾波器

Abstract

本篇論文主要是使用耦合矩陣合成法，將具有濾波響應的廣義柴比雪夫多項式進而合成所需的耦合矩陣，再藉由耦合共振器濾波器來實現帶通濾波響應。N階柴比雪夫多項式除了在通帶內是等連波響應外，可以透過預先置入最多N-2個傳輸零點的方式，增加通帶兩側的選擇度或是通帶內的相位線性度。本文中設計三個四階濾波器與一個六階濾波器，分別具有不同數目的傳輸零點，再透過量測結果驗證設計方法的正確性。此外並提出一種用來設計具有不對稱響應之四階濾波器的方法，利用三層板結構與孔隙耦合，可以實現所需要的響應。

In this thesis, the general coupling matrix synthesis methods are employed to synthesize the required coupling matrix for the specified Chebyshev filtering functions. In addition to have equal-ripple response in the passband, N-degree Chebyshev functions can have at most N-2 prescribed transmission zeros to improve the selectivity or group delay. Three fourth-order filters and one sixth-order filter, which have various transmission zeros, are designed and fabricated, and the measurement results are also included for verifying the accuracy of the synthesis method. Moreover, a design procedure for the fourth-pole filter with asymmetric filtering response is presented, in which multilayer configuration and aperture-coupled coupling are utilized to realize the filter response.