本論文提出使用散佈式耦合饋入技術以及步階式阻抗共振器(stepped-impedance resonator, SIR)的多頻帶通濾波器，由於散佈式耦合饋入技術的低負載效應，因此不需要額外的阻抗匹配電路。而步階式阻抗共振器具有縮小電路面積的功能，以及控制高頻諧波的位置。此兩種技術皆適合應用於設計多頻帶通濾波器。
利用上述架構，在步階式阻抗共振器加上變容二極體，來達到具有可調整中心頻率之特性，且在通帶內頻率響應特性不變。每個通帶的共振路徑皆為獨立的，所以各個通帶皆能獨立設計和調整其中心頻率，故在電路設計上具有良好的自由度。於本論文中有多頻帶通濾波器以及可調式多頻帶通濾波器的設計原理、模擬結果與實作結果，最後利用實作之電路來驗證設計的方法是有效的。

This thesis presents multi-band bandpass filter and tunable multi-band bandpass filter using distributed coupling technique and stepped-impedance resonator. Due to the low loading effect from distributed coupling technique, the proposed circuits does not need extra matching network. The stepped-impedance resonator can reduce the circuit size and control the harmonic. Both technologies are suitable for designing multi-band bandpass filter.
Based on this structure, varactors are added to the SIR. For achieving the center frequency can be tuned, and the performance in the passband is invariant. Because the coupling path of each passband is independent, each passband can be fully controlled and designed independently. Therefore, the circuit design has high design freedom. All of the designs, simulations, and measurements are presented and discussed in this thesis. Finally, good agreement is also achieved between simulation and measurement.

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