隨著無線通訊應用的快速發展，尤其是近幾年來，無線區域網路系統(wireless local area network ,WLAN)的快速擴展，具有多頻段應用的濾波器已經是微波電路和毫米波電路的基本元件。因此本論文提出利用微帶線使用殘段負載共振器、靴型線以及來源負載耦合饋入的方式來達到雙頻帶通濾波器。
在所提出的濾波器架構中，在第一頻段設計上有250MHz的頻寬與良好的選擇性，而第二頻段則是有較寬的頻寬可以滿足5.15GHz到5.85GHz的頻段需求以及較低的插入損失(S21)。藉由適當的調整饋入線和殘段負載共振器的間距，可以達到在低頻帶有好的反射損失(S11)。為了更進一步改善第一頻段和第二頻段之間的隔離度，在饋入線的地方蝕刻一段靴型線，可在4.3GHz產生零點而有帶拒的效果。
根據所提出的殘段負載共振器，雙頻帶通濾波器有三個零點。而高頻止帶可以一直延伸到10.75GHz都有好的抑制效果，可達到-20dB以下。

The rapid development for the wireless communication applications is happening in the multiple bands and filters are fundamental components extensively used in microwave and millimeter-wave circuits. Recently, the use of wireless local area network (WLAN) systems has expanded rapidly, demanding more multiband applications.
In this thesis, a microstrip-line dual-band bandpass filter using stub-loaded resonator (SLR) is proposed. The device has good selectivity in first pass band and wide bandwidth in second pass band. By properly adjusting the gap between source-load and SLR, good return loss at lower frequencies can be achieved.
To further improve the rejection level between the first pass band and second pass band, the spur-line is etched in the coupled feeding line to produce another transmission zero at 4.3 GHz.
Based on the proposed SLR, a dual-band bandpass filter with three transmission zeros is implemented. The upper stopband extends to 10.75 GHz to have good suppression below -20dB.

論文審定書 i
誌　謝 ii
摘　要 iii
Abstract iv
第一章 序論 1
1.1研究背景與動機 1
1.2研究方法與目的 2
1.3 濾波器規格 2
1.4 章節介紹 3
第二章 步階阻抗共振器和殘段負載共振器介紹及比較 4
2.1 步階阻抗共振器(Stepped Impedance Resonator) 4
2.2 殘段負載共振器(Stub-Loaded Resonator) 9
2.3 SIR和SLR之優缺點比較 12
第三章 雙頻帶通濾波器設計與模擬結果 13
3.1 耦合式共振器介紹 13
3.1-1 電耦合(電容耦合) 13
3.1-2 磁耦合(電感耦合) 15
3.1-3 電磁耦合(混合式耦合) 16
3.2 濾波器之電路架構 18
3.3 EM模擬結果 22
3.4 雙頻段間的止帶特性探討 28
3.5 其他效應的研究 30
第四章 實作與測量 36
4.1.1 量測結果 36
4.1.2 模擬和實測數據不相同之可能因素探討 38
4.2 特性比較 39
第五章 結論 40
參考文獻 41

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