在現代的通訊系統的射頻(Radio Frequency)前端電路中，濾波器佔有一個相當重要的地位，在近年來，無線技術和各式雲端線上服務的蓬勃發展，使得多頻帶通濾波器的發展最為亮眼，不但業界有需求，一方面從電路設計觀點來看，對學術研究也有相當程度挑戰性。

本論文設計應用於無線通訊系統之三頻帶通濾波器，其中一個特色就是第三頻帶和前兩頻帶的頻寬差異極大。整體濾波器架構採用兩組殘段負載共振器(Stub Loaded Resonator)，形成第二頻帶的共振器和殘段負載都嵌入在第一頻帶的共振器內，而達到縮小電路的目的。在決定前兩頻帶的共振頻率之後，經過適當安排可以使電路架構盡可能的變小，再採用T型殘段(T-shaped stub)和L型殘段(L-shaped stub)所產生的偶模態，跟前兩個共振頻率的第一混附波(Spurious response)，合成頻寬極寬的第三頻帶，因為兩個殘段負載都位於半波長共振器(Half-wave Resonator)的中心點，因此在調整第三個頻帶時，前兩頻帶並不會明顯的變化，此種架構會在各個頻帶的兩側，至少有一個傳輸零點(Transmission zero)以增加頻帶的選擇性(Selectivity)。第一個頻帶中心頻率為1.83GHz，插入損失小於0.7dB，反射損失小於21.4dB，1dB比例頻寬4.2%，第二頻帶中心頻率為2.36GHz，插入損失小於1.2dB，反射損失小於16.2dB，1dB比例頻寬2.4%，第三頻帶中心頻率為3.5GHz，插入損失小於0.5dB，反射損失小於15.5dB，1dB比例頻寬18.1%，五個傳輸零點分別在於1.59GHz、2.02GHz、2.3GHz、2.62GHz、4.42GHz，因此，此三頻帶通濾波器有良好的選擇性和頻帶間的隔離度。因為濾波器是全平面的設計，在製造和設計都較容易。最後，在5GHz時有插入損失小於17.6dB，可以防止5GHz的WLAN干擾。

In modern communications system of the RF (Radio Frequency) front-end circuit, filter occupies an important position, in recent years, the rapid development of wireless technology and a variety of online services in the cloud, makes the development of multi-band-pass filters is the most bright, not only the industry's demand, on the one hand from a design point of view, also a considerable challenge to academic research.

Designed for wireless communication system of three-band-pass filter, one of the features is the third band and the former two-band bandwidth significantly. Entire filter framework uses two sets of Stub Loaded Resonator, and formed a second band resonators and stump embedded in the first frequency band within the resonator, and the purpose of reducing the circuit. In decided The first two band of resonance frequency , after appropriate arrangements can make possible smaller circuit architecture, again used T-shaped stub and L-shaped stub by produced even-mode, front two a resonance frequency of first spurious response, synthesis bandwidth very wide of third band, because two a residual segment load are is located in half-wave resonator central point, therefore, when adjusting the third band, the first two bands and would not significantly change, such frameworks in the various frequency bands on both sides, there is at least one transmission zero to increase the frequency band selective. First band center frequency is 1.83GHz, the insertion loss of less than 0.7dB, return loss is less than the 21.4dB, 1dB bandwidth 4.2%, second band center frequency is 2.36GHz, the insertion loss of less than 1.2dB, return loss is less than 16.2dB, 1dB the bandwidth 2.4%, the third band center frequency 3.5GHz, insertion loss is less than 0.5dB, return loss is less than 15.5dB, 1dB bandwidth 18.1%, Five transmission zero in the 1.59GHz, 2.02GHz, 2.3GHz, 2.62GHz, 4.42GHz, and, therefore, this Tri-band-pass filters with good selectivity and isolation between bands. Because the filter is whole plane design, manufacturing and designs more easily. Finally, the insertion loss of less than 17.6dB in 5GHz,you can prevent 5GHz WLAN interference.

論文審定書…………………………………………………………… i
誌謝…………………………………………………………………… ii
中文摘要………………………………………………………….….. iii
Abstract……………………...…………………..……….…………. iv
目錄…………………………………………………………………... v
圖表目錄………………………………………………… ……….... vii

第一章 緒論…………………………………………..……………....1
1.1 研究動機和目的………………………………………………….1
1.2 文獻探討…….……………………………………………..........3
1.3 論文貢獻即章節介紹…………………………………………….3

第二章 共振器和微波濾波器基本理論………………………….....4
2.1 共振器……………………………………………………………4
2.1.1 簡介……………………………………………………....…...4
2.1.2 種類與參數……………………………………………….......4
2.2 傳輸線共振電路…………………………………………………7
2.2.1 一段開路的 / 2傳輸線…………………………………......8
2.2.2 使用微帶線的平面共振器……………………………….......9
2.3 濾波器的基礎理論……………………………………………...11
2.3.1 濾波器的特性參數……………………………………….......11
2.3.2 耦合式濾波器…………………………………………......….12
2.3.2.1 濾波器的等效電路與耦合原理………………..............…13
2.3.2.2 電耦合…………………………………………..............…13
2.3.2.3 磁耦合…………………………………………..............…15
2.3.2.4 電磁耦合(混合式耦合)………………………..............….17
2.3.2.5 濾波器的品質因素…………………………..............……19
2.3.2.6 臨界耦合…………………………..............………………21

第三章 極大頻寬差異的三頻帶通濾波器之分析與設計……...….…..22
3.1 第一頻帶(1.8GHz)分析與設計…………………………………22
3.2 第二頻帶(2.4GHz)分析與設計…………………………………29
3.3 第三頻帶(3.5GHz)分析與設計…………………………………32
3.3.1中心負載共振器(Centrally loaded Resonator)的奇偶模態分析….32
3.3.2 使用T型殘段(T-stub)和L型殘段(L-stub)合成寬頻的第三頻帶…...34
3.4 電路實做和模擬量測結果比較………………………………...41

第四章 結論………………………………………………………....43
參考文獻………………………………………………………..……44

[1] WiMedia Alliance. http://www.wimedia.org/en/index.asp

[2] UWB Forum. http://www.uwbforum.org/

[3] IEEE 802.15.3簡介, 交通大學資訊工程所 王友群著, http://people.cs.nctu.edu.tw/~wangyc/publications/reports/r003-book06-uwb.pdf

[4] M.H.Weng and H.W. Wu, “A novel triple-band bandpass filter using multilayer-based substrates for WiMAX,” in Proc.Eur.Microw.Conf.,Oct. 2007, pp. 325-328.

[5] C.H Lee et al, “Design of a new tri-band microstrip BPF using combined quarter-wavelength SIRs,” IEEE Microw. Wireless Compon. Lett., vol. 16, no. 11, pp.594-596, Nov.2006.

[6] F.C. Chen et al, “ Design of compact tri-band bandpass filter using assembled resonators,” IEEE Trans. Microw. Theory Tech., vol. 57, no.1,pp.165-171,Jan.2009

[7] C.I. Hsu et al, “Tri-band bandpass filter with sharp passband skirts desined using tri-section SIRs “ IEEE Microw. Wireless Compon. Lett., vol. 18, no. 1, pp.19-21, Jan.2008.

[8] F.C chen et al, “ Tri-band bandpass filter using stub loaded resonators,“ Electrion. Lett, vol. 44, no. 12, pp.747-749, Jun.2008.

[9] M.Mokhtarri et al, “ Coupling-Matrix design of dual and triple passband filters,” IEEE Trans. Microw. Theory Tech., vol. 54, no. 11, pp. 3940-3946, Nov.2006.

[10] X.P. Chen et al, “ Dual-band and triple-band substrate integrated waveguide filters with chebyshev and quasi-Elliptic responses,” IEEE Trans. Microw. Theory Tech., vol. 55, no. 12, pp.2569-2578, Dec. 2007

[11] D.M. Pozar, Microwave Engineering Reading 3th, MA:Addision Wesley, 2011

[12] J.S. Hong, and M.J. Lancaster, Microwave Filters for RF/Microwave Applications 2th .New York:Wiley, 2011,

[13] G.L. Matthaei, L.Young, and E.M.T. Jones, Microwave Filters,Impedance-Matching Networks, and Coupling Structures. New York:McGraw-Hill, 1980,ch.11.

[14] L.H. Hsieh and K. Chang, “Tunable microstrip bandpass filters with two transmission zeros,” IEEE Trans. Microwave Theory Theory Tech., vol. 51, no. 12, pp.520-525, Feb.2003

[15] X.Y Zhang, J Shi,J.X Chen ; Q,Xue, “ Dual-Bandpass Filter Design Using a Novel Feed Scheme” Microwave and Wireless Components Letters, IEEE, vol. 19, pp.350-352, 2009

[16] J. R. Montejo-Garai, “Synthesis of N-even order symmetric filters with N transmission zeros by means of source-load cross coupling,” Electron. Lett., vol. 36, no. 3, pp. 232–233, Feb. 2000.

[17] S. Amari, “Direct synthsis of folded symmetric resonator filters with source-loading coupling,” IEEE Microw. Wireless Compon. Lett., vol.11, no. 6, pp. 264–266, Jun. 2001.

[18] C. S. Cho, J. W. Lee, and J. Kim, “Dual- and triple-mode branch-line ring resonators and harmonic suppressed half-ring resonators,” IEEE Trans. Microw. Theory Tech., vol. 54, no. 11, pp. 3968–3974, Nov.2006.

[19] X.Y. Zhang, Quan Xue. “ Novel Centrally Loaded Resonators and Their Applications to Bandpass Filters” IEEE Trans. Micow Theory Tech, vol. 56, pp.913-921, 2008.

[20] X. Y. Zhang, J.-X. Chen, Q. Xue, and S.-M Li , “Dual-band filters using stub-loaded resonators,” IEEE Microw. Wireless Compon. Lett., vol.17, no. 8, pp. 583–585, Aug. 2007.

[21] M.T Doan, Wenquan Che, Kuan Deng, Wenjie Feng, “Compact Tri-Band Bandpass Filter Using Stub-Loaded Resonator and Quarter-Wavelength Resonator” Microwave Conference Proceedings (CJMW), 2011 China-Japan Joint, pp.1-4, 2011

[22] X.Y. Zhang ; Quan Xue ; B.J. Hu, “Planar Tri-Band Bandpass Filter With Compact Size” Microwave and Wireless Components Letters, IEEE Vol:20, Issue: 5, Publication Year: 2010 , Page(s): 262-264

[23] X.Y. Zhang ; B.J. Hu ; Quan Xue “ Design of Planar Tri-Band Bandpass Filter” Microwave and Millimeter Wave Technology (ICMMT), 2010 International Conference on Publication Year: 2010 , Page(s): 74-76