使用多重模態共振器實現多功能帶通濾波器

Bandpass filters by using multiple-mode resonators

吳俊儀(Chun-I Wu)

指導教授 ： 凃文化

國立中央大學/資訊電機學院/電機工程學系/碩士(2011年)

摘要

本論文為多重模態共振器的應用，依照共振器的特性分別設計出四頻段的帶通濾器與微小型高選擇度的寬頻寬止帶帶通濾波器。
藉由在開槽的二分之一波長共振器中心點上加一個八分之一波長的開路負載設計一個四頻段的帶通濾波器，而開槽的二分之一波長共振器可以改善每一個通帶之外部品質因子的自由度，再根據奇模與偶模的路徑可以決定四頻段的帶通濾波器之耦合結構。此外，每一個通帶之間的傳輸零點可使通帶的選擇度提升，整體電路面積為0.3λg×0.3λg = 0.09λg2。
另外，微小型高選擇度的寬頻寬止帶帶通濾波器，則是在半波長共振器的共振器中心點加入一個彎折的耦合線，而此負載型的共振器可以在通帶中產生三個傳輸極點，而通帶之外可以產生兩個傳輸零點，藉由調整彎折的耦合線與多重路徑，可以控制多重傳輸零點達成寬止帶的響應。從量測的結果其通帶為2.3 GHz至4.1 GHz的反射損耗為15 dB、插入損耗0.8 dB、群延遲最大的變化為0.8 ns、通帶之外的止帶響應隔絕度為4.3 GHz至10 GHz 皆大於20 dB，而整個電路面積大小為0.51λg×0.09λg = 0.05λg2。

關鍵字

多重模態共振器 ； 帶通濾波器

並列摘要

The applications of the multiple-mode resonators are presented in this thesis. With the multiple-mode resonators characteristics, the multiple-mode resonator can be designed in quad-band bandpass filter and compact sharp-rejection broadband bandpass filter with a wide stopband.
The quad-band bandpass filter by splitting half-wavelength resonator with eighth-wavelength stub-loaded resonator is presented. The split half-wavelength resonator can improve the freedom of the external quality factor of each passband. The configuration of the quad-band bandpass filter can be determined from odd- and even-mode excitative path. Moreover, the transmission zeros on both sides of the passband, which can greatly improve the selectivity of quad-band bandpass filter. The core circuit size is 0.09λg2 at the center frequency.
In addition, a compact sharp-rejection broadband bandpass filter with a wide stopband is also presented. The major building block of the proposed filter is a half-wavelength resonator loaded by a meandering coupled line. The loaded resonator could provide three transmission poles in the passband and two transmission zeros beside the passband. By adjusting the dimensions of the meandering coupled line and using multi-path cancellation technique, one can control multiple transmission zeros for a wide stopband. From 2.3 to 4.1GHz, the measured return loss is greater than 15 dB, and the measured insertion loss is less than 0.8 dB. The maximum group delay variation is 0.8 ns, and the core circuit size is 0.05λg2 at the center frequency. For the upper stopband performance, the rejection level is greater than 20 dB from 4.3 to 10 GHz.

並列關鍵字

multiple-mode resonators(MMR) ； bandpass filters

參考文獻

[1] P. Mondal and M.K. Mandal, “Design of dual-band bandpass filters using stub-loaded open-loop resonators,” IEEE Trans. Microw. Theory Tech., vol. 56, no. 1, pp. 150-155, Jan. 2008.

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

[3] C.-H. Lee, C.-I. G. Hsu and H.-K. Jhuang, “Design of a new tri-band microstrip BPF using combined quarter-wavelength SIRs,” IEEE Microw. Wirel. Compon. Lett., vol. 16, no. 11, pp. 594-596, Nov. 2006.

[4] Q.-X. Chu and X.-M. Lin, “Advanced triple-band bandpass filter using tri-section SIR,” Electron. Lett., vol. 44, no. 4, pp. 295-296, 2008.

[5] C.-I. G. Hsu, C.-H. Lee and Y.-H. Hsieh, “Tri-band bandpass filter with sharp passband skirts designed using tri-section SIRs,” IEEE Microw. Wirel. Compon. Lett., vol. 18, no. 1, pp. 19-21, Jan. 2008.