以鼠競環混成器與枝幹耦合器為基礎之寬頻帶通濾波器合成與設計

Synthesis and Design of Hybrid Ring and Branch Line Coupler Based Wideband Bandpass Filters

李建育(Jian-Yu Li)

指導教授 ： 張志揚

國立交通大學/電機學院/電信工程系所/博士(2013年)

https://doi.org/10.6842/NCTU.2013.00564

摘要

本論文發展以鼠競環混成器與枝幹耦合器為基礎之寬頻帶通濾波器架構，並提出完整的電路解析以及系統化的濾波器合成方法。所提出之兩種以鼠競環混成器為基礎的寬頻帶通濾波器架構分別具有一對可控制虛頻率位置的零點以及一對可控制實頻率位置的零點，藉由選擇適當的虛頻率零點位置可以使濾波器的通帶具有平坦的群延遲響應，而選擇適當的實頻率零點位置，則可以改善濾波器的選擇性。最後，利用雙側平行步階阻抗帶線實現具有帶拒響應以及寬上止帶之微小化寬頻鼠競環帶通濾波器。此外，亦提出兩種以枝幹耦合器為基礎之寬頻帶通濾波器架構，其分別具有一對可控制實頻率位置的零點以及兩對可控制實頻率位置的零點，此類寬頻帶通濾波器具有很高的選擇性，而就我們所知，目前並沒有以枝幹耦合器為基礎的寬頻帶通濾波器被提出。

關鍵字

寬頻 ； 帶通濾波器 ； 鼠競環混成器 ； 枝幹耦合器 ； 合成

並列摘要

This dissertation develops the configurations of hybrid ring and branch line coupler based wideband bandpass filters. The full analysis and systematic synthesis method are also presented. Two kinds of hybrid ring based wideband bandpass filters are proposed according to the position of the controllable transmission zero pair. The filter has a controllable transmission zero pair on the imaginary frequency that they can be arranged to improve the group delay flatness. On the other hand, the filter has a controllable transmission zero pair on the real frequency and the desired stopband suppression can be obtained by adjusting the optimal position of them. Finally, the double-sided parallel-strip stepped-impedance line structure is used to implement a miniaturized hybrid ring wideband bandpass filter with a notched band and an improved upper stopband. In addition, two types of branch line coupler based wideband bandpass filters are demonstrated. One has a transmission zero pair, and the other has two transmission zero pairs. They have good selectivity. To the best of our knowledge, the wideband branch line coupler based bandpass filter has not yet been presented before.

並列關鍵字

wideband ； bandpass filter ； hybrid ring ； branch line coupler ； synthesis

參考文獻

[1] L. Zhu, H. Bu, and K. Wu, “Aperture compensation technique for innovative design of ultra-broadband microstrip bandpass filter,” in IEEE MTT-S Int. Microwave Symp. Dig., vol. 1, pp. 315–318, 2000.

[2] J. T. Kuo and E. Shih, “Wideband bandpass filter design with three-line microstrip structures,” IEEE MTT-S Int. Microwave Symp. Dig., vol. 3, pp. 1593-1596, May 2001.

[3] K. Li, D. Kurita and T. Matsui, “An ultra-wideband bandpass filter using broadside-coupled microstrip-coplanar waveguide structure,” IEEE MTT-S Int. Microwave Symp. Dig., 2005.

[4] H. Wang, L. Zhu, and W. Menzel, “Ultra-wideband bandpass filter with hybrid microstrip/CPW structure,” IEEE Microwave Wireless Compon. Lett., vol. 15, no. 12, pp. 844–846, Dec. 2005.

[5] T. N. Kuo, S. C. Lin, and C. H. Chen, “Compact ultra-wideband bandpass filter using composite microstrip-coplanar-waveguide structure,” IEEE Trans. Microwave Theory Tech., vol. 54, pp. 3772–3778, Oct. 2006.