Design of Dual-Band Net-Type and Balanced Microwave Bandpass Filters

• Main Authors: HSIN-YUNG SHAO, 邵鑫永
• Other Authors: Chao-Hsiung Tseng
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/56895986239851612189

碩士 === 國立臺灣科技大學 === 電子工程系 === 97 === In this thesis, the stepped-impedance resonator (SIR) technique is mainly need to develop the partial net-type and full net-type dual-band microwave bandpass filters. Moreover, it is also applied to implement balanced and balanced-to-single-ended dual-band microwave bandpass filters. The detailed circuit design concept, implementation, and verification are presented in the thesis. Firstly, the principles of the stepped-impedance resonator are described. Followed by the design procedures, determination of parameters, and extraction of external quality factor and coupling coefficient between the resonators, the filters are realized and measured. In design of the dual-band bandpass filters, two resonance coupling paths are employed to improve the sharpness of the passband. The net-type filters focus on the circuit miniaturization, while the balanced filters focus on realization of the dual passbands. Based on the simulated and measured results of this thesis, partial net-type and full net-type dual-band filters can obtain the significant circuit size reduction. Although a number of vias are adopted in the circuit design, it does not lead to the increase of the insertion loss. The developed balanced filters successfully achieve two specified passband. However, the reflection coefficient, transmission coefficient, and common -mode suppression are not as good as expected. The reasons and the improvement methods will be discussed in the thesis.