Microwave Coupled-Line Filter Designs with Special Loadings and Connections

• Main Authors: Chen-ChiehFerng, 馮震傑
• Other Authors: Chih-Ming Tsai
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/78269878813017453745

碩士 === 國立成功大學 === 電腦與通信工程研究所 === 101 === In recent years, many new coupled-line filters structures have been proposed. However, the complete synthesis procedures and design equations are not well developed. In this thesis, coupled transmission-line models are used to derive the filters' equivalent circuits. They are then synthesized to realize Elliptic and Generalized Chebyshev functions. Therefore, the filters passband response could be well controlled by designers. Therefore, exact synthesis is more effective than only controlling transmission zero positions. Also higher order filters are proposed because equivalent circuits show the possibility. This thesis then discusses the methods for suppression of DC and first spurious passband. Asymmetric and three coupled-line structure are used for size reduction. Finally, the proposed designs are verified by using EM simulations and experiments. The terminals of two-coupled lines are usually open- or short-circuited except at the input and output ports. These circuits had been well studied. On the other hand, coupled-line sections with extra connection between terminals are seldom discussed in the literatures. In this study, these circuits have been studied. They are compared to other open-and short-circuited coupled line sections. The equivalent circuits are derived for references.