Miniaturized Bandpass Filters with Two Layer Folded Center Conductor

• Main Authors: Wen-Song Fan, 范文松
• Other Authors: Chi-Yang Chang
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/43887344844423564959

碩士 === 國立交通大學 === 電信工程系 === 87 === In this thesis, we describe a two layered bandpass filter. It is suitable to reduce size even using low dielectric constant substrate. A simple, non-time-wasting design procedures is also developed. The miniaturized filter can be used in 5-6GHz band in wireless communication, such as Hyper LAN 5.3 GHz and WLAN 5.7 GHz. Two types of miniaturized bandpass filters, namely, parallel edge coupled and comb type coupled bandpass filter, are developed. When comb type coupler is realized in microstrip circuit form, the unequal even- and odd-mode velocity degrades the filter performance seriously. By using analytical equivalent circuit model, this problem is solved. The yield can be improved by using this new design procedure. The cross-coupled filters can miniaturize the conventional bandpass filters, too. Hairpin-resonator bandpass filters with electric and magnetic cross coupling are introduced. Design procedures and equations for all types of filters are developed. An example for each type of filters are designed and fabricated to verify the accuracy of synthesis theory.