Research and applications of microstrip coupled line structure with high directivity

• Main Authors: Shih-Ming Wang, 王士鳴
• Other Authors: Chi-Yang Chang
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/82158195397427438131

博士 === 國立交通大學 === 電信工程系所 === 94 === This dissertation presents the research and applications of microstrip coupler with high directivity. In the first part, we proposed a meandered parallel-coupled line. It can speed up the even-mode phase velocity and make the modal phase velocities to be equal in microstrip structure. Therefore, we can get a good directivity in microstrip parallel-coupled coupler. With proper design, we can get an ultra high directivity in a narrow band or get a high directivity performance over broad bandwidth. We also apply the proposed structure to a half wavelength band pass filter and successfully cancel the first spurious passband. All the synthesis procedures of the proposed structure are described in detail. The second part presents a solution for miniaturizing microstrip loose coupler with high directivity.