Synthesis and Realization of Frequency-Dependent Coupled Stepped-Impedance Resonator Filters with a Quasi-Elliptic Function Response

• Main Authors: Ching-Luh Hsu, 徐慶陸
• Other Authors: Jen-Tsai Kuo
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/13623122076731860895

博士 === 國立交通大學 === 電信工程系所 === 96 === This dissertation aims at synthesis and realization of microstrip coupled- resonator filters with frequency-dependent cross-coupling. The first part presents the synthesis of trisection filters incorporating the frequency-dependent coupling to achieve a quasi-elliptic function response. In the admittance matrix of the lowpass prototype, the coupling is simply modeled by a constant J-inverter multiplied by the complex frequency variable s. In realization, tapped-line input/output is used and more zeros can be generated in the upper and lower rejection bands. The second part studies stepped-impedance resonators in a compact inline arrangement. It is found that certain transmission zeros can be created by nonadjacent frequency-dependent coupling. Enhanced attenuation rate in transition bands can then be obtained. Zeros created by tapped input/output structure are also investigated. For demonstrations, measured results for experimental filters are compared with simulation data.