具寬截止頻帶之縮小化微帶線低通濾波器

Abstract

本論文以步階阻抗低通電路為起點，提出一低通濾波器架構，利用平行共振電路原理，在原先高阻抗傳輸線上串接一段低阻抗傳輸線，並觀察濾波器參數變化對頻率響應的影響，運用電磁模擬軟體進行調整，使頻率響應內的零點與極點相互抵消，以增加濾波器截止帶的頻寬。

In this study, we propose a low-pass filter structure based on stepped-impedance low-pass filter, and a distributed parallel resonance circuit is used. The circuit has a section of high-impedance transmission line, that cascades another one with low-impedance, shunt with a coupled capacitor connecting with the terminals of two low-impedance lines. We can cancel the zero and the pole in band by using the variance of filter parameter.