부산대학교 도서관

This study investigates a modal filter (MF) based on the reflection symmetrical structure in the frequency domain for the first time. Frequency dependences of $\vert \boldsymbol{S}_{21}\vert$ up to 3.5 GHz, are obtained using three different software products with an increase of the separation between conductors from 450 to $2000\ \boldsymbol{\mu} \mathbf{m}$, We propose the analytical expression for a matched reflection symmetric MF with optimized parameters, which makes it possible to calculate values of resonance frequencies through values of per-unit-length delays without time-consuming calculations of a frequency response. We also performed optimization of the reflection symmetric MF using the criterion of maximizing the bandwidth of a useful signal. It was increased from 0.216 GHz to 0.248 GHz while keeping the first resonance frequency unchanged and maintaining matching.