半圆环形双模带通滤波器的设计

Design of Dual-Mode Bandpass Filter Using Semi-ring

本文提出一种由一个半圆环形谐振器和一个T型微扰构成的新型微带双模滤波器,T型微扰具有两个可调参数,增加了调整双模的自由度.合理设置输入和输出馈线之间的耦合结构,可以在双模滤波器通带两侧产生两个传输零点,从而改善滤波器的选择性.为了验证提出结构的正确性,设计了一个中心频率为2.4GHz双模带通滤波器.仿真结果表明:该滤波器具有10.5%的相对带宽,通带内插入损耗小于0.32dB,且带外衰减大于20dB.

A novel microstrip dual-mode bandpass filter is proposed which consist of a semi-ring resonator and a T-shape perturbation.The T-shape perturbation has two tunable parameters,which increase the degree of freedom of dual modes.By reasonable setting of input and output coupling structure,two transmission zeros appear both side the passband and the performance of filter is improved.In order to verify its correctness,a dual-mode bandpass filter is designed and fabricated with a center frequency at 2.4GHz.The simulated results show that the filter has 10.5%fractional bandwidth,apassband insertion loss less than 0.32dB and a stop band rejection better than 20dB.