小型化超宽阻带共面波导低通滤波器设计

小型化超宽阻带共面波导低通滤波器设计

内容简介：为了解决传统CPW低通滤波器尺寸偏大、阻带较窄和插入损耗偏大的问题,采用姿/4阶梯阻抗谐振单元( SIR)加载半圆形并联枝节( SISS)和缺陷地结构( DGS)单元的紧凑型结构设计了一个5阶CPW低通滤波器,分析了各单元结构参数对阻带性能的影响,引入微带线补偿方法对共面波导中心导体线特性阻抗进行局部补偿,改善了阻抗匹配性能,进一步降低了通带内的回波损耗和插入损耗。测试结果表明：该滤波器结构尺寸25 mm×18 mm,3 dB截止频率3.5 GHz,阻带范围3.8 GHz~17 GHz。实现了CPW低通滤波器的低插入损耗、超宽阻带和小型化。

Abstract：A conventional coplanar waveguide( CPW) low pass filter( LPF) has a large area,a narrow stop-band and a high insert loss. To solve this problem,a miniaturized super wide stop-band 5-order CPW LPF is presented,which is composed of quarter wavelength stepped impedance resonators( SIR) and defected ground unit( DGS) cascaded by semicircle stepped impedance shunt stubs( SISS) . The effect of parameter variation of SIR,DGS and SISS on band-stop characteristic is studied. By introducing micro-strip line compensation methods to compensate the characteristic impedance of CPW center conductor line, which can improve the impedance matching performances, and further reduce the return loss and insertion loss in the pass-band. The tested results show that the size of the filter is 25 mmí18 mm,3 dB cut-off frequency is 3. 5 GHz,stop-band ranges from 3. 8 GHz to 17 GHz. Finally,a miniaturization CPW LPF with low insert loss and ultra wide stop-band is realized.

作者：谢绰, 杨维明, 杨武韬, 李紫怡, 卜力,

关键词：低通滤波器, 共面波导, 超宽阻带, 缺陷地结构