新型D-CRLH传输线宽带带阻滤波器设计

摘要

A novel dual composite right/left-handed transmission line (D-CRLH TL) was proposed. Based on the D-CRLH TL cell, a miniaturized four-order wideband bandstop filter was designed.Left-handed capacitorand right-handed inductance were obtained by couplingof microstrip lines,right-handed capacitor was obtained by the rectangular patchand left-handed inductance was obtained by the stub.The centre frequency and bandwidth of the stopband could be controlled by adjusting the width of the rectangular patch and thelength of thestub. The size of this designed filter is 11.5mm×6.7mm, which equals to0.23λ×0.13λ(λis the wavelength of center frequency in the free space).The simulated and measured results show that thebandstop filter has a centre frequency of 5.6 GHz. The 20 dB stopband fractional bandwidth is50% and the 50 dB stopband fractional bandwidth is30%.%提出一种新颖的对偶复合左右手传输线(D-CRLH TL)结构单元,设计了一款小型化四阶宽带带阻滤波器.通过缝隙耦合形成左手电容和右手电感,位于结构下方的矩形贴片形成右手电容,与矩形贴片相连接的短截线形成左手电感.可以通过改变矩形贴片宽度和短截线的长度来调节带阻滤波器的中心频率和带宽.滤波器有效设计尺寸为11.5 mm×6.7 mm,等于0.23λ×0.13λ(λ为中心频率在自由空间的波长),尺寸较小.仿真测试结果表明该滤波器阻带中心频率为5.6 GHz,20 dB阻带带宽为50%,50 dB阻带带宽为30%.