基于分形CRLH-TL加载短截线超宽带滤波器设计  

Design of UWB Filter With Steep Rejection Slope Based on Fractal-shaped CRHL-TL

作　　者：张小宽[1] 袁俊超[1] 吴盛源 

机构地区：[1]空军工程大学防空反导学院,陕西西安710051

出　　处：《压电与声光》2017年第4期501-505,共5页Piezoelectrics & Acoustooptics

基　　金：国家自然科学基金资助项目(61372033);电磁散射辐射重点实验室创新基金资助项目(STES2014-2)

摘　　要：传统基于微带缝隙和逆开环谐振器(CSRRs)的复合左右手传输线的带宽较窄、通带内反射损耗较大,限制了其应用。因此,该文采用了Minkowski分形的微带缝隙代替传统微带缝隙,有效地展宽了带宽,并通过在微带缝隙两侧加载短截线的方式进一步增加了带宽并改善了高频端带外抑制特性。分析了结构的尺寸参数对其传输特性的影响,并根据S参数计算了色散曲线、提出了等效电路模型。最后,运用所提出的方法设计了一款超宽带带通滤波器。该滤波器仅采用一个复合左右手(CRLH)结构单元,获得了超带宽2.1~9GHz(相对带宽124.3%)和较小的带内反射损耗(小于0.8dB),同时滤波器在9.5~12GHz的阻带范围内传输抑制大于20dB。测量结果、仿真结果与等效电路结果基本吻合,验证了该设计方法的有效性。The conventional CRHL TL based on the microstrip slot and reverse open loop resonator has limits on its application because of the narrow bandwidth and large reflection loss in pass band.Aiming at above-mentioned problems,the conventional microstrip slot is replaced by Minkowski fractal microstrip slot to expand the bandwidth.Loading stub on both sides of the microstrip can also increase the bandwidth and improve the out-of-side rejection of high frequency end.The impact of size parameters of structure on the transmission characteristics is analyzed in this paper.The dispersion curve is calculated according to parameter S.Then,the equivalent circuit model is proposed.Finally,the band-pass filter with ultra-wideband is designed by the proposed method.The band-pass filter uses only one CRLH structural unit and the ultra-wideband of 2.1-9GHz（relative bandwidth 124.3%）has been obtained.The reflection loss is smaller than 0.8dB.At the same time,the transmission suppression of filter is larger than 20 dB at the stopband range of 9.5-12GHz.The results of measurement and simulation are basically consistent with the result of equivalent circuit,which verifies the validity of the design method.

关 键 词：复合左右手传输线 Minkowski分形曲线 短截线 超宽带 带通滤波器 

分 类 号：TN713[电子电信—电路与系统]