基于戟形人工表面等离激元的紧凑型宽带外抑制带通滤波器  

Compact broadband bandpass filter with wide stopband based on halberd-shaped spoof surface plasmon polariton

作　　者：孙淑鹏 程用志[1] 罗辉 陈浮 李享成[2] Sun Shu-Peng;Cheng Yong-Zhi;Luo Hui;Chen Fu;Li Xiang-Cheng(School of Information Science and Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;State Key Laboratory of Refractory Materials and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学信息科学与工程学院,武汉430081 [2]武汉科技大学,耐火材料与冶金国家重点实验室,武汉430081

出　　处：《物理学报》2023年第6期96-103,共8页Acta Physica Sinica

基　　金：湖北省自然科学基金创新群体项目(批准号:2020CFA038);湖北省重点研发计划(批准号:2020BAA028)资助的课题.

摘　　要：提出了一种基于戟形人工表面等离激元(spoof surface plasmon polaritons,SSPPs)的具有宽频带外抑制特性的紧凑型宽带带通滤波器.设计的滤波结构是通过在基板底层蚀刻周期性的戟形槽和在顶层加载带有月牙形贴片的微带到槽线过渡结构实现的.与传统的I形SSPPs相比,戟形SSPPs具有更好的慢波特性,基于戟形SSPPs设计的带通滤波器可以实现更紧凑的结构.设计的滤波器通带的上下截止频率可以分别通过调整SSPPs结构和微带到槽线过渡结构来调节.仿真结果表明,宽带带通滤波器中心频率为2.85 GHz,相对带宽为130%,通带内的回波损耗优于–10 dB,在5.6-20.0 GHz之间具有极强的–40 dB带外抑制.设计的宽带带通滤波器结构尺寸紧凑,仅为1.08λ_(g)×0.39λ_(g),其中λ_(g)是中心频率处的波长.为了验证宽带带通滤波器的有效性,采用传统的印刷电路板技术加工了宽带带通滤波器.测量结果与仿真结果吻合较好,验证了设计的可行性.本文所提出的宽带带通滤波器显示了在微波频率下开发SSPPs功能器件和电路的良好前景.In this paper,a compact broadband bandpass filter with wide out-of-band rejection characteristics based on halberd-shaped spoof surface plasmon polariton(SSPP)is proposed.The filtering structure is achieved by etching a periodic halberd-shaped groove at the bottom of the substrate and a microstrip-to-slot line transition with a crescent-shaped patch at the top.Compared with the traditional dumbbell-shaped SSPP,the halberd-shaped SSPP has good slow-wave property,and the designed bandpass filter based on halberd-shaped SSPP can achieve a more compact size.The upper cutoff frequency and lower cutoff frequency of the passband can be adjusted by regulating the SSPP structure and the transition structure from microstrip-to-slot line,respectively.The simulation results show that the center frequency of broadband bandpass filter is 2.85 GHz,with the relative bandwidth of 130%,and the return loss in the passband is better than-10 dB,and the extreme strong out-of-band rejection of-40 dB from 5.6 GHz to 20.0 GHz.The size of the broadband bandpass filter is compact,only 1.08λ_(g)×0.39λ_(g),where λ_(g) is the wavelength at the center frequency.In order to verify the effectiveness of the wideband bandpass filter,the traditional printed circuit board technology is used to fabricate the wideband bandpass filter.The measurement results are in good agreement with the simulation results,verifying the feasibility of the design.The proposed broadband bandpass filter shows promising prospects for developing SSPP functional devices and circuits at microwave frequencies.

关 键 词：人工表面等离激元 宽带带通滤波器 微带到槽线过渡结构 

分 类 号：TN713.5[电子电信—电路与系统]