基于沙漏形人工表面等离激元和交指电容结构的双频滤波器设计  

Dual-band filter design based on hourglass-shaped spoof surface plasmon polaritons and interdigital capacitor structure

作　　者：罗宇轩 程用志[1] 陈浮 罗辉 李享成[2] Luo Yu-Xuan;Cheng Yong-Zhi;Chen Fu;Luo Hui;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4期65-73,共9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);湖北省重点研发项目(批准号:2020BAA028)资助的课题。

摘　　要：本文提出了一种在共面波导(coplanar waveguide,CPW)上加载沙漏形人工表面等离激元(spoof surface plasmon polaritons,SSPPs)和交指电容结构的双通带滤波器.首先,在共面波导传输线上引入了沙漏形SSPP单元结构和交指电容结构,以获得高分数带宽、低插损的通带特性.然后,通过加载交指电容环路谐振器激发陷波,形成双通带滤波器.仿真结果表明,所提出的双通带滤波器具有良好的上边带抑制和双通带滤波性能.两个通带的相对带宽分别为46.8%(1.49—2.40 GHz)和15.1%(2.98—3.63 GHz),可在4.77—7.48 GHz的范围内实现超过—40 dB的抑制,且可通过改变相应的结构参数独立调控两个通带的上、下截止频率.为深入了解双通带滤波器的工作原理,给出了相应的色散曲线和电场分布、LC等效电路分析.最后,根据优化后参数数值,加工出滤波器原型实物.实验结果与仿真结果吻合良好,由此表明提出的双通带滤波器在微波频率的集成电路应用中具有重要意义.In this paper,a dual passband filter with spoof surface plasmon polaritons(SSPPs) and interdigital capacitance structure loaded on a coplanar waveguide(CPW) is proposed.First,the hourglass-shaped SSPP unit-cell structure and the inter digital capacitor structure are introduced on the coplanar waveguide transmission line to obtain high fractional bandwidth and low insertion loss passband characteristics.Then,a dual passband filter is formed by loading the interdigital capacitor loop resonator to excite the trapped waves.The simulation results show that the proposed dual passband filter has excellent upper sideband rejection and dual passband filtering performance.The fractional bandwidths of the two passbands of the design are 46.8%(1.49-2.40 GHz) and 15.1%(2.98-3.63 GHz),respectively,which can achieve more than-40 dB rejection in a range of 4.77-7.48 GHz.The upper cutoff frequency and lower cutoff frequency of the two passbands can be independently regulated by changing the structural parameters of the proposed filter.In order to gain a more in-depth understanding of the operating principle of the dual passband filter,the corresponding dispersion curves and electric field distribution,LC equivalent circuit analysis are given.Finally,the prototype of the designed filter is fabricated according to the optimized parameter values.The experimental results are in good agreement with the simulation ones,indicating that the proposed dual-passband filter is of great importance in implementing microwave integrated circuits.

关 键 词：双通带滤波器 人工表面等离激元 交指电容结构 

分 类 号：TN713[电子电信—电路与系统]