采用分形贴片的一种新型带通滤波器

为了实现微波平面带通滤波器的小型化和高选择性,本文以一种分形结构贴片作为基本单元,通过一种直接抽头耦合结构,设计了单个分形贴片和多个分形贴片构成的新型微波平面带通滤波器.给出了滤波器性能的电磁仿真计算数值结果和实验结果.该类滤波器在小尺寸、低插入损耗和高选择性方面的性能明显优于传统的微带带通滤波器.     

基于半模基片集成波导互补开环谐振器的新型滤波器研究

一种新型的基于半模基片集成波导（HMSIW）表面上开互补谐振环高性能平面滤波器。该结构允许低于截止频 率以下传输正向波,利用具有高通特性的HMSIW 和CSRR 组成具有带通特性的滤波器,该滤波器具有体积小巧,损耗 低,易制作,并方便与其他电路集成等优势     

双模微带三角形贴片滤波器的改进设计

双模微带谐振器用于微波滤波器设计时具有独特的优点。近年来出现了一些由双模微带三角形贴片谐振器设计的滤波器,这类滤波器结构简单、尺寸小、通带损耗小、功率容限大。在传统的双模微带三角形带通滤波器的基础上,利用分形结构提出一种新型的双模微带三角形带通滤波器,并对此结构的性能进行了分析和研究。实验和测量结果表明,改进后的滤波器在保持原有滤波器性能的基础上,由于引入了分形结构使滤波器的尺寸更加紧凑、有更好的带外抑制能力。仿真和实测结果基本吻合。     

新型Koch岛分形耦合微带线带通滤波器

为抑制平面带通滤波器的二次谐波,实现高选择性和低插入损耗,提出了一种新型Koch岛分形结构,并将其应用到平面耦合微带线带通滤波器的设计中.仿真及测试结果表明:所设计的新型Koch岛分形耦合微带线带通滤波器的中心频率为3 GHz,3 dB通带宽度为10%;与传统的耦合微带线带通滤波器相比,该新型滤波器的二次谐波降低了11...     

基于分形耦合结构的微带带通滤波器设计

设计了一个中心频率为2GHz的传统结构的微带阶梯耦合带通滤波器,采用分形耦合结构进行谐波抑制,仿真结果表明:采用分形耦合单元比传统结构的耦合单元使滤波器二次谐波减小了25dB,通带插入损耗小于-0.55dB;通过对分形耦合单元进行优化,可使滤波器二次谐波抑制性能进一步改善37dB,而通带性能几乎不受影响。测量结果与仿真结果基本吻合。     

半模基片集成波导带通滤波器的设计

给出了一种新型半模基片集成波导（HMSIW）带通滤波器的设计和实验方案。该设计利用了半模基片集成波导的高通性质与周期性缝隙的带阻性质来产生带通滤波器的效果。设计的滤波器的中心频率在8GHz,带宽在12．5％左右,通带内插入损耗在1dB以下,回波损耗在-15dB以下,同时具有一定的带外抑制和良好的通带和阻带特性。文章最后用Ansoft HFSS软件进行了仿真实验。     

基于分形CRLH-TL加载短截线超宽带滤波器设计

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。     

数控电调带通滤波器的设计与制作

设计了一种新型电调谐带通滤波器,研究了数字信号控制滤波器电调谐的技术。采用数模转换器和高压运放实现数字信号与直流电压的转换;以变容二极管作为调谐元件;带通滤波器采用梳状微带线结构,并给出了结构参数。最后制作了一个由8位二进制编码控制的电调谐带通滤波器,其中心频率在300～1200MHz可调。测试结果与理论设计基本吻合。     

基于近零介电常数超材料的液晶可调带通滤波器设计方法研究

可调带通滤波器是物联网、卫星通信、智能天线等系统中不可缺少的关键器件之一。针对目前对可调带通滤波器小型化、低成本和高集成度等特点的应用需求,提出了一种基于液晶材料的可调带通滤波器设计方法。通过微带传输线结构实现了近零介电常数(epsilon near zero,ENZ)超材料单元结构的设计,并利用ENZ超材料的窄通道隧穿效应有效实现了窄带滤波功能,通过将3个ENZ超材料单元结构串联从而完成了带通滤波器基本结构的设计。在此基础上,将微波液晶材料引入ENZ超材料的隧穿通道中,利用液晶材料在外部驱动电压作用下介电参数可变的特性,最终实现了对带通滤波特性的有效调控。全波数值仿真结果表明,所提出的基于ENZ超材料的液晶带通滤波器能够实现中心频率15.88~16.73 GHz的调控,从而验证了设计方法的有效性。     

基于SGS的UWB滤波器设计

在传统哑铃型缺陷接地结构(defected ground structure,DGS)的基础上,提出了一种分割地结构(split ground structure),通过在传统哑铃型DGS上添加一条缝,形成了SGS结构,不仅有低通特性,而且产生了高通特性,即具有带通特性。借助于HFSS软件,比较了传统哑铃型DGS与SGS的仿真结果,分析了SGS结构参数变化对其频率特性的影响。并以此为基础设计了一种新颖的超宽带(UWB)带通滤波器,中心频率6.85 GHz,相对带宽110%,上边带20 dB阻带抑制达20 GHz。仿真结果表明,该滤波器具有较好的频率特性,说明基于SGS的UWB带通滤波器设计的有效性和可行性。     

Novel half-mode substrate integrated waveguide bandpass filters using semi-hexagonal resonators

In this paper, a novel bandpass filter is presented, designed, and implemented by using a triple mode semi-hexagonal Half-Mode Substrate Integrated Waveguide (HMSIW) cavity, which has the advantages of compact size, low insertion loss, and high selectivity in upper and lower passband. To realize a triple mode filter, the first resonant mode is shifted to near the next two modes using a via hole perturbation. Two microstrip open stubs connected to open edge of HMSIW resonator are introduced to generate two transmission zeros in the lower passband. The position of transmission zeros could be controlled by adjusting the coupling gap between the microstrip open stub resonators. By etching an E-shape slot on the top plate of HMSIW resonator, two other transmission zeros are produced in the upper passband. A wide-band planar six-pole bandpass filter, which has the advantages of wide bandwidth and small size, is also proposed and fabricated by cascading two triple mode resonators. Measured results indicate that 29% and 47% fractional bandwidth, as well as approximately 1 dB and 1.1 dB insertion loss, are achieved for the proposed filters. Measured results of all those filters agree well with the simulated results.     

Half Mode Substrate Integrated Waveguide (HMSIW) Bandpass Filter

This letter presents the design and experiment of the half mode substrate integrated waveguide (HMSIW) bandpass filters. Three-pole and five-pole HMSIW filters are simulated by using CST software and fabricated with a single layer standard printed circuit board process. Different external-coupling approaches are adopted in the design of the two filters. The measured results are in good agreement with the simulated results. Low insertion loss and good selectivity are achieved     

Miniaturised microstrip bandpass filters based on Moore fractal geometry

This paper presents new microstrip bandpass filter design topologies that consist of dual edge-coupled resonators constructed in the form of Moore fractal geometries of second and third iteration levels. The space-filling property for proposed fractal filters has found to produce reduced size shapes in accordance with sequential iteration levels. These filters have been prepared for ISM band applications at a centre frequency of 2.4 GHz using a substrate with a dielectric coefficient of 10.8, dielectric thickness of 1.27 mm and metallisation thickness of 35 µm. The output responses of each fractal bandpass filter have been determined by a full-wave-based electromagnetic simulator Sonnet software package. Simulated and experimental results are approximately compatible with each other. These responses clarify that these fractal filters have good transmission and return loss characteristics with blocked higher harmonics in out-of-band regions.     

新型半模基片集成波导镜像转接段的研究

本文提出了半模基片集成波导的镜像转接段设计,并对其功率分配方面的应用展开了研究.首先分析了半模基片集成波导应用于功分器设计的局限性,然后提出了通过镜像转接方式来实现具有双侧开口面的新型半模基片集成波导镜像转接段.通过仿真分析和实验测试验证了半模基片集成波导镜像转接段结构及其设计方法的可行性.最后设计了基于镜像转接段且具有对称结构的半模基片集成波导三路功分器.该功分器的仿真结果与实验数据表明,采用镜像连接段的半模基片集成波导器件具有良好的传输性能,有助于拓宽半模基片集成波导在功率分配网络设计方面的应用.     

集成宽带折叠半模基片集成波导带通滤波器

 本文提出并设计了一种新型的折叠半模基片集成波导（Folded Half-Mode Substrate Integrated Waveguide: FHMSIW）宽带带通滤波器,并给出了FHMSIW上层金属层槽缝式和中间金属层槽缝式宽带滤波器的仿真和测试结果。相对于半模基片集成波导（Half-Mode Substrate Integrated Waveguide: HMSIW）槽缝式滤波器,由双层PCB制作的FHMSIW槽缝式滤波器的尺寸减小了约一半。同时测试结果和仿真结果表明该宽带滤波器具有损耗小、带外抑制好等特性。     

A Millimeter Wave Six-Port Network Using Half-Mode Substrate Integrated Waveguide

A novel six-port network based on half-mode substrate integrated waveguide (HMSIW) is proposed. In this design, a HMSIW hybrid 3 dB coupler and a -90° phase shifter are designed as fundamental building block of six-port network. By combining four HMSIW couplers and one phase shifter, a HMSIW six-port network at 29–32 GHz is constructed. The six-port network is fabricated and measured. Measurement results agree well with simulation, and show good balance and phase relationship between ports.     

Ultra-Wideband Bandpass Filter Using Multilayer Liquid-Crystal-Polymer Technology

Novel ultra-wideband (UWB) bandpass filters are proposed based on quasi-lumped-element prototypes and implemented with multilayer liquid-crystal-polymer (LCP) technology. In this study, the broadside-coupled microstrip radial stubs and high-impedance microstrip lines are adopted as quasi-lumped elements for realizing compact UWB bandpass filters. By introducing a short-circuited high-impedance microstrip line as a shunt inductor and suitably designing quasi-lumped-element capacitors, a compact six-pole bandpass filter is implemented with the Federal Communications Commission (FCC) defined UWB specifications. To further improve the selectivity and wideband performance, an eight-pole filter of this type is developed by adding two shunt short-circuited microstrip stubs, which introduce a transmission zero at the upper passband edge. The proposed filters are fabricated using multilayer LCP technology. Good agreement between simulated and measured results of these filters are observed. The measured results show that the fabricated six-pole filter has good specifications for the FCC-defined UWB system. The fabricated eight-pole filter has an ultra-wide fractional bandwidth (139%) and a good stopband rejection level, which is higher than 38.1 dB from 10.57 to 18.0 GHz. The proposed filters are attractive for UWB communications and radar systems.      

A Novel Four-Way Ka-Band Spatial Power Combiner Based on HMSIW

In this letter, a simple low-loss planar spatial power-combining architecture based on half model substrate integrated waveguide (HMSIW) is proposed and studied. The power-combining structure is realized by transition between a HMSIW and parallel multiport planar microstrip lines. The power combiner is simulated and measured at 34.5–36.5 GHz. Measured results show a good agreement with simulation and a combining efficiency of 82% is achieved at 35 GHz.      

基于HMSIW的宽带带通滤波器设计

为有效减小C波段基片集成波导的尺寸和插入损耗,提出了一种基于半模基片集成波导的紧凑型宽带带通滤波器。该滤波器引入由单个谐振槽和多个谐振槽组成的缺陷微带结构,并对其性能进行了研究。通过HFSS仿真验证,引入的缺陷微带结构,不仅可以减小插入损耗,而且实现传输零点的引入,改善了阻带特性。该方法设计的半模基片集成波导带通滤波器具有集成度高、体积小、成本低、制造方便等优点,在C波段卫星和雷达中得到了广泛的应用。