一种基于阶跃阻抗波导带通滤波器的设计

利用阶跃阻抗谐振器(SIR)结构设计波导带通滤波器。该方法减小体积,又可以将杂散谐振频率向高端推移,从而增加阻带宽度,使得结构的设计获得很大的自由。最后,利用电磁场仿真软件对结构尺寸进行优化仿真,并实际制作一个中心频率为780 MHz(通带差损小于0.7 dB)的SIR带通滤波器。实测结果和仿真结果吻合良好,达到预计指标参数。该滤波器具有体积小,结构简单易于加工等优点。     

Compact microstrip stepped impedance wideband bandpass filter

A novel wideband bandpass filter with a very compact size is presented in this article. Using a side-coupled stepped impedance resonator, wideband characteristics with adjustable centre frequency and 3-dB fractional bandwidth can be obtained easily. Finally, a filter sample is designed and fabricated to provide an experimental verification on the proposed topology. Good insertion/return losses, flat group delay, wide bandwidth as well as ultra compact size are achieved as demonstrated in both simulation and experiment, which makes this filter a very promising candidate for applications in future wideband communication system.     

Compact triple-passband bandpass filter based on new modified stepped impedance resonators

This study proposed a triple-passband bandpass filter with compact size, low loss and high passband selectivity. The filter includes two coupled stepped impedance resonators (SIRs) and two embedded stub-loaded stepped impedance resonators (SL-SIRs), connected with coupling scheme at the symmetric plane of the filter. The filter is designed to have triple-passband at 2.4, 3.5 and 5.2 GHz for worldwide interoperability for microwave access (WiMAX) applications. By properly tuning the impedance ratio and physical length ratio of the SL-SIRs, the three passbands can be easily determined, at the same time, achieving the high passband selectivity and wide stopband. Besides, the transmission zeros near passband edges of each passband are generated by the proposed filter with cross-coupling structure. The measured results are in good agreement with the full-wave electromagnetic (EM) simulation results.     

Ultra wideband filter using dumbbell-etched stepped impedance resonator

In this article, an ultra wideband bandpass filter using the dumbbell-etched stepped impedance resonator (SIR) is presented. The filter consists of a dumbbell-etched SIR with an impedance ratio K?>?1 and the enhanced coupled input/output lines. The SIR is folded into a dumbbell shape to achieve a smaller circuit size than the filter with conventional SIR. The bandwidth can be analysed using the image-parameter method to obtain the proper dimension of the coupled lines and verified using electromagnetic simulation. The measured 3?dB fractional bandwidth of 110% and insertion loss |S ₂₁| less than 3?dB over the entire passband are achieved.     

Microstrip dual-band bandstop filter of defected ground structure and stepped impedance resonators

This article presents a compact microstrip dual-band bandstop filter (BSF), in which one λ_g/4 defected ground structure (DGS) pair is utilised to realise one stopband while two stepped impedance resonators (SIRs) help obtain another stopband and suppress the spurious harmonics. The design strategies and the equivalent circuits are introduced in detail. The measured results indicate 43.8% and 18.7% fractional bandwidth in the two stopbands (2.4 GHZ and 5.2 GHz) respectively, and the return loss is greater than 15 dB in the whole passband. In addition, size reduction can be conveniently achieved by adjusting the length of the SIRs and DGS.     

结构紧凑的高选择性宽带滤波器

摘 要：为实现结构紧凑和高选择性的宽带滤波器,在传统平行耦合线结构的基础上,作了适当改进,设计了三种结构新颖的三线耦合结构,均能够实现具有三个传输零点的宽带响应,且其中两个零点分别紧靠通带的上下边缘。加工并测试了基于其中一种结构的宽带滤波器,工作频率为2.6GHz,3dB相对带宽为63%,三个传输零点分别位于1.46GHz,3.77GHz和5.13GHz,介质基板采用Rogers 4003,厚度0.813mm。实测结果与仿真结果吻合良好,验证了结构的有效性。     

Miniaturized dual-band bandpass filter with good frequency selectivity using SIR and DGS

A miniaturized dual-band bandpass filter (BPF) using stepped impedance resonator (SIR) and defected ground structure (DGS) is presented. In order to get two desired passbands, two different transmission paths and source–load cross coupling have been implemented. One path is the SIR, and the other is the DGS. Meanwhile, it is easy to obtain good frequency selectivity by introducing several transmission zeros. The coupling scheme and current distributions are applied to demonstrate the flexible design approach. A dual-band BPF is designed, simulated, and fabricated to demonstrate the performance of the proposed dual-band filter. The measured results show that the fabricated dual-band BPF has two passbands centered at 2.41 and 3.52 GHz with the fractional bandwidth of 5.8 and 7.7%, respectively. The measured insertion loss is about 2 dB and 2.2 dB at the lower and upper passbands. The measured results show good agreement with the simulated ones.     

一种基于多模谐振器的超宽带带通滤波器设计

基于多模谐振器(MMR)理论,采用微带线-槽线混合结构,通过增加输入、输出之间耦合提高频率选择性,设计了一种结构紧凑体积小,频率选择性高的超宽带带通滤波器。利用电磁仿真软件HFSS对设计结果进行了仿真。仿真结果表明:该滤波器通带覆盖了3.5~10.4 GHz之间的频段,并具有较好的带内带外性能。对该滤波器进行了实物加工和测试,实测结果与理论分析和仿真结果吻合良好,该滤波器拥有较好的性能,可应用于超宽带无线通信系统。     

基于双同轴阶跃阻抗谐振器的带通腔体滤波器的设计

介绍了一种减小腔体滤波器体积的设计方法。分析了双同轴阶跃阻抗谐振器的谐振条件和未加载Q值,依据滤波器理论和运用HFSS软件设计了一个基于双同轴阶跃阻抗谐振器的带通腔体滤波器。在3.7～3.9 GHz的频带内,该滤波器插入损耗小于0.5 dB,回波损耗大于20 dB,测试与仿真结果相吻合。该滤波器具有体积小、结构简单易于加工等优点。     

Microstrip dual-band bandpass filter with independently tunable passbands using varactor-tuned stub loaded resonators

In this paper, a dualband bandpass filter with independently tunable passband is proposed. Two half-wavelength resonators with shunt stub have been placed side by side, fed with a common input-output microstrip line to achieve the individual tunability without affecting other passband. For tuning resonance frequency, varactor diodes are used at the ends of the half wavelength resonators and also at the end of the shunt stubs. Proper shunt stub length and width are derived numerically in such a way that only one control voltage is required in each passband. Measured results show that lower passband can be tuned in a frequency range from 1.78 to 1.96 GHz, whereas the upper passband varies from 2.27 to 2.39 GHz individually. H shaped DGS is integrated below the input-output feed lines to suppress higher order harmonics up to 21 GHz with more than 19 dB attenuation.     

基于缺陷地结构的小型化双频带带通滤波器

提出了一种新型的基于缺陷地结构的双频带带通微带滤波器.缺陷地结构采用双模开口谐振环形式, 并使用不同组合方式的双模开口谐振环产生两个通带.滤波器的两个工作中心频率分别为3.5 GHz和5.8 GHz, 其中第一个频带涵盖了所有全球微波互联接入的应用频段, 第二个频带可以应用于雷达设备.为了进一步证实这款滤波器的性能, 基于Roggers RT5880板材制作了滤波器实物, 整体滤波器的大小仅为20 mm×20 mm, 测量数据和仿真结果吻合较好, 并且有两个传输零点, 可以满足工程上的需要.     

基于C型DGS的双通带滤波器设计

基于环形谐振器的基础结构,提出了新型C型缺陷地结构(defected ground structure,DGS)的双通带滤波器。利用C型DGS结构的高阻抗传输线特性,通过调节C型DGS结构的长度与宽度尺寸,可以实现对双频段带通滤波器的工作频段控制。最后给出了一个2.4 GHz和3.45 GHz工作频段的微带双通带滤波器设计实例,其测试结果与仿真结果吻合。     

基于E型双模谐振器的源负载耦合带通滤波器设计

为实现滤波器的小型化和高性能,提出了两款中心加载的E型双模谐振器,并对其进行了奇偶模分析。在此基础上通过引入源负载耦合,采用ADS与HFSS软件进行了仿真与优化。开路支节加载与短路支节加载的E型双模谐振器分别比方环谐振器减少42.8%与52.6%。实测结果表明,设计的滤波器中心频率分别为4.22 GHz和3.75 GHz,相对带宽分别为33.6%和9.1%,带内插损分别为-0.9 dB和-1.9 dB,带外零点位置与计算仿真结果吻合良好。这两款滤波器不仅尺寸小、插损低,并且具有宽阻带、传输零点可调的优点,短路支节加载的双模滤波器在选择性与带外抑制方面性能更好,可以广泛应用于各种微波电路中。     

Tri-band microstrip bandpass filter using input/output cross coupling

A compact tri-band bandpass filter using input/output cross coupling is proposed. Three passbands can be adjusted by changing the characteristic impedance of the T-shaped structure with a shorted stub. The three passbands are designed to operate at 1.85, 3.5 and 5.2 GHz based on the T-shaped structure. Four transmission zeros are used to realise high selectivity for the passbands. Good agreement can be observed between the measured and simulated results.     

脊双模波导滤波器的分析及设计

介绍了一种能实现脊双模波导滤波器的新型结构,分析了其腔内模式的耦合极性,利用不同的耦合极性对频率响应的影响可实现具有一对传输零点的双模滤波器,也可实现无传输零点的双模滤波器.以相同脊谐振单元不同的放置方向组成的两种带通滤波器为例,利用AnsoftHFSS仿真得到了两种不同的频率响应,结果与理论分析一致.最后设计出了一个六阶三传输零点的双通带滤波器,带内插损均小于0.6 dB,回波损耗小于-15 dB.     

Compact interlocked-coupled filter using folded stepped-impedance resonators

A microstrip interlocked-coupled bandpass filter is proposed with a markedly compact structure. The low-impedance open-end line of the quarter-wavelength Stepped-Impedance Resonator (SIR) is replaced by two open-end high-impedance lines, which not only facilitate the coupling mechanism but also provide the strong electric coupling between resonators. With the proper utilization of folded SIRs, the occupied area of coupled-resonator pair can be reduced. By applying the proposed coupled-resonator pair, the passband filter with the compact size can be realized. Good agreement between measured and simulated results is observed. The proposed filter is desirable for compact and high-performance microwave circuit applications.     

Miniaturized microstrip bandpass filter designed using rectangular dual spiral resonator

A miniaturized microstrip bandpass filter based on a rectangular dual spiral resonator (DSR) is proposed in this paper. The rectangular DSR bandpass filter is centered at 3.65 GHz to suit for Wireless LAN (IEEE802.11y) application. The proposed filter offers transmission zero at the high side of out-of-band response. Across the bandwidth, the measured minimum insertion loss is about 1.7 dB, while the measured return loss is better than 19 dB. Measurement results are good agreement and closed to the simulated ones. The total circuit size of the miniaturized bandpass filter is about 0.145λ_g by 0.135λ_g, where λ_g is the guided wavelength at 3.65 GHz.     

A new method of symmetric dual-band bandpass filter coupling matrix synthesis

A coupling matrix synthesised approach for symmetric dual-band bandpass filter is presented in this article. The dual-band filter is viewed as a single-band filter with a transmission zero inside the pass-band. Separately considering the odd and even order of each single filter that composed symmetric dual-band bandpass filter, the corresponding transmission function is shown by analysing an additional transmission zero produced. Finally, a simulation example is used to verify the correctness of the theory.     

脊双模波导滤波器的研究

介绍了一种利用脊谐振器产生的正交准TEM简并模实现脊双模波导滤波器的新方法。通过分析脊谐振器放置在主模传输波导中不同位置的特性,建立了耦合拓扑结构图,实现了三种不同类型的频率响应。利用全波仿真软件AnsoftHFSS,分别以方形和十字交叉这两种脊谐振器作为基本单元,设计出了两腔四阶的脊双模波导滤波器,两个滤波器的插损均小于0.2 dB,回波损耗小于–23 dB,仿真结果与预期吻合。     

基于半模基片集成波导的新型带通滤波器研究

在半模基片集成波导上嵌入互补开环谐振器结构,设计了一种结构紧凑的新型带通滤波器.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半模基片集成波导和互补开环谐振器组成具有带通特性的滤波器,通过改变互补开环谐振器结构参数,非常容易调节带通滤波器通带频率,利用该特性可以更容易实现任意通带微波滤波器.该滤波器具有体积小巧、损耗低、易制作、方便与其他电路集成等优势.