一种耦合线加载的双通带滤波器

提出一种基于耦合线加载的双通带滤波器,该滤波器在开口矩形环内部加载两根相互耦合的微带,从而产生两个通带。与加载单枝节的双通带滤波器相比,该滤波器在设计时有更多可变参数和更小的调节步进。比如当耦合线宽度不等步进变化时通带中心频率会向相反方向变化,这一性质可以用作对两通带之间的频率间隔进行微调。测试结果表明,该滤波器有两个通带,其中心频率分别为3.78 GHz 和6.55 GHz,相对带宽分别为4.6%和4.8%。除此之外,还研究了调整加载耦合线的长度和宽度对滤波器频率特性的影响。仿真和实测结果之间良好的吻合证实了设计方法的有效性。     

一种新颖微带双通带带通滤波器的设计方法

本文提出了一种新颖的微带双通带带通滤波器的设计方法。该微带双通带滤波器由两个中心频率不同的滤波器组成,并采用耦合线实现外部耦合。设计中引入源与负载之间的耦合,得到了额外的有限频率传输零点,改善了滤波器的衰减特性。通过调节源与负载之间耦合的强弱,可以适当地调节传输零点的位置。经设计并加工了一款4阶微带开环结构双通带滤波器,实测响应与仿真响应吻合较好,验证了该方法的有效性。     

基于菱形SIW的小型化双频可控带通滤波器

提出了一种四分之一模菱形基片集成波导谐振腔,设计并制作了一款小型化的双频带通滤波器.引入了T型槽线结构,实现了滤波器双通带中心频率的调节.利用间隙耦合、高低阶模式耦合和源负载耦合,在带外产生了7个传输零点,提高了滤波器的频率选择特性.滤波器双通带中心频率分别为4.4和7.7 GHz,3 dB带宽分别为517和405 M...     

Ku波段微波宽带滤波器的优化设计

文章对半波长平行耦合线滤波器进行了研究。该微波宽带滤波器采用了耦合微带线式,由于结构紧凑、寄生通带的中心频率较高,适应频带范围较大,在微带结构中应用极为广泛。此文通过理论分析及计算并运用微波CAD软件进行优化,实现了Ku波段宽带微波滤波器的优化设计。     

应用于WLAN&WiMAX的小型化SIR可调双通带滤波器

对传统双频段耦合方案进行改进,提出一种新型双通带滤波器结构。该滤波器由两个对称阶跃阻抗谐振器(SIRs)组成,通过调节SIR的电长度,可以得到中心频率可调的通带。为了验证设计与分析的正确性,提出和设计了3个双通带滤波器。Ⅰ型滤波器两个通带的中心频率分别为2.4 GHz和3.5 GHz,相对带宽分别为5.8%和13.7%;Ⅱ型滤波器两个通带的中心频率分别为3.5 GHz和5.2 GHz,相对带宽分别为5.7%和9.2%;Ⅲ型滤波器两个通带的中心频率分别为2.4 GHz和5.2 GHz,相对带宽分别为6.3%和5.4%。Ⅰ型和Ⅱ型滤波器均适用于宽带互通微波互联接入(Wi MAX)和无线局域网(WLAN)应用。Ⅲ型滤波器适用于双频WLAN应用。对所有滤波器进行加工与实测,测试结果与仿真结果吻合较好。     

一种通带可控的双频SIW滤波器设计

提出了一种通过加载T形槽实现双频可控的基片集成波导带通滤波器。滤波器的双频特性由SIW腔内对称的T形槽线谐振器微扰TE101和TE102模得到。通过改变槽线谐振器的物理尺寸可以实现对滤波器两个通带中心频率的灵活控制。为了验证上述方法的可行性,设计了一个中心频率为3.77 GHz和9.27 GHz的双频滤波器。实测得该双频滤波器两个通带的回波损耗优于11 dB,在3.77 GHz时插入损耗为0.8 dB,第一通带的相对带宽可达13%。仿真和测试结果吻合较好,证实了设计方法的有效性。     

阶梯阻抗谐振器在微波双通带滤波器设计中的应用

阶梯阻抗谐振器（Stepped Impedance Resonator）寄生响应的位置可以通过调整谐振器阻抗比来控制,该特性使SIR成为设计双通带滤波器的理想谐振器。设计耦合谐振器双通带滤波器需要对两组外部品质因数和耦合系数进行综合,为了减少谐振器的数量同时简化耦合系数的提取,本文采用特定耦合结构设计滤波器,并研究了影响SIR主响应和第一寄生响应处外部品质因数的因素,设计了中心频率是1.9GHz和3.2GHz,部分带宽是5%和7%的双通带滤波器。仿真结果验证了设计方法的可行性。     

共面波导馈电的小型化双通带滤波器

提出了一种采用共面波导馈电的小型多模双通带平面滤波器,该滤波器采用内部嵌套的多模谐振器缩小了电路尺寸,利用奇偶模分析方法和弱耦合激励的方式分析了该多模谐振器的谐振特性,并依此推导出其谐振频率与物理尺寸的相互关系。为了满足滤波器的馈电,端口耦合并实现小型化,引入了异面共面波导馈电结构。文中给出了四个谐振模式的分析以及两个通带中心频率和带宽的控制机理,实现了滤波电路的频率和带宽的独立控制。最终实现了中心频率为2.39GHz 和4.34GHz,相对带宽分别为8.8%和13.4%的双通带平面滤波器。该滤波器中心频率和带宽独立设计可控,而且谐振器尺寸大小仅为0.09λg ×0.09λg 。本文所设计的滤波器结构简单、尺寸小,通带间隔离度较高、易加工制作,具有较高实用价值。     

同轴腔带通滤波器的一种设计方法

采用负阻线子网络…构造了多腔耦合的同轴带通滤波器电路模型，应用电路分析软件对滤波器进行了分析优化，得到腔体之间耦合系数和接入点位置。应用三维全波分析软件，分析了腔体结构参数与耦合系数和耦合窗的关系。以这种路和场的仿真、优化相结合的方法，得出了滤波器的耦合和输入输出结构参数。运用该方法设计的中心频率2．4GHz，通带100MHz的六腔滤波器的实际测试结果与仿真分析结果基本一致。     

多传输零点的新型五通带多模滤波器

针对目前多模滤波器通带数量以及通带选择性有待提高的问题,提出一款新型的基于枝节加载谐振器的五通带多模滤波器。该滤波器采用了一种新型的馈电和耦合方式,可以独立控制外部品质因数和控制多数通带的耦合系数。该滤波器不需要过孔,制作简单。由于源-负载之间的耦合以及多径传输效应的影响,产生了多个传输零点,提高了通带的选择性。进行了滤波器的设计,制作和测试,测试结果与仿真结果吻合,滤波器的五个中心频率位于1.6,3,3.8,4.7,5.7 GHz,其相对带宽分别为12.5%,11.7%,5.48%,8.51%,4.37%。     

基于新型缺陷地的谐波抑制微带滤波器设计

由于分布参数传输线频率响应的周期性,通常微带线带通滤波器在偏离主通带中心频率成分上会产生寄生通带,输出谐波.在研究经典哑铃DGS的基础上,利用新型DGS和SISS结构的单极点带阻和慢波特性,设计出五阶微带低通滤波器,并将之应用于三阶耦合线带通滤波器,改善其寄生通带.经过仿真验证,成功地抑制了三阶耦合线带通滤波器的谐波输...     

非平行微带线间的串扰抵消研究

非平行微带线是印刷电路板(PCB)上不可避免的互连结构。针对PCB 上非平行微带线间的串扰问题,用平行微带线近似非平行微带线,把平行耦合微带线间的串扰抵消方法应用到非平行耦合微带线中,提出了利用耦合传输线信道传输矩阵方法来进行远端串扰抵消,在对非平行耦合传输线信道传输矩阵进行特征值分解的基础上构建串扰抵消电路。仿真了非平行微带线间夹角分别为q=3°、5°、10°时的串扰,结果表明,该方法可以有效改善非平行微带线上信号眼图的质量,串扰抵消效果良好。     

Characteristics of Coupled Microstrip Transmission Lines-I: Coupled-Mode Formulation of Inhomogeneous Lines

This paper consists of two parts. In Part I, coupled-mode theory is employed to determine the effects of reflection at the various ports and unequal inductive and capacitive coupling coefficients on the coupling and directivity of two coupled lines. Since couplers utilizing microstrip lines generally have unequal inductive and capacitive coupling coefficients, the results presented here should be useful in explaining the behavior of microstrip coupled lines. It is shown how the difference in the coupling coefficients leads to finite directivity and, under certain conditions, to "codirectional" instead of "contradirectional coupling." In Part II, the coupling coefficients and other parameters of various microstrip-line geometries are presented. Using these parameters in the results obtained here leads to an improved understanding of and design criteria for coupled microstrip lines.     

一种带输入输出抽头的新型阶梯式阻抗微带带通滤波器

本文提出了一种利用阶梯式阻抗微带线构造微型带通滤波器的新型结构。在该结构中引入以零相位方式接入的微带抽头，与带集总电容的阶梯式阻抗微带滤波器相配合，通过在通带两侧分别产生两个传输零点，很好地改善了滤波器的带通特性。     

Riccati matrix differential equation formulation for the analysisof nonuniform multiple coupled microstrip lines

A Riccati matrix differential equation (RMDE) is formulated for analyzing nonuniform coupled microstrip lines (NCML's) in the frequency domain. The formulation is based on a reciprocity-related definition in the theory of multiconductor transmission lines under quasi-TEM assumption. The hybrid-mode nature of modal phase velocities and strip characteristic impedances for multiconductor microstrip structure is included. The nonlinear RMDE is first transformed into a first-order linear differential matrix equation which can be efficiently solved using method of moments. A convergence study is performed to investigate the sufficient number of basis functions used in the method. The voltage-scattering parameters of a tapered microstrip and two three-line structures are presented. The frequency responses of a pair of nonuniform coupled lines are measured and compared with calculated results     

Propagation Parameters of Coupled Microstrip-Like Transmission Lines for Millimeter-Wave Applications

A variational expression is derived for the propagation parameters of coupled microstrip-like transmission lines for millimeter-wave applications using the "transverse transmission line" method. Numerical results are presented for the coupled inverted microstrip lines, and for the coupled suspended microstrip lines. The effects of the top and sidewalls and also of the finite thickness of strip conductors on the even- and odd-mode impedances are studied. The use of a dielectric overlay in equalizing the even- and odd-mode phase velocities is investigated.     

基于耦合三线结构的宽带功分器研究*

由于传统的威尔金森功分器需要通过多级传输线的级联来拓展其工作带宽,增加了电路设计的复杂度。因此本文提出了一种基于耦合三线的宽带功分器结构。通过在四分之一波长传输线的两端分别引入一节耦合三线,使功分器实现了宽带特性。采用三线耦合器与阻抗变换理论,对影响功分器工作带宽、输入输出端口匹配度和隔离度参数进行了理论分析,并设计制造了基于此结构的宽带功分器。测试结果表明该功分器具有很好的端口匹配、传输损耗和端口隔离特性。     

Nonuniformly coupled microstrip transversal filters for analog signal processing

The Fourier transform relationship between frequency response and impedance profile for single nonuniform transmission lines is used to derive the time-domain step response of single and coupled nonuniform lines. The expression for the step response of a characteristically terminated nonuniformly coupled transmission line structure is shown to correspond to the characteristic impedance profile. By using this relationship, any arbitrary step response can be realizing by utilizing nonuniformly coupled strip or microstrip lines for possible applications as waveform-shaping networks and chirp filters. A numerical procedure to compute the step response of the nonuniform coupled line four-port is also formulated in terms of frequency-domain parameters of an equivalent cascaded uniform coupled line model with a large number of sections. Sinusoidal and chirp responses are presented as examples that are readily implemented using coupling microstrip structures. The step response of an experimental nonuniformly coupled microstrip structure is presented to validate the theoretical results.<>     

Effect of the Dielectric Anisotropy on the Propagation Properties of Microstrip Tapers with Height Variations

This paper deals with the design and application of nonuniform microstrip transmission lines on anisotropic substrates. A rigorous analysis is based on the use of Hertz vector potentials, moment method and transmission line theory to determine the dispersion characteristics of single and coupled tapered microstrip lines for accurate performance prediction. Results are presented for the main parameters providing the necessary information to design several devices on tapered microstrip, with variation on the strip width and dielectric height, for (M)MIC and antennas applications. A good agreement was observed with the results available in the literature for tapered lines on isotropic substrates.     

A planar-lumped model for coupled microstrip lines anddiscontinuities

A convenient model for analyzing coupled microstrip line discontinuities is presented. A planar-lumped model similar to the planar waveguide model for single microstrip lines is developed for coupled microstrip lines. Fields underneath the two strips and those fringing at the outer edge are modeled by two equivalent planar waveguides. Electric and magnetic field coupling in the gap region is modeled by a lumped network. The lumped network parameters are evaluated such that [C] and [L] matrices for the model are identical with those for coupled lines. The model is verified by comparing coupler characteristics with those obtained by the conventional coupled line analysis. Just as the planar model of a single microstrip has been used for characterizing microstrip discontinuities, the planar-lumped model developed is used for coupled line discontinuities. Examples given include coupled microstrip sections with chamfered bends located at right angles to single microstrip lines, for which the results are in good agreement with experimental values