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魏文 《电气电子教学学报》2008,30(4):16-18
面对在几个稳定静态工作点的电路中选择时,如何迅速判定各电路静态工作点稳定性能的优劣,是一个值得弄清的重要问题。本文给出了求出典型放大器偏置电路的戴维南等效电路,依此等效电路可直接看清电路工作时的物理意义,进一步判定各个放大电路静态工作点稳定性能的优劣。 相似文献
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The propagation characteristics and circuit properties of two inductively coupled superconducting transmission lines are studied. An expression for the attenuation of the coupled-line modes is derived for the case of low loss. It is found that for transmission line geometries of practical interest the low-loss expression agrees well with the more general numerical solution. The numerical solution is used to determine the dispersion characteristics of inductively coupled lines as a function of the superconductor thickness and the operating temperature. An equivalent circuit, with the same dispersion equation, is presented along with the relationship between the circuit element values and the physical parameters of the line. The characteristic impedances of the two dominant coupled-line modes are derived from the equivalent circuit expressions 相似文献
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Analytical solution of lossless field-excited multiconductor transmission lines is presented. The equivalent circuit of a multiconductor transmission line with distributed sources is reduced to a simple lumped parameter circuit with independent voltage sources at both the ends of the transmission line. The transient source waveforms are analytically estimated for exponential time dependence of the external field, as EMP, ESD, and lightning. The method is suitable for a direct implementation in computer-aided circuit analysis codes and enables a very fast analysis for any load condition. Some numerical results are presented for single conductor and multiconductor lines excited by all EMP plane-wave field 相似文献
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As an analytical method for nonuniform transmission lines (NTLs) equivalent transformations are extended to a more general case, namely a mixed lumped Brune-type section and a uniform transmission line (unit element, UE). Circuits consisting of a cascade connection of a lumped Brune section and a UE are equivalent to one consisting of a cascade connection of a nonuniform transmission line whose characteristic impedance distribution is expressed with a trigonometric function and a lumped Brune section. This equivalent transformation method is easily applied to a circuit consisting of a lumped C section and a UE. The equivalent circuit is a circuit consisting of an NTL and a lumped C section. In this case, the characteristic impedance distribution of the NTL may be expressed in terms of a hyperbolic function. Exact network functions of the NTLs are easily obtained from the equivalent circuits without solving the telegrapher's equation. By considering the limiting case of these equivalent transformations, equivalent transformations for circuits consisting of a cascade connection of a lumped resonance circuit and a circuit and a uniform transmission line are derived 相似文献
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针对泄漏同轴电缆作为分布式传感器应用于物联网和智能家居的室内安防入侵检测时,运用全波仿真软件HFSS不能有效仿真长距离的耦合漏缆的问题,提出了一种等效电路模型.利用参数提取软件,先提取单个开槽的缝隙单元的等效电路模型,然后借助于传输线理论,利用四个传输矩阵级联得到整段漏泄同轴电缆的传输矩阵.并考虑两根漏缆缝隙间相互耦合,提出了表征耦合特性的等效电路模型.将等效电路模型利用商用软件高级设计系统(advanced design system,ADS)进行电路搭建与仿真.仿真结果表明,本文提出的两根漏缆的等效电路模型与全波仿真结果非常符合,可以快速地仿真长距离的耦合漏缆结构,并大大节约了仿真时间. 相似文献
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高速电路非均匀互连线间电磁干扰分析 总被引:1,自引:0,他引:1
根据高速电路中线宽发生变化的非均匀互连线结构特点,利用分段线性和等效电路摸型的方法,结合HSPICE电路分析软件,提出了适用于任意条数的非均匀互连线的多导体等效电路模型及仿真模型,从倾斜角度、非均匀互连线长度和信号上升时间几个特殊因素方面,对高速电路中非均匀互连线间的电磁干扰规律进行了分析和总结。 相似文献
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A synthesis method for a stripline-type branch-line 3-dB hybrid which is based on an equivalent circuit derived by the planar circuit approach is presented. The equivalent circuit of an ideal 3-dB hybrid is derived first from those of the segmented circuit elements, i.e., four three-port junctions and four quarter-wave transmission lines. A systematic synthesis process is then developed upon the basis of the equivalent circuit. Practical hybrid circuit having optimized circuit patterns which were constructed for center frequencies of 3, 5, and 7 GHz are discussed. Their measured characteristics are described. The results are shown to agree well with the theory 相似文献
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An equivalent circuit for terminated hybrid-mode multiconductor transmission lines is presented. Existing CAD packages, such as SPICE, can be used for its implementation. Model parameters can be found from either a TEM or a full-wave analysis of the transmission lines. The equivalent circuit is used to simulate multiconductor microstrip for applications in high-speed integrated circuits. The accuracy of the TEM approximation is investigated for time-harmonic as well as pulse signal propagation. For some cases examined, the time-harmonic signal propagation data obtained using the TEM approximation become quite inaccurate at frequencies in excess of 20 GHz. The TEM approximation is adequate, however, for pulse propagation with 15-ps risetime and falltime pulses on the geometries investigated 相似文献
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本文结合付里叶变换和拉氏变换技术,得出了具有任意非零初始电压、电流分布的多导体传输线的等效时域线性网络模型,传输线可以为有耗丰均匀性,该模型可与常用电路分析软件接口,因而可处理非线性终端负载,给出了一个应用本文模型进行瞬态分析的例子。 相似文献
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《Microwave Theory and Techniques》1982,30(7):1034-1041
Distributed circuits consisting of a cascade connection of m -port stab circuits and multiconductor coupled transmission lines are equivalent to ones consisting of cascade connections of multiconductor coupled transmission lines whose characteristic impedances are different from original ones, m-port stub circuits, and an m-port ideal transformer bank. Because of the reciprocity of the circuit, values of transformer ratio must be identified. In the special case of a one conductor transmission line, these equivalent transformations are equivalent to Kuroda's identities. These extended equivalent transformations may be applied to mixed-lumped and multiconductor coupled circuits. By using these equivalent transformations, equivalent circuits and exact network functions of multiconductor nonuniform coupled transmission lines can be obtained. 相似文献
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Transient Analysis of Lossless Coupled Transmission Lines in a Nonhomogeneous Dielectric Medium 总被引:1,自引:0,他引:1
《Microwave Theory and Techniques》1970,18(9):616-626
An effective method for computing the transient response of an n-conductor transmission line system, which is characterized by multiple propagation modes of unequal phase velocities, is presented. To derive the computational algorithm, an equivalent circuit consisting of n decoupled transmission lines in conjunction with two congruence transformers was constructed and converted into two disjointed resistive n-ports. It is shown that the electrical behavior of the coupled transmission lines can be completely described in terms of the static capacitance matrices of the conductor system. The experimental results obtained on a three-conductor microstrip-printed circuit were found to be in excellent agreement with the computed results 相似文献
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A generalized method of moments (MoM)-SPICE iterative technique for field coupling analysis of multiconductor transmission lines (MTLs) in the vicinity of complex structures is presented. Telegrapher's coupling equations are modified with additional distributed voltage and current sources for more accurate analysis of the total current induced onto transmission line bundles in the presence of complex structures. These additional voltage and current sources are introduced to enforce the electric field boundary condition and continuity equation on MTLs beyond the quasi-static regime. The surrounding structure is modeled via the MoM and a SPICE-like simulator is used to simulate equivalent circuit model of the MTLs extracted via the partial element equivalent circuit method. The proposed technique is based on perturbation theory with the quasi-static current distributions on the transmission lines still assumed to be dominant. Validation examples for single and MTLs are given in the presence of complex structures. 相似文献
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On définit ici une cellule élémentaire, qui permet de construire un aiguillage, l'équivalent combinatoire d'un registre à décalage, un convertisseur virgule flottante/virgule fixe. L'utilisation de passages enterrés permettrait une réalisation en circuit intégré assez compacte, avec métallisation unique pour les interconnections. An elementary routing cell is defined, and used in several arrays: a programmable switch, a switching-network equivalent to a shift register and a floating/fixed-point convertor. Designing the last one for integration, with deep contacts would lead to a rather compact array, which needs only one interconnection metallisation. 相似文献
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A new element-saving equivalent circuit for the analysis of generalcoupled n -wire transmission lines
A novel efficient method for modeling the general coupled n -wire transmission line is proposed. The equivalent circuit presented has the following advantages: (1) no balanced lines are needed; (2) all element values are positive; and (3) the number of elements required by the equivalent circuit is at most equal to the number of nonzero couplings plus one. A simple method for deriving the equivalent circuit is outlined. Examples are supplied to show the application of the method 相似文献
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Wide-Band Operation of Microstrip Circulators 总被引:1,自引:0,他引:1
《Microwave Theory and Techniques》1974,22(10):849-856
Octave bandwidth operation of Y-junction stripline and microstrip circulators is predicted using Bosma's Green's function analysis. The width of the coupling transmission lines is found to be a significant design parameter. Theoretical and experimental results are presented which show that wide lines and a smaller than usual disk radius can be used to obtain wide-band operation. A microstrip circulator is reported which operates from 7-15 GHz. Also presented are an analysis of the input impedance and an approximate equivalent circuit for the Y-junction circulator which shows the relationship between Bosma's equivalent circuit and that of Fay and Comstock. 相似文献
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An equivalent transformation for the mixed lumped lossless two-portand distributed transmission line
It is shown that the circuit consisting of a cascade connection of a lumped type D section and a distributed transmission line is transformed to an equivalent circuit consisting of a cascade connection of a class of a nonuniform transmission line and a lumped type D section. Previously obtained equivalent transformations, i.e., Brune, type C, type A and type B sections, are included in the type D section transformation presented in this paper. The type D section is reduced into the Brune section and both type A and B sections are obtained as a degenerate case of the Brune section. Procedures for obtaining these transformations are given and a general theorem concerned with a mixed lumped lossless two-port and distributed transmission line transformation is established. By using these equivalent transformations, a new analytical method for nonuniform transmission lines is derived without having to solve the telegraph equations 相似文献
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提出了一种通过传递函数分析来确定在片传输线等效电路模型拓扑结构的新方法。通过这种方法,可分析得出由不同1-π单元组成的等效电路的拟合能力。通过对测量S参数的有理逼近构建了一个宽带宏模型。通过对比等效电路模型与宏模型的传递函数的零点和极点,开发出一种可靠且高效的确定传递函数等效电路结构的方法。分析发现复极点决定了模型的宽带拟合能力。共面传输线到50 GHz的测量S参数证明了本文提出的方法非常有助于寻找满足精度要求且最简单的拓扑。 相似文献