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     

Equivalent transformations for the mixed lumped Richards sectionand distributed transmission line

The authors introduce an analysis method for nonuniform transmission lines. Equivalent transformations between a circuit consisting of a cascade connection of a lumped Richards section, an ideal transformer, and a distributed transmission line and one consisting of a cascade connection of a class of a nonuniform transmission line, a lumped Richards section, and an ideal transformer, are given. Characteristic impedance distributions of these nonuniform transmission lines are expressed as hyperbolic or trigonometric functions. It is quite difficult to find the exact network functions of nonuniform transmission lines from the telegraph equation, but by using the equivalent transformation described it becomes possible to obtain exact network functions of a class of nonuniform transmission lines     

Equivalent Representations of Lossy Nonuniform Transmission Lines

Equivalent transformations, which were recently derived for mixed lumped and distributed circuits, may be extended to circuits consisting of lumped reactance, resistors, and Iossy transmission lines. It is shown that circuits consisting of a cascade connection of lumped element sections and Iossy uniform transmission lines are equivalent to circuits consisting of a cascade connection of lossy nonuniform transmission lines, lumped elements, and ideal transformers. Furthermore, by considering the limiting case of these transformations, equivalent transformations for circuits consisting of a cascade connection of lumped reactance, resistors, and nonuniform transmission lines are obtained. Exact equivalent circuits of Iossy even-order binomial form transmission lines are derived from these equivalent transformations.     

Kuroda's Identity for Mixed Lumped and Distributed Circuits and Their Application to Nonuniform Transmission Lines

Kuroda's identities, which are used in analysis and synthesis of distributed transmision line circuits, may be applied to mixed lumped and distributed circuits. It is shown that circuits consisting of cascade connections of lumped reactances and uniform transmission lines are equivalent to circuits consisting of a cascade connection of nonuniform transmission lines, lumped reactances, and ideal transformers. Moreover, by using these equivalent transformations, network functions of some nonuniform transmisssion lines can be derived exactly.     

Equivalent Representations of Nonuniform Transmission Lines Based on the Extended Kuroda's Identity

Kuroda's identity may be extended to circuits consisting of lumped reactance elements and nonuniform transmission lines. It is shown that these circuits are equivalent to circuits consisting of cascade connections of nonuniform transmission lines whose characteristic impedance distributions are different from original ones, lumped reactance elements, and ideal transformers. If a characteristic impedance distribution W(x) of an original nonuniform transmission line is given, a characteristic impedance distribution Z(x) of a transformed nonuniform transmission line may be uniquely obtained using W(x). Moreover, by using these equivalent transformations, network functions of these transformed nonuniform transmission lines can he derived exactly.     

Equivalent Transformations for Mixed-Lumped and Multiconductor Coupled Circuits

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.     

Equivalent Circuits of Binomial Form Nonuniform Coupled Transmission Lines

Equivalent circuits of nonuniform coupled transmission lines whose self and mutual characteristic admittance distributions obey binomial form are presented. Telegrapher's equations of these nonuniform coupled transmission lines can he solved exactly rising Bessel functions of fractional order. By decomposing the chain matrix, it is shown that equivalent circuits of these nonuniform conpled transmission lines consist of cascade connections of lumped reactance elements, uncoupled uniform transmission lines and ideal transformers.     

Design of transformerless quasi-broad-band matching networks forlumped complex loads using nonuniform transmission lines

A simple design method for transformerless and lossless quasi-broadband matching of a lumped RC load is presented by use of a parabolic nonuniform transmission line. The key idea in removing an ideal transformer from the matching network is based on impedance transformation of the nonuniform transmission line, whose mixed lumped and distributed equivalent circuit contains an ideal transformer. Illustrative examples and some design curves are presented     

Two-Port Equivalent Circuits of Two-Wire Parabolic Tapered Coupled Transmission Lines

Two-port equivalent circuits of two-wire parabolic tapered coupled transmission lines (PTCTL) with open or short terminal conditions on the remaining two ports are presented. First, two-port equivalent circuits of PTCTL, whose characteristic admittances increase along the lines, are shown. Second, two-port equivalent circuits of PTCTL, whose characteristic impedances increase along the lines, the dual of the previous circuits, are shown. These two-port circuits of PTCTL are expressed in terms of two equivalent representations, one having mixed, lumped and uniform distributed circuits, and the other consisting of uncoupled nonuniform distributed circuits.     

射频连接器与微带线组件焊接过渡段阻抗补偿研究

射频连接器与微带线组件常用于通信系统电路中,而组件焊接过渡段的阻抗不连续会使电路中的信号损耗增大.针对该问题,本文对射频连接器与微带线组件焊接过渡段进行研究,基于传输线理论,建立焊接过渡段的等效电路模型.讨论了焊接过渡段特征阻抗不连续的原因,同时提出了补偿优化方案.此外,通过电磁场与电路的联合仿真,提取出补偿前后等效电路模型的电参数,从等效电路模型的角度分析了补偿方案对组件过渡段复杂电磁特性的影响.有限元仿真分析与实验测试结果显示,补偿后组件的性能显著提高,证明了补偿方案有效可行.     

An efficient method for analysis of arbitrary nonuniformtransmission lines

The analytical solution of an ideal linear varied nonuniform transmission line (LNTL) has been obtained and the exact linear two-port ABCD matrix of LNTL has been given correctly for the first time. By using cascaded LNTL sections to approximate an arbitrary characteristic impedance profile, a new technique has been presented in this paper for analyzing an arbitrary nonuniform transmission line (NTL). The technique is far better than the conventional technique in terms of the computational accuracy and intensity since it uses a piecewise-linear characteristic impedance profile in place of the stepped profile used by the conventional technique. Several numerical examples have been given to demonstrate the method     

A genetic approach to the synthesis of composite right/left-handed transmission line impedance matching sections

A genetic approach for the synthesis of composite right/left-handed (CRLH) transmission line impedance matching sections is presented. Continuous parameter genetic algorithm (CPGA) is used for the synthesis. Examples for a uniform CRLH transmission line impedance matching section and a nonuniform CRLH transmission line impedance matching section are given.     

Error bound for the approximate Fourier transformation relationshipfor nonuniform transmission lines

In this paper, an error bound is presented for Bolinder's well-known approximate formula relating the input reflection coefficient and the local reflectivity parameter of a lossless nonuniform transmission line (NTL) via the Fourier transformation. Despite modern computers allowing an accurate analysis, Bolinder's formula is still of interest. First, it makes possible an approximate synthesis of NTLs which can be used in a subsequent optimization. Second, it supports an intuitive grasp for the electrical properties of NTL's     

Impedance Transformation and Matching for Lumped Complex Load with Nonuniform Transmission Line

New nonuniform transmission-linematching networks for a class of lumped complex loads are presented. A parabolic (or reciprocal parabolic) tapered transmission line, whose exact equivalent circuit is represented by a mixed lumped and distributed circuit, can transform the lumped series RC (or parallel RL) loads into different lumped impedances which are more convenient than the original load impedances for ordinary matching network design. Simple design procedures are described and useful design charts are given. Also, numerical examples are shown including experimental verification.     

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.<>     

A lower bound for the length of nonuniform transmission line matching sections

A lower bound for the length of a nonuniform transmission line section needed to match a given load impedance to a given real input impedance is derived. The bound depends not only on the load and input impedances, but also on the maximum and minimum permissible values of characteristic impedance within the nonuniform line. Several specific cases are presented to illustrate the tightness of the bounds.     

Exact capacitance of a lossless MOS capacitor

First order Ricatti equations are obtained for the capacitive 3-wire transmission line of a one-dimensional MOS capacitance which give an order of magnitude improvement in numerical computation time over the transmission matrix solution of the lumped section equivalent circuit model of the transmission line.     

Simplified model for avalanche-resonance-pumped semiconductor diodes

A simplified model for avalanche-resonance pumped semiconductor diodes is presented in terms of its voltage/current relation and its equivalent circuit. All signal levels can be handled and the compatibility with lumped or transmission line circuits will be useful for circuit modelling. Small- and large-signal examples for degenerate pumping are described.     

传输线场、路模型的一致性探讨

均匀传输线可以采用电磁场理论来建立分析模型。而电路理论在电磁场理论基础上、加上集中参数假设,也可建立均匀传输线的分析模型。本文在推导出两种分析模型基础上,论证了两种模型的一致性,并从场和路两方面剖析了传输线传播特性与其周围媒质传播特性的差异、以及影响传输线传播特性的因素。本文的探讨,有利于从事"电路理论"和"电磁场"课程教学的教师加深对均匀传输线传播特性参数的理解。     

A Nonuniform Coaxial Line with an Isoperimetric Sheath Deformation

For impedance matching in transmission lines, nonuniform lines, obeying laws of taper like the exponential, the Dolph-Chebyshev etc., are used. For the nonuniform coaxial line, constructional advantages can be derived for the same electrical performance if it has a uniform circular inner conductor with an outer conductor having an isoperimetric transition, from circular to elliptic cross section, in conformity with the established laws of taper. This problem has been examined in the paper, and the required design formulas as well as the design charts are developed. The effect of an impedance and geometric discontinuity at the low-impedance junction of such a nonuniform line and the concentric circular uniform line is discussed. The use of the isoperimetric transition line in microwave components is indicated.