微带线电磁辐射的等效建模与辐射干扰分析

随着信息技术的快速发展,通信设备中的电路集成度愈来愈高,微带线成为PCB板上产生电磁辐射的主要部件。文章采用FEKO电磁仿真软件实现了L形带线电磁辐射的等效建模,并基于此,仿真分析了微带线电磁辐射对邻近微带线的电磁干扰特性。首先,采用FEKO电磁仿真软件,建立L形微带线的电磁辐射模型,仿真得到其上方某一邻近平面的磁场分布。其次,根据镜像原理,构建微带线电磁辐射的偶极子阵列等效模型。最后,采用该偶极子阵列辐照PCB板上的单根微带线,分析微带线上的电磁干扰特性。     

平面传输线上瞬态脉冲信号的联合时—频描述

本文研究瞬态脉冲信号在微带线和共面波导传输线上的传输特性。用联合时－频描述方法将时域脉冲信号扩展到时间－频率的二维平面，通过时间窗、频率窗和时－频平面对矩形和高斯脉冲信号的瞬态特性进行比较分析，与传统的傅立叶分析相比，对瞬态脉冲信号的联合时－频描述，可以更直观、更全面地了解脉冲信号在平面传输线上任意时间、任意位置的瞬态变化。     

适用于Ka波段圆形电子注行波管的半圆形卷绕微带线慢波结构

提出了一种基于开槽介质基底的卷绕微带线慢波结构.由于金属曲折微带线印制在介质基底的半圆形槽中,这种卷绕微带线慢波结构非常适合圆形电子注行波管,从而使得采用这种新型慢波结构的行波管可以利用传统的周期永磁磁场进行聚焦.文章对提出的卷绕微带线慢波结构的色散特性,耦合阻抗,传输特性及注-波互作用进行了分析.和传统的平面微带线慢波结构相比,提出的卷绕微带线慢波结构具有更低的相速、更弱的色散和更高的耦合阻抗,从而使得其适合于低电压、宽频带、小型化的毫米波行波管.将同步电压及直流电流分别设置为6 550 V及0.1 A的情况下,基于该卷绕微带线慢波结构的Ka波段行波管在35 GHz处能够输出42.32 W的功率,对应增益为26.26 dB,且均匀聚焦磁场只需0.4 T.     

适用于Ka波段圆形电子注行波管的半圆形卷绕微带线慢波结构（英文）

提出了一种基于开槽介质基底的卷绕微带线慢波结构.由于金属曲折微带线印制在介质基底的半圆形槽中,这种卷绕微带线慢波结构非常适合圆形电子注行波管,从而使得采用这种新型慢波结构的行波管可以利用传统的周期永磁磁场进行聚焦.文章对提出的卷绕微带线慢波结构的色散特性,耦合阻抗,传输特性及注-波互作用进行了分析.和传统的平面微带线慢波结构相比,提出的卷绕微带线慢波结构具有更低的相速、更弱的色散和更高的耦合阻抗,从而使得其适合于低电压、宽频带、小型化的毫米波行波管.将同步电压及直流电流分别设置为6 550 V及0.1 A的情况下,基于该卷绕微带线慢波结构的Ka波段行波管在35 GHz处能够输出42.32 W的功率,对应增益为26.26 dB,且均匀聚焦磁场只需0.4 T.     

各向异性介质基片平面波导的直线法分析

本文将直线法推广应用于分析各向异性介质基片平面波导的色散特性,并对屏蔽单微带线和单鳍线的色散特性作了具体分析和计算,数值结果与有关文献结果基本一致.     

屏蔽微带线及耦合微带线的色散特性和高次模

本文用积分限具有间隙的奇异积分方程法对屏蔽微带线及耦合微带线进行了混合模全波分析,获得了具有快速收敛特性的色散方程。利用所得色散方程对屏蔽微带线和耦合微带线的传输特性进行了数值计算,与其他方法比较表明,用本方法所推得的色散方程只需很低阶矩阵即能获得有关色散特性和高次模的有用结果。     

一种按照指数函数相对振幅分布的新型周期DGS微带线设计

设计了一种新型一维周期接地缺陷结构(DGS)微带线。与传统的周期均匀DGS单元微带线不同的是,这种改进的周期DGS平面电路是一种补偿的微带线,每个DGS单元尺寸是不同的,尺寸按照指数函数e1/n(n为正整数)的相对振幅变化。本文设计了一个均匀周期DGS平面电路和两个改进的周期DGS平面电路,测量结果显示改进的周期DGS平面电路能够更好地抑制波纹和增大带阻带宽。     

多层微带线S参量模拟研究

利用CST Microwave studio对多层微带线的S参量进行了仿真模拟,以微带线的线条宽度为参量考察了微带线的传输及反射特性,并对模拟结果进行了分析.     

屏蔽微带线特性的谱域导抗法分析

本文用谱域导抗法分析了微带线的特性,研究了屏蔽盒对微带线传播特性和色散特性的影响。谱域导抗概念的引入大大简化谱域方法中冗长的场公式推导过程,其分析结果又能保证相当高的精度。本文的研究结果表明:屏蔽盒的顶盖使微带线等效介电常数变小,对色散特性影响不大;屏蔽盒的侧壁使微带线等效介电常数变大,并减小了微带线的色散。     

微屏蔽传输线的分析与计算

微屏蔽线（ＭＳＬ）是一种新型的平面传输线，其超高的频率响应和极低的色散特性，可望广泛地应用于各种毫米波电路中，本文把用于鳍线、微带线的谱域导抗法推广到这种半封闭的传输线中，分析、计算了两种微屏蔽传输线的色散特性。计算结果与有关的实验相吻合，为这种半封闭的新型毫米波传输线提供了一种有效的计算方法。     

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     

Dissipation Loss Effects in Isolated and Coupled Transmission Lines

This paper describes a computer-aided analysis of dissipation losses in uniform isolated or coupled transmission lines for microwave and millimeter-wave integrated-circuit applications. The analysis employs a quasi-TEM model for isolated transmission lines and for the even- and odd-mode transmission lines associated with coupled-line structures. The conductor and dielectric losses are then related to equivalent charge density distributions, which are evaluated using a method-of-moments solution. The transmission lines treated by this analysis may contain any number of Iossy conductors and inhomogeneous dielectrics, consisting of any number of different homogeneous dielectric regions. A development is provided to explicitly relate the four-port terminal-electrical performance of directional couplers to evaluated even- and odd- mode loss coefficients. Examples of evaluated losses are presented in graphical form for isolated lines of inverted microstrip and trapped inverted microstrip and edge-coupled microstrip with a dielectric overlay. The analysis accuracy has been confirmed using microstrip and coplanar waveguide configurations. A comparison is made of the total loss characteristics for microstrip, coplanar waveguide, inverted microstrip, and trapped inverted microstrip. Calculations are compared with measurements for the coupled-line structure. Accuracy of the solution and suggested refinements are discussed. Five computer programs are documented.     

Foreshortening of Microstrip Open Circuits on Alumina Substrates

One particular discontinuity encountered in microstrip circuitry, the end effect of microstrip lines, is discussed. Experimental data of the end effect of 10 microstrip lines are plotted and compared with previously published data. Results reported here are consistent with that which is known about the edge effect of uniform microstrip transmission lines.     

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。     

Perturbation analysis and modeling of curved microstrip bends

The curved microstrip bend consisting of a microstrip ring segment between two microstrip lines is analyzed for its transmission properties. The microstrip lines are modeled by equivalent ideal magnetic wall waveguides for which the electromagnetic field solutions are known. The field solutions in the microstrip ring segment are derived by using a perturbation analysis of a modified (magnetic wall) curved waveguide model. Other techniques have been formulated to evaluate the fields inside curved metallic waveguides. These include the use of an equivalent nonuniformly loaded straight waveguide and rectangular and annular model analysis. The perturbation solution for the fields in the equivalent curved waveguide model presented is readily adaptable to the mode-matching procedure, and is used to calculate the properties of the curved microstrip bend discontinuities. The frequency-dependent reflection and transmission coefficients of curved microstrip bends are determined and compared with those of the right-angle and chamfered right-angle microstrip bends     

Hybrid Mode Analysis of Microstrip Lines on Anisotropic Substrates

A rigorous hybrid mode analysis is applied to microstrip lines on anisotropic substrates to determine its high-frequency performance. The analysis is based on a general formulation of the problem of planar transmission lines on multilayered substrates with uniaxial anisotropy, of which the microstrip line is a special case. Exact solution is obtained using a functional equation technique which was previously developed and applied to microstrip and bilateral finlines. The results were used to check the validity of the concept of equivalent isotropic substrate, suggested by some authors to simplify the calculation of the parameters of these lines. Certain approximations are introduced to allow the efficient calculation of the characteristics of microstrips on anisotropic substrates at relatively high frequencies or for wide strips. Numerical results are given for some values of the parameters of microstrip lines on sapphire and include the regions of excitation of higher modes.     

Full-Wave Analysis of Inside Cylindrical Microstrip Lines by Finite Element Method

In this paper, a full-wave analysis using finite element method is presented to investigate the dispersion characteristics of inside cylindrical microstrip lines, which are essential to the design of some conformal microstrip circuits in millimeter wave bands. Numerical results of frequency-dependent effective dielectric constants are given for different structural dimensions and dielectric constants of substrate. Some useful conclusions are derived for the design of the special conformal microstrip lines.     

Network-analyser reflection measurements of microstrip circuits not requiring exactly reproducible coaxial-to-microstrip transitions

A measuring and correction procedure for network-analyser measurements of microstrip circuits is presented which does not need exactly reproducible coaxial-to-microstrip transitions. The transmission properties of the transitions and the parameters of the microstrip lines are determined by transmission measurements of two homogeneous lines; the input reflection coefficient of the coaxial-to-microstrip transition is measured directly at the microstrip circuit under test using sliding-load techniques. Assuming the transition to have low losses, its backward reflection coefficient can be calculated approximately. The measured scattering parameters of the microstrip circuit are corrected using these values, and a measurement example shows the results of this procedure.     

Variational Method for the Analysis of Microstrip-Like Transmission Lines

A theoretical method is presented by which microstrip-like transmission lines can be analyzed. These transmission lines are characterized by conducting strips, large ground planes, multi-dielectric-layer insulation, and planar geometry. The method is essentially based on a variational calculation of the line capacitance in the Fourier-transformed domain and on the charge density distribution as a trial function. A shielded double-layer microstrip line is analyzed by this method. Derived formulas for this structure are also applicable to simpler structures: a double-layer microstrip line, a shielded microstrip line, and a microstrip line. The calculated values of the line capacitance and the guide wavelength are compared with the measured values where possible. Oxide-layer effects on a silicon microstrip line and shielding effects on a sapphire microstrip line are also discussed based on this theory. The limitations and possible applications of this method are described.     

铁氧体介质基片微带线色散特性的研究

利用扩展的二维FD-TD方法研究了包含铁氧体介质的均匀微带线的色散特性.给出了铁氧体介质的厚度,微带线导带宽度以及铁氧体的外加恒磁场对其传输特性的影响.并对这类传输线在禁带附近模式容易传播的模式进行了讨论.