A New Technique for the Analysis of the Dispersion Characteristics of Microstrip Lines

Dispersion characteristics of shielded microstrip lines are investigated using a new technique. The method utilizes the well-known singular integral equation approach for deriving an alternate form of eigenvalue equation with superior convergence properties. It is shown that accurate numerical results may be obtained from this eigenvalue equation using only a 2x2 matrix equation. In comparison, the conventional formulation of the problem requires the use of matrices that are much larger in size. Aside from the numerical efficiency, the simplicity of the method makes it possible to conveniently extract higher order modal solutions for the propagation constants that affect the high-frequency application of microstrip lines. Even though the derivation of the determinantal equation requires some intricate mathematical manipulations, the user may bypass these completely and use the final eigenvalue equation which is programmable on the computer.     

Dispersion Characteristics of Microstrip Lines

A coupled-line analysis is used in conjunction with Carlin's model in order to find the frequency dependence of the propagation constant and of the characteristic impedance of dispersive microstrip lines. The characteristic impedance of the coupled lines decreases with frequency.     

A Technique for Computing Dispersion Characteristics of Shielded Microstrip Lines (Short Papers)

The boundary value problem associated with the shielded microstripline structure is formulated in terms of a rigorous hybrid-mode representation. The resulting equations are subsequently transformed, via the application of Galerkin's method in the spectral domain, to yield a characteristic equation for the dispersion properties of shielded microstrip lines. Among the advantages of the method are its simplicity and rapid convergence. Numerical results are included for several different structural parameters. These are compared with other available data and with some experimental results.     

圆柱型微带线的准静态特性

本文以平面微带线为中介使用保角变换法研究了非平面圆柱型微带线的准静态特性。文中给出了特性分析公式，并确定了用二分法进行尺寸综合要求的操作区间和目标函数。最后，进行了数值结果比较，效果良好。     

Dispersion Characteristics of Open Microstrip Lines

A method based on spectral-domain analysis is derived to compute effectively and automatically the effective relative permittivity of an open microstrip line. Simple but accurate closed-form expressions are used as the basis functions of the longitudinal and transverse current distributions. The numerical results are shown in tables and figures for various cases and compared WMI other available results. The results presented here are seen as having a high degree of accuracy and may be used as reference standards,     

A Circuit-Theoretic Approach to the Design of Quadruple-Mode Broadband Microstrip Patch Antennas

A novel method for the design of broadband patch antennas is described. The approach taken is to broadside couple two dual-mode patch antennas, resulting in a quad resonance antenna. The equivalent circuit of the antenna is similar to that of microwave filters, thus filter design techniques maybe employed to synthesize the antenna to obtain maximum return-loss bandwidth. This is the first time an increase in the bandwidth is achieved on a relatively thin substrate antenna as a result of coupling four resonant modes using two stacked circular microstrip patches. Electromagnetic simulation and measured results demonstrate bandwidth improvement of over four times that of a single-mode design.     

新型宽频带微带反射阵单元相位特性研究

分析由两个弯曲振子及一个普通振子构成的单层三谐振单元的相位特性。对三种基板结构下单元的相移特性进行了研究。结果表明,采用混合基板,增加泡沫的厚度,可以在较宽频带内获得平滑的相移特性,同时相位动态范围大于360°。与三层堆叠结构的相移特性进行了比较,仿真结果表明可以达到与其相近的效果。最后给出了一种改进型单元结构,能够在6-10GHz带宽内得到基本一致的相移特性曲线。利用该结构组成一个12×13单元的反射阵列,带宽内效率约为50%。     

椭圆微带线色散特性的直线法分析＊

本文用直线法对椭圆微带线的色散特性进行了研究,导出了色散特性方程.在共焦椭圆情况下,当频率较低时,本文结果与准TEM波分析结果趋于一致。同时给出了两种微带结构的色散曲线。     

微带线到共面波导的LTCC 宽带耦合互连过渡

在LTCC 多层电路结构中,不同形式的信号传输线之间往往采用垂直通孔互连,但由于互连通孔在高频时会 带来电感效应,且加工后会因变形而引入许多寄生参量,因此可选择耦合形式的互连过渡来实现不同传输线之间的互 连。本文针对微带线到共面波导,设计了一种可应用于LTCC 工艺的宽带耦合互连过渡结构,着重研究了耦合金属面 的宽度和耦合金属面侧边对地间隔对过渡结构频率特性的影响,并优化这些尺寸,得到了理想仿真结果：4.3GHz 到 12.7GHz 的频带内,回波损耗大于10dB,插入损耗最小到0.346dB,辐射损耗系数在小于12GHz 时,小于8.56%。     

A Spectral-Domain Analysis of Periodically Nonuniform Microstrip Lines

Periodically nonuniform microstrip lines are analyzed on the basis of a numerical field calculation. Floquet's theorem is used to express all field quantities in terms of their spatial harmonics, so that the problem can be treated similarly to the uniform microstrip line. The boundary-value problem for the microstrip line in an enclosure is formulated in a rigorous way and then solved using Galerkin's method in the Fourier-transform domain. Numerical and experimental results are presented for a sinusoidal and a zigzag-shaped microstrip line.     

常规微带线和有限宽接地板微带线的高精度近似算法

具有有限宽接地板的微带线在微波天线及微波混频器等领域早已得到广泛的应用。但是,有关这种微带线的计算方法至今未能解决,本文首先从常规微带线出发,分析比较现有的各种公式和数据,并结合作者早先提出的计算介质填充系数的方法,整理出一套分析常规微带线的高精度公式,在此基础上,提出一种将有限宽接地板微带线剖分为两个常规微带线并求极值的计算方法——等位面分割法,此方法物理概念明确,方法简单而又有很好的计算精确度。     

微粒群算法优化设计宽带微带天线

微粒群（PSO）算法具有概念简单、容易实现及收敛速度快等优点,离散二进制PSO是PSO在二进制空间的扩展。将离散二进制PSO算法与FDTD法相结合来优化设计宽频带微带天线,以矩形微带贴片天线为例,仿真结果显示,在将PSO算法中的微粒维数分别设置为20维和64维的情形下,通过对天线贴片形状的优化,天线的-10dB带宽由原来的4．4％左右拓宽至大约13．8％和14．5％,优化成效显著。     

一种新型双环宽带圆极化微带天线设计

针对微带天线存在固有频段窄、辐射效率低,且难以获得高增益的问题,设计制作了一种新型双环宽带圆极化微带天线。天线贴片单元采用由槽型环和带状环组成的槽带状结构。槽型环和带状环分别在频率较低部分和频率较高部分各提供一个最小轴比值,通过两个最小轴比值的适当结合达到明显的带宽增强效果。天线利用宽带巴伦结构进行馈电,有效增强了阻抗匹配。通过参数优化和实物制作,仿真与实测结果表明,该天线的阻抗带宽(VSWR≤2)和3 dB轴比带宽分别达到了37%和29.8%,增益达到6.4 dB。     

微带线在各向异性介质主轴旋转时的色散特性

首次用时域有限差分法（ＦＤＴＤ）研究了在电和磁双各向异性介质中张量［ε］和［μ］的主轴同时旋转时，开式和屏蔽微带线的色散特性。结果表明，其传播特性与［ε］和［μ］的光轴偏差角有明显的关系。     

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.     

直线法分析超导微带传输线

本文首次应用直线法结合二流体模型对超导微带传输线进行了分析。针对多层介质结构和普通结构，分别计算了衰减特性、色散特性以及特性阻抗。结果表明超导微带线比普通导体微带线具有更好的性能，如低损耗、低色散和较小的电路尺寸。与已发表的文献相比较验证了本文方法的可行性。     

Asymptotic Eigenequations and Analytic Formulas for the Dispersion Characteristics of Open Wide Microstrip Lines

Through the matched asymptotic expansions technique, asymptotic eigenequations for the even and odd modes of an open wide microstrip transmission line are derived. The eigenequations, and simplifications thereof which do not involve integration, can he solved easily for the effective permittivity. Even though d/W is assumed to be small, the solutions are good even if d/ W/spl cong/0.8 when compared with the numerical results of Jansen. From these eigenequations, asymptotic formulas for the effective permittivity can be derived which are excellent when d/ W/spl cong/0.2. When the frequency goes to zero, we reproduced the asymptotic formula derived under the quasi-TEM approximation in [8]. The asymptotic analysis provides good physical insight into the problem, otherwise unavailable from numerical analysis.     

一种结构新颖的半贴片宽带微带天线

设计了一种结构新颖的半贴片宽带微带天线。通过在圆形贴片上刻蚀两对环形槽,实现宽带特性,并在原有设计好的矩形贴片沿着馈电点所在的中轴线切掉一半贴片,减少了贴片一半面积,减小了尺寸。设计了这样一种半贴片宽带微带天线,不仅具有与原来全贴片基本相同的带宽特性,并且方向图与原天线基本相同,而且大大减小了天线尺寸。     

Spectral-Domain Approach for Calculating the Dispersion Characteristics of Microstrip Lines (Short Papers)

The boundary value problem associated with the open microstrip line structure is formulated in terms of a rigorous, hybird-mode representation. The resulting equations are subsequently transformed, via the application of Galerkin's method in the spectral domain, to yield a characteristic equation for the dispersion properties of the open microstrip line. Numerical results are included for several different structural parameters. These are compared with other available data and with some experimental measurements.     

一种有效减缩微带天线RCS的新方法

根据经典理论,对于线极化矩形贴片天线,其主模电场强度在平行于非辐射边的中心线上为零。如果沿此中心线对微带天线加载电阻,对其辐射性能影响不大,然而对散射性能则有很大改善。通过引入一种阻抗加载技术和接地板开槽技术使微带天线的RCS大幅减缩,结合小型化技术,微带天线的RCS得到进一步减缩,而且天线外形尺寸也比原天线有所减小。这样,就同时兼顾了微带天线的辐射性能和散射性能。