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.     

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.     

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。     

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.     

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。     

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。     

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.     

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.     

A Compact and Broadband Differential Microstrip Line to Rectangular Waveguide Transition Using Dipole Antenna

In this paper, a compact full Ka-band differential microstrip line (DML) to rectangular waveguide transition is proposed. The dipole antenna with semi-elliptic arms is introduced to transform the differential mode of DML to the TE10 mode of the rectangular waveguide directly. The two arms of the dipole antenna are connected together by a shorting strip to reduce the size of the dipole. Compared with the DML-to-waveguide transition using the fin-line topology, the size of the proposed transition has been reduced by 86 %. To verify this transition, a back-to-back structure is fabricated and tested. It provides a return loss of better than 15.2 dB and an insertion loss of 0.73 to 1.07 dB within a wide frequency range from 26.5 to 40 GHz. The measurement results show good agreement with the simulation results. Furthermore, a tolerance analysis is also performed via the simulation to prove that this transition is robust in the fabrication and mechanical assembly.     

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。     

Variational Method for the Analysis of Microstrip Lines

This paper reports a method for computing the line capacitance of a microstrip line based on the application of Fourier transform and variational techniques. The characteristic impedance, guide wavelength, and the surface potential distribution in the microstrip line are obtained for a range of structure parameters and the dielectric constant. The results calculated from the expressions developed in the paper are compared with the theoretical results presently available in the literature and good agreement is found. Comparison with available experimental results is also made where feasible. Possible applications and limitations of the method are discussed.     

A New Measurement System to Determine Material Properties of Polishing Pads

In this paper an innovative measurement system that has been developed to investigate the material properties of thin layers is presented. It is used to perform compression tests with small samples of polishing pads that are used for chemical-mechanical polishing of silicon wafers. The results show that a series connection of a Hookean spring and three Voigt–Kelvin elements is able to describe the behavior of the tested polishing pad. Compared with a series connection of a Maxwell element and a Voigt–Kelvin element, the presented model is able to represent the viscoelastic deformation with much higher accuracy.     

Correction to "Exact Analysis of Shielded Microstrip Lines and Bilateral Fin Lines"

The following corrections should be made to the above paper. On page 670, column 2, paragraph 2, the expression "electric wall symmetry (microscope case)" should read "electric wall symmetry (microstrip case)."     

A Frequency-Dependent Coupled-Mode Analysis of Multiconductor Microstrip Lines with Application to VLSI Interconnection Problems

The spectral Galerkin procedure is used to calculate the dispersion properties of multiple conductor microstrip lines. The resulting propagation constants are then used in a coupled-mode theory which demonstrates a frequency-dependent coupling of current in a five-conductor system. These results should he useful in the study of crosstalk between parallel microstrip lines used in VLSI interconnections.     

Rigorous Determination of the Parameters of Microstrip Transmission Lines

Statement of Problem--The purpose of this paper is to determine explicit expressions enabling calculation of the performance of the recently-introduced open-strip UHF transmission line, now rapidly coming into extensive use.