ANALYSIS OF THE CAPACITANCE OF RECTANGULAR SHIELDED LINE WITH OFFSET INNER CONDUCTOR

The partial charge-simulation method is presented for calculating the capacitances of rectangularshielded lines with offset inner conductors.The capacitances calculated by using this method are in goodagreement with those of other available methods.This method can improve the accuracy by increasing theterm number N of series.     

On the characteristic impedance of a coaxial line with elliptic cone outer conductor and angular strip inner conductor

The expressions of the characteristic impedance of a new kinds of transmission lines—elliptic cone coaxial line are derived. The formulas are based on the TEM and the transformation of the sphero-conal coordinate into two dimension plane. Also themethods using the graphical approximation and taking the geometrical average of the upper and lower bounds to the size of the line are put forward to calculate the characteristic impedance — of the elliptic cone coaxial line.     

Radiation from a dielectric coated hemispherical conductor fed by acoaxial transmission line

A dielectric-coated hemispherical conductor mounted on an infinite perfectly conducting ground plane and fed by a coaxial transmission line is investigated. Green's functions for the region above the ground line are derived with separated homogeneous and particular solution parts so as to be compatible with numerical analysis techniques. A magnetic field integral equation is constructed in terms of the unknown annular aperture tangential electric field and is solved by the method of moments. A comparison of the characteristics of the dielectric-coated hemispherical conductor and a flush-mounted coaxial line to an infinite homogeneous region above the ground plane is presented with respected to the tangential aperture electric field, with respect to the tangential aperture electric field, the coaxial line apparent input impedance, and the far radiated field     

The transfer impedance of cables with a nearby return conductor anda noncentral inner conductor

The transfer impedance Z_t of a cable is often assumed to be a characteristic of the shield only. We investigate the limits of this assumption by calculations and measurements. The first test cable was formed by a solid copper tube (“shield”) and a wire inside; several positions, also non-central, were chosen for the wire. The common mode current (between 10 Hz and 100 kHz) through the tube had as return path a single wire, which was placed at several positions, near and at some distance from the shield. A second cable with a braided shield was tested as well. The results show that both the differential mode and the common mode circuit have to be carefully defined for a particular Z_t. Varying either circuit may alter Z_t drastically. Consequently, the Z_t of a particular cable measured in a triaxial setup, is a characteristic of that setup and cannot always be used in another setup as in for instance cable bundles     

Propagation characteristics along a dielectric coated cylindrical conductor above the ground

The propagation characteristics along a dielectric coated cylindrical conductor above the ground are presented over a wide range of frequencies from 1 to 1000 MHz, partly in comparison with experiment.     

Accurate conductor Q-factor of dielectric resonator placed in anMIC environment

The unloaded Q-factor of a dielectric resonator is degraded due to conductor loss when it is placed in an MIC environment. The authors report approximate but quite accurate closed form expressions for the Q-factor due to conductor loss. The results obtained are in good agreement with those of rigorous numerical methods. The effect of geometrical parameters on the useful tuning range of the structure is studied. Finally, an explicit relationship between the resonant frequency sensitivity factors and the conductor Q-factor is derived     

Decoupling between two conductor microstrip transmission line

A numerical analysis of two-conductor transmission line with a rectangular notch in the dielectric between the strips is presented. Three media integral equations are derived and solved for the charge distributions. The decoupling between such two-conductor coupled microstrip transmission lines is investigated for asymmetric conductors. It is found that the coupling between two conducting lines can be reduced significantly by removing dielectric material between the lines which has a rectangular shape. For best decoupling, the width should be as wide as possible between the conducting lines but the depth should have an optimum somewhere in the base dielectric substrate     

Microstrip line on an artificial dielectric substrate

This letter presents a new version of an artificial dielectric substrate and a microstrip line built on top of this substrate. The substrate is fabricated as a two-dimensional array of metallic posts separated from the top conductor by a thin dielectric slab. This structure can show a very high effective permittivity and can therefore offer a substantial reduction in the dimensions of microwave circuit elements.     

基于支持区域的直线段匹配

以往的直线段匹配算法都是利用直线段之间位置顺序的限制条件,而基于支持区域的直线段匹配算法则充分利用了图像本身提供的灰度信息。每条直线段的支持区域为直线段提供几何和灰度的特性值,这些特性可以通过加权作为匹配度计算的一部分。使用支持区域,直线段的匹配更客观、准确。     

Characterization of small apertures in the center conductor of amicrostrip line

A closed form expression for the series reactance of an electrically small aperture in the center conductor of a microstrip line is determined using equivalent dipole moments due to the aperture and employing a quasistatic approach. The reactance of an inclined slot and a diamond shaped aperture are evaluated as a function of the aperture geometry in the lower microwave frequency band. The results based on this analysis are compared with those obtained from Oliner's formula. Experimental results are in fairly good agreement with the results obtained using the proposed theory     

Equivalent network for an aperture in the center conductor ofmicrostrip line

The equivalent circuits for discontinuities in the form of a thin transverse slot and a circular aperture in the center conductor of a microstrip line are determined by a quasi-static analysis using equivalent dipole moments. The series reactance as a function of frequency is evaluated in terms of the geometrical parameters of the discontinuity. Data obtained from transmission measurements are presented to support the theory     

Capacitance extraction of 3-D conductor systems in dielectric mediawith high-permittivity ratios

We describe a perturbation formulation for the problem of computing electrostatic capacitances of multiple conductors embedded in multiple dielectric materials. Unlike the commonly used equivalent-charge formulation (ECF), this new approach insures that the capacitances are computed accurately even when the permittivity ratios of the dielectric materials are very large. Computational results from a three-dimensional multipole-accelerated algorithm based on this approach are presented. The results show that the accuracy of this new approach is nearly independent of the permittivity ratios and superior to the ECF for realistic interconnect structures     

垂直电偶极子在涂敷介质导电平面上激起的场Ⅱ

对垂直电偶极子（VED）在涂敷介质层的非理想导电基底上激起的电磁场进行了讨论,获得了便于计算的解析表达式,并进行了数值计算。     

Effect of conductor backing on the line-to-line coupling betweenparallel coplanar lines

A good estimate of the coupling effect between parallel coplanar waveguide (CPW) lines is important, especially for monolithic microwave integrated circuit (MMIC) applications where unnecessary crosstalk between conductors could be a serious problem. This paper shows how these coupling parameters may be analytically obtained in the presence of the back-face metallization. Closed-form formulas are developed for evaluating the quasi-TEM characteristic parameters based upon the conformal-mapping method (CMM). Very good agreement is observed between the values produced by these formulas and by a spectral-domain method (SDM)     

任意形状导体介质混合目标的瞬态电磁散射特性分析

通过建立自由空间内多个导体介质混合目标的理论模型,根据电磁场等效原理和边界条件,建立了求解任意形状导体介质混合目标散射特性的时域电场积分方程(TDEFIE).导出了TDEFIE的时间步进算法(MOT)矩阵方程,并应用基于隐式MOT算法的TDEFIE对任意形状导体介质混合目标进行了瞬态分析,其数值结果说明了该算法的有效性.     

Microstrip transmission line excitation of dielectric resonatorantennas

A systematic investigation of the excitation of a cylindrical dielectric resonator antenna was undertaken to illustrate the possibility of such a feed structure and to characterise the coupling behaviour and radiation patterns of the system     

Variational analysis of a gap in the central conductor of arectangular coaxial line

Rectangular coaxial line (RCL) discontinuity in the form of a gap in the central conductor and steps in the outer conductor in the planes of discontinuity has been analyzed by a variational method. The orthogonal-mode functions of an RCL required for numerical computation of the discontinuity parameters have been determined using the Ritz-Galerkin technique. The capacitances of the equivalent Pi-network are presented as function of gapwidth, normalized frequency, and ratio of outer conductor dimensions for complete characterization of the discontinuity. The low-frequency series and shunt capacitance values are verified against the static capacitances computed separately by the finite-difference technique     

Electric polarizability for a thick eccentric annular aperture with a floating inner conductor

An electrostatic potential penetration into an eccentric annular aperture in a thick conducting plane is investigated when an inner conductor is electrically floating. Conformal mapping is used to transform an eccentric annular aperture into a concentric aperture. The Hankel-transform and eigenfunction expansion is utilized to solve the boundary-value problem for a concentric annular aperture. Computation is performed to illustrate the electric polarizability, capacitance, and potential distribution for various aperture geometries.     

Internal inductance and conductor loss associated with the groundplane of a microstrip line

In previous work, a closed-form expression for the current density on the ground plane of a microstrip line was presented. In this paper, we show how this formula for the current density is used to derive an expression for the internal inductance associated with the ground plane. Results are presented for different geometries that illustrate when the internal inductance of the ground becomes comparable to the external inductance of the microstrip line. We also illustrate that the integrals needed for the internal inductance calculation can be used to develop an expression for the conductor loss associated with the ground plane     

垂直电偶极子在有介质导电平面上激起的场

分析研究了垂直电偶极子在介质涂敷的理想导电平面上激起的电磁场 ,获得了场分量的解析表达式。分析表明 ,垂直电偶极子在介质涂敷的导电平面上激起的电磁场可分解为直达波、反射波、侧面波和吸附表面波。其中吸附表面波在沿介质表面传播的波数介于在空气层和介质层中传播波数 k0 与 k1之间 ,其幅度按ρ-1/ 2 规律衰减 ,在垂直于介质层方向则以指数规律衰减。文中导出的直达波、反射波、侧面波项则与文献 [1 ]中的结果完全一致。当介质层较厚时 ,由于表面波与侧面波相加的结果 ,总场将发生明显的干涉现象。