An analytical solution for the coupled stripline-like microstripline problem

An analytical method is presented for determining the Maxwell's capacitance matrix of multiconductor shielded microstrips with coupled conductors of arbitrary widths, spacings, and inhomogeneous media, in terms of elliptic integrals. The method is based on conformal mapping and the theory of singular integral equations. Two kinds of problems are presented as examples: the first consists of simple structures with one or two coupled striplines; the other type concerns the general case of multiconductor coupled structures for which simple analytical expressions are not available     

无畸变传输线方程的解析解

对均匀传输线方程作拉氏变换，得出线上电压电流的复频域解，在无畸变的条件下，根据拉氏变换表和拉氏变换的有关性质，得出了线上电压电流在阶跃激励下的时域解，通过计算实例验证了该算法的有效性。     

An improved approximation to the microstrip line capacitance

A new empirical formula is presented for the normalised capacitance of microstrip lines. The formula uses a single equation to represent the microstrip line capacitance over the useful range of the aspect ratio. The maximum error of the new formula is contained within 0.8 percent and the relative root-mean-square error is contained within 0.55 percent. The new formula can be easily implemented in computeraided design and analysis as well as in hand calculations using pocket calculators.     

An exact solution for the nonuniform transmission line problem

The theory of matrix functions is used to derive an exact solution for the nonuniform transmission line problem. The method has certain advantages over previous ones, which include independent variation of the line parameters     

An analytical approach to the analysis of dispersioncharacteristics of microstrip lines

An analytical method for determining the dispersion characteristics of microstrip lines is given. The method uses dual integral equations. The analysis is rigorous, and it expresses the solution of the dispersion equation in terms of the solution of a double infinite system of linear equations. The system coefficients are given by certain quadratures. The numerical examples reveal the high convergence order of the method     

An analytical solution to the problem of formation of an intense axially symmetrical cylindrical beam

The problem of calculation of electrodes that form an axially symmetrical cylindrical beam in the r regime (where the current is limited by the spatial charge) is considered. A new technique based on the variable separation method is proposed. It is shown that the technique can also be applied to solve the interior Dirichlet problem.     

An analytical approach to the partial scan problem

The scan design is the most widely used technique used to ensure the testability of sequential circuits. In this article it is shown that testability is still guaranteed, even if only a small part of the flipflops is integrated into a scan path. An algorithm is presented for selecting a minimal number of flipflops, which must be directly accessible. The direct accessibility ensures that, for each fault, the necessary test sequence is bounded linearly in the circuit size. Since the underlying problem is NP-complete, efficient heuristics are implemented to compute suboptimal solutions. Moreover, a new algorithm is presented to map a sequential circuit into a minimal combinational one, such that test pattern generation for both circuit representations is equivalent and the fast combinational ATPG methods can be applied. For all benchmark circuits investigated, this approach results in a significant reduction of the hardware overhead, and additionally a complete fault coverage is still obtained. Amazingly the overall test application time decreases in comparison with a complete scan path, since the width of the shifted patterns is shorter, and the number of patterns increase only to a small extent.     

An analytical approach to the dynamic topology problem

Currently, it is possible to modify (say, hourly) the topology of a data communications network by adding or deleting network links and/or by increasing or decreasing bandwidth on existing links in response to changing traffic loads and/or projected network conditions. The intent of this paper is to study a Markov decision process (MDP) model of the dynamic topology problem (DTP), the problem of activating and/or deleting links, as a function of the current traffic in the network and of the most recent network topology design. We present a decomposition of this model and structural results for the decomposition. The decomposition and structural results enhance the tractability of procedures for determining optimal link control policies. A numerical example is used to illustrate these results.Research supported by ARO Contract No. DAAG-29-85-K0089, NSF Grant No. ECS-8708183, and DCA Contract No. DCA 100-89-C-0031.     

An analytical solution to the diffraction problem of diagnosing the position and size of a sphere

A method for determining the position and dimensions of a body from the scattered field is described. The body (a metal solid sphere) is situated in the near-field zone of a transmitting antenna, and the receiving antenna is situated in the near zone of the body. The parameters of the body are calculated from the measured wave amplitudes in the dielectric waveguide of the receiving antenna. For calibration of the antenna, the body is replaced by a metal mirror.     

Frequency-dependent solution of suspended microstrip line with tuning septums

The frequency-dependent effective dielectric permittivity and equivalent characteristic impedances of the technically most relevant modes of the suspended microstrip line with tuning septums are derived using the conventional spectral domain approach. Normalised numerical results are presented in a very large frequency band.     

Stripline to microstrip line aperture coupler

Aperture coupling between stripline and microstrip line is analyzed as a function of the electric and magnetic polarizabilities of the aperture, using Bethe's small-aperture coupling theory. A coupling expression for the general case of an aperture in the common ground plane is derived. Coupling variations with aperture dimensions for the case of a thin slot, a hole, a diamond, a rounded end slot, and an ellipse are determined using McDonald's polynomial approximations for the electric and magnetic polarizability for small apertures. Experimental results for the case of a thin slot and a circuit aperture are also presented     

An optimal solution to a scattering problem

The purpose of this letter is to illustrate the application of a parameter optimization approach to a numerical solution of electromagnetic scattering problems for perfectly conducting bodies. The simple problem of scattering by a circular cylinder is chosen to illustrate the optimal approach and the numerical results obtained by using two different optimization techniques as compared with the exact solution.     

An analytical solution to a double-gate MOSFET with undoped body

A one-dimensional (1-D) analytical solution is derived for an undoped (or lightly-doped) double-gate MOSFET by incorporating only the mobile charge term in Poisson's equation. The solution gives closed forms of band bending and volume inversion as a function of silicon thickness and gate voltage. A threshold criterion is derived which serves to quantify the gate work function requirements for a double-gate CMOS     

The solution of end effects of microstrip line by open resonator model

An open resonator model is presented to analyze the end effects of microstrip. Both the reactance and radiation effects are taken into account. The numerical results are compared with the published data.     

Light-controlled microstrip line coupler

Journal of Infrared, Millimeter, and Terahertz Waves - We have analyzed coupling properties of the coupled microstrip lines whose substrate contain electron-hole plasma by means of the spectral...     

Waveguide to microstrip line transition and power divider

A novel waveguide to microstrip line transition and power divider with a planar structure is presented. The transition and power divider is designed on both sides of a single layer dielectric substrate, and can be used as a feed of an array antenna with a waveguide feed structure or as a complete integration of waveguide components with active components such as MMIC. Experimental results are shown and compared with simulations; it is shown that good return and insertion loss characteristics are obtained for the K-band     

Analysis of microstrip line to waveguide end launchers

The expression for impedance is derived using the self-reaction concept with the assumption of a sinusoidal current distribution existing in the conductor loop. Three different cases of end launchers are computed for their corresponding input impedances. Comparison between calculated and measured input return loss of an end launcher shows good agreement between theory and experiment at Ka-band frequencies     

Magnetically scannable microstrip antenna employing a leakygyromagnetic microstrip line

Rigorous full-wave spectral-domain analyses of a magnetically scannable gyromagnetic microstrip leaky-wave antenna are presented. Varying the DC magnetic bias field by ~6.5%, the maximum radiation angle of the leaky-wave antenna, measured from the horizon, shifts from zero to almost 90°