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Electromagnetic fields unintentionally radiated from power-line communications used in factories interfere with wireless communications. It is important to distinguish the mechanism of this undesired and unintentional radiation from that of wired communication as it affects wireless communications. In particular, unintentional radiated emissions should be reduced in order to construct a stable wired/wireless communication network. This paper focuses on power-line communication as it is used in a factory. The power distribution network in the factory consists of multiple cables bundled together. The effects of cables other than the power cable that applies the communication signal to the radiated electromagnetic field are investigated. Some of the signal power reaching the reciever is converted into common-mode current by an imbalance mismatch. The common-mode current is one of the main causes of unwanted electromagnetic radiation. To predict this conversion, an imbalance difference model is created to account for multi-conductor transmission lines such as those in the power distribution network of the factory. The proposed model can calculate the amount of common-mode excitation associated with changes in the load condition of the power lines. To verify the proposed method, the authors measured the change in common-mode current due to the difference in pairs of power lines to which the signal is applied. The calculation using the proposed model could estimate the amount of reduction in common-mode current to within an error of 1 dB. [ABSTRACT FROM AUTHOR]

The features of calculating the matrices of per-unit-length parameters and characteristics of multiconductor transmission lines have been considered. The method of calculation of the matrices of primary per-unit-length parameters of multiconductor transmission lines has been presented. The criteria for the accuracy of the calculation of the capacitance matrix have been formulated. It has been noted that it is necessary to accurately account for the mutual influence between the transmission line conductors for a correct estimation of the distortions of the signals propagated in it. The influence of the per-unit-length parameters of multiconductor transmission lines on responses and eye diagrams at the end of their active conductors has been demonstrated. The influence of the distances from the extreme conductors to the boundaries of the cross-sections of transmission lines on the accuracy of calculating their capacitance matrices has been studied. Using the method of moments, it has been shown that known approaches to determining these distances do not always give accurate or efficient results. On the example of several transmission lines with different numbers of dielectric layers and conductors, as well as with the shield and without it, the minimum values of this distance at which it is possible to achieve an accurate and efficient calculation of their capacitance matrices have been determined. [ABSTRACT FROM AUTHOR]

A possibility of improving protective characteristics of transmission lines by cascading of multiconductor modal filters (MFs) with different geometric configurations is studied. Three-conductor MFs based on an asymmetric coaxial structure and a microstrip line and four variants of cascade structures consisting of two and three sections of such MFs are considered. Simulation of the time response to an ultrashort pulse (USP) and parametric optimization are performed. Attenuation of USP by a factor of 27.4 is achieved. [ABSTRACT FROM AUTHOR]

In this paper, impact of the causality of frequency-dependent models of soil on the effective area of grounding grids buried in single and two-layer soils is studied. In the analyses, the computationally efficient multi-conductor transmission line method is used. The simulation results show that the causality plays an important role on the effective area so that it can decrease or increase the effective area in comparison with the non-causal model. This reduction or increase depends on the low-frequency resistivity of dispersive soil and current waveform. The relative error due to non-causality is considerable only for the subsequent stroke current, whereas for the first stroke current, it is low enough to be ignored. In addition, the burial depth effect on the effective area in causal and non-causal-dispersive soils is investigated. With the aim of more accurate design, comprehensively predicting formulae for effective area versus low-frequency resistivity of soil, burial depth and current waveform under causal assumption are proposed. Finally, importance of effective area based on causal and non-causal models on the lightning-induced voltage on the soil surface is investigated. [ABSTRACT FROM AUTHOR]

In this paper, a model of aerial multiconductor transmission lines with frequency-dependent electrical parameters for the simulation of time-domain electromagnetic transients due to incident electromagnetic fields is presented. The frequency dependency of the electrical parameters is taken into account using the penetration impedance; this allows applying the method of characteristics without having to resort to modal transformations. With this alternative approach, transforming the transmission line partial differential equations to ordinary differential equations is performed in the phase domain, which simplifies the mathematical development of the method and also the numerical solution. The validity of the proposed model is shown with five study cases involving different transmission systems and excitations. [ABSTRACT FROM AUTHOR]

A miniature bandpass filter of new design with original stripline resonators on suspended substrate has been studied. The proposed filters of third to sixth order are distinguished for their high frequency-selective properties and mush smaller size in comparison to analogs. It is shown that a broad stopband extending above three-fold central bandpass frequency is determined by weak coupling of resonators at resonances of the second and third modes. A prototype sixth-order filter with a central frequency of 1 GHz, manufactured on a ceramic substrate with dielectric permittivity ε = 80, has contour dimensions of 36.6 × 4.8 × 0.5 mm. Parametric synthesis of the filter, based on electrodynamic 3D model simulations, showed quite good agreement with the results of measurements. [ABSTRACT FROM AUTHOR]

A new crosstalk reduction technique is proposed, which utilizes defective ground plane structures. With some basic defective ground plane structures, near end crosstalk (NEXT) and far end crosstalk (FEXT) of the coupled lines are reduced, without significant change in signal transmission property. As per the 3X thumb rule, the spacing between two traces must be three times that of the trace width, in order to avoid crosstalk. Without using additional Printed Circuit Board components in the design, a new method is proposed to reduce the crosstalk with the spacing of 0.5 mm and the line width chosen for 50 Ω characteristic impedance. The method proposed has been validated by fabrication and measurements. Both time domain and frequency domain responses are analyzed. Due to the narrow band property of these defective ground structures, the usable bandwidth is narrow. In order to achieve wide usable bandwidth, multiple defective ground structures are used. [ABSTRACT FROM AUTHOR]

The problem of diagnostics of multiconductor structures is considered. Results of a physical experiment on pulsed signal propagation through a flat cable are given. The possibility for contactless determination of cable wire breaking using modal probing is confirmed. [ABSTRACT FROM AUTHOR]

Taking advantage of the hyperbolic characteristics of the telegrapher equations, this paper applies the Lax-Wendroff technique, usually used in fluid dynamics, to transmission line analysis. A second-order-accurate Lax-Wendroff difference scheme for the telegrapher equations for both uniform and nonuniform transmission lines is derived. Based on this scheme, a new method for analyzing lossy multiconductor transmission lines which do not need to be decoupled is presented by combining with matrix operations. Using numerical experiments, the proposed method is compared with the characteristic method, the fast Fourier transform (FFT) approach, and the Lax-Friedrichs technique. With the presented method, a circuit including lossy multiconductor transmission lines is analyzed and the results are consistent with those of PSPICE. The nonlinear circuit including nonuniform lossy multiconductor transmission lines is also computed and the results are verified by HSPICE. The proposed method can be conveniently applied to either linear or nonlinear circuits which include general transmission lines, and is proved to be efficient. [ABSTRACT FROM AUTHOR]

Mirror-symmetric matrices have important applications in studying odd/even-mode decomposition of symmetric multiconductor transmission lines (MTL). In this paper, we propose an iterative algorithm to solve the mirror-symmetric solution of matrix equation AXB + CY D = E. With it, the solvability of the equation over mirror-symmetric X, Y can be determined automatically. When the equation is consistent, its solution can be obtained within finite iteration steps, and its least-norm mirror-symmetric solution can be obtained by choosing a special kind of initial iteration matrices. Furthermore, the related optimal approximation problem is also solved. Numerical examples are given to show the efficiency of the presented method. [ABSTRACT FROM AUTHOR]

This work presents a thorough derivation of the full-wave transmission-line equations on the basis of Maxwell's theory. The multiconductor system is assumed to be composed of nonuniform thin wires. It is shown that the mixed potential integral equations are equivalent to generalized telegrapher equations. Novel, exact, and compact expressions for the multiconductor transmission-line parameters are derived, and their connection to radiation effects is shown. Iteration and perturbation procedures are proposed for the solution of the generalized transmission-line equations. [ABSTRACT FROM AUTHOR]

An effective method of computer calculation and optimization of characteristics of multioctave low-noise transistor amplifiers is presented. The method was used to design a three-stage amplifier built on the basis of microstrip technology using packaged transistors and chip resistors and capacitors. In a 0.5- to 12.0-GHz frequency band, the following characteristics are obtained: a noise ratio of 2.2–3.2 dB, a gain of >25.6 dB, a gain flatness of ±1.2 dB, a voltage standing wave ratio of <2.8 and <2.2 at the input and output, respectively. [ABSTRACT FROM AUTHOR]

Abstract  A harmonic expansion method is utilised to determine the capacitance and inductance parameters of a few multiconductor transmission-line (MTL) structures comprising a set of dielectric-coated conductors in close contact seated on a ground plane. Results are presented in tabular form in order to provide microwave software developers with useful data for benchmarking purposes. In addition, an analysis of the effective permittivity characterizing the normal modes of the inhomogeneous MTL structures is presented. [ABSTRACT FROM AUTHOR]

The X-ray radiation of gas-filled diodes has been studied with the use of a multichannel detection unit based on microstrip GaAs ionizing-radiation detectors. It has been shown that a detector responses to X-ray pulses of subnanosecond duration and allows studies of the characteristics of X rays to be performed at short pulse durations and small exposure doses. Data on X rays formed in various diodes filled with atmospheric-pressure air have been obtained. [ABSTRACT FROM AUTHOR]

This paper presents an analysis method, based on MacCormack’s technique, for the evaluation of the time domain sensitivity of distributed parameter elements in high-speed circuit networks. Sensitivities can be calculated from electrical and physical parameters of the distributed parameter elements. The proposed method is a direct numerical method of time-space discretization and does not require complicated mathematical deductive process. Therefore, it is very convenient to program this method. It can be applied to sensitivity analysis of general transmission lines in linear or nonlinear circuit networks. The proposed method is second-order-accurate. Numerical experiment is presented to demonstrate its accuracy and efficiency. [ABSTRACT FROM AUTHOR]

The MacCormack method is applied to the analysis of multiconductor transmission lines by introducing a new technique that does not require decoupling. This method can be used to analyze a wide range of problems and does not have to consider the matrix forms of distributed parameters. We have developed software named MacCormack Transmission Line Analyzer based on the proposed method. Numerical examples are presented to demonstrate the accuracy and efficiency of the method and illustrate its application to analyzing multiconductor transmission lines. [ABSTRACT FROM AUTHOR]

In the field of high-speed circuits, the analysis of mixed circuit networks containing both distributed parameter elements and lumped parameter elements becomes ever important. This paper presents a new method for analyzing mixed circuit networks. It adds transmission line end currents to the circuit variables of the classical modified nodal approach and can be applied directly to the mixed circuit networks. We also introduce a frequency-domain technique without requiring decoupling for multiconductor transmission lines. The two methods are combined together to efficiently analyze high-speed circuit networks containing uniform, nonuniform, and frequency-dependent transmission lines. Numerical experiment is presented and the results are compared with drat computed by PSPICE. [ABSTRACT FROM AUTHOR]

Abstract This paper presents an analysis of frequency dependent propagation characteristics of microstrip lines with anisotropic substrate and overlay. The method involves setting up of the Greens functions corresponding to the structure and formulating a dispersion relation in Fourier transform domain. The dispersion relation is constructed in a Galerkins procedure. Numerical results are also presented. [ABSTRACT FROM AUTHOR]

The radiation from electromagnetic bandgap (EBG) microstrip structures is studied. The results show that the radiation from an EBG microstrip structure at most of the frequencies in the stopband and the passband is larger than that of the corresponding conventional microstrip line. Therefore, EBG microstrip circuit s should be shielded and new EBG microstrip structures whose radiation is little should be developed. [ABSTRACT FROM AUTHOR]

The article proposes a microstrip model for studying properties of superlattices. It is simple and can be easily manufactured. Its main advantage is that its properties are closer to the real layered structure of a superlattice than those of waveguide analogues. This advantage is due to the fact that the basic oscillation modes propagating in microstrip transmission lines are quasi-TEM waves whose rf-field structure virtually coincides with the structure of the fields of transverse waves propagating in superlattices. At the same time, waves propagating in waveguides are either E or H waves that have either electric or magnetic rf-field components along the propagation direction, respectively.