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Article
Publication date: 1 September 2005

Sonia Leva and Adriano Paolo Morando

To provide a unified analytical tool, based on Park transformation, for the theoretical and practical analysis of a lossy three‐phase transmission line.

Abstract

Purpose

To provide a unified analytical tool, based on Park transformation, for the theoretical and practical analysis of a lossy three‐phase transmission line.

Design/methodology/approach

The results obtained in the study of TEM waves propagation in two‐wire line can be extended to a symmetric m‐wire line by employing the modal analysis. This approach relates the dynamic of m‐wire guided field to the propagation of m modal voltages and currents acting on m single‐wire decoupled transverse electromagnetic (TEM) lines. In the symmetric three‐phase system case, the modal analysis includes, as a particular case for m=3, the symmetric component theory. In previous papers, the authors applied the Park transformation to study the wave propagation of (TEM) three‐phase symmetrical lines. The formulation proposed and tested considers the lossless TEM wave propagation of a three‐phase line without consideration to the dissipations phenomena present in the line itself. Taking into account the obtained results, the extension of the developed approach to the lossy three‐phase transmission line transient analysis is very useful on both theoretical and practical points of view.

Findings

The symmetrical three‐phase line Park model for the lossy transmission line transient analysis, regarded as vector formulation of the line modal analysis, has been presented. The proposed examples highlight how, thanks to the Park model, the dynamic analysis of the three‐phase line in distorted and unsymmetrical systems becomes an integral part of the more general and well‐established power electric system dynamic theory.

Originality/value

The three‐phase transmission line transient analysis presented in this paper emphasizes the conceptual contents, specific to the Park approach. Furthermore, it gives some results very important for the practical analysis of a lossy three‐phase transmission line.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 24 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 February 1985

C. CHRISTOPOULOS

A technique for studying the propagation of surges on lines in the presence of corona and a lossy earth is presented. Each line section is modelled by lumped circuit components…

Abstract

A technique for studying the propagation of surges on lines in the presence of corona and a lossy earth is presented. Each line section is modelled by lumped circuit components representing corona and earth effects. The component values are readily obtained from theoretical and experimental investigations. The circuit is solved in the time domain using transmission line modelling (TLM). The results show good agreement with other experimental and theoretical investigations.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 4 no. 2
Type: Research Article
ISSN: 0332-1649

Article
Publication date: 1 September 2002

M. Condon

The paper presents a new technique for the transient analysis and simulation of lossy coupled interconnects. The approach is based on identifying natural modes of oscillation…

Abstract

The paper presents a new technique for the transient analysis and simulation of lossy coupled interconnects. The approach is based on identifying natural modes of oscillation unlike many other transmissionline models which are based on travelling waves. The approach follows directly from that previously presented by the author (Wilcox and Condon 1997) for the simulation of a single‐phase coaxial power cable. The technique is readily applicable to modelling coupled interconnects and avoids the time‐consuming convolution of many existing transmissionline modelling approaches.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 21 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 April 1993

L. Guan, C. Pusarla, G. Halkias and A. Christou

As speed and complexity of electronic systems increase, the interconnect density has become the critical limitation to the performance of electrical systems. The performance of…

Abstract

As speed and complexity of electronic systems increase, the interconnect density has become the critical limitation to the performance of electrical systems. The performance of computing and switching systems can be increased by optimizing the interconnect density and throughput. At the board to board level, electrical interconnects at high speeds require a bulky and expensive backplane. At the chip to chip area, the allocation of interconnects limits the performance of the chips. Electrical lossy lines limit the maximum interconnect distance due to reflections, risetime degradation, increased delay, attenuation and cross talk . Optical interconnects present the possibility of solving the interconnect problems by potentially achieving a high bandwidth and high volume density of channels. At high data rates (greater than 1 Gb/s) several channels may operate with negligible mutual interference.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 12 no. 4
Type: Research Article
ISSN: 0332-1649

Article
Publication date: 1 December 2001

Georg Hebermehl, Friedrich‐Karl Hübner, Rainer Schlundt, Thorsten Tischler, Horst Zscheile and Wolfgang Heinrich

The design of microwave circuits requires detailed knowledge on the electromagnetic properties of the transmission lines used. This can be obtained by applying Maxwell’s equations…

Abstract

The design of microwave circuits requires detailed knowledge on the electromagnetic properties of the transmission lines used. This can be obtained by applying Maxwell’s equations to a longitudinally homogeneous waveguide structure, which results in an eigenvalue problem for the propagation constant. Special attention is paid to the so‐called perfectly matched layer boundary conditions (PML). Using the finite integration technique we get an algebraic formulation. The finite volume of the PML introduces additional modes that are not an intrinsic property of the waveguide. In the presence of losses or absorbing boundary conditions the matrix of the eigenvalue problem is complex. A method which avoids the computation of all eigenvalues is presented in an effort to find the few propagating modes one is interested in. This method is an extension of a solver presented by the authors in a previous paper which analyses the lossless case. Using mapping relations between the planes of eigenvalues and propagation constants a strip in the complex plane is determined containing the desired propagation constants and some that correspond to the PML modes. In an additional step the PML modes are eliminated.The numerical effort of the presented method is reduced considerably compared to a full calculation of all eigenvalues.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 20 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 January 1994

J. Poltz

Digital systems utilize frequencies into the GHz range Attempts to reduce the propagation delay by lowering the interconnect capacitance (decreasing cross‐sectional dimensions…

Abstract

Digital systems utilize frequencies into the GHz range Attempts to reduce the propagation delay by lowering the interconnect capacitance (decreasing cross‐sectional dimensions) cause an increase in wire resistance which, in turn, increases the rise time and indirectly slows down the response Therefore, it is impossible to optimize VLSI and packaging interconnections to maximize the clock rate without analyzing losses (solving Helmholtz equation) and implementing lossy transmission line models This paper presents modeling and simulation of a gate array interconnect.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 13 no. 1
Type: Research Article
ISSN: 0332-1649

Article
Publication date: 1 December 2001

Lorenza Corti, Massimiliano de Magistris and Antonio Maffucci

A time domain discrete model for nonuniform transmission lines, based on a complementary formulation of the transmission line equations, is considered. By recasting the line

Abstract

A time domain discrete model for nonuniform transmission lines, based on a complementary formulation of the transmission line equations, is considered. By recasting the line equations in terms of flux and charge, one has to discretize alternatively only one of the two equations, the other being exactly verified. This approach has been widely used in electromagnetics to evaluate the discretization error. With reference to simple examples, we show how the error estimation can be used for a selective meshing of the line, leading to much better approximation with the same computational effort.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 20 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 June 2001

S. Barmada, A. Musolino and M. Raugi

The analysis of multiconductor transmission lines excited by an electromagnetic field is investigated here by the use of the wavelet expansion. The exciting field is taken into…

Abstract

The analysis of multiconductor transmission lines excited by an electromagnetic field is investigated here by the use of the wavelet expansion. The exciting field is taken into account considering its contribution in terms of equivalent distributed voltage and current along the line. The resulting equations are expanded in the wavelet domain on both the variables (space and time), leading to an algebraic system in a Lyapunov form which is solved by the use of standard techniques.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 20 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 July 2014

Devendra Kumar Sharma, Brajesh Kumar Kaushik and R.K. Sharma

– The purpose of this paper is to propose an analytical model for estimating propagation delay in coupled resistance-inductance-capacitance (RLC) interconnects.

Abstract

Purpose

The purpose of this paper is to propose an analytical model for estimating propagation delay in coupled resistance-inductance-capacitance (RLC) interconnects.

Design/methodology/approach

With higher frequency of operation, longer length of interconnect and fast transition time of the signal, the resistor capacitor (RC) models are not sufficient to estimate the delay accurately. To mitigate this problem, accurate delay models for coupled interconnects are required. In this paper, an analytical model for estimation of interconnect delay is developed for simultaneously switching lines. Two distributed RLC lines coupled inductively and capacitively are considered. To validate the proposed model, SPICE results are compared with the proposed analytical results. Each line in the coupled structure is terminated by a capacitive load of 30fF. The driving signal is considered symmetrical with equal rise and fall time of 5 ps and OFF/ON time of 45 ps. The model is validated for both in-phase and out of phase switching of lines.

Findings

It is observed that the model works well for both the phases of inputs switching. The derived expressions of delay exhibit complete physical insight, and the results obtained are in excellent agreement with SPICE results. Comparison of analytical delay with SPICE delay shows an average error of < 2.7 per cent.

Originality/value

The analytical expressions for interconnect delay are derived for the first time under simultaneously switching scenario. This model is useful to estimate delay across the inductively and capacitively coupled interconnects.

Details

Journal of Engineering, Design and Technology, vol. 12 no. 3
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 11 May 2012

Martyn Gaudion

The purpose of this paper is to discuss nickel gold plating of PCB traces and its adverse effects on signal integrity, and to explore the other key drivers in optimising yields…

265

Abstract

Purpose

The purpose of this paper is to discuss nickel gold plating of PCB traces and its adverse effects on signal integrity, and to explore the other key drivers in optimising yields and controlling PCB processes that impinge on signal integrity.

Design/methodology/approach

The paper is a response to requests from PCB fabricators to explain why the losses on impedance controlled traces on PCBs were sometimes higher than expected.

Findings

While nickel is acceptable on short lengths of pad to accommodate gold plating, plating the whole trace length is generally not good practice from a digital signal integrity perspective. In addition, with the fastest serial transmission rates in the 10 to 20 GHz region and long serial words in some situations designers may need to consider both the associated high and low frequency performance.

Originality/value

With the development of ultra high speed digital bus architectures, PCB fabricators will appreciate the need to add an understanding of the drivers of insertion loss (base material loss tangent data, foil roughness and copper cross sectional areas) to their existing experience of architectures with minimal losses.

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