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We introduce a novel parameterization scheme based on the generalized method of characteristics (MoC) for macromodels of transmission-line structures having a cross section depending on several free geometrical and material parameters. This situation is common in early design stages, when the physical structures still have to be finalized and optimized under signal integrity and electromagnetic compatibility constraints. The topology of the adopted line macromodels has been demonstrated to guarantee excellent accuracy and efficiency. The key factors are propagation delay extraction and rational approximations, which intrinsically lead to a SPICE-compatible macromodel stamp. We introduce a scheme that parameterizes this stamp as a function of geometrical and material parameters such as conductor-width and separation, dielectric thickness, and permettivity. The parameterization is performed via multidimensional interpolation of the residue matrices in the rational approximation of characteristic admittance and propagation operators. A significant advantage of this approach consists of the possibility of efficiently utilizing the MoC methodology in an optimization scheme and eventually helping the design of interconnects. We apply the proposed scheme to flexible printed interconnects that are typically found in portable devices having moving parts. Several validations demonstrate the effectiveness of the approach. Index Terms--Interpolation, parametric modeling, rational approximation, transmission line modeling.

We present a systematic methodology for the electromagnetic modeling of interconnected digital I/O ports. Digital drivers and receivers are represented through behavioral models based on radial basis functions expansions. Such a technique allows a very accurate representation of nonlinear/dynamic effects as well as switching behavior of real-world components by means of carefully identified discrete-time models. The inclusion of these models into a finite-difference time-domain solver for full-wave analysis of interconnected systems is presented. A rigorous stability analysis shows that use of nonlinear/dynamic discrete-time models can be easily integrated with standard full-wave solvers, even in the case of unmatched sampling time. A set of numerical examples illustrates the feasibility of this method. Index Terms--Behavioral models, digital I/O ports, finite-difference time-domain (FDTD) methods, nonlinear circuits, radial basis functions, transient analysis.

In this work, field excitation and bulk current injection (BCI) on a wire bundle are analytically compared. The equivalence of the two excitation techniques is investigated in order to ascertain the validity of using current injection testing rather than radiated immunity testing for an equipment connected at one end of the bundle. The wire bundle is modeled as a multiconductor transmission line which, throughout the analysis, is treated as a multiport device. The equivalence is discussed by comparing the effects that the sources produce at the terminal ports, with the aim to control the clamp voltage in order to match the incident field characteristics. This approach yields general results, which are not affected by any assumptions on the terminal networks. It is shown that one injection probe is not sufficient to assure the equivalence in the general case, but it is possible, although practically difficult, to achieve this result by employing two injection probes. In the simpler but more specific case of linear terminations, a test procedure is proposed which allows equivalence by using a single injection current probe. Since the ideal BCI procedure must represent a worst-case stress analysis for the equipment under test, the possibility of adopting BCI tests to reproduce the upper envelope of the radiation-induced currents is also investigated. In this case practical difficulties are evidenced and arise from the need of feeding the injection probes with a complicated frequency-dependent power distribution.

This paper proposes a circuit model for lossy multiconductor transmission lines (MTL's) suitable for implementation in modern SPICE simulators, as well as in any simulator supporting differential operators. The model includes the effects of a uniform or nonuniform disturbing field illuminating the line and is especially devised for the transient simulation of electrically long wideband interconnects with frequency dependent per-unit-length parameters. The MTL is characterized by its transient matched scattering responses, which are computed including both dc and skin losses by means of a specific algorithm for the inversion of the Laplace Transform. The line characteristics are then represented in terms of differential operators and ideal delays to improve the numerical efficiency and to simplify the coding of the model in existing simulators. The model can be successfully applied to many kinds of interconnects ranging from micrometric high-resistivity metallizations to low-loss PCB's and cables, and can be considered a practical extension of the widely appreciated lossless MTL SPICE model, of which maintains the simplicity and efficiency.

This paper deals with uncertainty propagation applied to the analysis of crosstalk in printed circuit board microstrip traces. Complex interconnection networks generally are affected by many uncertain parameters and their point-to-point transfer functions are computationally expensive, thus making Monte-Carlo analyses rather inefficient. To overcome this situation, a metamodel is highly desirable. This paper presents a sparse and accelerated polynomial chaos approach, which proves to be well adapted for high-dimensional uncertainty quantification and well suited for the sensitivity analysis of crosstalk effects. We highlight the significant advantage of the advocated approach for the design of microstrip line networks of complex topology. In fact, we demonstrate how a small number of system simulations can help to quantify the statistics of the output variability and identify a reduced set of high-impact parameters. [ABSTRACT FROM AUTHOR]

This paper addresses the generation of behavioral models of digital integrated circuits (ICs) for signal and power integrity simulations. The proposed models are obtained by external measurements carried out at the device ports only and by the combined application of specialized state-of-the-art modeling techniques. The present approach exploits a behavioral formulation, leading to models reproducing all the behavior of the IC ports as the input/output buffers and the core power delivery network. The modeling procedure is demonstrated for a commercial nor Flash memory in 90-nm technology housed by a specifically designed test fixture. [ABSTRACT FROM PUBLISHER]

This paper provides a novel iterative solution in an analytical (as opposed to numerical) fashion in the frequency domain for crosstalk on multiconductor transmission lines. The proposed method employs the distributed analytical representation of equivalent coupling sources and an iterative technique originated in transverse waveform relaxation. The effects of adjacent lines at each iteration are considered as equivalent distributed sources along the lines rather than lumped sources at the end of the lines or segments. By means of combined voltage waves, these equivalent distributed sources are further implemented analytically in the form of exponential function combinations, leading to a more efficient updating process since the time-consuming numerical integration over the line is avoided. The voltages and currents at the terminals are solved by the Baum–Liu–Tesche equation considering the symmetry of the coupled transmission lines. One major advantage is that the solution at each iteration is obtained analytically and exactly in terms of the per-unit-length parameters, loads, and some predetermined coefficients, which is highly suitable for illustrating the factors that influence the crosstalk. The validation results in a wide range cases show that the proposed method can efficiently handle transmission lines with a large number of conductors and lossy as well as frequency-dependent parameters. [ABSTRACT FROM PUBLISHER]