James Pingenot

Polar Integration for Exact Space-Time Quadrature in Time-Domain Integral Equations

A space-time polar quadrature technique for numerical integration of Greens function interactions in time-domain integral equations is presented. The method transforms 2-D surface space-time integrals associated with vector and scalar potentials to a 1-D integral that is performed using Gauss-Legendre integration. The advantage of the presented technique compared to standard 2-D Gaussian quadrature is that time delays between each section of the source basis function and the observation point are accounted for exactly in an analytic manner. This ensures highly accurate temporal behavior of the Greens function interactions thereby contributing to the stability of the overall time-domain integral equations

Towards system-level electromagnetic field simulation on computing clouds

Cloud computing is a potential paradigm-shifter for system-level electronic design automation tools for chip-package-board design. However, exploiting the true power of on-demand scalable computing is as yet an unmet challenge. We examine electromagnetic (EM) field simulation on cloud platforms.

Efficient hierarchical discretization of off-chip power delivery network geometries for 2.5D electrical analysis

Power delivery network (PDN) design is becoming even more critical with the advent of progressively complex environments on and beyond the die. Multicore chips, mixed-signal designs with multiple reference voltages, and complex 3D packaging situations lead to complicated PDN geometries with high-frequency demands and sharpening edge rates even when on-core frequencies are relatively constant. Early design iterations of such PDNs remain infeasible with 3D full-wave simulators even with the latest breakthroughs in solver technology. For reasonably well designed structures and moderate frequencies, fast 2.5D tools (particularly in the most evolved form of multilayered finite difference method (MFDM) [1]) work well. However, application of these methods to complex layouts containing cutouts, slots, vias, microvias and non-Cartesian shapes is challenging. First, generating a layer-wise consistent mesh from the complex layout is nontrivial. Second, use of globally uniform meshing, as generally employed forces a choice between an inaccurate or inefficient solution. This paper proposes an algorithm for rapidly generating layerwise consistent adaptive rectangular meshes for multilayered PDNs with the aim of significantly enhancing the speed, capacity and versatility of 2.5D methods. An efficient implementation of MFDM based on the adaptive mesh has been made. Results show that the algorithm is general enough to extend the applicability of these methods from simple PDNs to complex real-world models.

A Framework And Simulator for Parallel Fast Integral Equation Simulation of Microelectronic Structures

As a part of IBMs special session, this paper presents a framework and integral equation-based 3D electromagnetic simulator for parallel simulation of microelectronic structures including those of interest to IBM. The translators, mesher, and simulator is described and is validated for initial cases. Progress on the IBM benchmark is reported

Quantitative method of medication system interface evaluation.

The objective of this study was to develop a quantitative method of evaluating the user interface for medication system software. A detailed task analysis provided a description of user goals and essential activity. A structural fault analysis was used to develop a detailed description of the system interface. Nurses experienced with use of the system under evaluation provided estimates of failure rates for each point in this simplified fault tree. Means of estimated failure rates provided quantitative data for fault analysis. Authors note that, although failures of steps in the program were frequent, participants reported numerous methods of working around these failures so that overall system failure was rare. However, frequent process failure can affect the time required for processing medications, making a system inefficient. This method of interface analysis, called Software Efficiency Evaluation and Fault Identification Method, provides quantitative information with which prototypes can be compared and problems within an interface identified.

Device physics aware 3D electromagnetic simulation of Through-Silicon-Vias in system modeling

Three dimensional integrated circuits (3DICs) are generating considerable interest as a way to increase speed and density while reducing power and form factor. Among the different forms of 3D integration, the use of Through Silicon Vias (TSV) with micro-bumps in a passive interposer is a popular choice in applications ranging from wide IO memory to heterogeneous integration. Current compact modeling strategy aims at modeling TSVs with circuit elements whose values are typically computed from analytical expressions. This technique therefore does not capture system level coupling effects like TSV-Redistribution Layer (RDL) coupling. This paper presents a device physics aware 3D electromagnetic modeling of TSV structures with the capability of modeling full systems including coupling between conventional package-board layers and TSV embedded passive interposers, towards accurate signal and power integrity analysis and design.

A Hybrid FEM-BEM Unified Boundary Condition with Sub-Cycling for Electromagnetic Radiation

This paper details a hybrid solver using the coupled first-order equations for the E and H fields in the finite-element region. This formulation is explicit, with a restriction on the time step for stability. When this time step is used in conjunction with the boundary elements forming either an inhomogenous Dirichlet or Neuman boundary condition on the finite-element mesh, late time instabilities occur. To combat this, a unified boundary condition (UBC), for the second-order wave equation, is used. Even when this UBC is used, the late time instabilities are merely delayed if standard testing in time is used. However, the late time instabilities can be removed by replacing centroid based time interpolation with quadrature point based time interpolation for the boundary elements or by sub-cycling the boundary element portion of the formulation. This sub-cycling, for FDTD to reduce complexity, is shown here to improve stability and overall accuracy of the technique

A generalized TDIE framework for arbitrary time basis functions

A generalized formulation of the TD-EFIE (time-domain electric field integral equation) is presented, extending the work of Y.S. Chung et al. (see IEEE Trans. Antennas Propag., vol.52, no.9, p.2319-28, 2004). The framework shows that, for a large class of basis functions, the time integration can be analytically removed from the calculation. This allows the time-space integral to be computed to arbitrary accuracy through existing quadrature schemes. The result is a single, large matrix problem that is adaptable to different solvers, including marching on in time, marching on in order, fast solvers, and parallel solvers. While the formulation presented is specifically for the EFIE, it is equally applicable to other TDIEs.

Differential forms basis functions for better conditioned integral equations

Discretized differential-forms basis functions were formulated and implemented for surface integral equation problems. Making the degrees of freedom scale invariant with element size leads to better conditioning of the system matrix for both electrostatic and frequency-domain scattering problems on meshes with a large variation in patch size.