Guenter Wollenberg

Stability of full-wave PEEC models: reason for instabilities and approach for correction

The partial element equivalent circuit (PEEC) method is a widespread numerical method for creating full-wave models of interconnection structures in the frequency and time domains for use in modeling EMC problems. The possible instabilities of time domain solutions-so-called late time instabilities-can complicate the use of the method. Several attempts to improve the stability of time domain solutions have been made in the literature. A new mathematically correct approach for analyzing the stability of PEEC circuits is presented in this paper. The reason for instabilities is discovered, and a method for stability improvement is developed and tested.

PEEC Formulation Based on Dyadic Green's Functions for Layered Media in the Time and Frequency Domains

This paper presents a novel time- and frequency-domain concept of modeling with the partial element equivalent circuit (PEEC) method, which applies the mixed potential integral equation (MPIE) with dyadic Greens functions for layered media (DGFLM-PEEC). On the one hand, it represents an exact full-wave semianalytical solution for an arbitrary configuration of traces and via holes in multilayered printed circuit boards. On the other hand, the DGFLM-PEEC model is represented in a circuit form, and thus, may be included in general-purpose circuit simulators. The paper derives a general DGFLM-PEEC formulation, which may be applied to all types of the MPIE with dyadic Greens functions. Using this concept, a particular type of layered media, namely a lossy dielectric between two grounds (stripline region), is thoroughly investigated and used to set up a particular DGFLM-PEEC model. The closed-form expressions for partial inductances and potential coefficients have been derived for this case. The time- and frequency-domain DGFLM-PEEC models for the stripline region have been validated using the measurements and the simulation by the method of moments.

Stable and Effective Full-Wave PEEC Models by Full-Spectrum Convolution Macromodeling

A novel technique for time domain partial element equivalent circuits (PEECs) modeling is presented. The PEEC method is a well-known numerical method for creating full-wave models of interconnection structures in the frequency and time domains, which are being used for modeling electromagnetic compatibility (EMC) problems. The time domain solutions by PEEC can show the so-called late-time instabilities. Several attempts to overcome this problem have been made in the literature. The cause for instability has been revealed, and a stable time domain model has been given, however, with a reduced computational efficiency. A stable full-wave PEEC model based on a convolution macromodeling with a faster computation time is developed and tested in this paper

Fast computation of radiated power distribution in coupled wire systems by the PEEC method

This paper presents a new fast method that allows calculation of the radiated and incident power in arbitrary wire systems consisting electromagnetically coupled parts in the frequency domain. The main idea of the method is using the internal data of the partial element equivalent circuit (PEEC) model of interconnections for fast computation of the radiated power without field calculation. It provides the same results like the far-field analysis of radiation sources and the induced EMF method.

Coupling of PEEC models with transmission line models for simulation of wiring structures

In order to reduce the cost for the creation and simulation of partial element equivalent circuit (PEEC) models it is beneficial to describe sections, that fulfil the requirements for the transmission line equations (2D models) with transmission line (TL) models and couple them to the pure 3D PEEC models for the other parts. In this paper the coupling of PEEC models to the homogeneous TL model is demonstrated. Different discontinuities and nonuniformities are studied.

Peec-Models Based on Dyadic Green's Functions for Structures in Layered Media

This paper presents a novel concept of modeling with the PEEC method based on Dyadic Greens functions of layered media in time and frequency domain. On the one hand such models represent an exact full-wave semi-analytical solution for an arbitrary configuration of traces and via holes in multilayered PCBs. On the other hand they are represented in circuit form and can be calculated with common circuit simulators.

Stable time domain PEEC solution for pulse interconnection structures

Time domain methods for transient analysis of pulse excited interconnection structures are of big interest. Since frequency domain methods with IFT in a frequency range given by UWB pulses need much computation time, in particular, if system investigated have a low dissipation and the response time is relatively long in comparison with the exciting pulse. A further advantage of time domain methods is the opportunity for including non-linearities. Unfortunately, numerical time domain methods sometimes meet the problem of late time instability. This disadvantage holds also for the standard PEEC method and for MoM (MOT). The present paper provides a contribution for avoiding such instabilities. A modified full-wave PEEC method for obtaining stable time domain solutions is developed and tested.

Alternative PEEC Modeling with Partial Reluctances and Capacitances for Power Electronics Applications

Today power electronic design has to account for the interconnection structure. The method of partial elements (PEEC) is a suitable tool to describe arbitrary 3D interconnections. In engineering applications the number of volume and surface cells quickly becomes prohibitively high, due to the huge number of partial inductances and potential coefficients. Therefore, more efficient approaches are needed. It is possible to formulate the couplings in terms of partial reluctances and capacitances as the inverted matrices for the partial inductances and potential coefficients. The advantage of this modeling technique is based on the dominance of the diagonal matrix elements, so that very small values can be ignored under reservation of the passivity of the interconnection structure. Furthermore, one can derive a SPICE compatible circuit without the need for further tools. In this paper a suitable reduction procedure and implementation of the PEEC models with reluctances and capacitances are presented. The accuracy of the simulation results depending on the model reduction is discussed on a typical power electronics application.

PEEC Modeling for EMC-relevant Simulations of Power Electronics

This paper deals with the modeling of arbitrary oriented interconnection structures with the method of partial elements regarding EMC simulations of power electronics. 1D and 2D PEEC models were developed, implemented and tested as well in the simulation tool Ansoft Simplorerreg as in SPICE. An alternative approach for the PEEC modeling is used to overcome the huge simulation effort in real conductor arrangements because of the high number of inductive and ca-pacitive couplings. The coupling matrices of this kind of PEEC models are diagonal dominant and matrix sparsification by truncation methods can be used without loss of passivity of the interconnections. The application of the developed PEEC models is shown for two examples.

Modeling of common mode interferences produced by a switched mode power supply

This work deals with the examination of the influence of interconnections on fast transients in power electronic circuits and the creation of a simulation tool for modeling power systems with taking into account this phenomenon. The simulation tool must provide exact models of semiconductors and the possibility to implement parasitic influences of conductors. The PEEC method allows to represent the interconnection structure as an equivalent passive circuit. This fact enables the analysis of the power electronic circuit under consideration of interconnections. Ansoft Simplorer/spl reg/ is a wide spread professional code for modeling of power circuits. It can be expanded by additional elements programmed in C++. In this work a PEEC model is implemented into Simplorer/spl reg/. Thus, its possible to simulate the interconnections simultaneously with the standard lumped circuits.