Thomas Bauernfeind

For the metrological quantification of radiated emissions of integrated circuits, the two-port TEM cell and IC stripline methods are utilized. Analytical formulas have been developed in the past to use the TEM cell measurement for the extraction of an equivalent analytical representation of the measured device under test. The equivalent sources are described as an array of electric and magnetic dipoles and can be used for e.g. open-area emission test simulations. This paper summarizes the theoretical background of this extraction methodology and gives an instruction for the needed measurements and calculations. Furthermore, the accuracy of this equivalent source model is evaluated against full-wave finite element simulations and its portability to IC stripline measurements is investigated.

Energy efficiency is becoming one of the most important topics in electronics. Among others, wide band-gap semiconductors can raise efficiency and lead to shrinking volumes in power conversion systems. As different markets have regulations that require different designs, it is necessary to cope with a large variety of similar designs. By using effective modeling and simulation strategies, the efforts of building these variants can be diminished, and re-designs can be avoided. In this paper, we present a universally valid way to come to reasonable simulation results for conducted emissions of a power electronic system in the frequency range from 150 kHz up to 400 MHz. After giving an overview of the state-of-the-art, the authors show how to implement and set up a simulation environment for a gallium-nitride (GaN) power converter. It shows how to differentiate between important and not that important components for Electromagnetic Compatibility (EMC), how to model these components, the printed circuit board, the load, and the setup, including the Line Impedance Stabilization Networks (LISNs), etc. Multiport S-parameter strategies as well as vector fitting methods are employed. Computational costs are kept low, and all simulations are verified with measurements; thus, this model is valid up to 400 MHz.

To characterize the electromagnetic compatibility (EMC) of integrated circuits (ICs), especially the radiated emissions in the near field, transversal electromagnetic cell (TEM cell) or IC-stripline measurements (IEC 61967) are utilized. Due to the ongoing miniaturization and the increasing operating frequencies, accurate EMC characterization of ICs is becoming more important to achieve first-time-right designs. In order to avoid expensive redesigns, the prediction of these measurements in terms of a simulation workflow would be of high interest. Because of the high computational burden needed to conduct 3D full-wave finite element (FEM) simulations of both the device under test (DUT) and the measurement system, an equivalent representation of the DUT by means of analytical incident fields, such as Hertzian dipole moments, can be considered. In order to develop an order-reduced model of this kind, it is essential to have a solid understanding of the coupling and wave propagation effects inside the measurement systems. In the present paper, a fundamental investigation of the coupling paths between an IC-stripline and electric or magnetic dipole moments is presented and the results are compared to the existing analytical models. The results show that these analytical models, originally developed for TEM cells, are only partially valid for IC-striplines. It has also been shown that even for simple test structures, such as loop and monopole antennas, the representation in terms of one single dipole moment is insufficient.

Electronic based systems (EBS) tend to become smaller in size while at the same time their functionality, complexity, and operating frequencies increase. Therefore, accurate and broadband characterization of the electric behavior of the components of such EBS is becoming more and more important for first‐time right designs, especially for electromagnetic compatibility (EMC) and interference (EMI) issues. Although many of the manufacturers provide the electric characterization of their components up to, for example, 8.5 GHz, there is still a lack of information about the parasitic electromagnetic coupling of their components to others. To characterize this behavior in terms of measurement is demanding due to the small size and the high frequencies, hence the characterization by means of numerical simulations has become popular in the last years. Due to the fact that the components can be quite complex and their structure hard to model and simulate, like it is the case for the here investigated multilayer ceramic capacitors (MLCC), simplified models of the geometry have been typically used. In general, the electromagnetic behavior of multiple components close to each other is of interest, hence numerical efficient models must be deployed to analyze interfering effects toward each other. In the present paper we evaluate different 3D modeling strategies for MLCCs in terms of their capabilities to characterize the mutual coupling between such components.

In this paper, common practice RF design guidelines for SMA edge mount connectors are investigated in terms of numerical simulations and VNA measurements. These guidelines are used in a variety of applications for coaxial-to-planar interfaces but often do not provide information regarding the physical origins of increased insertion and transmission losses. The presented results in this work focus on different RF PCB design features and their impact on electromagnetic field distributions in the launching zone. The presented investigations should raise awareness on the issue of electromagnetic field resonances occurring in the RF frequency range and assist PCB design engineers to identify potential issues occurring at an coaxial-to-planar interface. The investigated PCB features facilitate a high performance RF PCB design up to a frequency of 26 GHz.

Estimating the coupling properties between a radiating structure and other conductive elements, the field behavior of the radiating source is essential to know. One well-known classification of the field behavior are the field-regions around antennas, namely, the far-field, the radiating near-field, and the reactive near-field. The different kinds of near-fields are distinguished by the reactive and radiating parts of the electromagnetic field, whereas in the far-field region the field behaves as a plane wave in the direction of propagation. One way to describe these field characteristics is to use the complex Poynting vector, which defines the electromagnetic power flow. This work presents a Poynting-vector-based approach to classify and visualize the field behavior around simple radiators using numerical simulations. First, the approach is applied to simple antenna structures such as dipoles and loop antennas. Later, the introduced field regions are utilized to predict the coupling behavior of practical applications, the coupling between single elements of a linear antenna array, and the coupling behavior of an electrically large loop antenna. It could be shown that the introduced approach, defining a surface description of the boundary between the near-field regions, enables the possibility of predicting the coupling behavior between radiating structures. The introduced error estimator for the far-field also delivers knowledge about the far-field quality in different angular directions and distances. All simulations have been executed applying a one-dimensional partial element equivalent circuit method.

Developing simulation models for electromagnetic field problems often deals with approximations of the full set of Maxwell’s equations, to obtain performant methods. This is also the case for the so-called Darwin model, which has the capability of including resistive, inductive, and capacitive effects without the need of solving full-wave Maxwell’s equations. However, an issue is the difficulty of prescribing realistic excitations of the model, e.g., via a terminal voltage. In this article, the straightforward prescription of the scalar potential on electric ports is investigated via Poynting’s theorem, with the outcome that it can be considered as physical voltage excitation up to frequencies, where the validity of the Darwin model itself is lost.

Purpose: The purpose of this paper is to show that the computation of time-periodic signals for coupled antenna-circuit problems can be substantially accelerated by means of the single shooting method. This allows an efficient analysis of nonlinearly loaded coupled loop antennas for near field communication (NFC) applications. Design/methodology/approach: For the modelling of electrically small coupled field-circuit problems, the partial element equivalent circuit (PEEC) method shows to be very efficient. For analysing the circuit-like description of the coupled problem, this paper developed a generalised modified nodal analysis (MNA) and applied it to specific NFC problems. Findings: It is shown that the periodic steady state (PSS) solution of the resulting differential-algebraic system can be computed very time efficiently by the single shooting method. A speedup of roughly 114 to conventional transient approaches can be achieved. Practical implications: The proposed approach appears to be an efficient alternative for the computation of time PSS solutions for nonlinear circuit problems coupled with discretised conductive structures, where the homogeneous solution is not of interest. Originality/value: The present paper explores the implementation and application of the shooting method for nonlinearly loaded coupled antenna-circuit problems based on the PEEC method and shows the efficiency of this approach.

The field regions around antennas are distinguished through the properties of the electromagnetic field. The knowledge of the boundaries between these regions is very important for e.g. measurement engineers or in the numerical simulation to ensure a proper behavior of their results. In the present work the validity of the boundaries suggested from the literature has been analyzed using error estimations for different properties of the electromagnetic field. Analyses are conducted on dipole antennas, loop antennas as well as on Yagi-Uda arrays with various dimensions. In addition, different concepts are introduced allowing the definition of a more convenient boundary between the field regions. The proposed rules satisfy the IEEE standard definitions in a better way. For the numerical computations a one dimensional Method of Moments is applied.