Heinz-Dietrich Bruns

Bio: Heinz-Dietrich Bruns is an academic researcher from Hamburg University of Technology. The author has contributed to research in topics: Printed circuit board & Method of moments (statistics). The author has an hindex of 12, co-authored 59 publications receiving 593 citations. Previous affiliations of Heinz-Dietrich Bruns include University of Hamburg.

Physics-Based Via and Trace Models for Efficient Link Simulation on Multilayer Structures Up to 40 GHz

Abstract: Analytical models for vias and traces are presented for simulation of multilayer interconnects at the package and printed circuit board levels. Vias are modeled using an analytical formulation for the parallel-plate impedance and capacitive elements, whereas the trace-via transitions are described by modal decomposition. It is shown that the models can be applied to efficiently simulate a wide range of structures. Different scenarios are analyzed including thru-hole and buried vias, power vias, and coupled traces routed into different layers. By virtue of the modal decomposition, the proposed method is general enough to handle structures with mixed reference planes. For the first time, these models have been validated against full-wave methods and measurements up to 40 GHz. An improvement on the computation speed of at least two orders of magnitude has been observed with respect to full-wave simulations.

Numerical Electromagnetic Field Analysis for EMC Problems

Abstract: Much progress has been made in the use of computational electromagnetics for the analysis of electromagnetic compatibility (EMC) problems during recent years. This paper reviews the improvements in some of the most important techniques of the field: the method of moments, the finite-difference time-domain method, the finite-element method, the transmission-line matrix method, and the partial-element equivalent-circuit method. The results of computer codes on the basis of such methods have to be validated, and some of the respective possibilities are addressed.

A Combined Method for Fast Analysis of Signal Propagation, Ground Noise, and Radiated Emission of Multilayer Printed Circuit Boards

Abstract: This paper presents a method for fast and comprehensive simulation of signal propagation, power/ground noise, and radiated emissions by combining the merits of the physics-based via model, the modal decomposition technique, the contour integral method (CIM), and the equivalence principle. The physics-based via model combined with the modal decomposition technique is an efficient technique for signal integrity analysis of multilayer PCBs and packages. The CIM can be used to calculate the voltage distribution between arbitrarily shaped power planes. Far-field radiation can be obtained by applying the field equivalence principle. In this paper, we integrate the four techniques to analyze all the three effects in a fast, concurrent, and holistic manner. To the best knowledge of the authors, the four techniques are integrated here for the first time. Various structures are simulated and validated with full-wave simulations up to 20 GHz. It is shown that a reduction in simulation time of more than two orders of magnitude is achieved in comparison to a standard full-wave electromagnetic solver.

Extension of the Contour Integral Method to Anisotropic Modes on Circular Ports

Abstract: In the analysis of power/ground planes in multilayer substrates, circular ports are often used for modeling of via transitions. The electric and magnetic fields on excited ports are usually assumed to be isotropic. This assumption may not hold in certain scenarios such as vias in very close proximity, where anisotropic modes can be excited. This paper first extends voltage and current definitions of circular ports to account for the non-uniform field distribution along the port perimeter and the anisotropic propagating modes. The effect of these modes on the parallel-plate impedance can be captured in the contour integral method (CIM) by discretizing the port perimeter with line segments. However, the computation time grows rapidly as the number of modeled ports increases. Therefore, the CIM is extended here to incorporate analytical modal expressions to improve the computational efficiency based on the new port definition. The derivation starts with solutions under the assumption of infinite planes, and then is expanded to take finite plane boundaries into consideration. Application examples using the extended CIM will be demonstrated and validated against the conventional CIM with ports modeled numerically. The significance of anisotropic propagating modes for dense via arrays will also be discussed.

Introducing a Mixed-Mode Matrix for Investigation of Wireless Communication Related to Orbital Angular Momentum

Abstract: This paper introduces a mixed-mode matrix representation of scattering parameters that is suitable for the investigation of wireless communication based on orbital angular momentum (OAM). For this purpose, a unitary transformation matrix is defined, which contains the transmitted and received amplitudes as basis vectors corresponding to OAM-based communication between two antenna arrays. The mixed-mode matrix is then obtained from the corresponding similarity transformation of the standard scattering matrix available, e.g., from numerical simulations or measurements. The mixed-mode matrix allows better physical insight into OAM-based communication by clearly separating all modes and is more efficient than postprocessing of single-antenna results in a system simulator. Mode conversion/isolation and proper mode termination can be easily quantified. Also, it allows generalizing the interpretation of OAM-based communication by focusing on the property of a constant phase difference within each antenna array. The usefulness of this approach is demonstrated using method of moments (MoM) simulations of dipole radiators in various arrangements of a transmitting and a receiving array. Systematic parameter studies that reveal dependencies of OAM-based communication are possible by using the mixed-mode matrix. As an application, communication patterns are studied, in order to obtain the suitable position and relative orientation in space for good mode isolation or communication.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Signal Integrity Design for High-Speed Digital Circuits: Progress and Directions

Abstract: This paper reviews recent progress and future directions of signal integrity design for high-speed digital circuits, focusing on four areas: signal propagation on transmission lines, discontinuity modeling and characterization, measurement techniques, and link-path design and analysis.