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Item type:Publication, Access status: without files , Relational SI/PI-database for a data-driven approach to PCB design automation and performance predictionThe introduction of machine learning (ML) methods into the design process of printed circuit boards drives the need for large quantities of readily available data. This paper addresses the problems of engineers to find ML-ready data that can be easily reused and combined to enhance printed circuit board (PCB) design by storing the defining parameters in a normalized format within a relational database It implements search and filter functions to obtain relevant data quickly. The database contains data that was used to address a variety of different signal integrity (SI) and power integrity (PI) related problems. Details of the database structure, necessary data conversion steps, currently stored datasets, and a statistical analysis there of are described. This database is capable to be automated to a degree that ML agents can interact with it.Publicationtype: Journal Article24 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Engineering-informed design space reduction for PCB-Based power delivery networksAn engineering-informed approach to reduce a feasible design space for printed circuit board (PCB)-based power delivery networks (PDNs) of high-speed digital systems, is proposed. A reduction in the sampling of a factor of three decades from more than × 106 sampling points to × 103 sampling points is achieved. This enables to generate data samples for training machine learning (ML) tools being applicable in the design process of the PDNs for a subset of the formerly defined design space. Reducing the complexity is performed by focusing on a specific problem namely a PCB with two via arrays and a fixed PCB size. First a data-driven sensitivity analysis of the different PCB design parameters is performed reducing the design space of parameter variations which show a very small impact on the PDN impedance. Second, a physics-informed and data-supported reduction of the PCB stackup is performed showing the possibility to cover a wide range of stackups with minimal stackup definition. All investigations are performed in the frequency range from mathrm {1∼ MHz} to mathrm {1∼ GHz} , relevant for investigations of the decoupling of PCB-based PDNs. Based on a developed PDN design flow, artificial neural networks (ANNs) are trained to predict key features of the electromagnetic (EM) behavior of the PDN. All generated data samples are provided in the SI/PI-database as Touchstone files (https://www.tet.tuhh.de/en/si-pi-database).Publicationtype: Journal Article14 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Multiconductor Transmission Lines for Orbital Angular Momentum (OAM) Communication Links(2022-02); ; ; ; In this article, the orbital angular momentum (OAM) mode system, known from antenna communication, is applied and extended to various multiconductor transmission lines. In the context of this work, an OAM mode describes the excitation of a multiport system with a voltage distribution that is an eigenmode of a cyclic system. The OAM mode system is the complete system composed of all N OAM modes for a N -port system. For two conductors, the OAM mode system is shown to be equivalent to the differential- and common-mode systems. A transmission line carrying OAM modes must be used as a feed line in OAM communication links and, because of the orthogonality of the modes, it can be used to transmit multiple signals without mode conversion. An OAM communication link is defined in the context of this work as the components used from mode excitation of the transmitter to mode decomposition of the receiver. Using the analogy of OAM communication with antenna arrays and transmission-line theory, the excitation, geometry, characteristic mode impedance, mode power, and matching of a transmission line carrying OAM modes are derived. The matching is implemented with a mode decomposition and mode matching network on both sides of the transmission line. The performance of the system is verified numerically, with a 2-D boundary element method (BEM) solver based on the method of moments. Implementations of the OAM mode system for multiconductor cables, microstrip lines, and striplines are examined. In addition, the behavior of the mode transmission if the OAM modes are mismatched is evaluated and compared to a single conductor transmission line.Publicationtype: Journal Article46 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Vertical Integration of Passive Microwave Components Using Functional Via Structures in LTCC Multilayer SubstratesA recently developed concept for designing passive microwave components using functional vertical interconnect accesses (vias) for vertical integration in printed circuit boards (PCBs) is extended and transferred to the low temperature cofired ceramic (LTCC) technology. Given the changed material properties and new technology constraints, it is shown how and to what extent the controlled vertical interconnect accesses (via) structures can behave as quasi-transmission lines, thus allowing for another degree of freedom in component design. To demonstrate the validity and utility of functional vias, several novel microwave components are proposed and subsequently analyzed including vertically integrated 2- and 3-way Wilkinson power dividers, as well as vertically integrated 90° and 180° hybrid couplers. Prototypes for the 2-way and 3-way power dividers were manufactured on an LTCC multilayer substrate. Both measurement and full-wave simulation results are in excellent agreement and thus provide a proof of the concept.Publicationtype: Journal Article59 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A multistage adaptive sampling scheme for passivity characterization of large-scale macromodels(IEEE, 2021-03-01); ; ; ; This article proposes a hierarchical adaptive sampling scheme for passivity characterization of large-scale linear lumped macromodels. In this article, large scale is intended both in terms of dynamic order and especially number of input-output ports. Standard passivity characterization approaches based on spectral properties of associated Hamiltonian matrices are either inefficient or nonapplicable for large-scale models, due to an excessive computational cost. This article builds on existing adaptive sampling methods and proposes a hybrid multistage algorithm that is able to detect the passivity violations with limited computing resources. Results from extensive testing demonstrate a major reduction in computational requirements with respect to competing approaches.Publicationtype: Journal Article43 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Efficient prediction of equalization effort and channel performance for PCB-based data links(IEEE, 2017-09-28); ; ; ; High-speed data links that utilize multilayer printed circuit boards suffer from loss, dispersion, and intersymbol interference. Often, equalization and error correction are required to make these channels functional at gigabit data rates and demand costly analyses. The characterization of loss-dominated links can be generalized and simplified by means of a normalized link length as presented herein. Based on a correlation of this normalized length and observed eye opening, a novel assessment of wired digital links for frequencies up to 50GHz and data rates up to 30 Gb/s is proposed. It allows for an efficient prediction of the amount and type of required equalization for a given link as well as determining maximum tolerable loss for a given equalizer configuration. The proposed method and its applicability are demonstrated by means of practical examples.Publicationtype: Journal Article214 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Efficient total crosstalk analysis of large via arrays in silicon interposers(2016-12-01); ; ; ; In this paper, we present for the first time a rigorous crosstalk analysis of through silicon via (TSV) arrays consisting of several hundreds of TSVs in interposers with metallized surfaces, using the physics-based via (PBV) modeling approach for applications up to 500 GHz. The PBV modeling approach is valid for complete and almost complete metallizations of the substrate where radial wave propagation in the parallel-plate structure dominates the electromagnetic properties and is utilized with models of good accuracy for localized and propagating fields in the inhomogeneous dielectrics. The approach shows very good to good agreement of crosstalk results for frequencies up to 500 GHz in comparison to full-wave simulations and attains a speedup of at least two orders of magnitude in comparison to general-purpose simulators. The definition of a weighted power sum for total uncorrelated crosstalk is applied for all channels in the TSV array. These power sum results give more meaningful insights into the global effects of the parameter variations than single crosstalk contributions. Based on variations of several technology and design parameters of TSVs, we derive quantitative estimations of the impact of these parameters on the total crosstalk.Publicationtype: Journal Article78 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A rigorous approach for the modeling of through-silicon-via pairs using multipole expansions(IEEE, 2015-11-25); ; ; ; This paper presents a novel multipole expansion method for the rigorous analysis of wave propagation along a through-silicon-via (TSV) pair. TSV models are often constructed using equivalent circuits under the assumption that the interfaces between different media are equipotential. In comparison with that, the proposed method is a rigorous full-wave solution of the propagation mode. It takes advantage of cylindrical wave expansion functions and matches the boundary conditions at both the metal-to-insulator and insulator-to-silicon interfaces exactly. The method is validated against a full-wave finite-element method solver, and analysis examples using the method are demonstrated in a frequency range up to 100 GHz.Publicationtype: Journal Article82 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Efficient computation of localized fields for through silicon via modeling up to 500 GHz(IEEE, 2015-11-17); ; ; ; This paper presents methods for the modeling of the localized (near) fields of vertical interconnects in silicon interposers and the applications of these methods for the efficient computation of the electromagnetic properties of through silicon via structures. The localized fields are due to the mode conversions of the coaxial-to-radial waveguide junctions present in these structures. Because exact analytical techniques exist only for the homogeneously filled junction, an efficient numerical technique is proposed in this paper for the modeling of the inhomogeneous cases. This technique provides accurate results in the form of network parameters with three ports, which can be applied, e.g., in the framework of the physics-based via models. The finite-difference frequency domain method for the case of rotational symmetry is adapted to variable grid distances along the axial and radial coordinates, and interface conditions for the inhomogeneous filling of silicon and electrically isolating silicon dioxide are implemented. The method is validated with full-wave results from finite-element simulations and with the results from the published analytical methods that are adapted to the layered structures. The main focus is in the modeling for signal integrity analysis from the frequencies where the skin effect is well developed at about 100 MHz up to 100 GHz. Nevertheless, good agreement with the results from finite-element simulations up to 500 GHz is obtained for several relevant example structures, and a speedup of at least two orders compared with the finite-element simulations is achieved.Publicationtype: Journal Article48 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Characterization of TSV-induced loss and substrate noise coupling in advanced three-dimensional CMOS SOI technology(IEEE, 2013-10-30); ; ; ; Electrical loss and substrate noise coupling induced by through-silicon-vias (TSVs) in silicon-on-insulator (SOI) substrates is characterized in frequency and time domains. A three-dimensional (3-D) test site in 45-nm CMOS SOI including copper-filled TSVs and microbumps (μC4's) is fabricated and measured to extract the interconnect loss. Good correlation to the electrical circuit models is demonstrated up to 40 GHz. In addition to a buried oxide layer, a highly doped N+ epilayer used for deep trench devices in 22-nm CMOS SOI is considered in full-wave electromagnetic simulations. Equivalent circuit models are extracted to assess the impact of noise coupling on active circuit performance. A noise mitigation technique of using CMOS process compatible buried interface contacts is proposed and studied. Simulation results demonstrate that a low-impedance ground return path can be readily created for effective substrate noise reduction in 3-D IC design.Publicationtype: Journal Article54