Torsten Reuschel

Energy-Aware Signal Integrity Analysis for High-Speed PCB Links

This paper proposes a novel approach to evaluate design alternatives for high-speed links on printed circuit boards. The approach combines evaluations of signal integrity and link input power. For a comprehensive analysis, different link designs are made comparable through the application of identical constraints, with the link input power as the single figure of merit for a systematic, quantitative comparison of design alternatives. The analysis relies upon a combination of efficient physics-based via and trace models, statistical time-domain simulation, and an analytical input power evaluation, which allows it to handle links consisting of a large number of channels while fully taking into account interchannel crosstalk. The proposed approach is applied to study two fundamental design decisions at the PCB level-single-ended versus differential signaling and signal-to-ground via ratios of 1:1 versus 2:1-for a link consisting of 2048 vias and up to 175 striplines with an aggregate data rate of 1 Tb/s. It is found that both design decisions have a considerable impact on the required input power of the link.

Segmented Physics-Based Modeling of Multilayer Printed Circuit Boards Using Stripline Ports

This paper introduces physics-based stripline ports for a segmented optimization of component footprints on printed circuit boards (PCBs). A segmentation is used for dividing a digital communication system into well-defined parts that are considered to be mostly independent. This technique is widely used in conjunction with generic 3-D electromagnetic field solvers, but it is new to physics-based models that until now only allow for ports at the upper and lower via ends, i.e., on PCB surfaces. Evidence of feasibility is provided by means of correlation with measurements and full-wave simulations up to 40 GHz. Since physics-based models can efficiently capture and simulate even systems of thousands of elements within acceptable computation time, the results of a segmented simulation can easily be compared to the full-board environment. The corresponding results are correlated to investigate limitations.

Efficient Total Crosstalk Analysis of Large Via Arrays in Silicon Interposers

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.

On the Treatment of Arbitrary Boundary Conditions Using a Fast Direct

This communication adapts the formalism of hierarchical (H-) matrices to the direct solution process (LU decomposition) of the method of moments (MoM) in the frequency domain. A novel clustering approach based on physical constraints is presented and extended to treat dielectric bodies as well as arbitrary boundary conditions. Comparisons with other numerical methods are provided. The analyses show a considerable speedup of the computation times and a significant reduction of required memory compared with the traditional MoM solution process, especially for highly resonant structures where iterative solvers like the multilevel fast multipole algorithm show poor convergence.

{\mathcal {H}}

This contribution presents the system design procedure and performance of an array fed reflector antenna. Combining the inherent benefits of a reflector antenna—high gain, low-cost, and simplicity—with the agility provided by a scannable active array feed, enables a new range of applications, for instance in commercial mobile antenna terminals. The whole arrangement features a restricted field of view for either scanning or multibeam applications. To minimize system cost, a planar patch antenna array in printed circuit board technology is used for the feed and the reflector diameter is restricted to 60 cm. To obtain optimal performance, both the reflector and the feed are specifically designed for the desired application, i.e., mobile satellite communication at Ka-band. A comprehensive study of various rotationally symmetric reflectors is carried out to determine arrangements maximizing the field of view and still complying with the respective regulations. For the feed, a 30 GHz transmit array with 49 elements is developed, enabling 2-D scanning in a ±6° conical sector. It includes a wideband signal distribution network and frontend electronics.

-Matrix Solver in MoM

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.

An Electronically Scannable Reflector Antenna Using a Planar Active Array Feed at Ka -Band

The decomposition, i.e., segmentation, of multilayer printed circuit board links into constitutive parts by means of network parameter representations is widely accepted. This work examines implications of this procedure regarding differential links. For the first time, the physics-based single-ended stripline port is generalized to model coupled striplines in the environment of multilayer PCBs. Notably, results are general in nature and are not limited to the employed methods. The proposed approach allows for segmentation and computationally efficient simulation of links between very large via pin fields, where differential stripline pairs pose a common routing scheme. Its feasibility is validated using self-contained physics-based simulations as well as measurements and full-wave simulation results up to 40 GHz.