Articles by Yuriy Shlepnev

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How Interconnects Work: Bandwidth for Modeling and Measurements

Modeling and measurement of digital serial interconnects is usually done in the frequency domain. That means that the minimal and maximal frequencies (or bandwidth) should be defined even before the analysis or measurement begins. This post introduces a simple and practical way to identify the bandwidth with a numerical analysis of defects in a single bit (SBR) or single symbol response (SSR).


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Validation of Bend Models with Measurements

Bends in PCB traces look like very basic, simple structures that are easy to simulate. Technically, one can do the analysis with any electromagnetic solver with sufficiently accurate port de-embedding capabilities. The reflections from a bend in fine-line, high-speed digital interconnects are relatively small and may not even be detectable with measurement. So, who cares? Read on to find out more.


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Modeling PCB Interconnects with Geometry and Material Parameters Variations for 56 Gbps Links

Measured S-parameters and cross-sections of PCB interconnects are used in this paper to identify the parameters of electrical models suitable for statistical analysis of interconnects with manufacturing variations. The constructed models reproduce observed effects of geometry and material properties variations on the loss, delay, and impedance, and they are suitable for yield analysis of interconnects with up to 56 Gbps signals.


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40 GHz PCB Interconnect Validation: Expectations vs Reality

What does it take to design PCB interconnects with good analysis-to-measurement correlation up to 40 GHz? Is it doable with typical low-cost PCB materials and fabrication process, typical trace width, via back-drilling and the shortage of space to place the stitching vias? This paper reports lessons learned from validation projects with the goal to build a formal procedure for systematic prediction of interconnect behavior up to 40 GHz. Topics include: selection of test structures, connectors and measurement equipment, and analysis uncertainties.

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