Signal integrity diagnosis and physical-based circuit modeling for 5G/6G connectors in high-speed electrical links

High-speed 5G/6G connectors have become a critical bottleneck in next-generation digital systems due to escalating data rates and stringent signal integrity (SI) requirements. This dissertation addresses these challenges by introducing a physics-based signal integrity diagnosis and modeling framework for multi-gigabit connectors. The approach combines field-based resonance analysis with a novel distributed physical-based transmission-line (dPBTL) circuit model, including an extended mixed-mode dPBTL (mm-dPBTL) formulation, to efficiently capture and interpret complex connector behaviors. Key contributions include explicit modeling of differential/common-mode signal paths loaded with ground-cavity and signal stub resonant structures, which are often responsible for narrowband SI degradations, and a mixed-mode analysis methodology to evaluate inter-mode and inter-pair interactions with resonant features. The proposed equivalent-circuit models faithfully reproduce full-wave connector responses over broad frequencies while maintaining physical transparency into resonant mechanisms. Applied to state-of-the-art connectors (e.g., PCIe 5.0 and OSFP), the framework demonstrates excellent agreement with 3D electromagnetic simulations and measurement data, enabling accurate prediction of S-parameters, NRZ/PAM-4 eye diagrams, and industry compliance metrics without resorting to time-intensive full-wave solves. The results show that this fast, interpretable SI tool can guide design pathfinding by pinpointing root causes of reflection, loss, crosstalk, mode conversion, and resonance issues and evaluating mitigation strategies. Ultimately, the developed modeling approach accelerates the design cycle for 5G/6G interconnects and provides engineers with deeper insight into achieving reliable high-speed link performance.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• He, Yulin

Contributors dc:contributor

• Feng, Milton
• Jin, Jianming
• Dallesasse, John
• Schutt-Aine, Jose E
• Zhao, Yang

• Signal Integrity
• Transmission Line
• 5g
• Ethernet
• Interconnect
• High-speed
• Mixed Mode
• Multimode
• Resonance
• Failure Analysis
• Full Wave Simulation
• Equivalent Circuit
• Modeling

Statement dc:rights

• Copyright 2025 Yulin He

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/130038

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F130038