Return to discussion board
Pending response

How to evaluate signal quality margin for PCIe Gen4 channels?

When designing PCIe Gen4 channels, what methods are typically used to evaluate signal quality margin? Is eye diagram template testing sufficient?

PCIeEye DiagramSignal Quality
High-Speed Design2026-08-161890Answer

2Answer

Accepted Answer

High-frequency discrepancies are typically caused by the following: 1 Material parameters (Dk/Df) not accurately modeled for frequency dependence; 2 Conductor surface roughness model not enabled; 3 Inconsistent port calibration reference planes. First, verify material settings and enable the Huray roughness model, then compare simulated and measured group delay.

Senior Engineer2026-08-19

Additionally, verify that the mesh is sufficiently fine. At high frequencies, the skin depth decreases, so ensure there are at least 3 to 4 mesh layers across the conductor cross-section. Also, placing radiation boundaries too close to conductors can introduce errors.

Simulation Expert2026-08-19

Write Answer

Answer to get+5 points