Return to discussion board
Answered

How do I select the resonant frequency for installing decoupling capacitors?

In power integrity design, how should you select the self-resonant frequency of decoupling capacitors? Is it better to be closer to the target noise frequency?

Decoupling capacitorResonancePDN
PI Learner2026-08-173453Answer

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