What EMC risks are associated with PCB ground plane segmentation for edge computing boxes?

Improper PCB ground plane partitioning for edge computing boxes can disrupt high-frequency return paths, forcing signals to detour and creating loop antennas that pose a strong risk of common-mode radiation. This includes:

1) Sudden impedance increases across partitions, leading to signal reflection and differential-mode radiation;

2) Ground potential differences increase common-mode noise in analog-to-digital interfaces;

3) ESD discharge paths lengthen, increasing inductance and causing TVS clamping failure.

Countermeasures include:

1) Avoiding critical high-speed signals crossing partitions; if crossing is necessary, using a series common-mode inductor (CML3225A-101T) or adding a ferrite bead (PBZ1608E600Z0T) at the partition bridge;

2) Single-point grounding only in low-frequency analog areas, with a unified ground plane in high-frequency areas;

3) Ground plane via density >1 via/mm² to ensure low-impedance interconnects.

Using EMC simulation tools during the design phase to assess ground plane integrity can reduce redesign risks.