How to meet the RS (radiated interference immunity) standards for power FTUs?

Radiated interference immunity (RS) requires both shielding integrity and internal circuit immunity.

Chassis shielding: 1.5mm thick aluminum alloy with conductive pads at gaps; gap length less than λ/20 (18cm at 80MHz).

Cable shielding: Shielded cables are used, with 360° grounding of the shielding layer connectors.

Internal circuitry: Sensitive circuits are locally shielded; the clock circuit is kept away from chassis gaps; a common-mode inductor CMZ3225A-501T is used in the power supply.

With this design, the FTU passes the IEC 61000-4-3 RS test (10V/m, 80MHz-1GHz), functioning normally without resets or malfunctions.