When Enclosures and Seams Start Talking

MIL STD 461G extends RS103 radiated susceptibility testing up to 18 GHz to represent the electromagnetic environments created by modern military systems. Contemporary platforms operate alongside high-frequency radars, data links, and electronic warfare emitters that produce fields well above the ranges traditionally emphasized in older standards.

At these frequencies, the dominant coupling mechanisms change. Enclosure seams, fasteners, apertures, connector interfaces, and cable shield continuity become primary entry points for electromagnetic energy. Features that are electrically insignificant at lower frequencies can behave as efficient coupling paths once wavelengths become comparable to mechanical dimensions.

Designs that demonstrate strong immunity performance below 6 GHz often degrade rapidly as frequency increases. Shielding effectiveness drops, small gaps begin to radiate or receive energy, and cable shields lose continuity. RS103 testing in the upper frequency range reveals weaknesses that are invisible at lower frequencies.

Because of this, RS103 performance above 6 GHz is increasingly scrutinized by customers who understand modern RF threat environments. Passing these upper bands is no longer viewed as a formality but as evidence of true enclosure integrity and system-level robustness.