MIL-STD-461 RE101

RE101, as specified in MIL-STD-461, is a radiated emissions test designed to measure and limit low-frequency magnetic field emissions (often below 100 kHz) from electronic equipment or subsystems. This test ensures that the Equipment Under Test (EUT) does not radiate magnetic energy at levels that could interfere with other nearby systems or devices, especially in environments where multiple electronic systems operate in close proximity.

In an RE101 test setup, a magnetic field sensing loop (or loop antenna) is positioned at a prescribed distance and orientation relative to the EUT. The EUT is powered and operated in all relevant modes to capture the full spectrum of its emissions. The loop antenna scans across the required frequency range, recording the magnetic field intensity at each frequency. Any emissions exceeding the standard’s specified limits are documented and must be resolved through redesign, shielding, filtering, or other mitigation measures.

The test is typically performed in a shielded enclosure, ensuring a controlled environment free from external interference. Operating conditions—such as normal or worst-case modes—are carefully selected to represent real-world usage. By passing RE101, manufacturers demonstrate that their product remains compliant with MIL-STD-461 requirements for low-frequency magnetic emissions, thus minimizing the potential for mutual interference with nearby sensitive equipment in mission-critical and high-reliability applications.