Radiated Emissions Test Systems
EMI receivers for radiated emissions measurement, paired with an antenna and chamber.
Radiated emissions measurement relies on the same EMI receivers used for conducted emissions, paired with an antenna and chamber — the receiver instrumentation is shared infrastructure across both disciplines.
Understanding the Test Setup
Radiated emissions testing measures the electromagnetic energy a product radiates into free space, rather than what it feeds back onto its cables.
- EMI receiver — the same receiver used for conducted emissions measurement, now paired with an antenna instead of a LISN.
- Antenna — biconical/log-periodic antennas cover 30MHz–1GHz, horn antennas extend above 1GHz; the antenna type and calibration factor must match the frequency range under test.
- Semi-anechoic chamber or open-area test site (OATS) — provides the controlled, reflection-free environment the standard requires; without it, ambient RF and reflections make results unrepeatable.
- Antenna mast and turntable — the antenna is scanned in height (1–4m) and the EUT rotated 360° to find the worst-case emission level, per CISPR 16-1-4.
- Preamplifier — often needed ahead of the receiver to recover sensitivity lost to cable loss, particularly at higher frequencies.
