Electromagnetic compatibility (EMC) is the concept of enabling different electronics devices to operate without mutual Electromagnetic Interference (EMI) when they are operated in close proximity to each other.
EMC is of increasing importance as the number of wirelessly connected devices increase. This is because all electronics circuits have the possibility of radiating or picking up unwanted electrical interference which can compromise the operation of one or other of the circuits.
EMC/EMI testing is a critical step in the design and manufacturing processes of electronic devices. Various regulatory bodies, including the FDA, FCC, and ISO, have set specific limits on the emissions that can be released from an electronic device.
Regulatory Guidelines for EMC Testing include:
- FCC Part 15 rules define limits for the amount of unlicensed radio frequency interference that can be produced by consumer electronics and other devices.
- MIL-STD 461 and MIL-STD 464, which outline EMC and environmental requirements for components/subsystems and systems for military applications.
Outside of the U.S., various ISO, IEC, CISPR and other standards define acceptable limits of EMI and overall EMC. In some industries and markets, compliance with these standards is voluntary. In others, it is a requirement.
These EMC regulations provide improved reliability and safety for anyone using electrical and electronic equipment because they assure the device does not interfere with the operation of other equipment or fail to operate as intended due to interference from others emissions.
Failing to pass EMC compliance testing can result in fines and product recalls. Consequently, manufacturers are now conducting EMC pre-compliance testing to mimic the compliance test set up within an acceptable margin to uncover potential problems and reduce risk of failure before the expensive compliance test.
EMC pre-compliance testing typically involves:
- Spectrum analyzer with quasi-peak detector
- Preamplifier (optional)
- Antenna with non-metallic stand for radiated emissions
- Line impedance stabilization network (LISN) for conducted test
- Power limiter for conducted test
- EMC near-field probes for diagnostics (optional)
- Oscilloscope with frequency and time correlation capabilities to assist in debugging (optional)
- EMC testing software
Want to learn more? Tonex offers several courses in EMI/EMC Training such as:
For more information, questions, comments, contact us.