Electromagnetic compatibility testing in EMC lab
EN 61000 – 4–3:2006 +A1 +A2 Electromagnetic compatibility (EMC) — Part 4 – 3: Testing and measurement techniques — Radiated, radio-frequency, electromagnetic field immunity test
Analog: IEC 61000 – 4-3:2006 Electromagnetic compatibility (EMC) — Part 4 – 3: Testing and measurement techniques — Radiated, radio-frequency, electromagnetic field immunity test
International standard EN 61000 – 4-3:2006 +A1 +A2 defines immunity requirements for electrical and electronic equipment to radiated electromagnetic fields. This standard defines test levels, test procedures and various test setups. This standard does not define Pass/Fail criteria, therefore it must be used together with generic and specific product standards where product requirements are stated.
Electronic equipment activity in radio frequency range causes radiated electromagnetic fields and these leak out of equipment enclosure through apertures and cables. Every type of equipment leaks RF fields and it is called unintentional emissions and such equipment is called unintentional transmitter.
Some type of industrial, scientific, medical equipment uses RF energy intentionally to perform specific functions. This may include microwave heaters, induction heaters, dielectric heating equipment, inductive power transfer/charging equipment. This equipment is called intentional transmitters.
Fixed radio, TV and radar transmitters, cell phones, laptops etc. are permitted to use narrow frequency spectrum to transmit and receive information. This kind of equipment is also called intentional transmitters.
Intentional and unintentional radiators create electromagnetic environment where other equipment must perform their functions. This equipment should be tested to verify that it performs in its intended environment without degradation of performance.
This standard defines four immunity levels. Frequency ranges and immunity level selection depends on generic standard and product standard selection. Test levels in table are defined in V/m RMS values without modulation.
Equipment testing is carried out in anechoic chamber. Equipment under test is located on wooden table 0.8m above ground reference table. Antenna is located in 3m distance (other distance can be defined). Electromagnetic field is generated and equipment under test and all connected cables are exposed to RF field.
Usually frequency range 80MHz-2.7GHz is considered. RF field is 1kHz sine wave 80% amplitude modulated. Example of modulated and unmodulated signal.
The tests results are classified in terms of loss of function or degradation of performance. International standard EN 61000 – 4-3:2006 +A1 +A2 does not define Pass/Fail criteria. This is defined by generic or specific product standards. EN 61000 – 4-3:2006 +A1 +A2 defines performance criteria that can be used to evaluate equipment under test performance.
Performance criterion A
Normal performance within limits specified by the manufacturer;
Performance criterion B
Temporary loss of function or degradation of performance. Self-recovery after the test, without operator intervention;
Performance criterion C
Temporary loss of function or degradation of performance. Operator intervention needed for recovery after the test;
Performance criterion D
Loss of function or degradation of performance which is not recoverable. Damage
of hardware or software, or loss of data.
In almost all generic standards and product standards performance criterion A is required.