Changes Introduced with IEC 61000-4-3:2020 Edition 4.0

IEC 61000-4-3 is a standards publication covering electromagnetic compatibility (EMC) testing and measuring techniques for radiated electromagnetic field immunity testing. From time to time, changes are made to test standards to address shortcomings, improve testing methods, react or respond to industry changes, and to establish a more controlled and repeatable test process.

IEC 61000-4-3:2020 Edition 4.0 was released in September 2020, which cancels and replaces Edition 3 published in 2006, including Amendment 1:2007 and Amendment 2:2010. The changes that were made in Edition 4.0 are outlined below.

Multiple Signal Testing

Testing with simultaneous multiple frequencies is now permitted. Using this multiple signal, or multiple-tone, approach can result in a significant decrease in test time due to the reduction in the number of dwell times required, as several test frequencies will be completed at the same time. Section 8.3 describes multiple signal testing, and informative Annex I (Testing with Multiple Signals) provides additional detail and guidance.

Cable Layout

More control of and definition of cable layout has been added, with additional description details and figures added. Controlling positioning and location of cables improves test consistency and leads to more reproducible test results. Section 7 contains EUT positioning and cable layout requirements. Additional guidance is provided in informative Annex G (Cable Layout Details) and informative Annex H (Test Setups for Large EUT’s).

Uniform Field Area and Large EUTs

In IEC 61000-4-3:2020 Edition 4.0 there were multiple updates regarding the Uniform Field Area (UFA). To begin with, the lower edge of the UFA previously being fixed at 0.8 meters. It was determined that under this condition, the lower region of floor-standing equipment might not experience controlled illumination. This fixed height requirement has now been removed, and the lower edge of the UFA can be at any height, provided several criteria are met. (See section 6.3.1 and section 7.3.) The intent is to fully illuminate a floor standing EUT, however achieving a UFA close to a metallic floor is difficult, and might preclude full EUT illumination. Additional guidance is provided in informative Annex H (Test Setups for Large EUT’s).

Previously, floor-standing equipment required recording of field measurements at 0.4m height. In the current edition, this requirement is eliminated if the EUT can be raised to a height such that less than 0.5m of the EUT is below the UFA. Additional details are provided in Section 7.3.

A note was added in Section 6.3.3 that when performing the UFA calibration, the probe is oriented in the same manner as it was when the probe was calibrated, to lower the uncertainty of the field measurement.

When using the minimum 0.5m x 0.5m 4-point Uniform Field Area (UFA), an additional center 5th point has been added. This provides further characterization of the field within the smaller UFA, ensuring that a small EUT sitting within the 0.5m x 0.5m UFA will see a consistent field. See section 6.3.1.

Also, although the UFA is typically square, this is not required, as long as it can be constructed from 0.5m × 0.5m squares. This is described in section 6.3.1. For example, for an EUT shaped like the letter ‘L’, an ‘L’-shaped UFA could be created using 0.5m x 0.5m squares.

Maximum Frequency

In the new edition, the upper frequency limit of 6.0 GHz has been removed, allowing the product standard committees to define an appropriate frequency limit. This will allow flexibility for testing at higher frequencies as spectrum use continues to expand to ever higher frequencies.

Testing Level vs Calibration Level

Historically, testing at field levels lower than a calibrated field level has been allowed. Testing at field levels higher than the calibration field level is now permitted, provided that the linearity of the system can be demonstrated. This provides flexibility in being able to test multiple requirements without having to run a full 16-point field calibration for each required field level. This is described in Section 6.3.1.


The -6 dBc harmonic limit measured in field, previously in Section 6, has been removed since a suitable test measurement method is not described. This requirement is under consideration by the committee and may be re-introduced at a future time.

Other notable Annex changes/additions:

  • Informative Annex B ‘Field Generating Antennas’ added a description for ‘combination antenna’.
  • Informative Annex D ‘Amplifier Compression and non-Linearity’ includes extensive updates.
  • Informative Annex F ‘Selection of Test Methods’ updated with additional detail.
  • Informative Annex G is now ‘Cable Layout Details’.
  • Informative Annex H is now ‘Examples of Test Setups for Large and Heavy EUT’s’.
  • Informative Annex I is now ‘Testing with Multiple Signals’.

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