⚡ Immunity to radiated radio-frequency electromagnetic fields — field amplitude-modulated 80 % with a 1 kHz signal

Electronics and EMC PN-EN 61000-4-3:

Overview

The standard is applicable to the immunity requirements of electrical and electronic equipment to radiated electromagnetic energy. It establishes test levels and the required test procedures. The object of the document is to establish a common reference for evaluating the immunity of equipment subjected to radiated radio-frequency electromagnetic fields. The test method described represents a consistent way of assessing the immunity of a device or system to radio-frequency fields from sources that are not in close proximity to the equipment under test; the test of immunity to sources in close proximity is defined by IEC 61000-4-39. Particular attention has been paid to protection against radio-frequency emissions from digital radiotelephones and other emitting devices.

In accordance with IEC Guide 107, this is a basic electromagnetic compatibility publication, intended for product committees, which are responsible for deciding whether this immunity standard is to be applied and, if so, for determining the appropriate test levels and performance criteria.

In laboratory practice the test is carried out in the range from 80 MHz to 1 GHz, and the test site may be an anechoic chamber or a GTEM cell. A GTEM cell is a coaxial conductor flaring out in the shape of a pyramid, completely shielded, and makes it possible to test both immunity to radio-frequency fields and the level of disturbance emission from the device under test. Typical field strength levels in tests are 1 V/m, 3 V/m and 10 V/m; in tests beyond the standard values from 15 V/m to 50 V/m in steps of 5 V/m are used.

SEARCH KEY CORRECTED (23.09.2026). The key field had the form "PN-EN IEC 61000-4-3", and the "Laboratories" tab searches by the beginning of the notation — as a result it showed 9 entries at 7 laboratories. In the accreditation scopes the same standard appears in two parallel forms, because the IEC element entered the number only with the newer edition: "PN-EN 61000-4-3" — 16 entries at 14 laboratories, "PN-EN IEC 61000-4-3" — 9 at 7; there are 4 laboratories in common, 17 in total (counted by the beginning of the notation, with a number boundary). The key has been set to the more numerous form; we give the other one here explicitly, because matching by the beginning of the notation does not cover both at once. THE KEY ENDS WITH A COLON (23.09.2026): "PN-EN 61000-4-3" is also the beginning of the designations of parts 4-30, 4-34 and 4-39 — other standards of the series — so without the colon the tab showed 22 entries at 16 laboratories, of which 6 entries concerned those parts. With the key "PN-EN 61000-4-3:" it shows 16 entries at 14 laboratories — this standard only. Outside the tab remain 5 laboratories: three with only the form with the IEC element (AB 082, AB 261, AB 1765), one with the number in the middle of the field, after other documents (AB 1132), and one with a notation without the PN prefix (AB 053). THE COST OF CHOOSING ONE FORM DEPENDS ON THE BREADTH OF THE SUBJECT OF THE ENTRY: for an entry on the whole PN-EN 61000-4 series the key without the IEC element does not lose a single laboratory — all twelve using IEC also have notations without it for other parts of the series; for an entry on a single part from one to six are lost.

Method principle

The equipment under test is placed in an electromagnetic field of a set strength and its operation is observed as a function of frequency. The test signal is a sinusoidal carrier amplitude-modulated with a 1 kHz sinusoidal signal at a modulation depth of 80 %, which represents the real threats from transmitters. The frequency is swept over the set range in steps of 1 % of the current frequency. Before the test the test site is calibrated, determining the uniform field area — the area in which the field strength is known and repeatable; a calibration procedure known as the "constant power" method is used, and the number of calibration points is chosen according to the size of the area. The value of the field strength during the test is proportional to the power fed to the test site.

Applications

• Compliance testing of electrical and electronic products with the electromagnetic compatibility directive
• Assessment of the immunity of electronic circuits to fields from radio transmitters and digital telephony
• Testing of electricity meters and other measuring instruments subject to the MID directive
• Immunity testing in a GTEM cell together with measurement of disturbance emission from the same test site
• Tests beyond the standard at field strengths from 15 V/m to 50 V/m to assess the immunity margin

Key parameters

Standard

Standard number

PN-EN IEC 61000-4-3:2021-06

Title (PL)

Kompatybilność elektromagnetyczna (EMC) — Część 4-3: Metody badań i pomiarów — Badanie odporności na promieniowane pole elektromagnetyczne o częstotliwości radiowej

Title (EN)

Electromagnetic compatibility (EMC) — Part 4-3: Testing and measurement techniques — Radiated, radio-frequency, electromagnetic field immunity test

Step-by-step procedure

1. Determining the test conditions

   Adopt the test level and frequency range in accordance with the product requirements; the standard is a basic EMC publication, and the appropriate levels and performance criteria are set by the product committee.

2. Calibration of the test site

   Determine the uniform field area by the "constant power" calibration procedure, with the number of calibration points chosen according to the size of the area, sweeping the frequency in steps of 1 % over the whole test range.

3. Checking the modulation

   Verify that the test signal is amplitude-modulated with a 1 kHz sinusoidal signal to a depth of 80 %, checking the waveform of the control voltage on the oscilloscope.

4. Positioning the equipment under test

   Place the equipment under test in the uniform field area, under operating conditions representative of its use, with the power and signal leads routed so as not to disturb the field distribution.

5. Exposure

   Apply a field of the set strength, for example 1 V/m, 3 V/m or 10 V/m, sweeping the frequency over the test range and observing the operation of the equipment under test.

6. Locating critical frequencies

   If irregularities are found, increase the density of measurement points in order to determine more precisely the frequencies at which malfunction occurs.

7. Tests beyond the standard

   To assess the immunity margin, the field strength may be increased at selected frequency points from 15 V/m to 50 V/m in steps of 5 V/m.

8. Assessment and report

   Assess the behaviour of the equipment according to the performance criteria from the product requirements. In the report state the test site, frequency range and step, field strength, modulation parameters, operating conditions of the equipment under test and the result.

Required equipment and apparatus

Health and safety (OHS)

• High-strength electromagnetic fields — the test is carried out in a closed chamber, without people in the field, with a door interlock
• The GTEM cell is completely shielded and protects the surroundings against emission — do not open it during exposure
• High-frequency power amplifiers — risk of RF burns on touching the signal path under power
• The absorbers in the chamber are flammable and dusty — no open flame, care when cleaning
• The equipment under test may behave unpredictably in the field (spontaneous switching on) — securing of moving parts

Frequently asked questions