IEC 61000-4-3: radiated RF field immunity

Hugues Orgitello updated 7 Oct 2026 14 min read

Radiated RF field immunity is the mirror of radiated emissions: the same kind of absorber-lined room, but the EUT is now the target of a field driven by a power amplifier, and must keep working. IEC 61000-4-3 defines the levels (1, 3, 10 and 30 V/m plus an open level), the 80 % AM test signal, the uniform field area and the sweep. It does not choose the level or the pass criterion: EN 55035, the generic standards and EN 301 489-1 do. The fourth edition dates from 8 September 2020, while the European product and generic standards still refer to the 2006 edition with its two amendments.

Normative frame

IEC IEC 61000-4-3 is a basic EMC publication (IEC Guide 107) prepared by IEC SC 77B. The first edition dates from 1995. Edition 4.0 was published on 8 September 2020 and cancels and replaces edition 3.0 (2006), Amendment 1:2007 and Amendment 2:2010. Its stability date on the IEC record is 2027.

The scope is radiated RF fields from sources not in close proximity to the EUT. Since 2020 the scope sends close-proximity sources to IEC 61000-4-39. The standard also states that it is an independent method: other methods cannot be used as substitutes for claiming compliance with it. Product standards can still offer alternatives, which is what EN 55035 does with TEM waveguides (IEC 61000-4-20) and reverberation chambers (IEC 61000-4-21).

Editions and what changed

Document	Date	What it means for a test plan
IEC 61000-4-3 ed. 1.0	1995	First edition
IEC 61000-4-3 ed. 3.0	2006	Levels 1 to 4 and X; general range 80 to 1000 MHz; radio telephone ranges 800 to 960 MHz and 1.4 to 6.0 GHz
Amendment 1 and Amendment 2	2007, 2010	Folded into edition 4.0
IS 14700 (Part 4/Sec 3)	September 2008	Indian adoption, identical to IEC 61000-4-3:2006, freely readable
IEC 61000-4-21 ed. 2.0	2011	Reverberation chamber method
IEC 61000-4-39 ed. 1.0	2017	Radiated fields in close proximity
IEC 61000-4-3 ed. 4.0	8 September 2020	Multiple test signals described; more on EUT and cable layout; upper frequency limitation removed; field characterisation and amplifier linearity check specified
IEC 61000-4-20 ed. 3.0	18 February 2022	TEM waveguides, including large EUTs and cables
EN 55024:2010	Left the EMC list on 16 September 2022	EN 55035 is the multimedia immunity route
IEC 61000-4-3 stability date	2027	Next decision: reconfirm, revise, amend or withdraw

Which edition the calling standards use

The calling standards use dated references. EN 55035:2017 (Table 1 note and 4.2.2.2) names IEC 61000-4-3:2006/AMD1:2007/AMD2:2010. ETSI EN 301 489-1 V2.2.3 names EN 61000-4-3 (2006), A1 (2008) and A2 (2010), clauses 6, 7 and 8. The generic standards IEC 61000-6-1:2005 and IEC 61000-6-2:2005 cite IEC 61000-4-3 without a date. For a test claimed against these standards, the 2006 text with its amendments is the reference, which is why the clause details below are quoted from that edition. In edition 4.0 the clauses moved: test levels and frequency ranges are clause 5, the uniform field area is 6.3, the test setup is clause 7, step sizes are 8.4 and evaluation is clause 9.

What the calling standards ask

Calling standard (EU list status)	Frequency range	Level (unmodulated)	Modulation	Criterion
EN 55035:2017+A11:2020, multimedia (cited)	80 to 1000 MHz swept	3 V/m	80 % AM, preferably 1 kHz	A
EN 55035, spot frequencies (±1 %)	1800, 2600, 3500, 5000 MHz	3 V/m	80 % AM, preferably 1 kHz	A
EN 61000-6-1:2007, residential, commercial, light industry (cited)	80 to 1000 MHz; 1.4 to 2.0 GHz; 2.0 to 2.7 GHz	3 V/m; 3 V/m; 1 V/m	80 % AM, 1 kHz	A
EN 61000-6-2:2005, industrial (cited)	80 to 1000 MHz; 1.4 to 2.0 GHz; 2.0 to 2.7 GHz	10 V/m (3 V/m in 87 to 108, 174 to 230 and 470 to 790 MHz); 3 V/m; 1 V/m	80 % AM, 1 kHz	A
ETSI EN 301 489-1 V2.2.3, radio equipment, clause 9.2	80 to 6000 MHz, outside the exclusion band	3 V/m	80 % AM, 1 kHz (400 Hz if the wanted signal uses 1 kHz)	A (continuous phenomena)
IEC 60601-1-2 ed. 4.1, medical, Table 4	80 MHz to 2.7 GHz	3 V/m professional healthcare facility; 10 V/m home healthcare	80 % AM, 1 kHz	Basic safety and essential performance
ISO 11452-2:2019, road vehicle components	80 MHz to 18 GHz	Specified by the user; suggested levels in Annex B	Per ISO 11452-1	Per test plan

EN 55035 supersedes EN 55020, EN 55103-2 and EN 55024; its date of withdrawal for conflicting standards was 28 July 2022. The 2019 editions of the generic standards are not in the EMC list (see CE tests). For radio equipment, the level and range come from EN 301 489-1 (see RED tests).

EN 55035 adds three options that IEC 61000-4-3 does not give by itself: the swept test may use a step of up to 4 % at twice the specified level, testing may be restricted to the most sensitive face if it is known over the whole range, and the independent windows method (0.5 m by 0.5 m) may be used for the spot frequencies above 1 GHz.

The test signal

The test level is the RMS value of the unmodulated carrier. For testing, the carrier is 80 % amplitude modulated by a 1 kHz sine wave. With 80 % AM the peak-to-peak envelope reaches 1.8 times the carrier: for a 1 V carrier, the maximum RMS value defined in the standard is 1.8 V, which is 20 log(1.8) = 5.1 dB above the carrier.

Annex A gives the reasoning against pulsed modulations. Tests compared sine wave 80 % AM at 1 kHz, a "GSM-like" 1:8 duty cycle at 200 Hz and "DECT-like" pulsing at 100 Hz on hearing aids, analogue telephones and radio sets. The conclusion was that the immunity level correlates with the maximum RMS value of the field, and sine wave AM was kept because it is simple, readily generated, and already used in IEC 61000-4-6. Its listed disadvantages are that it does not simulate TDMA and may miss some failure mechanisms.

Severity levels and environment classes

Level	Carrier field	Maximum RMS with 80 % AM	Environment class in Annex E	Protection distance, 2 W GSM	8 W GSM	0.25 W DECT
1	1 V/m	1.8 V/m	Low level: broadcast stations beyond 1 km, low-power transmitters	5.5 m	11 m	1.9 m
2	3 V/m	5.4 V/m	Moderate: portable transceivers under about 1 W with restrictions; typical commercial	1.8 m	3.7 m	0.6 m
3	10 V/m	18 V/m	Severe: portable transceivers of 2 W or more, not closer than 1 m; typical industrial	0.6 m	1.1 m	0.2 m
4	30 V/m	54 V/m	Portable transceivers within 1 m	0.2 m	0.4 m	0.1 m
X	Open		Negotiated in the product standard or specification

The protection distances come from Table E.1 of IEC 61000-4-3:2006 (Equation E.1, E = k√P / d with k = 7, using the maximum RMS field and the effective radiated power). The standard warns that the far-field equation is not accurate at the shortest distances and that reflections cause fluctuations of the order of ±6 dB. The table is a planning aid: it tells you how close a phone can come to equipment tested at a given level.

Test facility and field calibration

Facility and equipment

Because of the field strengths involved, the test is made in a shielded enclosure. The facility is typically an absorber-lined room: a fully anechoic chamber, or a semi-anechoic chamber modified with additional absorbers on the ground plane. Recommended equipment is an RF generator able to apply 80 % AM at 1 kHz, a power amplifier whose harmonics in the UFA stay at least 6 dB below the fundamental, linearly polarised antennas (biconical, log-periodic, horn or other), an isotropic field probe with a fibre-optic link, and means of recording the forward power. The 2006 measuring setup chains a controller, signal generator, power amplifier, directional coupler and power meter, transmitting antenna, field sensor and field meter.

 Controller -> Signal generator -> Power amplifier -> Directional coupler -> Transmitting antenna
                                                           |                        |
                                                      Power meter            field in the UFA
                                                                                    |
                                                    Field meter <- fibre <- Isotropic field sensor
                                                                       (calibration, no EUT)

Annex C notes that ferrite tiles usually behave as reflectors above 1 GHz, so a small ferrite-lined chamber may fail the uniformity requirement there. The suggested fixes are a horn or double-ridge antenna, a shorter distance (down to 1 m) with the independent windows method, and carbon-loaded absorber on the wall behind the EUT. See EMC chamber types.

Uniform field area

UFA parameter (IEC 61000-4-3:2006, 6.2)	Requirement
Plane	Vertical, calibrated with no EUT in place, both polarisations
Size	At least 1.5 m by 1.5 m unless the EUT and its wires fit a smaller area; never below 0.5 m by 0.5 m
Lower edge	0.8 m above the floor; field also recorded at 0.4 m for information
Grid	0.5 m spacing (16 points for 1.5 m by 1.5 m)
Tolerance	-0 dB to +6 dB of the nominal value
Compliant points	At least 75 % (12 of 16); all 4 points for a 0.5 m by 0.5 m UFA
Distance	Field sensor at least 1 m from the antenna; 3 m preferred; distance stated in the report
Frequency step	At most 1 % of the present frequency
Calibration field	Ec at least 1.8 times the test field Et, with an unmodulated carrier
Saturation check	Reduce the generator by 5.1 dB: the forward power must drop by 3.1 to 5.1 dB, otherwise the amplifier is saturated
Validity	Full calibration annually and after chamber changes; validity checked before each batch of tests

Two calibration methods are given, constant field strength and constant power, and they are considered equivalent. The calibration records the forward power for the calibration field. During the test, the forward power is calculated from it: Pt = Pc - 20 log(Ec / Et). In edition 4.0 the UFA is clause 6.3, a minimum-size UFA has a fifth grid point in the centre (Figure 5), and the amplifier linearity check is specified in Annex D.

When the EUT face does not fit the UFA, partial illumination (with a UFA of at least 1.5 m by 1.5 m) or, above 1 GHz, the independent windows method is used.

Test setup and procedure

EUT and cable layout

• Configuration as close as possible to the actual installation, with covers in place; panel or rack equipment tested in its panel or rack.
• No metallic ground plane is required. Table-top equipment on a non-conductive table 0.8 m high; floor-standing equipment on a non-conductive support 0.05 m to 0.15 m high.
• Low-permittivity supports such as rigid polystyrene, because wood or glass-reinforced plastic can reflect above 1 GHz.
• Manufacturer-specified cables; unshielded parallel conductors when nothing is specified. If possible, at least 1 m of cable exposed to the field. Excess length of cables between units of the EUT bundled low-inductively at the approximate centre into a bundle 30 cm to 40 cm long.
• Body-worn equipment may be tested like table-top equipment, but product committees are encouraged to specify a human body simulator.

Edition 4.0 adds informative examples for bottom-fed and overhead cables, multiple cables and auxiliary equipment, and large EUTs with several UFA windows, and defines a common-mode absorption device that may be applied on cables leaving the test area.

Procedure

1. Write the test plan: EUT size and operating conditions, table-top or floor-standing, facility and antennas, frequency range, dwell time and step, UFA size, partial illumination, test level, cables and ports, acceptable performance criteria, and how the EUT is exercised.
2. Verify the calibrated field before testing.
3. Place the EUT with one face in the calibration plane.
4. Sweep with the modulated signal. In incremental sweeps the step does not exceed 1 % of the preceding frequency.
5. Dwell at each frequency for at least the time needed to exercise the EUT and let it respond, and never less than 0.5 s. Sensitive frequencies such as clock frequencies are analysed separately as the product standard requires.
6. Normally test each side of the EUT, each with the antenna vertical and then horizontal. Fewer faces may be justified; large EUTs may need more than four azimuths.
7. Record effects and their duration, and classify them.

Performance criteria

IEC 61000-4-3 recommends a classification, not a verdict:

Class (clause 9)	Observed effect
a	Normal performance within the specified limits
b	Temporary loss of function or degradation that ceases with the disturbance, recovered without operator intervention
c	Temporary loss of function or degradation that needs operator intervention
d	Loss of function or degradation not recoverable, due to damage to hardware or software, or loss of data

The generic and product standards turn this into criteria A, B and C. For continuous radiated RF, every calling standard in the table above applies criterion A: EN 55035 defines it as continuing to operate as intended without operator intervention, with no degradation, loss of function or change of operating state below the performance level specified by the manufacturer. IEC 60601-1-2 instead assesses basic safety and essential performance (see IEC 60601-1).

Medical proximity fields

IEC 60601-1-2 ed. 4.1 adds proximity tests with RF wireless communication equipment on top of the 80 MHz to 2.7 GHz sweep. As reproduced in manufacturer declarations, Table 9 covers seven bands: 380 to 390 MHz at 27 V/m, 430 to 470 MHz at 28 V/m, 704 to 787 MHz at 9 V/m, 800 to 960 MHz at 28 V/m, 1700 to 1990 MHz at 28 V/m, 2400 to 2570 MHz at 28 V/m and 5100 to 5800 MHz at 9 V/m, with pulse modulation at 18 Hz or 217 Hz (FM is also listed for 430 to 470 MHz). The proximity magnetic field tests use IEC 61000-4-39. For proximity sources in general, IEC 61000-4-3:2020 points to IEC 61000-4-39.

Claims the texts contradict

Common claim (including on earlier versions of this page)	What the text says
Edition 4.0 (2020) added a "1.4 to 6 GHz extension"	The 2006 edition already tested 800 to 960 MHz and 1.4 to 6.0 GHz for digital radio telephones (clause 5.2). The 2020 edition removed the upper frequency limitation
The levels are 3, 10 and 20 V/m	Table 1 gives 1, 3, 10 and 30 V/m (levels 1 to 4) and an open level X; 20 V/m is not a listed level
"Level X is 30 V/m and above"	30 V/m is level 4; X is an open level of any value
EN 55024 is a current route for IT equipment	EN 55024:2010 left the EMC list on 16 September 2022; EN 55035 supersedes it
EN 55035 asks 3 V/m only from 80 to 1000 MHz	It also asks 3 V/m at 1800, 2600, 3500 and 5000 MHz (±1 %)
EN 61000-6-2 asks 10 V/m everywhere from 80 to 1000 MHz	3 V/m in the broadcast bands 87 to 108, 174 to 230 and 470 to 790 MHz
IEC 61000-4-3 does not deal with performance at all	Clause 9 recommends a four-step classification (a to d); the criteria A, B, C come from the product or generic standard
Medical: 10 V/m for "urgent care"	IEC 60601-1-2 Table 4 uses 3 V/m for the professional healthcare facility and 10 V/m for the home healthcare environment
I/O cables are laid in a 30 to 40 cm serpentine	At least 1 m of cable is exposed if possible; only excess length between EUT units is bundled, low-inductively, into a 30 to 40 cm bundle
A 3 V/m calibration cannot be scaled to another level because the field distribution changes	The test power is derived from the calibration as Pt = Pc - 20 log(Ec / Et). What limits it is amplifier saturation: Et must not exceed Ec / 1.8
Dwell time 0.5 to 3 s	At least 0.5 s and at least the time to exercise the EUT and let it respond; EN 55035 says it should not exceed 5 s
ISO 11452-2 goes "up to 200 V/m", "level IV 100 V/m, up to 2.7 GHz"	ISO 11452-2:2019 covers 80 MHz to 18 GHz; the user specifies the severity, with suggested levels in an informative annex

Mitigating a radiated immunity failure

When the EUT fails at a given frequency, the approach is the inverse of emissions: reduce coupling of the field into the sensitive internal point. Three paths are common.

• Cable coupling. The cable acts as a receiving antenna and brings a common-mode current to the circuit. Mitigation: common-mode ferrite effective at the failing frequency, filtering at the connector referenced to the chassis, shield terminated 360 degrees.
• Aperture coupling. A slot or ventilation opening radiates efficiently when its length approaches half a wavelength. Mitigation: shorter openings, conductive gaskets on removable covers, mesh on vents.
• Direct PCB coupling. At higher frequencies, traces and high-impedance nodes can pick up the field directly. Mitigation: local shielding, decoupling, continuous ground plane, guard traces on sensitive analogue signals.

Identify the path with discriminating experiments: add a ferrite on one cable, close one aperture temporarily with copper tape, shield one PCB area. See EMC coupling mechanisms.

Working on radiated immunity diagnosis on a product in CE or medical preparation for a real product? AESTECHNO can audit your design and certification plan. Get in touch

What to remember

• IEC 61000-4-3 ed. 4.0 was published on 8 September 2020 and replaces the 2006 edition and its 2007 and 2010 amendments. EN 55035:2017, EN 301 489-1 V2.2.3 and the generic standards still use dated references to the 2006 text.
• Levels are 1, 3, 10 and 30 V/m plus X. The level is the unmodulated carrier; 80 % AM at 1 kHz brings the maximum RMS to 1.8 times that value.
• The UFA is a vertical plane with a 0.5 m grid, normally 1.5 m by 1.5 m, with -0/+6 dB at 75 % of the points, calibrated without the EUT at 1.8 times the test field.
• The sweep uses steps of at most 1 % and a dwell of at least 0.5 s, on each face in both polarisations.
• EU levels: 3 V/m and spot frequencies to 5 GHz for multimedia (EN 55035), 3 or 10 V/m for the generic standards with 1.4 to 2.7 GHz bands, 3 V/m to 6 GHz for radio equipment (EN 301 489-1). Criterion A in all of them.

For EU application see CE tests and RED tests. Acronyms are in the glossary.

See also

• Radio: RX blocking, selectivity and intermodulation tests
• IEC 61000-4-6: conducted RF immunity
• IEC 61000-4-8: power-frequency magnetic field immunity
• ESD per IEC 61000-4-2: method and test levels
• Surge and Burst (IEC 61000-4-5 / 4-4): EMC transients
• Voltage dips and interruptions (IEC 61000-4-11)
• Radiated emissions
• EMC chamber types
• ECE R10 automotive EMC

Sources & references

1. IEC 61000-4-3:2020 (Edition 4.0), published 8 September 2020, stability date 2027, significant technical changes, IEC webstore.iec.ch/en/publication/59849
2. IEC 61000-4-3:2020 preview: foreword, scope, terms, table of contents, IEC (preview hosted by iTeh Standards) cdn.standards.iteh.ai/samples/100266/3b514021a3db4adbbf46899a64b655e3/IEC-61000-4-3-2020.pdf
3. IEC 61000-4-3:2006 (Edition 3.0) record, IEC webstore.iec.ch/publication/4209
4. IS 14700 (Part 4/Sec 3):2008, identical to IEC 61000-4-3:2006, full text (Table 1, clauses 6.2, 7, 8, 9, Annexes A, C, E), Bureau of Indian Standards (via Public.Resource.Org) law.resource.org/pub/in/bis/S04/is.14700.4.3.2008.pdf
5. EN 55035:2017+A11:2020, Electromagnetic compatibility of multimedia equipment, immunity requirements, CENELEC www.cenelec.eu/dyn/www/f?p=104:110:::::FSP_PROJECT,FSP_LANG_ID:60147,25
6. CISPR 35:2016, electromagnetic compatibility of multimedia equipment, immunity requirements, IEC webstore.iec.ch/en/publication/25667
7. Commission Implementing Decision (EU) 2019/1326, harmonised standards for EMC, consolidated text of 10 June 2022, Publications Office of the European Union publications.europa.eu/resource/celex/02019D1326-20220610
8. Commission communication under Directive 2014/30/EU, OJ C 246, 13 July 2018 (EN 61000-6-1:2007, EN 61000-6-2:2005), Publications Office of the European Union publications.europa.eu/resource/celex/52018XC0713%2802%29
9. IS 14700 (Part 6/Sec 1):2008, identical to IEC 61000-6-1:2005, Table 1 enclosure port, Bureau of Indian Standards (via Public.Resource.Org) law.resource.org/pub/in/bis/S04/is.14700.6.1.2008.pdf
10. IS 14700 (Part 6/Sec 2):2008, identical to IEC 61000-6-2:2005, Table 1 enclosure port, Bureau of Indian Standards (via Public.Resource.Org) law.resource.org/pub/in/bis/S04/is.14700.6.2.2008.pdf
11. ETSI EN 301 489-1 V2.2.3 (2019-11), clause 9.2, radio frequency electromagnetic field (80 MHz to 6 000 MHz), ETSI www.etsi.org/deliver/etsi_en/301400_301499/30148901/02.02.03_60/en_30148901v020203p.pdf
12. IEC 61000-4-20:2022 (Edition 3.0), emission and immunity testing in TEM waveguides, IEC webstore.iec.ch/en/publication/34378
13. IEC 61000-4-21:2011 (Edition 2.0), reverberation chamber test methods, IEC webstore.iec.ch/en/publication/4191
14. IEC 61000-4-39:2017, radiated fields in close proximity, immunity test, IEC webstore.iec.ch/en/publication/30202
15. IEC 60601-1-2:2014+AMD1:2020 CSV, Medical electrical equipment, collateral standard, electromagnetic disturbances, IEC webstore.iec.ch/publication/67554
16. Manufacturer EMC declaration reproducing the IEC 60601-1-2 ed. 4.1 radiated and proximity test levels (secondary source), PARI Pharma www.pari.com/fileadmin/Electromagnetic-compatibility-4.pdf
17. ISO 11452-2:2019, Road vehicles, component test methods for electrical disturbances from narrowband radiated electromagnetic energy, absorber-lined shielded enclosure, ISO www.iso.org/standard/72840.html