IEC 61000-4-6: conducted RF immunity test method

Hugues Orgitello updated 7 Oct 2026 17 min read

IEC 61000-4-6 is the basic EMC test method for immunity to conducted disturbances induced by radio-frequency fields, from 150 kHz to 80 MHz. It does not radiate a field: it drives a disturbing voltage onto the cables of the equipment under test through coupling/decoupling networks (CDNs), EM clamps, current clamps or direct injection, with a 150 ohm common-mode impedance at each end. The current text is edition 5.0, published by IEC on 6 June 2023, but the European standards that call the test still refer to older editions: EN 55035:2017+A11:2020, which replaced EN 55024 (withdrawn from the EMC list on 16 September 2022), applies the 2008 edition. The method fixes levels 1, 2 and 3 at 1, 3 and 10 V e.m.f. and an 80 % AM test signal at 1 kHz; the product, generic or radio standard chooses the level and the pass criterion. This page gives the edition history, the injection devices and their selection rules, the setup and sweep requirements, the levels per calling standard, and the readings that the texts contradict.

Editions and what the calling standards cite

The edition matters because each calling standard uses a dated reference, so the clause numbers and some requirements differ by standard.

Date	Event	Source
31 October 2008	IEC 61000-4-6 edition 3.0	IEC catalogue, lifecycle
23 October 2013	Edition 4.0, a technical revision (CDN use, clamp calibration, reorganised clause 7, new Annexes H, I, J)	IEC catalogue record
27 November 2013	CENELEC adopts it as EN 61000-4-6:2014, replacing EN 61000-4-6:2009 (dow 27 November 2016)	EN 61000-4-6:2014 foreword
12 June 2015	Corrigendum 1 to edition 4.0 (no amendment was ever published)	IEC catalogue, lifecycle
6 June 2023	Edition 5.0 published; edition 4.0 withdrawn the same day	IEC catalogue record
2027	Stability date of edition 5.0	IEC catalogue record

Calling standard	Edition of the basic method it applies
EN 55035:2017+A11:2020 (multimedia)	IEC 61000-4-6:2008, edition 3.0 (4.2.2.3 and table notes)
ETSI EN 301 489-1 V2.2.3 (radio equipment)	EN 61000-4-6:2014, edition 4.0, clauses 5 to 8
EN 61000-6-1:2007 and EN 61000-6-2:2005 (generic)	Undated reference, so the latest edition applies

Edition 5.0 lists five significant technical changes: the selection of injection devices was revised; the auxiliary equipment (AE) impedance check for clamp injection was removed, with the former Annex H; the saturation check was revised; a new Annex H covers testing with multiple signals; and level setting is done only with a feedback loop. The clause details on this page are quoted from the edition 4.0 text (EN 61000-4-6:2014), the one EN 301 489-1 applies, and are flagged where edition 5.0 changed them.

Position in the IEC 61000-4 series

Reference	Phenomenon
IEC 61000-4-2	Electrostatic discharge (ESD)
IEC 61000-4-3	Radiated RF electromagnetic field, above 80 MHz
IEC 61000-4-4	Electrical fast transients (EFT/burst)
IEC 61000-4-5	Surge
IEC 61000-4-6	Conducted disturbances induced by RF fields, 150 kHz to 80 MHz
IEC 61000-4-8	Power-frequency magnetic field
IEC 61000-4-11	Voltage dips, short interruptions and variations

The test is called by almost every EMC immunity standard for products with cables. The scope excludes equipment that has no conducting wire or cable (mains supply, signal line or earth connection) able to couple it to the disturbing field. Note 1 of clause 5 in the 2013 text points to IEC 61000-4-3 for frequencies above 80 MHz and lets product committees choose a lower or higher transition frequency (Annex B).

Why cables, and why 80 MHz

Clause 4 explains the model. The source is a field from intended RF transmitters acting on the whole length of the cables connected to installed equipment. The equipment is assumed small compared with the wavelength, and its cables behave as passive receiving antennas, in resonant mode (λ/4 or λ/2 open or folded dipoles). They are therefore represented by coupling and decoupling devices with a common-mode impedance of 150 ohm to the reference ground plane, and the EUT is connected between two such 150 ohm connections, one feeding the RF source and one providing the return path. The common-mode current through the EUT then produces near fields around it. The standard itself warns that driving one cable at a time only approximates reality, where all cables are excited at once with different amplitudes and phases.

Annex B (informative) ties the frequency range to size. The start frequency follows F = c0 / (10 L), where L is the cable length plus the equipment size: a mouse with only a 2 m cable would start at 15 MHz. Small battery-powered equipment under 0.4 m with no metallic cable need not be tested below 80 MHz, and battery-powered equipment smaller than a quarter wavelength, with no connection to earth or other equipment and not used while charging, need not be tested at all. Mains-connected equipment starts at 150 kHz. For small equipment, product standards may extend the stop frequency up to 230 MHz, with a common-mode impedance of 150 ohm ± 60 ohm from 80 to 230 MHz (Table B.1).

Test levels and test signal

Clause 5, Table 1 of the 2013 text (Table 1 is also "Test levels" in edition 5.0):

Level	U0, dBµV	U0, V (rms, unmodulated, e.m.f.)
1	120	1
2	129.5	3
3	140	10
X	Special	Specified in the product specification

The level is the open-circuit voltage of the source, set at the EUT port of the coupling device. In the 2013 level-setting procedure (6.4.2), the generator is adjusted until the measuring equipment behind a 150 ohm to 50 ohm adapter reads Umr = U0 / 6, that is U0 minus 15.6 dB: half the e.m.f. appears across the matched load, and the adapter loaded by 50 ohm divides it by 3 again. The adapters themselves must show an insertion loss of 9.5 dB ± 0.5 dB. Frequency steps during level setting are at most 1 % of the current frequency.

For the test, the signal is 80 % amplitude modulated by a 1 kHz sine wave. Figure 2 gives the waveforms for level 1: the unmodulated signal has 1.00 V rms (2.82 V peak to peak), the modulated one 5.09 V peak to peak, with a maximum rms value of 1.80 V. Product committees may choose other modulation conditions (note 2 to clause 5). The 2013 amplifier check raises the generator by 5.1 dB and requires the output to rise by 3.1 to 7.1 dB; edition 5.0 revised this saturation check.

Annex C (informative) relates the levels to environments: class 1 is a low-level environment (radio and television stations more than 1 km away, low-power transceivers); class 2 is moderate, with portable transceivers typically under 1 W used with restrictions near the equipment, a typical commercial environment; class 3 is severe, with portable transceivers of 2 W or more used no closer than 1 m, high-power broadcast transmitters nearby and possibly ISM equipment, a typical industrial environment.

Coupling and decoupling devices

Clause 6.2 of the 2013 text makes CDNs the preferred devices, for reproducibility and to protect the AE. The main parameter is the common-mode impedance seen at the EUT port (Table 3):

Frequency band	Required common-mode impedance
0.15 to 24 MHz	150 ohm ± 20 ohm
24 to 80 MHz	150 ohm, +60 ohm / -45 ohm
80 to 230 MHz (only when extended, Table B.1)	150 ohm ± 60 ohm

Type (Table 4, 2013)	Lines	Examples in the standard
CDN-M1, M2, M3	Power (AC and DC) and earth connection; one, two or three wires	AC mains, DC in industrial installations, earth connection
CDN-Sx	Screened cables (shield connected at both ends)	Coaxial cables, cables used for LAN and USB connections, audio cables
CDN-T2, T4, T8	Unscreened balanced lines: one, two or four pairs	ISDN lines, telephone lines
CDN-AF2, AF8	Unscreened unbalanced lines	Any line not in the other groups

All power connections should preferably have CDNs, but other injection methods may be chosen for high power (16 A or more) or complex supplies. The CDN must not be unduly degraded by saturation of its magnetic material from the EUT current. A screened cable whose shield is not connected at both ends is treated as unscreened. Decoupling networks need at least 280 µH at 150 kHz, with reactance of at least 260 ohm up to 24 MHz and 150 ohm above.

The 2013 selection rules (Figure 12) are: use a CDN if a suitable one exists; otherwise clamp injection (EM clamp or current clamp); for screened cables where clamp injection is not applicable, direct injection onto the shield through 100 ohm.

Method	How it couples	Requirements in the 2013 text
CDN	Coupling and decoupling in one unit, 150 ohm common mode	Only two 150 ohm networks needed per test: one injecting, one loaded with 50 ohm; all other cables decoupled
Current clamp	Transformer whose secondary is the cable under test	Insertion of the clamp may raise the transmission loss of the setup by no more than 1.6 dB
EM clamp	Combined capacitive and inductive coupling	Annex A: 0.15 to 80 MHz, length 650 mm ± 50 mm; provides decoupling above 10 MHz
Clamp, AE impedance not met (7.7)	Same clamps	Current monitored and limited to U0 / 150 ohm; the reduced test voltage goes in the report
Direct injection	Onto the cable shield through 100 ohm	Decoupling network between injection point and AE; injection point 0.1 to 0.3 m from the EUT

With clamp injection the coupling and decoupling functions are separated: the AE provides the common-mode impedance and is subjected to the same current as the EUT, so it must be immune at the test level. Edition 5.0 removed the AE impedance check for clamp injection and revised the device selection; read its clause 7.4 before reusing the 2013 flow chart.

Setup

Requirements of clause 7 in the 2013 text:

• EUT on an insulating support 0.1 m ± 0.05 m above the reference ground plane, at least 0.5 m from any metal object that is not part of the setup.
• Coupling and decoupling devices on the ground plane, in direct contact with it, 0.1 to 0.3 m from the projection of the EUT (distance L, not necessarily the same on every side).
• Cables between the EUT and the devices as short as possible, never bundled or coiled, at least 30 mm above the ground plane.
• The total cable length between EUT and AE, including the internal wiring of any CDN, must not exceed the maximum length specified by the EUT manufacturer.
• Several cables running close together for more than 10 m, or in a cable tray or conduit, are treated as one cable. EN 55035 adds that multi-conductor cables are tested as a single cable and must not be split into groups of conductors.
• Multi-unit equipment: preferably test each unit as the EUT with the others as AE; units permanently connected by short cables (1 m or less) may be treated as one EUT, and their interconnecting cables are not tested.
• Where several CDNs are connected, the one loaded with 50 ohm is chosen in this order: CDN-M1 on the earth terminal, CDN-M3 (or M4, M5) on the mains of class I equipment, the nearest CDN-Sn, CDN-M2 on class II mains, then the nearest other CDN.
• Hand-held parts and keyboards get the artificial hand.

The test can generally be done without a shielded enclosure, since the applied levels and setup geometry are not likely to radiate much energy, but local radio regulations apply and an enclosure is needed if the radiated energy exceeds the permitted level.

Sweep, dwell and report

Clause 8 of the 2013 text: the range from 150 kHz to 80 MHz is swept with the levels from the level-setting process, 80 % AM at 1 kHz. Steps must not exceed 1 % of the preceding frequency. The dwell time at each frequency must not be less than the time needed to exercise the EUT and let it respond, and in no case less than 0.5 s. Critical frequencies, such as clock frequencies, are analysed separately. Because frequency changes can create transients that upset the EUT, the level may be lowered a few dB before each change.

With 1 % steps, 150 kHz to 80 MHz is about 630 frequencies, so the 0.5 s floor alone means more than 5 minutes per port and level. EN 55035 caps the dwell at 5 s and, to save time on equipment with many configurations or long cycles, allows steps up to 4 % at twice the specified level, recorded in the report.

The test report (clause 10) must record, among other items, the coupling device on each cable and the length of its internal cables, which coupling devices were loaded with 50 ohm for each injection port, the frequency range, the sweep rate, dwell time and step, the level applied, and the justification of the pass or fail decision.

Performance criteria

Clause 9 only recommends a classification: (a) normal performance within limits; (b) temporary loss of function or degradation that ends when the disturbance stops, without operator intervention; (c) temporary loss needing operator intervention; (d) loss not recoverable because of damage or data loss. The generic, product and radio standards turn this into their own criteria. For conducted RF, EN 55035, EN 61000-6-1, EN 61000-6-2 and EN 301 489-1 all apply criterion A (or, for EN 301 489-1, its criteria for continuous phenomena).

EN 55035 has two specific rules: equipment processing chrominance or similar sub-carrier signals (PAL, NTSC, SECAM) is assessed with criterion B within ±1.5 MHz of the sub-carrier, and equipment whose primary function is telephony gets extra spot frequencies at 0.2, 1, 7.1, 13.56, 21, 27.12 and 40.68 MHz (±1 %).

Levels per calling standard

Standard	Ports	Level and range	Criterion
EN 55035:2017+A11:2020, Tables 2 to 4	AC mains; analogue/digital data ports and DC network power ports that support cables over 3 m	3 V from 0.15 to 10 MHz, 3 V to 1 V from 10 to 30 MHz (linear in log frequency), 1 V from 30 to 80 MHz	A
EN 61000-6-1:2007 (residential, commercial, light industrial)	AC power; signal ports with cables that may exceed 3 m; DC power	3 V, 0.15 to 80 MHz	A
EN 61000-6-2:2005 (industrial)	AC power; signal ports with cables that may exceed 3 m; DC power	10 V, 0.15 to 80 MHz, 3 V in the 47 to 68 MHz broadcast band	A
ETSI EN 301 489-1 V2.2.3, clause 9.5	AC mains; signal, wired network, control and DC power ports if cables may exceed 3 m	Level 2, 3 V, 150 kHz to 80 MHz, 1 % steps, 400 Hz if the wanted signal is modulated at 1 kHz	Continuous phenomena (6.1)
IEC 60601-1-2:2014+A1:2020 (medical, secondary sources)	Per its tables	3 V, 0.15 to 80 MHz; 6 V in the ISM bands, and in amateur radio bands for home healthcare	Basic safety and essential performance

In every row the level is the rms value of the unmodulated carrier and the modulation is 80 % AM at 1 kHz. The generic standards also allow the level to be defined as the equivalent current into a 150 ohm load, and EN 61000-6-2 waives the signal-port test where normal functioning cannot be achieved because of the CDN. EN 301 489-1 excludes the transmitter and receiver exclusion bands and disregards narrowband responses of receivers. EN 55035 notes that, when clamps are used, an extra isolation device may be needed to protect the AE.

Medical equipment

The fourth edition of IEC 60601-1-2 (2014, amended 2020) is a collateral standard, assessed against basic safety and essential performance rather than criteria A, B and C. As reproduced in manufacturer declarations and laboratory summaries, its conducted RF test is 3 V from 0.15 to 80 MHz, raised to 6 V in the ISM bands inside that range, and for the home healthcare environment also in the amateur radio bands. See the IEC 60601-1 page.

Automotive: ISO 11452-4

Vehicle components use ISO 11452-4, now in its fifth edition (2020), which replaced the 2011 edition. It shares the idea of injecting current onto cables but not the parameters.

Aspect	IEC 61000-4-6	ISO 11452-4:2020
Typical range	150 kHz to 80 MHz (230 MHz if a product standard extends it)	BCI 100 kHz to 400 MHz (lower limit extended from 1 MHz in 2020); tubular wave coupler 400 MHz to 3 GHz
Devices	CDN preferred, then EM or current clamp, direct injection on screens	Current injection probe (BCI) or tubular wave coupler
Level	e.m.f. U0 of 1, 3 or 10 V, or X	Set by the user over the frequency range; suggested levels in Annex D
Level control	Level set at the EUT port of the coupling device, 150 ohm environment	Substitution method, or closed-loop method with power limitation
Layout	EUT 0.1 m above ground plane; devices 0.1 to 0.3 m from EUT	DUT 50 mm above the table; harness 1700 mm (+300/0), or 1000 mm (+200/0) for closed loop; probe at 150 mm ± 50 mm (substitution) or 900 mm (closed loop)
Location	Shielded enclosure only if radiation exceeds local limits	Shielded enclosure required

Dwell time, step sizes, modulation and severity definitions come from ISO 11452-1. Vehicle approval under UN Regulation No. 10 applies these bench methods to ESAs: see the ECE R10 page.

Claims the texts contradict

Claim	What the text says
The current reference is IEC 61000-4-6:2013+AMD1:2017	Edition 4.0 never had an amendment, only a corrigendum (June 2015). Edition 5.0 replaced it on 6 June 2023
The standard is published by "TC 77B"	It is subcommittee SC 77B of IEC technical committee 77
EN 55024 is a current route for IT equipment	EN 55024:2010 left the EMC list on 16 September 2022; EN 55035 replaced it
EN 55035 asks 3 V across 150 kHz to 80 MHz	3 V up to 10 MHz, sloping to 1 V at 30 MHz, 1 V up to 80 MHz
The level is the voltage at the EUT port	It is the e.m.f. of the source; with the matched 150 ohm load half of it appears, and the adapter reading is U0 / 6
CDN-M1 is "neutral only"	CDN-M1, M2, M3 are one-, two- and three-wire power networks
CDN-AF networks are for antenna ports	CDN-AFx are for unscreened unbalanced lines
An Ethernet port must use CDN-T8, never CDN-S	Table 4 lists LAN and USB cables under screened cables (CDN-Sx); CDN-T8 is for four unscreened balanced pairs
The EM clamp needs at least 0.3 m of cable to the EUT	Coupling devices sit 0.1 to 0.3 m from the EUT; clamp injection also requires decoupling on other cables and an AE placed 0.1 m above the plane
The ground plane must be at least 1 m by 1 m	No such size; for impedance and adapter checks it must exceed the setup projection by at least 0.2 m on all sides
The dwell is "0.5 s or one full cycle, whichever is longer"	At least the time to exercise the EUT and let it respond, and never less than 0.5 s
IEC 60601-1-2 (fourth edition) asks for 10 V on ISM bands	As reproduced in manufacturer declarations, it asks for 6 V in the ISM bands (and in amateur radio bands for home healthcare)
ISO 11452-4 BCI covers 1 to 400 MHz with a 1.5 or 1.7 m harness	The 2020 edition gives 100 kHz to 400 MHz and a 1700 mm harness (1000 mm for closed loop)

Pitfalls observed in the laboratory

• Wrong network for the cable. The CDN must match the line type of Table 4 and hold the common-mode impedance of Table 3; on a balanced cable, the CDN conversion ratio should be better than that of the cable or the connected equipment. When no suitable CDN exists, multi-pair balanced cables often go to clamp injection.
• AE not decoupled. All cables not under test must carry decoupling networks, and only one other network may be loaded with 50 ohm, so that there is one loop with 150 ohm at each end.
• AE failing under clamp injection. With clamps the AE receives the same current. The 2013 text suggests a decoupling device, preferably a loaded EM clamp, between EUT and AE when the AE fails.
• CDN saturation on high-current supplies. The standard warns that the CDN must not be degraded by saturation from the EUT current, and allows other injection methods at 16 A or more.
• Dwell shorter than the EUT cycle. The 0.5 s floor is a minimum; a product that reports every few seconds needs a longer dwell, and EN 55035 caps it at 5 s.
• Unmodulated carrier. The test signal is 80 % AM; a CW test applies a lower maximum rms level (1.0 instead of 1.8 times the carrier) unless the calling standard says otherwise.
• Mixing up 4-6 and 4-3. Extending 4-6 up to 230 MHz under Annex B does not remove the radiated test of the calling standard. See the IEC 61000-4-3 radiated RF immunity guide.
• Mixing up immunity and emission. IEC 61000-4-6 checks what the product withstands; conducted emission is measured with a LISN under CISPR methods. See the conducted emissions and LISN test guide.

See also

• Radio: RX blocking, selectivity and intermodulation tests
• 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 + interruptions (IEC 61000-4-11)

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Connection with CE marking and the EMC Directive

IEC 61000-4-6 itself is not cited in the Official Journal: presumption of conformity comes from the product, generic or radio standard that calls it, under the EMC Directive 2014/30/EU or the RED 2014/53/EU. For the generic immunity table see the CE tests page, and for EN 301 489-1 clause 9 see the RED tests page.

For the definitions of the terms used on this page (CDN, EM clamp, current clamp, common mode, AE, criterion A/B/C, EUT, port), see the glossary.

Going further

Its high-frequency counterpart has its own page: 4-3, radiated RF immunity above 80 MHz. Vehicle components use ISO 11452-4 under UN R10, covered on the ECE R10 page, and medical equipment carries its own immunity levels through the IEC 60601-1-2 collateral, covered on the IEC 60601-1 page.

Not covered on this site: characterisation of EM clamps and decoupling clamps (Annex A) and the measurement uncertainty budgets of Annex G, which belong to the laboratory rather than to the product test plan.

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Sources & references

1. IEC 61000-4-6:2023 (Edition 5.0), published 6 June 2023, stability date 2027, IEC webstore.iec.ch/en/publication/65586
2. IEC 61000-4-6:2023 preview: foreword with the five technical changes, scope, terms, clause 4, table of contents, IEC (preview hosted by iTeh Standards) cdn.standards.iteh.ai/samples/103507/cb4fcce7fa8e44dd96eb2ec6f0f872b5/IEC-61000-4-6-2023.pdf
3. IEC 61000-4-6:2013 (Edition 4.0) record, lifecycle of all editions and corrigendum, IEC webstore.iec.ch/publication/4224
4. EN 61000-4-6:2014 (IEC 61000-4-6:2013), French version, full text (clauses 5 to 10, Annexes B and C), copy distributed at an ITU training course, CENELEC (hosted by ITU) www.itu.int/en/ITU-D/Technology/Documents/Events2016/CI_Training_ARB_Tunis_April16/Session8/EN_61000-4-6_2014.pdf
5. EN IEC 61000-4-6:2023, European adoption of the fifth edition, CENELEC (catalogue entry hosted by iTeh Standards) standards.iteh.ai/catalog/standards/clc/5a4029fd-8e3f-4efb-b2ce-54c4731d5a5a/en-iec-61000-4-6-2023
6. EN 55035:2017+A11:2020, Electromagnetic compatibility of multimedia equipment, immunity requirements (Tables 2 to 4, 4.2.2.1, 4.2.2.3), CENELEC www.cenelec.eu/dyn/www/f?p=104:110:::::FSP_PROJECT,FSP_LANG_ID:60147,25
7. CISPR 35:2016, electromagnetic compatibility of multimedia equipment, immunity requirements, IEC webstore.iec.ch/en/publication/25667
8. Commission Implementing Decision (EU) 2019/1326, harmonised standards for EMC, consolidated text of 10 June 2022 (EN 55024:2010 withdrawn 16 September 2022), Publications Office of the European Union publications.europa.eu/resource/celex/02019D1326-20220610
9. 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
10. IS 14700 (Part 6/Sec 1):2008, identical to IEC 61000-6-1:2005, Tables 2 to 4, Bureau of Indian Standards (via Public.Resource.Org) law.resource.org/pub/in/bis/S04/is.14700.6.1.2008.pdf
11. IS 14700 (Part 6/Sec 2):2008, identical to IEC 61000-6-2:2005, Tables 2 to 4, Bureau of Indian Standards (via Public.Resource.Org) law.resource.org/pub/in/bis/S04/is.14700.6.2.2008.pdf
12. ETSI EN 301 489-1 V2.2.3 (2019-11), clause 9.5, radio frequency common mode, ETSI www.etsi.org/deliver/etsi_en/301400_301499/30148901/02.02.03_60/en_30148901v020203p.pdf
13. IEC 60601-1-2:2014+AMD1:2020 CSV, Medical electrical equipment, collateral standard, electromagnetic disturbances, IEC webstore.iec.ch/publication/67554
14. Manufacturer EMC declaration reproducing the IEC 60601-1-2 conducted RF levels (secondary source), PARI Pharma www.pari.com/fileadmin/Electromagnetic-compatibility-4.pdf
15. IEC 60601-1-2:2014+A1:2020 test details, conducted RF levels for home healthcare (secondary source), Element Materials Technology element.com/nucleus/2023/medical-emc-testing-details-of-iec-60601-1-2-2014-a1-2020-edition-4-1
16. ISO 11452-4:2020, Road vehicles, component test methods, Part 4, Harness excitation methods, ISO www.iso.org/standard/74108.html
17. ISO 11452-4:2020 preview: foreword, scope, clauses 4 to 7, ISO (preview hosted by iTeh Standards) cdn.standards.iteh.ai/samples/74108/ec982a7d799e46bc9ee6fbac9b25cb7c/ISO-11452-4-2020.pdf