IEC 61000-4-6 Standard: how to test RF conducted immunity

The IEC 61000-4-6 is the international standard that defines conducted immunity tests for disturbances induced by radio-frequency (RF) fields.

Its purpose is to verify that electrical and electronic devices continue to operate correctly even when simulated RF voltages, similar to those that may occur in real disturbed environments, are present on their power or signal lines.

The test falls within the IEC 61000-4 series, which is dedicated to electromagnetic compatibility (EMC) testing methods, and complements:

1. IEC 61000-4-2 (electrostatic discharge);
2. IEC 61000-4-3 (electrostatic discharge).

Applications fields

IEC 61000-4-6 applies to any device that has at least one cable connection (power, signal, or communication). The frequency range covered goes from 150 kHz a 80 MHz, extendable up to 230 MHz in specific cases.

Completely isolated devices, those without any connection that could act as a coupling path for conducted disturbances, are excluded.

Purpose of the test

The purpose is to simulate the effects of RF conducted fields on equipment cables and verify that the Equipment Under Test (EUT) maintains correct operation.

The disturbance, a slowly varying 1 kHz-modulated RF signal, is generated by an RF source with AM 1 kHz, 80% modulation and injected into the cables using coupling devices such as:

• CDN (Coupling Decouplin Network) for standardized lines;
• Injection clamps or EM Clamps , for non-disconnected or non-standard cables.

During the test, the device must continue to operate without failures or abnormal behavior.

Test Severity Levels

IEC 61000-4-6 defines four severity levels, expressed as RMS injected voltage:

Each level represents increasing disturbance intensity.The device must meet performance criteria A, B, C, or D as defined in the standard.

Test setup and required equipment

The test setup for IEC 61000-4-6 typically includes:

1. RF generator with AM 1 kHz modulation
2. Linear RF amplifier with adequate power and 150 kHz–80 MHz bandwidth
3. CDN or coupling clamp
4. 150 Ω reference load
5. Power meter or analyzer for calibration

Proper calibration of the injection level is essential to ensure repeatable and compliant results.

RF Amplifiers for IEC 61000-4-6 testing

Recommended RF amplifier solutions include:

PA9-250/250

Band: 9 kHz – 250 MHz | Power: 250 W | Gain: 51 dB
Ideal for IEC 61000-4-6 testing and multi-purpose EMC setups.

For IEC 61000-4-3 radiated immunity tests:

PA27-1000/500

Band: 27 – 1000 MHz | Power: 500 W | Gain: 54 dB
Suitable for laboratories performing extended EMC test ranges.

Both amplifiers offer stability, linearity, and reliability under variable load conditions, ensuring consistent and repeatable test results.

Acceptance Criteria

During conducted immunity testing, the EUT is evaluated according to the following criteria:

IEC 61000-4-6 is one of the key standards for verifying immunity to RF conducted disturbances. With a broad range of RF solutions designed to meet different testing and regulatory requirements, MPB supports EMC laboratories in performing accurate, compliant tests and ensuring conformity to international standards.