Modern society deals with radio waves constantly, such as when we use our mobile phones, wireless computer networks, and other communications applications. Conducted radio frequency (RF) testing is a continuous Electromagnetic Compatibility (EMC) test commonly required for commercial, automotive, and military equipment or products. Testing requirements, frequency range, setup, as well as the required test equipment will vary by standard and test level. One standard that focuses on these EMC tests is IEC 61000-4-6 Ed. 5.0 en:2023—Electromagnetic Compatibility (EMC) – Part 4-6: Testing And Measurement Techniques – Immunity To Conducted Disturbances, Induced By Radio-Frequency Fields.
What Does Conducted Immunity Mean?
Conducted Immunity refers to the ability of electronic equipment to resist external electromagnetic interference that is coupled through the power or signal lines. In other words, it refers to the device’s ability to resist unwanted RF voltages and currents that get coupled to the external wires and cables. These coupled RF voltages and currents are unwanted noise that could hamper the intended functions of the device.
Conducted immunity testing involves simulating potential disturbances from other devices powered by the same power network or inductively coupled onto its I/O lines. It is used to determine whether the Equipment Under Test (EUT) has the ability to comply with the given limits to function in an RF-exposed environment. This testing is done by simulating potential disturbances from other devices powered by the same power network or inductively coupled onto its external wires or cables.
What Is IEC 61000-4-6?
IEC 61000-4-6:2023 relates to the conducted immunity requirements of electrical and electronic equipment to electromagnetic disturbances coming from intended radio-frequency (RF) transmitters in the frequency range 150 kHz up to 80 MHz. The objective of this standard is to establish a common reference for evaluating the functional immunity of electrical and electronic equipment when subjected to conducted disturbances induced by RF fields. The test method in the standard describes a consistent method to assess the immunity of an equipment or system against a specified phenomenon.
Equipment not having at least one conducting wire or cable (such as mains supply, signal line or earth connection) which can couple the equipment to the disturbing RF fields is excludedfrom the scope of IEC 61000-4-6:2023.
What Is the Test Equipment Required for Conducted Immunity Testing?
The critical test equipment required for IEC 61000-4-6:2023 conducted immunity testing is:
- Signal Generator
- Power Amplifier
- Voltmeter or Power Meter
- Coupling Devices
- Decoupling Devices
- CDN (Coupling-Decoupling Network)
- Injection Clamp—Current Clamp or EM Clamp
- Insulating Sheet or Support— Non-Conductive Coating, Foot, Roller, and/or Caster
- Direct Injection
- Frequency Selective Measurement Equipment (Signal Analyzer, Spectrum Analyzer, Network Analyzer, Receiver, etc.).
- Level Meter in Control Loop (LMC) or the Test Generator (TG) Contributions
Test Method for Conducted Immunity Testing
Conducted immunity testing, which is typically run by a software-controlled test system in a testing lab, subjects the equipment under test (EUT)—such as mains, communication lines, interface cables—to a source of disturbance comprising electric and magnetic fields, simulating those coming from intentional RF transmitters. The leads entering and exiting the EUT behave as passive receiving antenna networks and signal conduction paths for both intentional and unintentional signals. Between those cable networks, the susceptible equipment is exposed to currents flowing “through” the equipment. Conducted immunity testing can be conducted as follows:
- An RF signal generator and the EUT are connected to the mains AC or DC supply.
- The RF signal generator and amplifier generate an electromagnetic field.
- This electromagnetic field is injected into cables of the EUT by an injection device (e.g., CDN, direct injection devices, or EM clamp).
- The EUT is also connected to a frequency selective measurement equipment like an analyzer to monitor the current and voltage waveforms and operation of the EUT.
IEC 61000-4-6 Ed. 5.0 en:2023—Electromagnetic Compatibility (EMC) – Part 4-6: Testing And Measurement Techniques – Immunity To Conducted Disturbances, Induced By Radio-Frequency Fields is available on the ANSI Webstore and as IEC 61000-4-6:2023 RLV, which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
