RF Immunity & RF Immunity Testing Guide

If you’re designing an electronic device, you’ll need to verify that it complies with regulations for electromagnetic compatibility (EMC) before marketing it to the public.

EMC testing involves measuring several major performance indicators for your device, including its ability to function when it’s exposed to radio frequency signals.

This is referred to as radio frequency immunity testing, or RF immunity testing. Testing a device for radio frequency immunity verifies that it can operate as it should when it’s used in the vicinity of a radio-emitting device, such as a phone or Wi-Fi equipment.

Below, we’ll walk you through the fundamentals of RF immunity, the importance of RF immunity testing for your device, and the testing procedures that are used to measure a device’s ability to operate when exposed to RF signals.

Understanding these concepts and processes is critical if you’re aiming to achieve a certification mark, such as FCC, CE or ISED.

To request a free quote for immunity testing for your device, or to ask our team a question about the testing and compliance processes for FCC Part 15, CE and other EMC regulations, you can contact us online or call us at 866-540-5287. 

What is Radio Frequency Immunity?

Radio frequency immunity refers to your device’s ability to continue operating normally when it’s exposed to radio frequency waves, without displaying the effects of radio frequency interference and failing to function properly.

Interference can seriously affect your device’s performance. In sensitive applications, such as a medical device or equipment used in critical infrastructure, a failure to continue operating when exposed to interference may have serious consequences. 

RF interference can come from a variety of sources, including radio transmitters, mobile phones and Wi-Fi equipment. Some devices may inadvertently transmit radio frequency interference as a byproduct of their design. 

During the compliance testing process for FCC, CE, ISED and other compliance marks, devices are tested to verify that they can function when exposed to radio frequency waves.

This type of testing is radio frequency immunity testing. It involves testing your electronic device in an anechoic chamber while under the influence of induced RF fields to verify that it continues to function as intended. 

RF Immunity and FCC Certification

Achieving a high level of radio frequency immunity is a critical part of complying with regulations for electromagnetic compatibility, such as FCC Part 15.

By law, electronic devices sold in the United States must demonstrate that they meet a range of minimum performance standards related to EMC. These include standards for emissions, such as radiated emissions and conducted emissions, and standards for electromagnetic immunity.

RF immunity testing is a key component of the certification process for FCC compliance. If your device cannot pass these tests, or does not complete testing, it’s not eligible to receive an FCC mark and cannot legally enter into the market in the United States.

Currently, testing for radio frequency immunity is required for both FCC equipment authorization procedures: FCC certification and the Supplier’s Declaration of Conformity (SDoC) process. 

This testing ensures that your electronic device can withstand interference from other electronic devices and continue to function properly, which is important for both consumer satisfaction and safety. 

When your device meets RF immunity requirements, it demonstrates that it can operate in real world environments where various RF sources are present. This isn’t only necessary for market access, but also for assuring customers that your product is reliable and durable.

Common Radio Frequency Immunity Standards

Several international and regional standards specify clear requirements and procedures for RF immunity testing. These standards ensure that devices are tested consistently and meet all the necessary performance criteria for electromagnetic compatibility.

Common radio frequency immunity standards include:

• IEC 61000-4-3. This standard specifies testing and measurement techniques for devices subject to radiated radio frequency electrical fields. It covers the 80 MHz to 6 GHz range and is commonly used as a standard for consumer and industrial electronic devices.
• EN 61000-4-3. This European version of IEC 61000-4-3 is required for compliance in the European Economic Area (EEA), which uses the CE mark. It ensures that products sold in Europe meet the minimum required levels of RF immunity.
• FCC Part 15. In the United States, radio frequency immunity requirements are a part of the FCC Part 15 rules. Compliance with FCC Part 15 is mandatory for all devices sold in the United States.
• ISED. In Canada, the Innovation, Science and Economic Development (ISED) Canada regulations set out clear requirements for electromagnetic compatibility, including radio frequency immunity, for electronic devices. 

How RF Immunity Testing Works

• Preparation. Before testing, your device (referred to as the “device under test”) is set inside an anechoic chamber and configured to the manufacturer’s specifications. The device is powered on, and any necessary peripherals and accessories are connected.
• Baseline performance measurement. Your device’s performance is measured under normal conditions, without any RF interference. This provides a baseline against which the effects of radio frequency exposure can be compared.
• RF signal generation. A radio frequency signal generator is used to create controlled radio frequency waves at various frequencies and power levels. These waves are then directed at the device under test using specialized antennas.
• Exposure to RF fields. The device under test is exposed to RF fields at a wide variety of frequencies and intensities, depending on the testing standards. This exposure can simulate the RF environment the device will operate under in a real-life setting.
• Monitoring and assessment. During the exposure to RF fields, the device under test’s performance is monitored to detect malfunctions, interruptions or deviations from normal functioning.
• Post-exposure performance measurement. After the test period of RF exposure, your device will be tested again to measure any degradation in performance when compared to pre-testing.
• Documentation and reporting. Detailed reports of the testing conditions, procedures and your device’s results are compiled into a comprehensive report. This report is vital for demonstrating compliance with EMC regulations and applying for certifications.

Contact Us to Discuss RF Immunity Testing

Completing radio frequency immunity testing for your device is a critical step in meeting EMC compliance standards and regulations, including EN 61000-4-3 (required for CE marking) and FCC Part 15 (required for US market access).

As an ANSI-accredited electronics testing lab, we specialize in testing consumer and industrial devices. Our team can complete RF immunity testing and other test procedures for your device and assist you at every step of the certification process.

To request a free quote, or to ask our engineers your questions about RF immunity testing and compliance, contact us online or call us on 866-540-5287.