Meaning
Compliance procedures verify that electronic devices can operate reliably when exposed to external radio frequency fields. Radiated immunity testing involves subjecting the equipment under test to controlled electromagnetic fields across a specified frequency range while monitoring its performance for any degradation. This evaluation ensures that the product is resilient against ambient interference in its operating environment.
Enclosure Evaluation
Shielding effectiveness of the product’s chassis and the design of its filtering circuits determine its susceptibility to interference. During radiated immunity testing, the device is exposed to fields of varying intensity, often ranging from three to ten volts per meter, depending on the target market. This exposure reveals any design weaknesses that could lead to operational failures.
Calibration Routine
Establishing a uniform electromagnetic field requires a systematic setup. Before executing radiated immunity testing, the laboratory must calibrate the field using the substitution method to ensure that the field strength is consistent across the test volume. This calibration involves recording the forward power required to achieve the target field strength at each frequency step.
This recorded power is then applied during the actual test with the device in place, ensuring that the test field is accurate.
System Integration
Automatic software control coordinates the operation of the signal generator, power amplifier, and field probe. This automation allows radiated immunity testing to be performed efficiently across thousands of frequency points. It also ensures that any anomaly in the test field is detected and corrected immediately.
