Application Note: Proper Use Of RF Field Probes Used In EMC Radiated Immunity Testing

By Jason Smith, Jason Galluppi, and Pat Malloy, AR

RF field probes are perhaps one of the most underrated components of a radiated immunity test system. While we rely heavily on data sheets to select all the other devices required to generate a given field level, only a live test using a trusty field probe will measure the resultant field level and thus, validate the RF test system. While we assume that all measurements meet the accuracy published in the probe’s data sheet, it must be noted that these indispensible tools can be a source of considerable error if not used correctly. This application note will review the underlying concepts of field measurement with an emphasis on the proper application of field probes.