A comparison of methods and results using the semi-anechoic and reverberation chamber radiated RF susceptibility test procedures in RTCA/DO-160D, Change One

RTCA/DO-160D, Environmental Conditions and Test Procedures for Airborne Equipment, defines a series of minimum standard environmental and electromagnetic compatibility test conditions (categories) and applicable laboratory test procedures for airborne equipment. Change One, issued in December, 2000, includes a complete revision of Section 20 - Radio Frequency Susceptibility (Radiated and Conducted), which contains two different radiated RF susceptibility test procedures: reverberation chamber (which was extensively changed), and semi-anechoic chamber (which was updated). A comparison of the two procedures is provided, including chamber specifications, test setups, calibration methods, and test procedures. A comparison of radiated susceptibility test results using both methods is also discussed. This paper is a follow-up and completion of the work performed in 2002 and presented by the author at the 2002 IEEE International Symposium on EMC. The paper presented at Minneapolis in 2002 contained limited test results (1 GHz to 3 GHz) due to limitations of time and test facility availability. Also, the reverberation chamber that was used for comparison of results was not fully compliant with the requirements specified in RTCA/DO-160D, Change No. 1. In contrast, the results presented here are based on data collected in a reverberation chamber and anechoic chamber that are both fully compliant with the requirements in RTCA/DO-160D, Change One. In addition, the reverberation chamber used to gather this data was calibrated in accordance with RTCA/DO-160D, Change One, including a determination of field uniformity, which was found to be well within the requirements of the standard. The author would also like to clarify that the intent of this paper is not to promote or advocate either of the test methods discussed, but instead, to make the EMC testing community aware of the real-world differences in test results when using these two methods. By using a test artifact that is intended to represent the "typical" item that would be tested in these two types of chambers, the data is (hopefully) more meaningful to the EMC test personnel and EMC project managers that need to make informed decisions about which method to use, and where their testing should be performed. Finally,- as is usually the case with this type of experiment, it seems clear that more data, from other reverberation and semi-anechoic chambers, testing the same artifact (or other artifacts), would be a very useful addition to the cumulative knowledge base that all of us EMC test "geeks" need in order to make good decisions about testing, and also to direct future development or revisions of EMC test standards.