Uncertainty Budget in Microwave High-Power Testing

Space-borne radio frequency (RF) systems must cope with hard qualification procedures, including the evaluation of high-power handling capability of equipment for space applications. Whatever the electrical parameter is being measured, the general rule of thumb throughout a verification process is to check whether the system can operate up to certain thresholds, which are defined to ensure total reliability for the mission along its operative lifetime. Therefore, assessing and reducing the uncertainty linked to their measurement are mandatory issues as it directly affects the accuracy of the qualification process and hence the safety of the whole space mission. This article presents a novel comprehensive study of all variables affecting measurement uncertainty for high RF power test activities. This study is focused on space applications, and, in particular, multipactor testing, because they comprise the largest number of variables. This is not a restricting case; in fact, the outcome of this work is applicable both for space and ground RF applications. As a conclusion, a complete uncertainty for RF high-power testing is obtained, and, where possible, mitigation actions have also been defined.