Electromagnetic compatibility of unmanned aircraft : Examination of legislation and evaluation of two commercial systems

Sammanfattning: Electromagnetic compatibility (EMC), or the field of reducing emissions from and increasing immunity against electromagnetic interference, is an essential part of designing modern electronics. As one would expect, EMC is especially important for things such as aircraft and aviation equipment where outages or disturbances could have severe consequences. The problem presented in this thesis was to consolidate the available legislation regarding EMC for unmanned aircraft and then apply this information onto two commercial systems still under development. Based on the applied rules, pre-compliance measurements were then performed to identify problematic areas of their designs in regards to EMC, or more specifically radiated emissions and electromagnetic immunity. The research process for the legislation involved reading through mainly the official documents and directives published by the European Commission, the European Parliament and the European Aviation Safety Agency (EASA), looking up declarations of conformity made by drone manufacturers and also contacting accredited EMC labs for information on how they usually prove compliance for drones. The conclusion of this research being that (for EMC purposes) drones need to follow either the EMC directive 2014/30/EU, the radio equipment directive 2014/53/EU or the essential requirements of directive 2018/1139/EU depending on the intended usage of the drone and its technical specification. As for application of legislation onto the two commercial systems, because there were no drone-specific EMC standards (i.e voluntary ways to more easily prove conformity) in the EU some simplifications would need to be made. This took the form of applying parts of both the EN 55032 (applicable for multimedia equipment) and EN 301 489-1 (applicable for radio equipment) standards for radiated emissions and immunity testing respectively. While the application of legislation in the end was more simplified than initially planned, the goal of condensing down the available information was still achieved. As for the measurements, it should be noted that while most of the problematic areas that caused the systems to break the limits in the chosen legislation were indeed successfully identified on both systems there are still measurements that should be done in the future. This includes testing conducted emissions and immunity against transient electromagnetic phenomena such as electrostatic discharge (ESD).