RCs (Reverberation Chambers) has historically been used mainly for aerospace and military purposes in EMC (Electromagnetic Compatibility) testing, but the interest also seems to increase in the automotive industry (the development of an international standard for vehicles is in progress). The vehicles of the future will most likely be electrified, wirelessly connected and autonomous, i.e., more control units, more communication systems, and more sensors, will be implemented in the vehicles requiring increased robustness against all possible electromagnetic interferences. EMC testing in an RC is a step in the direction of ensuring this robustness for the future vehicle platforms. Compared to a traditional EMC test method in a fully or semi-AC (Anechoic Chamber), testing in an RC has the advantage that the electromagnetic field will be isotropic, randomly polarized and homogeneous in a statistical sense, i.e., the exposed object will be surrounded by electromagnetic energy from all directions. It can be considered relatively expensive to build a brand new RC with motorized stirrers and associated measurement instrumentation, instead it would be desirable to perform immunity tests in a more cost-effective conductive fabric tent. The great advantage is the flexibility, the tent can be set up almost anywhere, even in already existing semi-ACs, such set-up is referred to as VIRC (Vibrating Intrinsic Reverberation Chamber). This thesis aims to develop a new test method in a VIRC environment. In order to achieve good RC conditions, the electromagnetic field must be statistically Rayleigh distributed. Furthermore, it is of great importance to avoid LoS (Line of Sight) between the antenna and the test object, and to achieve good stirring in the tent. Provided this can be achieved, there are still some challenges by testing in a tent. For example, the classical dwell time of two seconds for immunity testing in EMC is not possible to achieve in a VIRC environment. The validation in this thesis shows that the dwell time or the total exposure time in the tent might be enough to trigger possible malfunctions in today's modern high-speed communication vehicles. Furthermore, it is showed, testing in a VIRC gives good field uniformity and repeatability, and can trigger malfunctions that are not triggered in traditional EMC testing in semi-AC, i.e., ALSE (Absorber-Lined Shielded Enclosure) testing.

As the automotive industry advances through technology integration, components are designed to operate at increasingly higher frequencies. Consequently, there will be an increasing demand for automotive electromagnetic compatibility (EMC) testing. Testing and certification institutes, such as RISE Research Institutes of Sweden AB, thus face an urgent need to develop innovative solutions that can effectively address this growing demand. This master thesis work concerns one EMC test method in particular - the On-board Transmitter (OBT). This is a test which mainly serves to test the immunity of vehicles to electromagnetic disturbances originating from hand-held devices. The conventional test is performed in an anechoic chamber and the methodology requires a substantial amount of time. The intent with this work is thus to evaluate the potential of a novel OBT method where the concept of a reverberating chamber is applied inside the vehicle compartment. Initially, the conventional method was examined from two mock-ups of idealized cases, and it was observed that the electromagnetic field in the near-field region of the transmitter is highly erratic. It was also concluded that the test setup is particularly sensitive to the polarization of the transmitter. With these findings in mind, the accuracy of the conventional method was deemed questionable. Evaluation of the proposed Reverberating On-board Transmitter (ROBT) method proved that the electromagnetic environment inside the vehicle did not resemble a perfect reverberation chamber. Which was expected as the absorbing material such as seating and upholstery likely prevents a field distribution similar to that in a reverberation chamber. Still, the intent of the project was to find a test method superior to the conventional method and it can be stated that the ROBT method is an adequate option due to its capacity to expose the electronics to isotropic radiation. This was found from two measures which this thesis introduces: expected isotropicity eiso, a relative measure of the electric field components and DDoF, a quantification of the spatial distribution inside a reverberation chamber. / EMC VERifiering av Autonoma fordon i modväxlad kammare (EMCVERA)