Electromagnetic Interference With the Mobile Communication Devices in Unmanned Aerial Vehicles and Its Countermeasures

One of the threats to industrial unmanned aerial vehicles (UAVs), which require a high level of safety, is the degradation of control wireless communication performance due to electromagnetic interference. Self-jamming caused by unintentional electromagnetic (EM) noises from the multiple electronic devices installed in a UAV, such as the power supply and camera, is a fundamental issue independent of the surrounding environment. UAVs are susceptible to self-jamming since electronic devices as noise sources are densely mounted inside their chassis. Therefore, evaluating the self-jamming problem and taking countermeasures to achieve high safety in wireless communication performance are important. In this paper, we focus on mobile communications used for UAV operation and evaluate the impact of EM noise generated by a commercial industrial UAV on the receiver sensitivity of an onboard mobile communication device. It was found that EM noise generated by the UAV degrades the sensitivity in the three communication bands, 800 MHz, 1800 MHz, and 2100 MHz, used over the air. In particular, receiver sensitivity was degraded by up to 29 dB in the 800 MHz band, indicating that the self-jamming problem is not negligible for the safe operation of industrial UAVs. In addition, countermeasures for self-jamming were taken at the mechanical design level to suppress EM noise to a level that does not degrade mobile communication performance. The results of this study show that countermeasures for self-jamming are an important element for safe UAV operation.