Unmanned Aerial Vehicles (UAVs), particularly the DJI Phantom 4, are increasingly utilized across multiple sectors, including aerial photography, agriculture, and disaster response. However, as their integration into the Internet of Things (IoT) continues to expand, so does the risk posed by Electromagnetic Interference (EMI), which threatens their operational performance. A recent study published in Scientific Reports on March 23, 2025, investigates this vulnerability, employing Characteristic Mode Analysis (CMA) along with experimental validation.
The study uniquely includes all subsystems of the DJI Phantom 4 in its analysis, enhancing the accuracy of the CMA model compared to prior work that often relied on simplified UAV models. "By applying CMA, researchers can more accurately target their experimental measurements, reducing the need for exhaustive testing while still ensuring that all critical EMI interactions are thoroughly analyzed," wrote the authors of the article.
As UAVs play crucial roles in inspecting critical infrastructure, the implications of EMI are profound. The DJI manual cautions against operating near high-voltage power lines due to increased risk of interference, highlighting a pressing need for understanding the electrical behaviors of these flying machines under different electronic encounters.
Employing the FEKO30 2023 software, researchers compared the UAV's electromagnetic behavior across three stages of subsystem integration. The analysis indicated that longer power supply wires, particularly those connecting the UAV motors to electronic speed controller (ESC) boards, exhibited the highest susceptibility to EMI-induced failure. "These insights provide applicability across a range of UAV designs, facilitating improved performance in electromagnetically dense environments," wrote the authors of the article.
In practical terms, the research confirmed that UAVs are more susceptible to EMI at higher frequencies. During experimental validation, the UAV was subjected to electromagnetic fields from a testing source with an effective isotropic radiated power (EIRP) of approximately 22 kW at 2.45 GHz. Measurements showed that performance degraded significantly at different distances from the source, becoming critical as the UAV approached 0.6 meters.
Data indicated that across all test distances, the motors, due to their long wiring, were especially prone to interference. At close ranges, such as 0.6 meters, both the motors and the GPS board were completely disabled. The measured field strengths highlighted how the UAV's components interacted with various levels of electromagnetic exposure, with readings increasing from 272 V/m at three meters to 1360 V/m at 0.6 meters.
The study outlines crucial recommendations to mitigate these risks, suggesting shielding on power supply cables modeled after coaxial cables, which could potentially enhance the UAV's electromagnetic resilience. "This research underscores the necessity of shielding power supply cables, akin to coaxial cable design, to enhance the UAV’s electromagnetic resilience," wrote the authors.
Understanding the electromagnetic vulnerabilities of UAVs has significant implications for their design and operational capabilities, particularly as these technologies grow in importance. As researchers continue to develop and refine UAV applications, ensuring their resilience in electromagnetically dense environments will be critical not only for operational safety but also for expanding their functional capabilities. This work lays the foundation for further investigations into EMI mitigation techniques across various UAV platforms, promising optimized designs for the future.
