To enhance the survivability of unmanned aerial vehicles (UAVs) in complex electromagnetic environments, a model is presented to assess the complex electromagnetic interference (EMI) effects on UAV data links. Based on the mechanism of electromagnetic interference, three key parameters are introduced: the loss-of-lock threshold A_t, the effect–time ratio D, and the effect index τ. An assessment model is then developed using these parameters. By classifying interference into sinusoidal-type and noise-type, the model is capable of predicting the interference effects of complex interference scenarios comprising in-band single-tone, partial-band noise, and out-of-band interferences that generate in-band third-order intermodulation components. Measurements of A_t and D from single-source EMI effect tests, along with validation from three-source and four-source EMI effect tests, confirm the model’s efficacy. Results indicate that the A_t is inversely proportional to the D and correlates with the bit error rate. The maximum error between the experimental and theoretical values of τ is 0.709 dB, demonstrating the validity and applicability of the model. Finally, a four-level EMI effect assessment method was proposed. The assessment method could provide theoretical support for anti-interference decision-making systems and enhance the UAVs’ anti-interference capability in complex electromagnetic environments.

This study investigates the electromagnetic radiation effects on inter-unmanned aerial vehicle (UAV) data links in ad hoc networks within complex electromagnetic environments through theoretical and experimental approaches. Using the Autel V3E UAV as the test subject, the bit error rate performance of a frequency-hopping/16QAM system under noise jamming was theoretically analyzed, revealing the intrinsic relationship between electromagnetic interference parameters (frequency offset and bandwidth) and the system’s loss-of-lock threshold. Through electromagnetic irradiation experiments, a novel cross-module interference mechanism, termed “back-door coupling,” was discovered and validated. This mechanism demonstrates that out-of-band interference at 1.22 GHz can effectively disrupt the 2.4 GHz data link through nonlinear effects. The experimental system compared the effectiveness of noise, modulated signal, and multi-tone jamming, identifying vertical polarization and a 20 MHz baseband bandwidth as the optimal jamming parameters. This study offers valuable insights for designing anti-jamming UAV data links and developing low-power precision jamming strategies.