Abstract: Aimming at the datalink of quadrotor unmanned aerial vehicle (UAV) is susceptible to be interferenced by high intensity radiated field (HIRF) in low altitude airspace, this paper proposes a method of field-circuit joint simulation
to investigate the interference effect. Firstly the antenna coupling effect of UAV model under HIRF is investigated
with electromagnetic simulation software, and the coupling voltages under different irradiation directions, different
signal types and different pulse width coefficients are analyzed. Secondly, the radio frequency (RF) front-end cir
cuits of the datalink are integrated into the simulation with circuit design and analysis software to assess the interference effect. The results demonstrate that the smaller the pulse width coefficient, the stronger the interference
caused by Gaussian pulses. Additionally, under identical pulse width coefficients, modulated Gaussian pulses induce stronger interference than Gaussian pulses. Moreover, the addition of the interference signal leads to a significant increase in the peak value of the intermediate frequency (IF) output signal of the RF front-end, the shift of the
peak frequency and a decrease in signal-to-noise ratio.

Key words: high intensity radiated field (HIRF), unmanned aerial vehicle (UAV) datalink, field-circuit joint simulation, interference effect