Performance Evaluation of High Power Microwave Systems Against UAVs A Probabilistic Antenna Propagation Framework with Sensitivity Analysis

We develop a probabilistic, antenna- and propagation-centric framework to quantify the effectiveness of high-power microwave (HPM) engagements against unmanned aerial vehicles (UAVs). The model couples stochastic UAV kinematics, a beam-steering jitter-to-gain mapping, and atmospheric propagation (free-space spreading with gaseous and rain loss) to obtain closed-form statistics of the received pulse energy. From these, we derive analytically evaluable per-pulse and cumulative neutralization probabilities using log-normal closures and Gaussian--Hermite quadrature, and we provide a dwell-time expression under a standard pulse-independence assumption. Analytical predictions closely match large-scale Monte-Carlo simulations across broad parameter ranges. For a representative commercial threshold $E_{\mathrm{th}} = 10^{-2}\,\mathrm{J}$, the model predicts $\bar{P}_{\mathrm{kill}} \gtrsim 0.4$ per pulse and $P_{\mathrm{kill,tot}} > 99\%$ within about $0.1\,\mathrm{s}$ at kHz PRF; for hardened platforms with $E_{\mathrm{th}} = 10^{-1}\,\mathrm{J}$, $\bar{P}_{\mathrm{kill}} < 1\%$ and $P_{\mathrm{kill,tot}} < 20\%$ after $1\,\mathrm{s}$. A closed-form sensitivity (elasticity) analysis shows performance is dominated by slant range ($S_{\bar{R}} \approx -2$), with strong secondary dependence on aperture diameter and transmit power; pointing jitter and atmospheric variability are comparatively less influential in the evaluated regimes. The framework yields fast, accurate, and physics-faithful performance predictions and exposes clear antenna/propagation design levers for HPM system sizing and risk-aware mission planning.