Influence of a Hypersonic Ablative Plasma Wake-Field on the Performance of a Vivaldi Antenna

Ablation of a thermal shield covering a supersonic vehicle can change the characteristics of the plasma sheath, inevitably affecting the propagation of incident electromagnetic waves. The effect of ablation of the heat shield coating in the radio attenuation measurement-C (RAM-C) vehicle on the Vivaldi antenna radiation is quantitatively analyzed for the first time in this article. Ray tracing is used with an integrated model of an ablative plasma sheath and an X-band Vivaldi antenna to obtain the disturbed electric field for a thermal protection layer with different ablation parameters. Numerical results show that the ablation parameters of the thermal protection layer strongly affect the antenna performance. Ablated particles with higher densities and bigger radii cause more energy attenuation of the incident waves. This conclusion can provide a quantitative reference for the study of thermal shield materials.