This study investigates the “blackout” communication problem caused by the plasma sheath during hypersonic flight, with a focus on the wake region. We present the first systematic analysis of high-frequency (1–150 GHz) signal propagation paths in this region. Using a ray-tracing method based on a fourth-order Runge–Kutta algorithm, we simulate electromagnetic wave transmission through the wake of a blunt-cone plasma sheath. A key discovery is the emergence of waveguide transmission modes in the 6–90 GHz band, where signals become confined and guided within the wake region of plasma sheath itself. We identify and explain three distinct physical mechanisms governing this phenomenon, which are a large-gradient total reflection barrier, a small-gradient refraction–reflection synergy, and a composite mechanism combining both. Statistical analysis of propagation paths further reveals that the waveguide effect occurs primarily under specific incident-angle and frequency combinations. Our results demonstrate that actively leveraging this natural waveguide phenomenon in the wake region can significantly enhance the stability and reliability of communication links under blackout conditions. This work provides a novel perspective and a potential pathway for designing robust communication systems for hypersonic vehicles.
Lu et al. (Fri,) studied this question.