Plasma Windowing for Hypersonic Radio Communications

An ongoing issue with hypersonic flight is radio communications blackout due to the plasma sheath that develops around the flight vehicle as it travels through the atmosphere, impeding radio communications with the vehicle. An integrated solution for satellite communications using a phased antenna array with a hypersonic flight vehicle is presented. The two-pronged approach uses a S-band RF field upstream from the antenna array and a constant magnetic field generated under the antenna array. The S-band RF field induces a ponderomotive force on the plasma free electrons, sweeping them into channels between the antenna array elements. The constant magnetic field causes these electrons to be bound within their channels, opening windows in the plasma over the antenna array. Together, these two effects may enable satellite Ku band transmissivities up to 80%.