Hypersonic or re-entry plasma communication

Plasma generated around a vehicle traveling at hypersonic velocities can be a significant impediment to fixed-frequency communications, particularly for GPS navigation signal reception. Under two complementary U.S. Air Force Phase II SBIR programs, we have been developing technology for improving communication through plasmas. ReComm (ReEntry and Hypersonic Vehicle Plasma Communication System) creates a physical communication window utilizing plasma density reduction and HyPASS (Hypersonic Plasma Adaptive Sensor System) improves the communication channel through that window by implementing an antenna matching system. The HyPASS system uses two diagnostic probes attached to frequency-adaptive vector network analyzer hardware to measure plasma parameters, and can use these parameters to adjust a matchbox, reducing the reflection at the signal antenna due to the plasma mismatch. The system also provides real-time information about local plasma parameters. When used in concert, ReComm and HyPASS are expected to provide a 25 dB or more increase in signal reception, thus enabling more bandwidth and broader communication envelopes for hypersonic vehicles.