Antenna design in the Plasma Environment

Development of the ballistic missile targets is a complex undertaking, particularly since radio-frequency (RF) blackout caused by plasma formation during re-entry complicates antenna designs for Global Positioning System (GPS) and telemetry signals. To minimize the cost of the design/build/test process, proposed designs should be first simulated and refined in a virtual prototyping environment before further developed in hardware. However, the available virtual prototyping software is currently not capable of predicting the coupled response of the plasma-antenna system, and is therefore inadequate for designing active or impedance-matched antenna systems. We propose to develop a working prototype of a coupled CFD/CEM solver that has the basic features required to simulate re-entry plasmas, utilizing a continuation method that couples a time-dependent CFD solution to a time-dependent CEM solution using different time scales. Verification and validation of this methodology will be performed on a model with characteristics relevant to MDA ballistic missile targets. This tool will implement the appropriate physical models to facilitate the design of antennas in a plasma sheath and provide a flexible software architecture that can be applied to a broader range of problems and ultimately interface with existing solver environments.