Comparative Effects of Simulated Reentry Wake Plasma on Three Base-Mounted Microwave Antennas.

摘要

The effect of a simulated reentry plasma sheath and ionized wake on three types of base-mounted microwave antennas at 1.2 GHz are discussed. Simulation is produced in the MIT Supersonic Wind Tunnel using a pylon-mounted blunt cone model. Microwave antenna are mounted in the model base and a DC arc jet inside the model expels plasma from the model nose. This plasma forms a sheath about the nose and expands behind the model to form a plasma-filled wake. This report presents the results of low and high power tests of three base-mounted antenna types: 1/4 wave monopole mast, annular cavity-backed slot and J-slot. The terminal impedance of the mast was affected most by plasma and the cavity-backed slot least.