Radiation characteristics of planar rectangular apertures covered by a layer of moving cold plasma

The changes created by the motion of a plasma layer on the radiation characteristics of a planar rectangular aperture are discussed. The plasma covers the aperture and moves in a direction parallel to the aperture plane. Only the simplest form of plasma is considered; i.e., lossless, isotropic and homogeneous. Radiation patterns were computed for plasma motion (1) normal and (2) parallel to the H-plane aperture aperture axis. These results compare well with those derived earlier for line source and slot radiators. The admittance properties of the aperture for case (1) were also investigated and were found to change significantly for small plasma speeds (β<0.1), when the plasma layer is thin and when operating near plasma resonance