Plasma simulation by artificial dielectrics and parallel-plate media

Abstract

A plasma in the absence of dc magnetic fields is representable, from the electromagnetic viewpoint, as a lossy dielectric with a complex index of refraction whose real part is less than one. Its electrical properties, such as propagation constant and intrinsic impedance, can be simulated by microwave structures, such as artificial dielectrics of lossy metallic rods, and by <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</tex> - plane parallel-plate guides. Design techniques are presented for application to the modeling of plasma media. Examples include problems of radiation from antennas on a plasma-coated ground plane, with magnetic line sources and electric aperture radiators simulated by parallel-plate guides and rodded media, respectively. Radiation patterns of these models show good agreement with established theory. Waveguide measurements on the rodded media also confirm the expected propagation and impedance characteristics.