Loaded two-element ring antenna for electron plasma waves


  • Y. Morita,

  • S. Egashira,

  • M. Honjoh


A short, coil-loaded two-element ring antenna including a transmission line, immersed in a warm, isotropic plasma, is investigated as a boundary value problem in the frequency range where electron plasma waves exist. The wave potential of electron plasma waves launched from a two-element ring antenna has been enhanced by a factor of 4–6 in comparison with the case of an unloaded one-element ring antenna, when a suitable inductive load is inserted at the feeding point of element 2, and the distance between element 1 and element 2 is chosen as an optimum element spacing. Theory is substantiated by the experiments. In addition, the unidirectional radiation patterns of the antenna for electron plasma waves are predicted by the present theory.