Radiation from an electric dipole in a plasma column

The radiation characteristics of an axially oriented electric dipole in an isotropic plasma column are investigated. Surface waves are found to be excited for frequencies of less than 1/¿2 times the plasma frequency. The dependence of the power carried by the surface wave, as well as that carried by the space wave, on the frequency and the radius of the plasma column is examined. The surface waves are found to be excited with maximum efficiency at about half the plasma frequency. The radiation pattern in the far zone is evaluated and found to have, in general, a maximum in the broadside and a null in the end-fire directions. The normalised radiation resistance is found to vary as the square of the frequency for small column dimensions and high frequencies.