Measurement of the impedance of a linear antenna in a magnetoplasma

Abstract

Impedance of a monopole antenna oriented at various directions with respect to the static magnetic field has been measured in an RF‐generated magnetoplasma. The antenna length is comparable to a free space wavelength. To interpret the experimental results, theoretical values of the input impedance have been calculated by using the EMF method with a uniaxial approximation for the magnetoplasma and some other assumptions. The agreement between theoretical values and measured data has been fairly good except that the effective collision frequency has been much higher than that expected from the collision cross section. Some interesting resonance phenomena of the antenna impedance, depending on the antenna length and the slant angle with respect to the static magnetic field, have been observed.