Radiation resistance of a circular current filament in a magnetoionic medium

The radiation from a circular filament of electric current immersed in an unbounded, loss-free magnetoionic medium is considered for the case in which the axis of the loop is oriented parallel to the direction of the magnetostatic field. An integral expression for the radiation resistance of the current loop is obtained for the case of a constant current distribution around the loop. The radiation resistance is found to be finite for all frequencies except the upper hybrid resonant frequency, where it becomes infinite as a result of the limitations of the magnetoionic theory which is used in this investigation. Numerical results of the radiation resistance of the current loop are given for some typical values of the parameters of interest.