Radiation field produced by an infinite slot in an infinite cylinder surrounded by a homogeneous plasma sheath

The radiation properties of a slotted cylindrical antenna surrounded by a homogeneous plasma sheath have been investigated. The slot is axial and extends along the entire length of the cylinder, and it is fed by a voltage of constant magnitude and phase. The antenna is insulated from the plasma by a thin dielectric coating. General expressions for the field components are derived and then simplified by making some physical approximations. The radiation patterns produced by the antenna are discussed for the following two cases: (a) when both the dielectric coating and the plasma sheath are thin and (b) when only the dielectric coating is thin. For both cases, field expressions are derived for operating frequencies above the plasma frequency and below it. The effects of collision between the particles in the plasma are taken into account. Results for the collisionless case can be obtained from the general expressions given. Numerical results are obtained for the radiation patterns produced by the antenna under various physical situations.