Radiation enhancement mechanism for a cylindrical metallic antenna surrounded by a thin plasma layer

Based on the dispersion equation obtained from Helmholtz equation in the sheath region and plasma layer region, and free space region of the azimuthally symmetric surface wave, the propagation constant properties on the interface of the plasma layer region and free space region, the mode radiation enhancement characteristics in the free space region are studied. The analytical results indicate that the collision effect has an evident influence on the attenuation constant, but the impact on phase constant can be ignored when the wave frequency is equal to the plasma frequency. While the radiation enhancement phenomenon due to a plasma layer is confirmed, both the sheath thickness and plasma layer thickness have a notable effect on the amplitude of the maximum radiation enhancement intensity. These analytic results have an important theoretical guidance value in the optimization of plasma antenna radiation field.