Radiation Characteristics of a Plasma Column Antenna

By means of the study on electromagnetic (EM) waves propagating along the plasma column, it is found that the radiation of a plasma column is caused by two kinds of operation modes. The first one is a guided mode which leads to a surface current radiation, and its operation condition is obtained by boundary conditions and physical properties of plasma. The second one is a leaky mode which results in a leaky wave radiation, and its operation condition is presented by analyzing normalized complex propagation constant. With further dealing with the leaky mode, its far field is got by applying the Schelkunoff’s equivalence principle on the surface of the plasma column. Radiation patterns of two kinds of modes are presented in their respective operation frequency bands, and reveal the radiation characteristics of the plasma antenna. The presented results are very helpful for further investigation in the design and application of plasma column antenna.