Plasma can be used to create antennas: its conductivity is given by free electrons resulting from gas ionization. This process is obtained with the application of an intense electromagnetic field to a glass tube filled with a low pressure gas. The pump signal needed for ionization and gas discharge parameters have to be carefully chosen in order to optimize plasma antenna design and realization; in particular discharge working conditions have to be defined to obtain the desired antenna properties in terms of efficiency and effective length. For this purpose a self-consistent numerical model of a surface wave driven plasma column has been developed. This tool helps to understand the physical aspects involved in the problem and allows a parametric investigation to be carried out