The work aims to theoretically and experimentally investigate the radiation characteristics of the plasma window antenna for beam-steering applications. The antenna system consists of a wire antenna in the center, surrounded by a circular array of 22 cylindrical plasma columns. The research reveals that the radiation pattern of the antenna system can be simply controlled by exploiting the variable parameters, such as working frequency, driving current, and plasma configurations. It implies that the beam narrows as the plasma antenna aperture decreases, implying a greater directivity. By electrically tuning the plasma, a maximum directivity of 9.09 dBi and a minimum half-power beam width of 35.86^∘ emerged for a specific configuration. The results show that higher currents prevent radiation from escaping from the plasma shell, while higher frequency microwaves are more likely to penetrate the plasma blanket.