Plasma control of the directional pattern of a multislot waveguide antenna

The possibility of controlling the directional pattern of a multislot waveguide antenna with the help of a gas-discharge tube placed inside the waveguide was studied experimentally. Since the dielectric parameters of the waveguide depend on the plasma density in the discharge column, they can be controlled by varying the discharge current. The high efficiency of such plasma control was demonstrated experimentally: as the discharge current was varied from 0 to 200 mA, the antenna directional pattern turned by ～17°.