Voltage Breakdown Characteristics of Microwave Antennas

The problem of voltage breakdown and its effects is discussed for a pulse antenna system. Voltage breakdown occurs at power levels when the pressure is reduced. The minimum breakdown potential occurs approximately at the pressure where the frequency of collision between electrons and gas atoms is equal to the frequency of the applied field. Experiments were made to determine the power levels required to produce breakdown and the effect of breakdown on the VSWR, pulse shape, radiation pattern, and radiated power. It is shown that all four of the quantities vary with pulse width and peak power.