Parameters of the electric strength of air in a surface antenna during the emission of an ultrahigh-frequency pulse with a trapezoidal envelope

On the basis of the breakdown criterion and the equation of continuity of electrons in air, the amplitude and energy parameters of the electric strength of air in the surface antenna of a powerful microwave relativistic generator are determined when pulses are emitted with a trapezoidal envelope. Triangular and rectangular envelopes were considered as boundary cases of a trapezoidal envelope. The dependence of the parameters of electric strength on the shape of the envelope has been established. The calculation of the dependences of the breakdown field and the maximum permissible energy in a flat aperture on the pulse duration in the range of realizable durations of powerful relativistic microwave generators is carried out. For the same duration, the largest breakdown field has a pulse with a triangular envelope, and the smallest – a pulse with a rectangular envelope. Wherein a pulse with a triangular envelope has the lowest maximum permissible energy, and a rectangular one has the highest. The relationships between the maximum permissible energy and the breakdown field for the pulses under consideration are determined. With the same maximum permissible peak amplitude, the highest energy has a pulse with a triangular envelope, and the smallest – a pulse with a rectangular envelope.