Area distribution of HPM air-breakdown

Air-breakdown is a key problem for high power microwave(HPM) propagating. On one hand, field distribution of HPM antenna at near-field region exists in oscillating wave style, and some peak points will occur at local area, thus a series of problems occur, such as air-breakdown at near-field region, dielectric surface breakdown, etc. On the other hand, air-breakdown at far-field region must be considered for the improvement of single HPM sources and the development of power combining technology. The method and criterion to judge the air-breakdown should be studied. This paper presents the way based on the curves regular of air-breakdown threshold and antenna field distribution with the altitude. When initial field value is less than the air-breakdown threshold in the corresponding, and two curves exist at the intersection point, then air-breakdown may be in the propagating route while it will not occur in the near field region of antenna. The result is proved in related experiments.