High-Frequency Breakdown in Air at High Altitudes

The problem of microwave breakdown near antennas at high altitudes is considered in order to find limitations on transmission conditions. The fundamental processes are described briefly. The cw breakdown electric fields for frequencies of 100 mc, 3 kmc, 10 kmc, 20 kmc, and 35 kmc are computed on the basis of the available data on atmospheric composition. The maximum peak electric fields and powers for which pulses are almost completely transmitted are also computed for the same frequencies and for several pulse lengths. It is shown that considerably more power per unit area of aperture can be transmitted at the higher frequencies. The validity of the assumptions on which the calculations are based is considered.