Two-dimensional calculation of pulse power and energy loss in microwave air breakdown bandwidth broadening

Summary form only given. It has been demonstrated experimentally that bandwidth broadening results from air breakdown in the WR-284 rectangular waveguide. This bandwidth enhancement has been simulated with an implicit, two-dimensional, electromagnetic, electron fluid computer code for avalanche ionization. Code simulations have predicted the broadening of 3.5-ns, 0.342-GHz-bandwidth pulses at 2.8608 GHz incident on spatially Gaussian initial electron density profiles with an axial FWHM of 3 cm in 3.5-torr air. For incident amplitudes from 1 to 18.5 MV/m and peak initial densities of 10-10/sup 11/ cmsup -3/, transmitted 3 dB bandwidths of 0.352-3.21 GHz (12.3-112% relative to the incident frequency) and center frequencies from 2.82 to 4.72 GHz (98.6-165% relative) were obtained.