Breakdown characteristics of ultra-wideband high-power microwave transmission through the lower atmosphere

If the ultra-wideband high-power microwave (UWB-HPM) transmitting in the air with a breakdown threshold is lower than the field intensity of the pulse, it will cause the breakdown of background gas and generate plasma which varies rapidly in space and time. And the generated electrons will attenuate the field at the tail portion of the HPM. This erosion shortens the pulses and generates transmitted pulses with broadened bandwidth. Using finite difference time domain method (FDTD) can give numerical analysis about the UWB-HPM transmission in low-level atmosphere.