An alternative mathematical description of HEMP waveform

The commonly used mathematical description of HEMP waveform is the difference of double exponentials. A shortcoming of this description is the discontinuity of the first derivative at the initial time of waveform. Another description of the reciprocal of the sum of exponentials does need the time shift factor because its amplitude is not zero for finite negative time. To overcome these shortcomings, the p-power of double exponentials is proposed to describe HEMP waveform. The properties of this description are calculated and analysed, and show rather good performances. The derivative of this description is continuous at initial time of waveform and does not need of time shift factor. Finally, the parameters based on the description of p-power of double exponentials, according to the standards of IEC 61000-2-9, Bell laboratory and 1976 publication, are calculated and presented in this paper.