A New Method for the Spectral Density Calibration of Impulse Generators

Impulse generators capable of producing high voltage and narrow-width pulses are becoming increasingly useful as calibrated wide-band interference sources in the field of electromagnetic compatibility (EMC). These generators produce a discrete spectrum having essentially a (sin x)/x envelope and may have a 3-dB bandwidth exceeding 1 GHz. However, spectral density calibration of these generators can become exceedingly involved and is usually subject to error. Frequently, one source of error is the inability of some calibrating instruments to respond to wide-band signals in the same manner as single-frequency signals. A new technique of impulse generator calibration is described, based solely on the amplitude measurement of the frequency components and impulse generator repetition frequency. The method is simple and straightforward and is inherently more accurate than existing techniques, such as that presented in Military Standard 462. It should be regarded as a potential replacement for the present calibration technique currently serving the EMC community.