EMI Measurements from ESD between Charged Insulators

We present an experimental study of the emission from electrostatic discharges between dielectrics, focusing on the role of extended conductors close to the discharge region. In the absence of an antenna capacitively coupled to the arc, the electromagnetic emission is negligible, while with rod antennas of different lengths electromagnetic transients can be clearly measured. Analyzing the spectrum of such transients and setting the data with a simple lumped parameter model, we obtain an estimate of the capacitance in series with the rod antenna during the discharge. Furthermore, we have developed a technique to uniformly charge the dielectric plane used in our experiments, to make a quantitative study of the charge transfer possible