Very fast time domain measurement of voltage rising part due to micro gap discharge in air

Voltage rise and fall characteristics due to starting of very short gap discharge were investigated in time domain. The gap space was set very short for voltage below 1500 V as phenomena of CDM ESD and electrical contact of switch devices. The measurement system consists of a distributed constant line system with a coaxial type electrode, because the voltage transients were very rapid. The coaxial electrode has matched impedance for a characteristic impedance of semi-rigid cables of the distributed constant line system. An atmosphere around the coaxial electrode is normal air. This experimental system enables measurement of the high speed and high voltage transients of about 100 ps. As a consequence of the experiment, a relationship between source voltage and voltage rise and fall time were confirmed due to changed source polarity.