TECHNIQUES FOR MEASUREMENT OF INPUT IMPEDANCES OF ELECTRONIC EQUIPMENT IN THE FREQUENCY-RANGE FROM 1 MHZ TO 1 GHZ

Electromagnetic interference (EMI) can couple to electronic equipment through any number of interfaces of the equipment to its external environment, e.g., power and input/output signal cables or ventilation slots. In this paper the power cable interface to the equipment's power supply is investigated. Input impedances of power supplies in various electronic equipment operating under normal active conditions were measured in the common mode (phase-ground) from 1 MHz to 1 GHz. Such a wide frequency range is useful in studies of wide-band EMI such as electrostatic discharge (ESD). The results of these measurements are discussed and the possibilities of using them in further work are suggested.