A method to determine the injected real power into an IC Pin in case of a conducted immunity EMC test

The direct power injection (DPI) measurement method is an internationally accepted technique to verify the robustness of an integrated circuit (IC) against an injected RF signal. The requirements of this measurement method respecting the setup is fixed in the international standard IEC 62132-4 [1]. In this paper a method is presented which allows to determine the real power injection into the IC pin by considering the influence of the required test printed circuit board (PCB). To apply this method only the transmitted and reflected RF power, the voltage standing wave ratio (VSWR), which are already locked during the DPI test, and the scattering parameters (S-parameters) of the PCB injection path are needed. How to use the available measurement results and how to determine the required S-parameters of the PCB injection path is described in this paper.