Extraction of the internal impedance of VLSIs from the VLSI´s geometrical data

In order to simulate the emission of PCBs (printed circuit boards) it is necessary to describe the RF-(radio-frequency)-sources very exactly in a wide frequency range. Due to internal switching of VLSIs a lot of RF-current-noise can be seen on their supply-pins. These currents I(f) are depending on the relationship between the impedance Z(f) of the supply-system of the VLSI and Z(f) into the supply-system of the PCB at the supply-pins of the VLSI. This paper describes an effective method to extract Z(f) from the VLSI´s geometrical data and compares it to measurement of Z(f)