Direct Current Mode Stirred –Susceptibility Testing Results of a small EUT and Comparison to RC and SAC Results

The Direct Current Mode Stirred method (DCMS) has already been outlined in several papers before and is described shortly in here for consistency. In principle it combines the method of Direct Current Injection (DCI), which injects currents on surfaces of test objects and the Reverberation Chamber (RC) test method for Radio Frequency (RF) susceptibility testing. The motivation is mainly driven by the high efficiency of these two methods and the therefore resulting high field levels, which can be generated by moderate RF power requirements. The major drawback of the RC, with the lowest usable frequency (LUF) which ranges typically at some hundred megahertz, can be shifted towards very low frequencies when being combined with DCI. The DCI (or HLDD, High level Direct Drive) method is very effective in the low frequency range and is limited at higher frequencies, due to RF adaption and strong radiation. The highest usable frequency lies typically at some hundred megahertz. A combination of these two methods could allow much more effective susceptibility testing than with standard antenna radiation techniques.This paper outlines the measurement results, which were gained in four different RCs for the DCMS method with a small Equipment Under Test (EUT). Additionally, at some testing locations, IEC or MIL standard conformal susceptibility tests in a RC and Semi Anechoic Chamber (SAC) were done. Furthermore, it compares the results, which were gained in the four different RCs of different size and also shows the differences to the IEC or MIL standard conformal test results. A conversion factor of the DCMS method to IEC or MIL standard conformal susceptibility tests is foreseen in the future but is not part of this paper.