Characteristics of Radiation Emission from Mains Cable recognized by being terminated with Common Mode Impedance Stabilization Device

In this article, we investigated the influence on radiated emission characteristics in the condition that an mains cable of equipment under test (EUT) leaving from test area was terminated by balanced and unbalanced type common mode impedance stabilization devices. To investigate the influence by the same termination condition of mains cable, we performed the simulation analysis on radiated emission characteristics of the product with 3 wires (3W) mains cable which has a protective earth (PE) line and a product with 2 wires (2W) mains cable which has no PE line. With regard to this analysis, we conducted also the actual measurements with two types of mains cable by using a comb generator. From these results, we were able to estimate that the radiated emission from the products having 3W mains cable were became from 3 to 5 dB lower at a VHF band than the product having 2W mains cable. Furthermore, we investigated the influence on radiated emission characteristics by two terminating conditions when EUT setups including cable arrangement were changed. As a result, there was no difference compared with the maximum standard deviation of without device. This means it is insufficient only by establishing the termination condition of mains cable.