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VCCI had started Kit Module Program in 2005in order to control EMI of the modules. In this program, the electric current on the power line (PL) of the power distribution network (PDN) on the printed circuit board (PCB) is measured by the magnetic probe (MP) method which has been standardized by IEC for the EMI testing of LSI. In this paper, the test result of several kinds of module is presented. They were tested by the measurement method of Kit Module Program and by the measurement method of the radiated emission (RE) complying with IEC/CISPR22. As the result, it was clarified that the MP method is suitable for the test of the module. Although the compatibility with the current EMI test method of VCCI exists as the problem, Kit Module Program will offer the simple and convenient management method to the manufacturers of the module and IT equipment (ITE).

In recent years, personal computers have been constructed by combining modules such as a hard disc drive and memory boards. Although a simple method for measuring disturbances from such modules in the frequency range below 1 GHz has been proposed, device technology progress needs an evaluation method above 1 GHz. This paper describes a method using a magnetic probe for measuring disturbances in the range from 1 GHz to 6 GHz. A test board for use above 1 GHz was developed according to the specifications for use below 1 GHz, and the current distribution and decoupling characteristics were evaluated. The results show that the decoupling factor was less than -11 dB and the maximum current appeared at the nearest point to the decoupling capacitors. Analysis by the finite difference time domain (FDTD) method indicates that the calculated current distribution agrees well with the measured value and that the maximum current could be measured at the nearest point to the decoupling capacitors. Measurement results for a hard disc drive with a USB3.0 port indicate that the disturbance level could be measured at the nearest point to the decoupling capacitor.