Abstract
Recent electronic devices usually cannot pass radiated emission tests as the operating speed of these devices increases. In particular, when multiple clock drivers operate clock lines synchronously, the radiation noise level increases due to the overlapping of the noise sources. In conventional methods such as the near field measurement, it is impossible to identify a specific wiring connected to a noise source when the harmonic frequencies of each source overlap. In this paper, we verify whether the use of a notch filter, whose resonant frequency is equal to the problematic frequency in the radiated emission tests, and a switching circuit can identify the wiring connected to the noise source. Some experiments show that that location of the aforementioned circuit on the wiring of a PCB can identify the specific wiring connected to the noise source.
