2024 年 8 巻 1 号 p. 25-29
In recent years, as electronic devices have advanced, the component mounting density on electronic boards has grown, leading to circuit noise issues. Addressing this requires technology capable of precisely measuring high-frequency magnetic fields. We have been studying magneto-optical effects and high-frequency near-field measurements using pulsed lasers. In previous studies, we demonstrated the feasibility of measuring the magnetic field distributions across diverse electronic circuits, including actual circuits in commercial electronic devices. However, it is difficult to identify a noise source only by the intensity and frequency of the magnetic field obtained by magnetic field distribution measurement. This study proposes a visualization of noise propagation paths utilizing the phase information obtained by a magnetic field measurement system. For validation, we measured the magnetic field emitted by crosstalk noise, a typical type of noise in electronic circuits. We observed a time lag between the primary signal and the noise, as well as noise amplification over time. Our findings show the potential of our measurement method in pinpointing noise sources.
