Measurement method of near electric field from LED bulb and power line

The electromagnetic noise radiated from LED bulb and power line becomes one of cause of the EMI problems. The limits value of the magnetic radiation noise from the light illuminated products is established by the measurement of large loop antenna. However, the near magnetic field around the LED bulb was not detected. In this study, the near electric field from LED bulb and power line is measured by monopole antenna. The near electric field from 1 to 300 MHz can be measured by two types of monopole antennas. The characteristic of the near and far electric field is coincided with the frequency characteristics of the impedance of the power line. Since the power line operates the monopole type antenna, and the radiation electromagnetic wave is an electrical mode, the measurement of the near and far electric field must be needed to estimate the electromagnetic noise from LED bulb.