Although the EMC rule generally regulates the limited field strength in far electric field, the magnetic near field is practically often measured to evaluate the noise source of electric equipment. However, the magnetic near field strength is not always corresponding to the far electric field one by the complex transmission function from the source to the receiving antenna. The authors have been developing the new electromagnetic field measurement system based on the modulated scattering technique (MST) which could map the radiated noise distribution. Instead of a conventional metallic dipole scatterer, a dielectric spherical scatterer is introduced aiming to obtain the lower field invasiveness and the isotropic polarization for the incident wave. In this paper, the detecting process of scattered electric field by the dielectric sphere on the MST system was represented to the theoretical formulation. The numerical estimation by the analyzed equation showed that the dielectric scatterer could generate enough power to be measured, and a result of experimental measurement agreed with the theoretical one. The measurement sensitivity should be controlled by the scatterer's volume, the MST modulation ratio, and the scattering efficiency corresponding to the permittivity of the dielectric.
- Electric field measurement
- Modulated scatterer
ASJC Scopus subject areas
- Electrical and Electronic Engineering