Estimation of radiated emission sources with arbitrary directional current components using CISPR measurement system

Relating to the radiated emission sources finding method utilizing CISPR emission measurement system, which uses only amplitude data without phase data, the applicability to sources with arbitrary directional current components was studied. We propose a new finding algorithm in which the horizontal and the vertical current components are estimated at the same time by taking into account the contribution of horizontal current components when calculating the vertical electric field. As a result of experimental verification by using two spherical dipole antennas as ideal emission sources, estimated values show good agreement with the original ones in the frequency range from 300 MHz to 1 GHz, where the position estimation deviation /spl Delta/d was less than 0.15 m, the amplitude estimation deviation /spl Delta/j was less than 2.1 dB, and furthermore the angle of current direction could be estimated. Consequently, this method with the presented new algorithm can be applied to find radiated emission sources even when the current components point to arbitrary directions.