Extrapolation of radiated emissions from telecommunication equipment

EMC Impact of Disturbances Generated by Multiple Sources

“…However, the significant increase in electronic devices used nowadays might result in an increase in the overall noise floor and affect the immunity of neighboring devices and systems. As a result, the subject of the impact of an increasing number of devices on the overall emissions has attracted some attention recently [4][5][6][7][8][9], and it is currently being discussed within international standardization bodies (e.g., Comité International Spécial des Perturbations Radioélectriques (CISPR)). Understanding and quantifying such an impact are prerequisites to the proper evaluation of EMC of various electronic systems and devices and, if needed, to revisit international standards.…”

“…In the study by Takahashi et al [5], it was shown that by increasing the number of devices, the radiated emissions will increase. The assumed geometry of the problem in [5] was a linear array of current sources.…”

“…In the study by Takahashi et al [5], it was shown that by increasing the number of devices, the radiated emissions will increase. The assumed geometry of the problem in [5] was a linear array of current sources. The distance between the array elements was constant and equal to d. Each array element had the same amplitude but with a randomly varied phase between 0 to 2π rad.…”

“…The results show that by allowing the phase to vary from 0 to 2π rad, the radiated emissions from multiple devices are reduced from the voltage sum obtained for a constant and equal phase for all radiators (the same as the electric field sum) to the power sum curve. In the same paper [5], the phase variation for large telecommunication equipment was measured, and it was shown that the assumption of a randomly varied phase between 0 to 2π rad is valid. Finally, to check the validity of the random phase assumption, two experimental case studies including three spherical dipole antennas and actual large telecommunication equipment were presented.…”

“…It was concluded that the radiated emission from multiple devices agreed well with the power sum formula when each element has a randomly varied phase between 0 to 2π rad. Note that in [5], all of the considered devices were identical and represented by simple isotropic patterns. They were also configured in a linear array and had fixed orientations.…”