Journey to the Center of the Dipole

The electrical engineering sub-discipline of electromagnetic compatibility has been described as the study of second-order effects that were ignored in college. Investigating electromagnetic fields next to a dipole is one such topic. Don’t cite Hertz and his dipole – he didn’t go there.

An Equivalent Three-Dipole Model for IC Radiated Emissions Based on TEM Cell Measurements

An equivalent dipole model is proposed in this paper to represent the source of radiated electromagnetic emissions from an integrated circuit (IC). The height of an IC is usually much smaller than its length and width, so only three dipole moments are sufficient to characterize an IC in terms of its electromagnetic emissions. The dipole moments can be extracted from three TEM cell measurements. The radiated fields from the IC can then be calculated based on the extracted dipole sources. This IC emission model with three dipole moments is validated using the far-field measurements in a semi anechoic chamber for a test IC. For complex structures, it is desirable that the extracted dipole moments can be incorporated into a commercial full-wave tool as equivalent sources to simulate the radiations from an IC. This is demonstrated using an approach developed in this article.