Sources of problems in the GTEM field structure and recommended solutions

Abstract

The Gigahertz TEM (GTEM) cell is a special TEM device that is used for both emission and immunity testing up to 1 GHz and above. Based on previous comments and recommendations in IEEE EMC sessions and including suggestions from several members of international standardization groups a very practical as well as challenging experiment was conducted. The E-field structure of a GTEM 1750 has been further investigated in a number of relevant points within the test volume up to one Gigahertz. An empty cell as well as a loaded cell have been tested. The box under investigation was a metal cube of 30 cm. Additional support was gained from computer simulations, leading to more detailed field contour plots. Based on this work a number of improvements and retrofits for existing GTEM cells is given.