SERVICES (continued)

Example: Analysis of GTEM Fields

In early 1994 Metatech began an analysis program to study the response of small electronic systems exposed to EM fields in GTEM test cells. The purpose of this effort was to provide a better understanding of the interaction of test objects with the GTEM fields through a series of 3D calculations performed with advanced computer codes developed by Metatech. Results from this study will be used to evaluate the fidelity of box tests in the GTEM cell.

GTEM (Gigahertz Transverse Electromagnetic Mode) is a relatively new development in the field of EMC testing. The cell was developed by Diethard Hansen and Dietrich Koenigste in 1984 at the EMI Control Center of Asea Brown Boveri Ltd. in Baden, Switzerland. GTEM is manufactured under license by the Electro-Mechanics Company (EMCO) of Austin, Texas. As of 2002 more than 200 GTEMs had been installed worldwide.

Metatech has performed 3D calculations over a range of parameters, and plots were generated showing contours of peak fields at a number of ranges from the source and at specific frequencies between 50 to 500 MHz. The example shown below is a three-dimensional contour of the maximum peak predicted total electric field strength in dBV/m in a plane perpendicular to the GTEM longitudinal axis.

Nuclear and Lightning Electromagnetic Pulse (EMP)

Definition: "The electromagnetic radiation caused by Compton-recoil electrons and photoelectrons from photons scattered in the materials of the nuclear device or in a surrounding medium as the result of a nuclear explosion or lightning. The resulting electric and magnetic fields may couple with electrical and/or other electronic systems to produce damaging current and voltage surges." (ANSI C63.14, 1992)

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