Using GTEM cells for immunity tests on electronic boards with microcontroller

Theoretical considerations about the immunity tests within a GTEM cell are discussed. Electromagnetic field in a GTEM cell is presented. The conditions in a GTEM cell for a high degree of field uniformity according to the standard IEC/EN 61000-4-20 are discussed. The GTEM cells used for tests within the main equipment involved in the realisation of tests are presented (GTEM cell; Signal Generator/Power Meter; Field sensors; Connectors; Bi-directional Coupler; Power Amplifier; Spectrum Analyzer). The Equipment Under Test (EUT) is an electronic board containing a microcontroller, with the processor operating frequency around 40 MHz. For the immunity tests, three criteria are considered, based on standards. Methods for field calibration involved in immunity tests are discussed. The experimental determination concerning the immunity tests are presented within the main conclusions.