Upgrade of foam equipped semi anechoic chambers to fully anechoic chambers by the use of ferrite tiles

Different standard boards are developing EMC standards that allow a fully anechoic chamber being used for radiated EMC testing. In this paper an investigation is done on foam equipped semi anechoic chambers, that do not fulfil the requirements to become accredited for EMC emission testing. Additional absorbers are mounted on the ground plane to change the chambers to fully anechoic ones. It is shown whether they are usable for EMC testing using the new CENELEC standards for fully anechoic chambers. To lose as less chamber volume as possible, ferrite tiles are used for covering the metallic ground. The finite integration technique frequency domain is used for the calculation of the field distributions inside the semi and fully anechoic chamber. A short description of this technique is given. Additionally this paper explains the requirements for fully anechoic chambers to become accredited for emission testing.