105m Long anechoic chamber for high power microwave measurements

The anechoic chamber at the Gramat Research Centre is unique as far as its dimensions are concerned. To keep the cost of making such a facility anechoic to a minimum without compromising performance levels, SIEPEL implemented a completely original technique consisting in absorbent rings. The play of shadow zones makes it possible to mask the surfaces subject to specular reflections at grazing angles and to lay electromagnetic absorbent materials only on those surfaces illuminated by rays whose angle of incidence is between 50 degrees and normal.