RF Absorbing Materials
Pyramidal Foam absorber can be utilised for the frequency range 100MHz to 40GHz. The factor determining the lowest useable frequency is the physical size of the foam pyramid. The larger the dimensions of the pyramid, the lower the frequency of operation. Due to the volume consumed within an anechoic enclosure when using large pyramidal foam.
Ferrite Tiles are often overlaid with smaller Pyramidal Foam absorber to extend the anechoic performance down to 30MHz without losing valuable space.
Polyurethane foam loaded with carbon (and fire retardant) can be supplied in various dimensions.