Anechoic chamber for use in frequency range from MHz to GHz constructed with absorbers featuring a new design concept

In anechoic chambers for the bandwidth of 30 MHz to 1000 MHz, it is usual to use an absorber consisting of pyramid-shaped foamed urethane made out of a dielectric with carbon added and ferrite tiles. The absorption characteristics of combined absorber are limited to be applied in frequencies above 1 GHz because of the frequency dispersion of dielectric constant of the carbon used. In this paper, taking account of the dispersion characteristics, new design concept is proposed. The sufficient results in the 30 MHz to 6 GHz are obtained in a 3 meter anechoic chamber built with the absorbers fabricated on the new design concept.