Criteria for absorber's reflectivity lined in semi-anechoic chambers using ray-tracing technique

Abstract

Semi-anechoic chambers are used for EMC measurement from 30 MHz to 1000 MHz. Criteria for absorber's reflectivity lined in semi-anechoic chambers are discussed based on a ray-tracing analysis. The absorber's reflectivity of -15 dB and -20 dB for normal incidence is sufficient to satisfy a standard in 3 m and 10 m measurement methods, respectively. The dimensions of the chamber can be reduced to L=8 m, W=6 m and H=5 m for the 3 m method and to L=18 m, W=13 m and H=7 m for the 10 m method.