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

摘要

Semi-anechoic chambers are used for EMC measurement from 30 MHz to1000 MHz. Criteria for absorber's reflectivity lined in semi-anechoicchambers are discussed based on a ray-tracing analysis. The absorber'sreflectivity of -15 dB and -20 dB for normal incidence is sufficient tosatisfy 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 mfor the 3 m method and to L=18 m, W=13 m and H=7 m for the 10 m method