This letter proposes a new hybrid EM wave absorber with the crossed-wedge shape, which can be applied to 3 m semi anechoic chambers. In this study, we designed a new hybrid EM wave absorber with the crossed-wedge shape, which consisted of the inorganic and organic thin corrugated dielectric lossy sheet containing organic conductive fibers. Then the 3 m semi anechoic chamber is constructed in the size of 9.0 m6.0 m5.7 m (LWH) using these absorbers, and also the normalized site attenuation (NSA) is measured according to ANSI C63.4 in the frequency range of 30 MHz to 1 GHz. As a result, the measured NSA is obtained within 3 dB of the theoretical one.

This letter proposes the thinnest hybrid EM wave absorber using a composite magnetic material, which can be applied to the 3 m semi anechoic chambers. We experimentally designed a new hybrid EM wave absorber of the wedge shape, which was made from the ferrite powder, the inorganic fiber and binder. As a result, the length of this absorber could be realized only 6 cm, which was ascertained having the nonflammable. The 3 m semi anechoic chamber is constructed in the size of L9 mW6 mH5.7 m using this absorber, and then the site attenuation is measured according to ANSI C63.4 in the frequency range of 30 MHz-1 GHz. As a result, the measured normalized site attenuation is obtained within 3 dB to the theoretical normalized site attenuation.