Evaluation of 10 m semi-anechoic chamber characteristics

A 10 m semi-anechoic chamber constructed at Matsushita Communication Ind. Co., Ltd. in August 1997 was evaluated. It has wider space than conventional 10 m chambers. By securing nonreflecting object area required by CISPR16-1 at a whole EUT setting area on the 6 m diameter turntable, the influence of absorbers lining the walls could be suppressed in the frequency range of 30 MHz to 100 MHz. Therefore, the deviation from theoretical value was within 2 dB and the dispersion of site attenuation value was within 1 dB among five points, which were center point on the turntable and the front, rear, left and right position 3 meters apart from center. From these experimental results, it was verified that this chamber has the almost same characteristics as an open area test site for EMI measurement.