Anechoic Chamber: 18.7m x 11m x 8.5m
EMC Control Room: 6m × 2.5m × 3m
Amplifier Room: 3m × 2.5m × 3m
It mainly contain following parts:
1) The steel framework of Semi-Anechoic Chamber adopts
attaching-type or self-supporting structure;
2) the shielded body adopts welded-type shield panels (Note: Due to
electrochemical corrosion and mechanical vibration abrasion, the
shielding effectiveness of PAN-type structure will be further
weakened after 3 ~ 5years, and it could not keep the shielding
effectiveness of 100dB @ 1GHz ~ 18GHz. The maintenance cost of
PAN-type structure is relatively high. Therefore, we’d like to
recommend the welded-type shield panels.)
3) raised floor and metal reflective ground;
4) Electromagnetic shielded door;
5) Cut-off waveguide window;
6) Power line filter;
7) Signal box and interface board;
8) Electrical installation and lighting;
9) Fire alarm system;
10) CCTV and voice monitoring system;
11) Turntable and controller;
12) Antenna tower and controller;
13) Supporting shielded rooms (2sets): EMC control room and
amplifier room
2.1 Shielding effectiveness
Frequency Shielding effectivenss Frequency Shielding effectivenss
10kHz >70dB (magnetic field) 1MHz >100dB (electric field)
14kHz >70dB (magnetic field) 100MHz >110dB (electric field)
100kHz >90dB (magnetic field) 1GHz >100dB (plane wave)
1MHz >100dB (magnetic field) 10GHz >100dB (microwave)
100kHz >100dB (electric field) 18GHz >100dB (microwave)
2.2 Electrical characteristics / performance of anechoic chamber
Normalized Site Attenuation (NSA): compliant to the requirements of
ANSIC63.4 1992
10-meter measurement distance (in the circle of 4m diameter and 2m
high, centered at the EUT position):
30MHz ~ 200MHz, the theoretical deviation of NSA ≤±4dB
200MHz~1GHz, the theoretical deviation of NSA ≤±3.5dB；
3-meter measurement distance (in the circle of 3m diameter and 2m
high, centered at the EUT position):
30MHz~1GHz, the theoretical deviation of NSA ≤±3.5dB
Site VSWR: in the frequency range of 1~18GHz, it shall meet the
requirements of CISPR16-1-4, and then the Site VSWR of 3m
measurement distance is better than 6dB.
Field Uniformity: in the frequency range of 30MHz~18GHz, it shall meet the standard
requirements of IEC61000-4-3-1995 and EN61000-4-3-1996, namely: in
the hypothetical vertical plane 1.5m*1.5m within the EUT area (0.8m
above the floor), 3m measurement distance, it requires 75% evenly
divided 16 points’ field strength amplitude deviation shall be
within 0 ~ +6dB.
Background Noise Ratio: In the Semi / Full anechoic chamber, without EUT, and while
running the turntable, antenna tower, CCTV sensor and lamps, the
test level of the space background noise should be at least 10dB
lower than the limit level Class B stipulated in standard EN55022
under frequency of 30MHz-1GHz.
