Standard 3m Method Anechoic Chamber

Anechoic Chamber Introduction​

Designed for civilian EMC testing (radiated emissions and immunity), with typical technical parameters below:

Key Structural Parameters​

Test Distance 3m (EUT to antenna)
Internal Dimensions Length: ~9m (meets test distance and quiet zone requirements)
Width: ~6m (ensures quiet zone integrity)
Height: ~6m (accommodates antenna movement and quiet zone)
Absorbing Materials Walls/Ceiling: Carbon-loaded pyramidal/foam absorbers (0.3–0.45m height), covering 30 MHz–18 GHz (extendable to 40 GHz)
Floor: Metallic ground plane (galvanized steel/aluminum), per CISPR 16-1-4
Shielded Door Double-layer design, ≥100 dB shielding (30 MHz–18 GHz; optional 40 GHz)

Critical Performance Metrics

Shielding Effectiveness Low Frequency (14 kHz–1 MHz): ≥80 dB
High Frequency (1 MHz–18 GHz): ≥100 dB (typical 120 dB)
Grounding Resistance Standard: IEC 60364-6 (GB/T 16895.23)
Requirement: ≤ 4Ω
Insulation Resistance Standard: IEC 60364-6 (GB/T 16895.23)
Requirement: ≤ 2 MΩ
Quiet Zone Dimensions: Approximately 1.5 meters or 2 meters in diameter and height (at 3 meters from the antenna)
Normalized Site Attenuation (NSA) Compliance Standards: CISPR 16-1-4 (GB/T 6113.104), ANSI C63.4
Deviation: Within ±4 dB (30 MHz–1 GHz)
Site Voltage Standing Wave Ratio (SVSWR) Compliance Standards: CISPR 16-1-4 (GB/T 6113.104), ANSI C63.4
Requirement: ≤ 6 dB
Field Uniformity Applicable Standard: IEC 61000-4-3 (GB/T 17626.3, applicable only for radiated immunity testing)
Uniform Area: Field strength variation ≤ 6 dB within a 1.5m × 1.5m area (80 MHz–6 GHz)
Influence Assessment of Radiated Emission Test Table Compliance Standards: CISPR 16-1-4, ANSI C63.4
Requirement: The influence assessment results of the radiated emission test table must be incorporated into the uncertainty evaluation of radiated emission measurements
Ambient Noise Level At least 6 dB below the EMC product standard limits

Antenna & Turntable System

Antenna Types Dual-polarized (>30 MHz), 9 kHz–40 GHz coverage
Turntable Diameter: 2–3m, 500 kg–1 ton/m² load capacity
Accuracy: ±1°
Antenna Tower 1–4m height adjustment, ±0.5 cm precision

Compliance Standards

Radiated Emissions CISPR 32 (GB/T 9254.1), FCC Part 15, EN 55032
Radiated Immunity CISPR 35 (GB/T 9254.2), EN 55032

Auxiliary Systems

Power Supply & Filtering Power: Independent filtered power supply system providing clean power
Signal line filtering: All feedthrough interfaces shall be equipped with RF filters
Environmental Control Temperature: 20~25℃ (±2℃)
Humidity: 30%~70% RH (anti-condensation)
Safety Systems Emergency stop button, smoke alarm, fire suppression system
RF radiation safety monitoring (compliant with occupational health standards)

 

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