How to Choose the Right RF/EMI Shielding Box

The core principle for selecting an RF/EMI Shielding Box is to match your test frequency band, DUT size, shielding effectiveness, interface requirements, automation level, and budget. Below is a complete, practical selection guide:

1. Define Core Application (Set the Direction First)

RF Testing: Mobile phones, WiFi/Bluetooth modules, routers, IoT devices, 5G/6G chips

→ Choose RF Shielding Box

EMC / Electromagnetic Compatibility Testing

→ Choose EMI Shielding Box / Shielding Cabinet

Security / Signal Isolation (centralized mobile phone storage)

→ Choose Mobile Phone Shielding Cabinet (compliant with BMB49-2020)

2. Five Key Technical Parameters (Must Check)

1) Operating Frequency (Band Coverage)

2.4G WiFi / Bluetooth: 2.4–2.4835 GHz

5G WiFi: 5.15–5.85 GHz

WiFi 6E/7: 5.925–7.125 GHz

Cellular / 4G / 5G: 600 MHz–6 GHz

Selection:

Single-band testing → Choose narrowband, low-cost models

Multi-band / future-proof → Choose wideband 2–7 GHz or 10 GHz+

2) Shielding Effectiveness (SE, Most Critical Index)

Unit: dB (higher value = better shielding)

General R&D / production line: 60–80 dB

Certification lab / precision testing: 80–100 dB+

3) Internal Dimensions (Test Space)

Mobile phones, wearables, small modules:

Inner Dimension：

（L）310 x（W）250 x（H）160mm，(W)280 (D)300x (H)220 mm，

Routers, tablets: （D)460x（W）260x（H）220mm，400(L)mm×400(W)mm×400(H)mm

Rule: Internal space ≥ 1.5× the size of the DUT to reduce reflection interference.

4) Interfaces & Filtering (Determines Usability)

RF connectors: N-type, SMA, MCX (N-type recommended for high frequencies)

Data / power: USB, RJ45, RS232, DC

Key requirement: Must be equipped with EMI filters

→ Otherwise signals will leak through cables.

Quantity: Reserve 2–4 spare ports

5) Operation Mode (Efficiency / Cost)

Manual Shielding Box: Low cost, suitable for R&D or small-batch testing

Pneumatic / Electric Automatic Box: With pneumatic door, PLC control, anti-pinch function, compatible with test software

→ Essential for mass production lines

3. Material & Craftsmanship (Affects Service Life & Stability)

Aluminum Alloy: Lightweight, low cost, general-purpose

Stainless Steel: Durable, corrosion-resistant, higher cost

Galvanized Steel: Cost-effective, good wave absorption

Craftsmanship priorities:

Integrated molding / seamless welding, conductive gaskets (beryllium copper / conductive rubber), conductive oxidation at seams

(Do not fully apply insulating paint)

4. Scenario-Based Recommendations

R&D Laboratory (1–5 users)

Size: 30×30×30 cm

Frequency band: 2–7 GHz

Shielding: 70–80 dB

Interfaces: 2×SMA + 2×filtered USB

Type: Manual

Mass Production Line (1,000+ tests per day)

Size: 35×35×35 cm

Frequency band: 2–7 GHz

Shielding: 70–80 dB

Interfaces: 4×N/SMA + filtered LAN + filtered power

Type: Pneumatic automatic, supports PLC / software control

Security / Conference Room (Mobile Phone Shielding Cabinet)

Covers: 2G/3G/4G/5G/WiFi/Bluetooth/GPS

5. Common Mistakes to Avoid

❌ Only focusing on low price: Insufficient shielding effectiveness = useless purchase

❌ Interfaces without filtering: Cables are the biggest leakage path

❌ Excessively small internal space: Strong internal reflections, inaccurate test results

✅ Reserve redundancy: Frequency band, interfaces, and internal space

6. Quick Selection Checklist (Fill Before Inquiry)

Maximum test frequency: ____ GHz

Required shielding effectiveness: ____ dB

Max DUT dimensions (L×W×H): ____ cm

Required interfaces: RF×, USB×, LAN×, Power×

Operation: Manual / Pneumatic automatic

Budget: ____  thousand RMB/USD