Tunnel / conveyor antenna array
Specialty
What is it?
Tunnel antenna arrays are multi-antenna assemblies built into or around a conveyor opening to create a 360° read zone that captures every tagged item passing through. Unlike a simple portal with two antennas on opposite sides, a tunnel uses four or more antennas - top, bottom, left, and right - to eliminate dead spots caused by tag orientation or shielding. They are the standard in high-speed logistics sortation, airport baggage handling, and pharmaceutical serialisation lines where 100% read rates are required.
How it works
Multiple antennas are positioned around a rectangular or circular opening through which items pass on a conveyor belt. A multi-port reader cycles through all antenna ports at high speed, interrogating tags from every direction. The surrounding antenna coverage ensures that even tags shielded by the item's contents on one side are visible from another angle. Photoelectric sensors trigger reading only when an item enters the tunnel, and some systems integrate with barcode scanners, dimensioning cameras, or weigh scales for multi-modal identification. Read rates exceeding 99.9% are achievable with properly tuned tunnel installations.
Industries
Use cases
- High-speed sortation line item identification
- Airport baggage reconciliation
- Pharmaceutical unit-level serialisation verification
- E-commerce order verification before shipping
- Multi-item carton content verification
- Automated returns processing
Pros
- 360° coverage eliminates tag orientation blind spots
- Achieves near-100% read rates for compliance-critical applications
- Handles high conveyor speeds (200+ items per minute)
- Integrates with other sensors for multi-modal identification
- Pre-engineered systems reduce site survey effort
Cons
- Expensive - multi-antenna systems with custom mounting hardware
- Requires precise alignment and tuning during installation
- Fixed opening size - cannot accommodate items larger than the tunnel
- Multi-port readers are more expensive than basic two-port models
- Maintenance requires specialist knowledge to re-tune after repairs
Specifications
| Form factor | Specialty |
|---|---|
| Polarization | Circular |
| Frequency | UHF (860–960 MHz) |
| Gain | 6–8 dBic per element |
| Beamwidth | 70°–90° per element (combined coverage 360°) |
| Read range | 0.3–2 m (across tunnel opening) |
| Connector | RP-TNC or N-type (multiple ports) |
| IP rating | IP54–IP65 |
| Dimensions | Varies by tunnel opening size - 0.5 m to 2 m wide |
| Price range | $2,000–$15,000 per tunnel assembly |