Near-field shelf antenna
Near-field
What is it?
Near-field shelf antennas are designed to read tags only within a few centimetres of the antenna surface. Unlike far-field antennas that project a beam across a room, near-field antennas create a tightly contained read zone directly above or below the antenna pad. This precision makes them ideal for item-level retail, pharmaceutical dispensing, smart shelves, and any application where you need to know exactly which items are on a specific shelf, in a specific drawer, or on a specific tray - without accidentally reading items nearby.
How it works
Near-field UHF antennas use segmented or loop antenna designs that create strong magnetic coupling within a few centimetres of the surface but produce almost no far-field radiation. The tag must be physically close to the antenna to be energised and read. Some designs use a series of small loop elements along a strip (for shelf edges), while others use a flat pad with a meandered trace pattern. The read zone boundary is sharp - a tag 5 cm above the antenna reads reliably, while a tag 50 cm away is invisible. This is the opposite of far-field antenna behaviour and is achieved by deliberately cancelling far-field radiation patterns.
Industries
Use cases
- Smart retail shelves for real-time stock levels
- Pharmaceutical cabinet and drawer inventory
- Jewellery tray counting
- Library shelf inventory (book-level)
- Point-of-sale item identification
- Medical supply cabinet tracking
Pros
- No stray reads - only counts items physically on the shelf
- Item-level accuracy in dense environments
- Multiple antennas can be placed close together without interference
- Thin, flexible form factors fit inside shelves and drawers
- Works with standard UHF tags - no special tags needed
Cons
- Very short read range by design - not suitable for pallet-level tracking
- Requires one antenna per shelf or zone - high antenna count
- More expensive per-read-point than a single far-field antenna
- Indoor use only - no ruggedised options
- Cable management can be complex with many shelf antennas
Specifications
| Form factor | Near-field |
|---|---|
| Polarization | Near-field (magnetic coupling) |
| Frequency | UHF (860–960 MHz) or HF (13.56 MHz) |
| Gain | N/A (near-field - read zone defined by antenna geometry, not gain) |
| Beamwidth | N/A (defined by antenna pad dimensions) |
| Read range | 0–30 cm (by design) |
| Connector | SMA or proprietary |
| IP rating | IP50–IP54 (indoor use) |
| Dimensions | Varies - shelf-width strips, A4/A3 pads, or custom shapes |
| Price range | $150–$600 per antenna pad |