The Iron feno wave

RFID Tags on metal containers:

Why metal is an Other Microwave Problem, and How We Solved It? 

Target keywords: RFID tag on metal, microwave-safe RFID metal container, RFID for metal food packaging

Reusable food containers don't come in one material. Alongside plastic and composite trays, industrial and connected catering increasingly rely on containers with metal content — stainless steel trays, metallic lids, foil-lined compartments — because metal holds up well to repeated washing, reheating, and heavy handling. That durability is exactly what makes it a problem for RFID.

Metal and microwaves already have a difficult relationship on their own: a metal object in a microwave oven can create electrical arcing and sparking, independent of any tag attached to it. Add an RFID tag into that environment, and you're combining two separate failure modes at once — the tag's own vulnerability to microwave power, and the antenna-detuning effect that any metal surface has on a standard RFID inlay. Most tags on the market aren't designed to survive either condition. Ours had to survive both together.

Why metal breaks a standard RFID tag before the microwave even turns on?

A conventional UHF RFID inlay uses its antenna to couple with the reader's radiofrequency field. Placed directly against or near a metal surface, that antenna gets detuned: the metal reflects and absorbs the RF signal, shifting the tag's resonant frequency and collapsing its read range — sometimes to the point of making the tag unreadable at any practical distance. This is a well-documented limitation in RFID engineering, and it has nothing to do with heat. It happens the moment the tag touches metal, microwave or not.

Then add the oven microwave. As covered in our previous work on microwave-resistant tags, a standard RFID tag exposed to microwave power (900–950W, an order of magnitude above the few hundred milliwatts an RFID tag is designed for) risks electrical arcing at the antenna, which damages the substrate or the chip. On a metal container, the additional risk is: the metal itself is already prone to arcing under microwave exposure, so a poorly designed tag sitting on that surface is placed at the center of the problem rather than at its edge.

The result: a tag built specifically for metal content in a microwave

FenoWAVE-8638-IRON-M8-V1 is our answer to this dual constraint. It's built on a patented concept: a very small UHF module coupled to a secondary antenna, designed to remain flexible and to keep working in the presence of metal rather than being detuned by it. Securing microwave-safe on metal content.

Built for connected catering, not just single-use tracking.

FenoWAVE-8638-IRON-M8-V1 was specifically designed to meet the monitoring needs of connected catering and industrial food supply chains — containers that carry metal components and go through repeated wash-and-reheat cycles as part of their working life, not a single pass before disposal. Each tag is individually encoded, both printed (optional) and RFID-readable, so the container's identity stays accessible at any point in its cycle — from kitchen to wash station to reheating and back.

Key specifications

·        RFID chip: Impinj M830 (UHF Gen 2, ISO18000-6C)

·        Operating frequency: 865–928 MHz (Europe)

·        Read range: up to 4m (measured on Voyantic equipment; varies with reading station and container material, excluding food and liquids)

·        Multi-reading: up to 100 tags per reading booth

·        EPC memory : 96/128 bits

·        Data storage: 50 years (Tamb < 55°C)

·        Antenna dimensions : 86 x 38 mm

·        Manufactured in France, on Fenotag's own fully automated lines — no manual steps performed in Asia

Contact us for more information