To power these NFC electronic price tags, electromagnetic induction is used to generate a current in the passive device. The basic idea is that you can use a wire coil to generate an electromagnetic wave, which is then absorbed and converted back into a current through another wire coil. This is very similar to the technology used in wireless charging technology. Active devices are responsible for generating magnetic fields. This is done with simple wire coils that create a magnetic field perpendicular to the alternating current flowing through the wire.

The NFC digital price label sensing circuit and the microchip passive device on the back of the NFC sticker work in the same way, just the opposite. Some power is always lost over the air, but over short distances, the resulting current is enough to power the circuits in the NFC tag.

These circuits can be tuned to specific frequencies to increase the sensitivity of the device to charging frequency. This maximizes energy transfer in the air. When the tag is powered up, it can synchronize and send data at 106, 212 or 424 Kbps over the 13.56MHz NFC transmission frequency, just like regular NFC communication between phones or other larger devices.

There are several different tag types available, each of which provides different levels of storage and transfer speeds. Only 106 kbit/s. As small as it may sound, this data is enough for some very simple information. These labels are designed to be cost-effective and can be reused if you change the data stored on them.

NFC tags are cheap and efficient compared to other forms of short-range wireless communication because they are very cheap to manufacture and maintain, but can still be used in a wide range of applications. With very simple circuits and very few components, NFC tags can be mass-produced at very low unit cost.

Combine low cost with no need for any power, and you have a cheap and efficient way to communicate quickly with other smart devices. From launching apps to exchanging web addresses and buying train tickets, NFC aims to make our lives easier just by using our smartphones.

With the introduction of mobile payment methods that cannot use NFC, more and more smartphones are beginning to support NFC communication. Don't be surprised if you see more and more of these little labels popping up all over the place.