What are NFC Tags?

NFC has recently become one of the most talked about “newish” technologies both on and off the internet, NFC Tags are a related sub-technology that enhance what NFC does in the real world. In fact, Near Field Communication and related contactless technology is the very reason this website exists. But as with all new developments, we have new terms to learn and concepts to understand. For many of our readers, this post will contain information that is already known. However, for anyone just starting to learn about NFC Tags or their current and potential uses, or you have a client you need to quickly educate, we hope this NFC Tags 101 helps.

Who invented and makes NFC Tags?

To answer this question, we have to look to the precursor to NFC and NFC Tags. As with most technological advances, NFC is an adjunct of a bigger, more established technology known as RFID. RFID stands for Radio Frequency Identification and it’s been in use since the 1970′s. Not to put to finer point on it, RFID is a technology that uses communication through the use of radio waves to transfer data between a reader and an electronic tag attached to an object for the purpose of identification and tracking.

You have probably come in contact with RFID multiple times and not even realized it. If you have ever seen your FEDEX / Business Post / TNT / UPS delivery person scan a package before they deliver it to your hands, that’s accomplished with an RFID reader and RFID tags. If you have had your pet chipped so if they ever get lost, yes you’ve guessed it, the chip is an encoded RFID tag. If you live in a country that has new style passports and you have a strange copper coiled antenna stuck in the back which they scan when you arrive in a country, again RFID. RFID is used a lot for retail where it tracks packages and stock. We could write another ten pages about RFID, its roots, applications and future. But this article is about NFC Tags.

NXP Semiconductors (then a division of Philips) co-invented NFC & NFC Tags with Sony and other ecosystem partners. UPM RFID is the company who manufactures the chips & NFC Tags. NFC is a type of RFID, but has differing attributes that sets it apart. We’ll go into that next.

What’s the difference between RFID & NFC Tags?

NFC Tags only work over a very short distance where RFID can transmit from short distances to miles away. A typical range of between four and a theoretical eight centimeters is usually quoted by those in the know, but with some NFC Tags you may even need to get a little closer than that.

How does an NFC Tag work?

NFC Tag

NFC is the sharing, pairing, and transaction technology. It works with RF (radio frequency) fields. The best analogy we can think of to describe an RF field would be to have you imagine a magnetic field stretching out from a magnet  that is attempting to interact with another object. However, these are not magnetic fields in the truest sense; they are radio fields and when they meet the NFC-Forums specifications for what is defined as NFC, they operate at 13.56 Mhz. They work at rates ranging from 106 kbit/s to 848 kbit/s which is very slow compared with your home broadband internet connection. NFC Tags only store small amounts of information, currently between 96 and 512 bytes of memory to be exact, so they don’t need to be fast. Unlike another contactless technology Blue Tooth, NFC establishes a connection within 0.1 of a second. That’s fast!

Okay, so we know NFC Tags connect fast, have slow data transfer rates and don’t hold an awful lot of data, but how does NFC work? To answer this we are going to use our magnet analogy again. Have you ever played with a magnet and a pin before? If you have, you will notice that the pin has no noticeable magnetic power of its own. But when subjected to a magnetic field that emanates from a magnet a pin can retain a smaller magnetic field of its own after the main magnet is removed. We often refer to this as the pin being magnetized. With us so far? Good. A passive (not powered by electricity) NFC Tag only has a very small radio frequency that alone is not powerful enough to interact with much at all, but when you expose it to a more powerful RF field, its own field is strengthened. Of course, NFC Tags that are powered have their own RF Fields. NFC Tags, like the one pictured above, are passive and many of which you will find in the real world (in posters and other media) and will interact with will probably be passive.

Now here is that same information we just discussed above but in the NFC technical sense. NFC always has an initiator and a target; the initiator actively generates an RF field that can power a passive target. Passive NFC Tags are always the target and in the future the initiator will likely be our smartphones. The term NFC peer-to-peer communication is when both initiator and a target are active (powered) which in our example would be two phones, or in our analogy two magnets coming together. Next stop types of NFC Tags in Part 2 of our NFC 101 Series.