How do NFC tags and readers work?


NFC, or Near Field Communication, is a popular wireless technology that allows you to transfer data between two devices that are in close proximity to each other. For some short-range applications, such as mobile payments, it is often a faster and safer alternative to QR codes. Actually, there is nothing special about this technology, as long as you have a reading device, you can read data from various NFC tags.
      NFC tags are versatile and are often useful in situations where you want to transfer small amounts of data effortlessly. After all, hitting a surface requires less time and effort than using Bluetooth pairing or other traditional wireless communication methods. For example, digital cameras and headphones have embedded NFC tags that you can tap to quickly initiate a connection to the device.
      Having said that, do you know how they work? Next, let's take a look.
      How NFC tags work
      NFC tags come in a variety of shapes and sizes. The simplest are usually made in the form of square or round stickers. These tags have an extremely simple structure: they consist of a thin copper coil and a small storage space on a microchip. .
      The coil allows the tag to wirelessly receive power from the NFC reader through a process called electromagnetic induction. Essentially, whenever you bring a powered NFC reader close to the tag, the latter powers up and transmits any stored data within its microchip to the device. If sensitive data is involved, the tags can also use public key encryption to prevent malicious attacks.
      Since the basic structure of an NFC tag is so simple, you can fit the hardware you need into a whole bunch of form factors. Take hotel key cards or general access cards, these are usually made into a plastic card with some copper wires and some microchip memory on it. The same principle applies to NFC-equipped credit and debit cards, which contain thin copper wires that run along the perimeter of the card.

      Notably, powered NFC devices like smartphones and tablets can also function as NFC tags. Unlike RFID, which only supports one-way communication, NFC can facilitate two-way data transfer. For example, this allows your phone to emulate an embedded NFC tag, such as those used for contactless payments. Of course, these are more advanced devices, but the basic modes of operation are still the same.