What is RFID and what can it be used for?

RFID or Radio Frequency Identification technology is everywhere. Employee ID cards, on items you buy in a store and even in our pets. It is a simple but ingenious technology that comes into its own in a world where everything is increasingly digitized. Quite impressive for a technology that has been in use since World War II.

That makes this a great time to familiarize yourself with what RFID is and the various applications it’s used for today.

The physical components of RFID

An RFID system consists of two main components. First, you have the RFID tag itself. This contains the ID information, usually with reference to a large external database. Second, we have the RFID reader. This is the device that retrieves the information stored in the RFID tag.

Since this technology uses radio waves to send and receive information, both tags and readers need some sort of antenna to work.

RFID tags consist of an integrated circuit and an antenna. In other words, a microchip containing the electronic components. The integrated circuit is connected to a small antenna. These components are common to all RFID tags, but they vary greatly in size, shape and appearance. Depending on what they serve.

For example, employee ID cards used to open doors place the RFID between sheets of plastic. When the RFID chip is inserted into living things, it is contained in a biologically neutral glass capsule. Just to name two approaches.

The data in RFID chips

RFID tags have very little storage space. Most tags only have enough space for 96 bits. Although as many as 2000 bits are possible.

Note that the extended ASCII character set uses eight bits per character and there is not much space. With the available space it is possible to store, for example, a name or telephone number. However, it is much more common for the data stored in an RFID chip to refer to a record in an external database.

RFID chips also have memory that varies in terms of readability and writability. Most RFID chips are probably of the read-only type. Where the data cannot be changed out of the box. Since the stored RFID number can be associated with any database entry, this is a popular and cost-effective way to use large quantities of RFID tags. It also helps that the serial numbers are unique and cannot be tampered with. This is the kind of label you find on pill bottles and other mass products.

There are also write-once cards, also known as “field programmable” RFID chips. Data can be written to these chips once, but from that moment on they can only be read out. These are useful for small scale applications. Then you have read-write tags, which can be overwritten if necessary.

What are Active vs Passive RFID Tags?

There are two main variants of RFID tags. The one most people encounter is passive. It does not have its own power source. Instead, it gets energy from the RFID reader through the antenna, which it uses to empty its small cache of data.

The benefits of passive RFID tags are many. Since they require no maintenance or power, they can be permanently embedded in objects. This makes it easy to protect them from damage or to hide them.

The downside is that passive tags have a shorter range than active tags. Which have an internal power source that allows them to transmit their signal constantly or at fixed intervals. RFID technology uses very little power, so even active units can run for a significant amount of time without recharging or needing a new battery.

RFID Frequencies

RFID tags operate in a number of different frequency bands:

  • Low Frequency: 30Khz – 500Khz. These tags have a very short range, usually just inches.
  • High Frequency: 3MHz – 30MHz. These tags range from inches to feet.
  • Ultra High Frequency: 300MHz – 960MHz. An average reach of 25 feet.
  • Microwave frequency: 2.45 GHz, with a range of more than 30 feet.

Passive tags are usually low or high frequency where the ultra high and microwave frequency tags require active power to operate.

RFID & Smartphone NFC

Many newer, more expensive smartphone models have a feature known as “NFC” or Near field communication† This is a wireless communication feature that uses the same protocol (essentially language) as RFID.

The big difference here is that NFC devices can be used as an RFID reader as well as simulate RFID tags. There are many applications for this, with ‘tap and pay’ contactless mobile payments being a good example. Two NFC devices can also send data to each other if they are close enough to touch.

NFC is not a universal RFID system. It only worked on the 13.56MHz high-frequency RFID band, giving the design a very short range.

RFID Blocking

RFID signals can be blocked with the right materials. Since passive tags need to be fairly close to the reader to work, they have been used in bank cards. In many countries you can now “tap and pay” at ticket machines. This has also led to a new form of crime, where small amounts of money can be stolen by reading these cards through wallets.

Alternatively, the RFID tag may be copied using a stealth reader. NFC technology in smartphones is one way to do this.

Therefore RFID Blocking Wallets have since become popular. Cards containing RFID technology can be stored in a special pouch that prevents the card from being read without the owner’s knowledge.

The many applications of RFID

One of the first and most useful applications of RFID technology was livestock tracking. Now it is also widely used to track products, components and other movable property. RFID technology can track an item from where it is made to where it is sold.

RFID, as mentioned above, is used in bank cards, smart cards and various authentication systems. With the rise of the internet of things (IoT) it is also becoming an essential part of the digitization of physical objects.

Pets and some people are also injected with RFID tags. In the case of pets, it is a way to get lost animals back. In humans, they may also have medical applications, as some RFID systems may also contain sensors.

RFID, or something similar, will almost certainly play a big part in giving real-world objects and entities a digital identity. As everything becomes more automated, this is the only real way to make sure we know where everything is and what is happening to it.

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