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What are RFID Tags and How do They Work?

  • Mahesh Tiwari
  • Jan 15, 2024
  • RFID
What are RFID tags and how do they work

RFID, which is short for Radio Frequency Identification technology, is growing rapidly and businesses in retail, supply chain and logistics, manufacturing, asset management, and inventory management are increasingly using RFID tags and labels to identify trade items as well as streamline the day-to-day business operations. The global RFID tag market is predicted to cross 9.5 billion USD by 2030 from 4.4 billion USD in 2023 while the RFID tag market in the USA alone accounts for 745.33 million USD market size (2021). The US RFID tag market is expected to grow at a CAGR (Compound Annual Growth Rate) of 9.1% during the forecast period of 2022-2030.

RFID tags are the new barcodes. When MIT AutoID-Centre proposed to use RFID tags and newly developed EPC (Electronic Product Code) for the retail ‘Out of Stock’ problem, in the early 2000s, lowering the cost of RFID tags in future development was the major goal. Sanjay Sarma and David L. Brock (who created EPC) predicted that the cost of RFID tags has to be less than 10 US Cents, preferably 5 US Cents, for it to replace UPC-12 barcodes, which already had the entire market to itself. 

In subsequent years, the cost of RFID labels was minimized due to low-cost microchip development and EPC. Now an RFID label (RAIN RFID/UHF PASSIVE RFID) costs 4-5 US Cents (5-6 Indian Rupees). Well, that’s some crucial context of how RFID came to be what it is today. 

RFID is a wireless automatic identification and data capture (AIDC) technology that uses electromagnetic fields to transmit and receive encoded data in the form of RF signals (Radio Frequency Signals). 

AN RFID system uses a combination of an RFID reader, an antenna, and an RFID tag to execute its tasks. The RFID tag is very important for these components.

What Are RFID Tags?

Radio Frequency Identification Tags are smart labels that can be applied to anything you want to track. They have an integrated circuit (IC) chip and an antenna wrapped in a plastic, paper, or metal casing. These tags are small electronic devices that work as a tracking system and track assets like vehicles, animals, equipment, and other items by using radio frequency to search for, identify, and track them. RFID tags exchange data to streamline and automate complicated and time-consuming processes for asset tracking and identification in a variety of industries, including manufacturing, healthcare, retail, apparel, logistics, entertainment, and gate access control.

How Does RFID Tag Work?

RFID tags use an Integrated Circuit (IC) chip to modulate the radio frequency signal received from an RFID reader And then backscatter or return the signal in the form of radio waves to the RFID reader which reads the data from this signal.

Battery inside some Active RFID tags only helps to send the signal quickly and farther than traditional passive RFID tags. The IC chip inside the tag also handles the anti-collision protocols meaning the tag signal is unique and the RFID reader can differentiate between RF signals. During the communication, the Antenna of the tag catches the RF wave from the RFID reader, energies the IC chip, and backscatters the signal to the RFID reader. It is unique to the tag. 

Benefits of RFID tags over QR codes

Like barcodes, QR codes are also images and need a clear line of sight to be read while RFID tags don’t require this. Though QR code labels provide better readability than a traditional barcode, it is no match for an RFID label.

RFID tags can also be read more than once at a time but not QR codes. You can read only one QR code, using a scanner, at a moment. Apart from that, an RFID label can be read from a distance of up to 12m (RAIN RFID) while you need to scan a QR Code in close proximity (max. 100cm).

In the apparel business, for instance, clothing should be easily viewed on hangers and handled, felt, and tried on by consumers, who may even move the merchandise to other areas of the store or shelves. With a new passive RFID location tracking system, Amazon has improved Just Walk Out technology by utilizing radio frequency identification (RFID) to track location and meet the unique needs of softline shopping

RFID Tags or Barcodes: Which one is better?

RFID tags use an IC chip and can store more data than barcodes which are basically images that can be read horizontally only. RFID tags have more life and can be read only by RFID readers whereas a barcode can be read using a mobile or a barcode scanner. A clear line of sight is also required here.

RFID tags are tamper-proof and versatile and all of this makes RFID tags more useful.

What kinds of RFID tags are being used?

Based on tracking needs range, duration, and frequency, RFID tags are of 3 kinds that are widely used in various businesses and personal capacities.

For example asset management, inventory, logistics, retail, banking, health, national security, law firms, schools and libraries, etc.

Active RFID Tags,

- Passive RFID Tags, and

- Battery-assisted Passive (BAP) or Semi Passive or Semi-Active RFID Tags. 

What are Active RFID Tags

Active RFID tags are those tags that use a battery for power supply hence active. When in the vicinity, these tags catch the RF signal from the RFID Reader and communicate back the data attached to the tags to the reader. 

Active (UHF) RFID tags can have a long-range for they use an internal battery. With beacons, the range can be over 100m. Internal battery power boots the signal, which also helps these tags overcome barriers in sending out RF signals back to the RFID Reader. 

Some Active RFID tags also have other important features like GPS, Wi-Fi, Bluetooth, etc. for better connectivity. 

Lifespan of Active RFID Tags

Active RFID readers have a short lifespan because they use batteries and are always active. Some UHF active RFID tags last 3-5 years depending on their beacon rate. 

Cost of Active RFID Tags

The cost of active tags is higher than a passive RFID tag for the reason that active RFID tags come with batteries. These tags have a long read range going up to 100m. An active RFID tag can easily cost around INR 700 and more, USD 10 onwards.

What are Passive RFID Tags

Passive RFID tags are those that do not use a battery and are only active when an RFID Reader sends a signal and energies the IC chip inside. The tags then send the data to the reader. It remains dormant otherwise. 

Lifespan of Passive RFID Tags

Passive RFID Tags do not use a battery and thus last significantly longer than active RFID tags. The Lifespan of Passive RFID Tags can be over 12-15 years. 

Cost of Passive RFID Tags

Passive RFID tags are easy to fabricate. Since these tags don’t consist of a power source in the form of batteries, passive RFID labels are inexpensive and cost around 4-5 US cents (5-6 INR). If you want to purchase passive RFID hard tags, these tags could easily cost around INR 30 or more. 

What are Battery Assisted Passive (BAP) RFID Tags

These BAP tags wait for an RF signal from the RFID reader in the area and then turn on the battery to power the IC chip and return the signal/data to the RFID Reader.

Lifespan of semi-passive (BAP) RFID Tags

These tags have a higher lifespan than active RFID tags and less than Passive RFID tags. Battery capacity is important in this regard. 

Cost of Semi-Passive RFID Tags

Battery-assisted passive RFID tags or semi-passive RFID tags also come with batteries and that is why, these tags also cost significantly more than a passive RFID label. These tags can work like an RFID beacon and cost around INR 700 or more (USD 10-25).

Chipless RFID tags

Chipless RFID tags are the latest and ongoing development in the field of RFID technology. As the name suggests, these tags do not come with a silicon microchip, unlike chipped RFID tags. Chipless RFID tags are easily fabricated and cost around 0.01 USD, and with low cost like this, chipless RFID tags are headed to replace barcodes from the retail and FMCG item identification for good. 

Chipless RFID sensors are also developed that provide low-cost sensing of temperature, humidity, strain, toxic gas, fill level, etc. 

Chipless RFID tag fabrication consists of using resonators and reflectors as base material which are useful in the time domain and frequency domain encoding of these tags since these tags don’t use silicon microchips.

To conclude...

RFID tags are an important feature of an RFID system. The data is written on the tag which is translated by an RFID reader by Radio Frequency waves. RFID tags, unlike barcodes, don’t need a clear line of sight to be read. Whether it's using RFID to track location of vehicles in a fleet or streamlining RFID tracking systems for manufacturing, the possibilities are endless. While semi-passive RFID tags offer extended read ranges and enhanced data capabilities, passive UHF RFID tags (RAIN RFID) provide cost-effective long-lasting solutions leading to wide adoption of passive RFID tags.

RFID tags have witnessed significant development over the last few years. The cost of RFID tags has come down significantly, from 40-50 US Cents earlier to 4-5 US cents. This enhanced affordability, coupled with continuous technological developments, is leading to increased adoption of RFID tags across various sectors. The future holds immense potential for this technology, as its expanding array of capabilities and decreasing cost unlock new opportunities for efficient tracking and management of physical assets.

Disclaimer: The information presented here is for general information purposes only and true to best of our understanding. Users are requested to use any information as per their own understanding and knowledge. Before using any of the information, please refer to our Privacy Policy and Terms and Conditions.

  • Created on Jan 07, 2023

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