Mar. 26, 2025
RFID (Radio Frequency Identification) is a wireless technology that uses electromagnetic fields to automatically identify and track objects, animals, or people.
The first applications of RFID go all the way back to the 1930s, when the British wanted to be able to tell the difference between Allied aircraft and the enemy on their radar in real time. The technology then evolved to become the RFID we recognise today. It is used for tracking objects, contactless payments, and more.
Radio frequency identification is very useful in numerous applications, particularly the Internet of Things and Big Data. Physically, an RFID tag is most often a flat square (like a patch) with an antenna and an electronic chip on a substrate.
Every RFID system consists of three components: a scanning antenna, a transceiver and a transponder. When the scanning antenna and transceiver are combined, they are referred to as an RFID reader or interrogator. There are two types of RFID readers -- fixed readers and mobile readers. The RFID reader is a network-connected device that can be portable or permanently attached. It uses radio waves to transmit signals that activate the tag. Once activated, the tag sends a wave back to the antenna, where it is translated into data.
The transponder is in the RFID tag itself. The read range for RFID tags varies based on factors including the type of tag, type of reader, RFID frequency and interference in the surrounding environment or from other RFID tags and readers. Tags that have a stronger power source also have a longer read range.
RFID tags are made up of an integrated circuit (IC), an antenna and a substrate. The part of an RFID tag that encodes identifying information is called the RFID inlay.
There are two main types of RFID tags:
Active RFID. An active RFID tag has its own power source, often a battery.
Passive RFID. A passive RFID tag receives its power from the reading antenna, whose electromagnetic wave induces a current in the RFID tag's antenna.
There are also semi-passive RFID tags, meaning a battery runs the circuitry while communication is powered by the RFID reader.
Low-power, embedded non-volatile memory plays an important role in every RFID system. RFID tags typically hold less than 2,000 KB of data, including a unique identifier/serial number. Tags can be read-only or read-write, where data can be added by the reader or existing data overwritten.
The read range for RFID tags varies based on factors including type of tag, type of reader, RFID frequency, and interference in the surrounding environment or from other RFID tags and readers. Active RFID tags have a longer read range than passive RFID tags due to the stronger power source.
smart labels are simple RFID tags. These labels have an RFID tag embedded into an adhesive label and feature a barcode. They can also be used by both RFID and barcode readers. Smart labels can be printed on-demand using desktop printers, where RFID tags require more advanced equipment.
Based on Operating Frequency
Low Frequency (LF) RFID
Frequency Range: Typically 125–134 kHz.
Characteristics: LF systems have a shorter read range (usually a few centimeters to a meter) and slower data transfer rates. They are less affected by interference from metals and liquids, making them suitable for animal tracking and access control.
High Frequency (HF) RFID
Frequency Range: Around 13.56 MHz.
Characteristics: HF tags provide moderate read ranges (up to about 1 meter) and are commonly used in applications like smart cards, library systems, and payment systems. They offer a good balance between range and data rate.
Ultra-High Frequency (UHF) RFID
Frequency Range: Typically 860–960 MHz.
Characteristics: UHF systems offer longer read ranges (several meters) and faster data transfer rates, making them suitable for applications like inventory tracking, supply chain management, and large-scale asset tracking. However, they can be more sensitive to interference from metals and liquids.
Microwave RFID
Frequency Range: Often around 2.45 GHz.
Characteristics: Microwave RFID provides even higher data rates and can support longer read ranges under optimal conditions. They are less commonly used compared to LF, HF, and UHF systems but can be found in specialized applications requiring rapid data transfer and longer communication distances.
RFID technology was first used by the military. Then, following its development, it was applied in the private sector, especially in industry from the 1980s after the invention of the microprocessor (electronic chip).
RFID systems are a solution that can make everyday life easier:
contactless payment with a bank card
ticket validation on public transport
inventories and loans in a library
automatic road tolls
key-less ignition for cars
timing race competitors (marathons, car races, etc.)
tracking pets
access to restricted areas using an RFID card, and so on.
RFID technology is also being used for the new generation of biometric passports and identity cards.
The system is also very widely used in industrial and commercial sectors. In commerce there are numerous mechanisms based on RFID that are used for:
Product inventory with rapid identification
Simultaneous reading of several items at the till
Re-stocking alerts for empty shelves, and more.
In the industrial sector there are many benefits:
monitoring logistics chains
tracking tools
traceability of assembly tests
quickly and easily identifying a production batch, which is especially useful when there is a malfunction and potential health risk
managing warehouses, etc.
Like all technologies, RFID offers benefits, for instance:
The need for handling and manoeuvring is reduced: RFID is designed to cut down interaction times (contactless payment, contactless inventories, etc.).
It simplifies life, with no need to seek out contact points or labels to read, unlike bar codes and QR codes.
RFID tags can be very small, and so integrated anywhere, even into a thin bank card, into clothing, or under the skin of an animal.
Connected to the internet with Wi-Fi, RFID technology can be used to transfer data securely over very long distances.
Near-field communication (NFC) enables data to be exchanged between devices by using short-range, high-frequency wireless communication technology. NFC combines the interface of a smart card and reader into a single device.
| Radio frequency ID | Near-field communication |
| Uni-directional | Bi-directional |
| Range up to 100 m | Range less than 0.2 m |
| LF/HF/UHF/Microwave | 13.56 MHz |
| Continuous sampling | No continuous sampling |
| Bit rate varies with frequency | Up to 424 Kbps |
| Power rate varies with frequency | <15 milliamperes |
RFID (Radio Frequency Identification) technology offers numerous benefits across industries, but it also faces several challenges that can impact its performance and adoption. Here are some of the key challenges:
Metal and Water Interference: Metal surfaces reflect RFID signals, and water absorbs them, leading to signal loss or distortion.
Electromagnetic Interference (EMI): Other wireless devices, such as Wi-Fi and Bluetooth, can interfere with RFID communication.
Passive RFID tags rely on the reader’s energy, limiting their effective range compared to active RFID tags, which have a built-in power source.
The read range varies depending on the frequency used (LF, HF, UHF, or microwave RFID).
RFID systems require investment in tags, readers, middleware, and integration with existing IT infrastructure.
Maintenance costs, such as replacing damaged tags and upgrading systems, add to the total cost.
Different RFID frequencies and protocols exist across regions and industries, leading to compatibility challenges.
Lack of universal standards can cause interoperability issues when integrating with global supply chains.
Large-scale RFID deployments generate vast amounts of data that need proper management and analysis.
Unauthorized access to RFID data can lead to security concerns, such as cloning or tracking without consent.
Harsh environments, such as extreme temperatures, chemicals, and moisture, can affect the lifespan and performance of RFID tags.
Some tags may need protective encasements, adding to costs and complexity.
Governments and regulatory bodies impose restrictions on RFID frequencies and usage to prevent interference with other communication systems.
Privacy concerns arise when RFID is used for personal tracking or customer profiling without consent.
Many businesses still rely on barcode-based systems, making RFID integration a complex and costly transition.
Middleware and software customization are often required to ensure smooth operation with existing databases.
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