A Guide to RFID (Radio Frequency Identification) Technology

By  //  July 15, 2022

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RFID, or Radio Frequency Identification in full, is a wireless non-contact utilization of radio waves to transmit data. These systems often include antennas. RFID tags and an RFID reader. If you have never heard of it, you may wonder what is RFID and how it functions.

When items have RFIS tags, users can uniquely and automatically spot and track assets and inventory.

RFID is auto-ID technology taken to another level since the tags can be read without a line of sight. Also, depending on the type of RFID, you can have a range of a few centimeters up to 20+ meters. This technology has advanced since its first application in World War II when they used it to identify ally and enemy airplanes. 

As the technology keeps improving with time, the cost of using and implementing it continues to decrease, making the RFID technology more efficient and cost-effective.

How do RFID systems work?

The Radio Frequency Identification system relies on specific main components to work. These include:

1. Tags

Tags are tasked with transmitting and storing data. They are attached to items that have information that needs to be decoded. RFID tags contain embedded microchips responsible for keeping programmable data and tag ID. This data is what is transferred to the reader through antennas.

2. Readers

The RFID readers are considered the brains of the entire system. They are crucial for normal functioning since they are responsible for receiving incoming radio waves and converting them into digital data stored in the PC’s database. They get data from the tags and are connected to antennas. 

They are sometimes called interrogators because they receive and convey radio waves facilitating communication.

3. Antennas

These transmit information from the tags to readers. RFID systems can have integrated or standalone antennas that the reader can use for receiving and sending signals properly.

4. Computer database 

The information stored in RFID tags is housed in the computer database for easy retrieval and access. It is necessary to mention that these systems can manage data and devices, configure hardware components, facilitate remote monitoring, and program tags. RFID uses AIDC (Automatic Identification and Data Capture) technology. 

The latter uses automation to identify specific objects and gather relevant data about these items. Moreover, RFID assists by directly storing data in computer databases with little to no human intervention. Radio waves facilitate all these processes.

Through these main components, the tag with its integrated circuit contains all the necessary information that needs to be stored. That might then be looped with an antenna, which transmits data. The data has to be conveyed to the interrogator, which will convert the received radio waves into useful information. 

The entire process demonstrates how information moves from the RFID tags to the computer database and can be used for future analysis.


RFID tags categories

RFID systems transmit data using different electromagnetic field frequencies. Therefore, tags are categorized according to the frequencies at which they are built to operate. RFID tags fall within three significant frequency ranges; low-frequency tags, high-frequency tags, and ultra-high frequency tags.

1. Low-frequency tags (LF)

This falls under the primary frequency range of between 125kHz and 134kHz. The tags can read a span of just a few inches and is the lowest data transfer rate of all the frequencies. These tags only store small amounts of data. 

Applications: Asset tracking, healthcare, animal tracking, and car control.

2. High-frequency tags (HF)

These are the most widely used tags globally, with a primary frequency range of 13.56MHz. The reading range is 30 cm, and it is possible to read multiple tags simultaneously under HF. The tags can carry up to 4K of data and can be easily read when attached to things containing tissue, water, liquids, metal, and wood.

Applications: Personal ID cards, credit cards, airline baggage, and library books.

iii. Ultra-high frequency tags (UHF)

Two different tags use different frequencies under UHF:

4. UHF passive tags

These tags utilize energy from the system’s reader. The primary frequency range is between 860MHz and 960MHz. The read range is 25 meters, and the data transmission rate is high with a broad range of tag sizes.

Applications: Manufacturing, supply chain tracking, electronic rolling, and pharmaceuticals.

5. UHF active tags

These are operated by batteries and have a primary frequency range of 433MHz. The read capacity ranges from 30 to 100+ meters. UHF active tags also have a large memory capacity and high data transmission rate.

Applications: Construction, auto manufacturing, and vehicle tracking.


RFID technology has been around for several decades, and the demand for these types of equipment has surged rapidly over recent years. That can partly be attributed to mandates from the U.S. DoD and retail giants such as Walmart requiring their suppliers to use RFID technology to enable product traceability.