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What is RFID, and How does It Work? Basics of Radio Frequency Identification

  • Mahesh Tiwari
  • Jan 18, 2024
  • RFID
What Is RFID, and How Does It Work? Basics of Radio Frequency Identification

“RFID is a wireless technology that uses an RFID tag, an RFID reader and antenna to identify and track tagged items using radio frequency signals coming from the RFID tag attached to the items. The RFID reader catches the RF signals through the antenna and decodes the data for the end users.”

As businesses and societies grapple with various modern age challenges in day to day business operations and various aspects of life respectively, a technology based, or several technology-based, innovative solutions become crucial to move forward.  With surge in ambitious industrial and utility operations, use of IoT and AI (Artificial intelligence) in such large scale operations is becoming a new normal. I mean we live in a smart city and are surrounded by technology at every step. Under these circumstances let’s take time to understand one such technology that is radio frequency identification (RFID).

Table of Contents:

1. What is RFID?

2. RFID components explained: RFID tags, RFID readers and RFID antennae.

3. How does RFID work?

4. What are the applications of RFID?

5. How RFID is a better Alternative than Barcodes and BLE?

6. Why UHF Passive RFID is the most Popular?

7. The Future of RFID technology

8. Privacy concerns arising due to increased use of RFID?

What is RFID?

Since I already mentioned that I want this blog post simple and precise enough to be understood by all, I’d say that RFID is short for radio frequency identification which means RFID is a technology which is based on radio waves to identify something, an asset, for example. 

Radio waves are a part of electromagnetic spectrum, from extremely low frequency of 3Hz to  very high frequency of 30MHz. To explain further, 3Hz frequency wave will mean extremely low energy but extremely high wavelength of 100Mm or 100000Km and the very high frequency of 30MHz will mean higher energy and a wave length of 10m, you can say a shorter wave!
RFID uses this radio wave frequency and not only RFID, other forms of radio communications use radio wave frequency. 

The UHF RFID stands for ultra high frequency RFID and uses a frequency range over 300MHz to 3GHz which comes in microwave range on the spectrum. As the name suggests, it is a shorter wave but high in energy.

RFID Components Explained: RFID Tags, RFID Readers and RFID Antennae

For RFID to function as it is intended there are few components that are essential and you must know about them. These are an RFID tag, an RFID reader, an RFID antenna and a computer system to store data but that is optional.

What Are RFID Tags?

RFID tag is a housing of a microchip and electronic coil capable of generating magnetic field. It sometimes houses an antenna as well. We call that integrated RFID tag or RFID tag with an antenna.

Types of RFID Tags?

RFID tags are what are attached to articles, individuals or animals we want to track or identify. It comes in 3 categories that are battery powered or Active RFID tags, passive rfid tags or tags without batteries and then there are battery assisted RFID tags that use battery only to transmit signals on regular intervals.

a) Active RFID tags

Active RFID tags come with battery and are capable of transmitting RF (radio frequency) signals all the time. These offer higher range than passive RFID tags and strong signals that can overcome interference as well.

Interference here means disturbance in radio frequency reaching from tag to the reader. It can happen due to various reasons. Water and metal surfaces or other RF signals on the same frequency can cause interference.

UHF active RFID is used for outdoor tracking with the help of careful installation of RFID reader at various intersections.

The main disadvantage in case of active RFID tags is that these are heavy (due to battery) and costly.

b) Passive RFID tags 

Passive RFID tags don’t come with batteries which means that these tags depend on radio frequency signals coming from the RFID reader to be activated and transmit back signals. 
These tags are used for identification and asset tracking in retail stores, healthcare, inventories, libraries etc.

Since UHF passive RFID tags are a cost effective, high range (up to 15m) tracking option, these are the most popular.

c) Batter Assisted Passive (BAP) RFID tags:

Battery assisted tags means they come with batteries but transmit signals on regular intervals to save power and last long (few years). These types of RFID tags act as beacons, like a lighthouse, to transmit signals once in a while. 

LF, HF and UHF RFID tags:

RFID tags are also classified on the basis of frequencies they operate on.

The classification is done as followings:

1. Low Frequency 

LF RFID tags work on low frequency range of 30 kHz-300kHz, 125kHz being typically used in this category. The read range is within few cm. 

2. High Frequency

High frequency (HF) RFID tags operate on the frequency range of 3MHz- 30MHz, 13.56 MHz, same as NFC, being the most popular.

3. Ultra High Frequency 

UHF RFID tags operate on the frequency range of 300MHz-3Ghz. In India UHF frequency range is 865-867MHz, in USA, it is 902-928 MHz, and in Europe, it is 865-868MHz.
Passive UHF RFID tags offer a read range of up to 15m and Active UHF RFID tags can offer a read range of up to 100m.

RFID Hard Tags, Inlays, labels and Anti Metal tags:

Apart from above mentioned categories of RFID tags, RFID tags are also classified into the kinds of housing they come in.

If it is just an RFID chip, antenna on a film substrate, it is called RFID inlay (dry), if it has adhesive then it’s called RFID wet inlay. If an inlay is wrapped in a paper or polyester label, then it is called an RFID label.

When RFID chip and the antenna (or not) is housed in a hard ABS plastic, then it’s called an RFID hard tags. 
Since metal and water surfaces cause a certain degree of interference in radio frequency transmission (due to eddy currents, intrusive magnetic field), anti metal tags are designed to be used on metal surfaces.

All of these tags find different application based on size and other needs.

RFID scanners/readers:

RFID Scanners or Readers are another important component that are used to emit and receive RFID signals. It reads the RF signals coming from the RFID tag, through an antenna, and sends the decoded message on a screen. It could be computer screen or the RFID scanner/reader screen itself as some scanners/readers come with screen and storing capabilities.

It’s worth noting that you should always go with higher frequency scanners/readers or a scanner/reader that matches the frequency range of tags you’re using for obvious reasons.

Readers also come in various categories suitable for various uses. There are hand held RFID readersfixed RFID readersUSB RFID readers etc.

RFID antennas:

RFID antenna is a device to make it easy for RFID reader or RFID tag to communicate RF signals. Sometimes RFID tags come with integrated antenna and sometimes an external antenna is used to catch signals from the tags/reader. 

Based on range and need, there are near field antennae and Far Field antennae. 

How does RFID work?

Now coming to how all these RFID components come together for an RFID system to work, it is important to know that RFID technology is mainly used for identification and data capture and tracking needs.

When an asset is tagged with an RFID tag, let’s say a UHF passive RFID tag, the antenna receives the reader signal and powers up the tag. The tag then sends the encoded message to the RFID reader which is decoded by the RFID reader and sent to a screen for the end use/ storing needs. This process - the reader activating the tag, the tag transmitting data, and the reader receiving and decoding it - is the core of how RFID tracking works.

So basically RFID reader and RFID tag transmit and receive RFID signals, with the help of an antenna to communicate.

What are the applications of RFID?

Now that you know how RFID works and some basic details about RFID components, it is time to see RFID in action. Since RFID is an AIDC technology and far better than other AIDC technologies like Barcodes/ QR codes, BLE etc., in many aspects, it is used in many businesses and industries.

I’ve written many blogs on how RFID can improve supply chain management retail operations, streamline logistics, and can be used for marketing and event managementlivestock management and for crowd management, ticketing and security at various Indian Pilgrimages and shrines, at airports etc., so I’ll just sum up this section with its main uses.

Since RFID has the capacity to identify assets and auto capture data, and it doesn’t need a clear line of sight to do so, it is very helpful in taking stock of an inventory pretty quick. It provides employees with enough time to manage other tasks and improves efficiency.

RFID, when used in tandem with other technologies, can provide accurate information on assets and their movement even on a mobile screen.

RFID based passports have been a great security help at immigration desks as well.

Why UHF Passive RFID is the Most Popular?

UHF Passive RFID is the most used RFID tag and there are various reasons for that. Since UHF Passive RFID tags work on ultra high frequency range of 300MHz to 3 GHz, it provides an identification range of up to 15m. 

Passive UHF RFID, being a cost effective, efficient option for identification and inventory management, is used heavily in retail, asset management, healthcare, libraries and for tool/ machinery component tracking in manufacturing sector.

Retail sector often struggle with lack of accurate inventory details that result in retail stock shrinkage and high losses. A Forbes report stated that shoplifting and inventory shrinkage in retail has become a 100B$ and 46.8B USD problem respectively. Under these circumstances, use of a cost effective, efficient RFID tagging solution becomes imminent and UHF passive RFID is just the right tool in that regard.

How RFID is a better Alternative than Barcodes and BLE?

When it comes to selecting which AIDC tool should be used for identification and tracking needs, it always depends on the scale of the business operations and inventory. Though barcodes and BLE are used in various businesses, and do the job quite well, RFID offers certain advantages over these two.

Barcode system suffers from low read rate and requires a clear line of sight to function, and BLE, though cost efficient, cannot provide the kind of visibility is needed in inventory management. 
RFID on the other hand is not only cost effective but quite efficient with high read range, high read rate as well and it doesn’t need a clear line of sight to get the job done.

The Future of RFID Technology

According to various reports from Statista and other market research, the RFID market is growing exponentially. The increased supply chain disruptions, the pandemic and changing customer behavior have forced many businesses to incorporate an increased degree of automation in their day to day business operations. Many retail businesses are quickly adopting various AIDC technologies and RFID is at the forefront. American retail giant Wal-mart recently asked its huge list of suppliers to start tagging supply boxes with RFID for removing human errors and streamlining the inventory control.

According to verified market research, the RFID global market is projected to reach USD 23.47B by 2030 growing at a CAGR of 9.97%, between 2022 and 2030 and Retail and Logistics have been the leaders in RFID implementation.

Industry 4.0 is all about leveraging technology to increase automation, enhance productivity and customer experience and I, as, believe that RFID can be an important factor in this. 

Privacy Concerns Arising Due to Increased Use of RFID?

It is a no brainer to conclude that technology has completely reformed many businesses and use of RFID in retail, supply chain and manufacturing has done a tremendous job. But as businesses try to incorporate more automation to improve business processes and enhance customer experience, people are also conscious of how their personal data is being used. Managing Privacy concerns and individual safety with increasing use of technology has been the biggest dilemma of this decade.

For the lack of clear data privacy laws in various countries and lack of regulations in data collection and uses, many people are worried about using some technologies and rightly so.

In 2003, the Italian clothing manufacturing brand Benetton tried to implement women garments with RFID tags  but later dropped it due to huge protests by RFID privacy activists, lead by a Harvard scholar Katherine Albrecht who wrote an interesting book titles ‘spychips’ on the same issues.

Though there are privacy concerns regarding use of RFID tags in day to day products, with clear guidelines and regulations, these concerns can be addressed as well and RFID can be the change it is meant to be, for many businesses.

Where to Purchase RFID Tags and RFID Readers in India?

Now that you know most of the things that you need to know RFID and if you’re thinking of implementing RFID system at your workplace, the main concern is where you can get authentic and reliable supplies?

There are various RFID tag, RFID reader and antenna suppliers and manufacturers in India and abroad and you can find them Online pretty easily, I suggest you consider EnCstore. We have a wide range of UHF RFID tags, Readers and RFID antenna to cover your varied needs and you get a reliable, experienced supplier. Our team of RFID experts can guide you on implementation as well.

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 Mar 22, 2023
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