What is RFID Module and How Does it Work

RFID or Radio Frequency Identification System is a technology widely used in different industries. You might not be aware of what is RFID and how it works but you might have already experienced it in modern supermarkets where there is an automated checkout system. It is the RFID technology that lets you easily walk out from the billing section without requiring you to enter each item’s price manually before checkout. Let’s understand more about this technology and some important technical aspects.  

What is RFID Module - Learn more in this Guruface Blog.

Table of Contents

1. Introduction

2. Elements of RFID Module

3. How does RFID Work?

4. Applications of RFID Modules


A popular method for storing and retrieving data in devices with radio frequency capabilities is radio frequency identification or RFID. RFID systems typically include one or more RF tags, an RF reader, and a database. RFID Modules can even be used in various Raspberry Pi Projects as well.

Devices can exchange information without making physical contact Using radio frequency identification (RFID). In this blog, let us dive in and understand what this technology is, how it operates, and how you can use it.


The two essential parts of an RFID system, also known as a radio frequency identification system, are:

  • A tag that is affixed to the object that needs to be identified
  • A reader who scans the tag.

RFID Module - Essential Parts

A reader is made up of an antenna that produces a high-frequency electromagnetic field and a radio frequency module. In contrast, tags are often passive devices (it does not have a battery). It is made up of an antenna for receiving and transmitting signals as well as a microchip for processing and storing information.

An electromagnetic field is produced by the reader when the tag is brought close to it. As a result, electrons pass through the antenna of the tag and energize the chip. The chip then reacts by sending the reader another radio signal containing the information it has previously saved.

 A computer or microcontroller receives the data that the reader has collected and interpreted from this backscatter.

RFID Tag - Data Flow

Instead of continually checking to see if a card is nearby, the RC522 RFID module can be designed to emit an interrupt, alerting us when a tag approaches it. The RFID tags have unique identifiers, which the reader can use to identify them in the database. RFID tags can be active or passive. Meaning,

They either require external power (active)


They are powered by the reader upon scanning (passive).

While active RFID tags are utilized for asset tracking in wider spaces over greater distances and for road tolls, passive RFID tags are most frequently employed for shipment tracking, inventory management, and security access.


The key component of Radio Frequency Identification System is a microelectronic component, typically a microchip that contains information. It can store a lot of data despite often being quite small. How does the tag interact with readers when they lack a power source of their own? Here, electromagnetic plays a role.

How RFID Tags interact with readers - Guruface blog

When a passive tag is in close proximity to a reader, the reader’s antenna sends electromagnetic energy to the tag. The tag’s antenna is made of conductive material, which when electromagnetic waves strike causes an electric current to flow, powering the tag’s integrated circuit.

Electro magnetic energy transmission - Explaining how RFID tags work

After then, the tag “turns on” and begins transmitting data. The reader’s task is to translate the signal received from the tag into useful information.


Here are some of the popular applications of RFID modules.

  1. Logistics & Inventories: RFID tags are frequently used in large shipments of commodities, such as retail products, to track the location, composition, and movement of goods. One of the biggest users of this technology for tracking product shipments is Wal-Mart.
  2. Passport: RFID tags are included in passports in a number of nations. These tags are used to retain personal data ASW (including a passport holder’s photo) and keep tabs on travelers who enter and leave the country.
  3. Identification: Both people and animals can have RFID chips implanted to track their travels, grant access to restricted areas, or aid in the recovery of lost pets.
  4. E payment- Highway Tollgate: RFID technology is used by highway toll payment systems, including E-Z Pass in the eastern states, to electronically collect tolls from passing vehicles. Cars use the E-Z Travel lane to pass through the toll booth without stopping, and the toll is automatically debited from a pre-paid card.
  5. Libraries: Libraries utilize RFID tags in books and other materials to keep track of inventory and circulation, store product details (such as titles and authors), and prevent theft. RFID technology makes it possible to check books in and out as well as do time-consuming activities like shelf inventory swiftly and effectively because tags can be read without having to touch the object.

Hope you got a detailed understanding of what is RFID and how it works. We also have blog posts on similar interesting and highly useful technologies like Accelerometers, IR Sensors, and PIR Sensors. Take a look at them and double up your knowledge.

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Marini is the Senior Robotics Trainer at Guruface Academy. She holds a Master's Degree (MS) in Electronics and is an experienced Instructor with a demonstrated history of Training students across the Globe in Various Robotics platforms. Marini is also a Professional Stem Educator with sound knowledge of Electronics, Coding, Robotics, Artificial Intelligence, etc.