RFID has become a popular technology for tracking and automating many business operations in the modern world. Almost every mid to large company and industry utilizes these systems. Be it manufacturing, sporting retail, jewelry, warehousing, healthcare, etc. One essential part of this technology is the RFID Readers. These play an important role in the functioning of these systems.
So, today, we will discuss all you need to know about RF Readers.
What is an RFID Reader?
Radio Frequency Identification utilizes radio signals and electromagnetic induction/signal backscattering to communicate information wirelessly. These systems have three primary components required to function, namely – Tags, Readers, and Antennas.
An RFID reader is a device that converts the radio signals sent by the tag, into electrical signals. A reader is connected to one or more antennas. Then antennas are responsible for broadcasting signals to the tags and receiving signals from them. Once the antennas receive the signals, they will send them to the reader. The reader will use a chip to convert these signals into a readable format and send them to the display/computer.
A reader can receive and convert signals from up to a thousand tags, per second. There are several types of readers available in the market, operating on different frequencies & compatible with different applications.
What is the Working Principle Behind a Radio Frequency Identification Reader?
The reader is connected to antennas which provide them with power. The reader will send signals to the antennas which will broadcast them. This creates a field of influence around the antennas, known as interrogation zones. This zone is divided into two segments, namely: Near-Field, and Far-Field.
Depending on the zone inside which a tag is, it will use different methods to communicate, namely – Inductive Coupling, and Radiative Coupling.
(A). Inductive Coupling
This occurs when a tag is inside the near-field communication zone of a reader. Inside this zone (within 10 centimeters), the tag is close enough to the antenna, that the signal is powerful enough to induce electrical charge within the tag using electromagnetic conduction. The tag uses this charge to power up and broadcast a signal back to the reader.
(B). Radiative Coupling
This phenomenon occurs inside the far field of an antenna. If a tag is inside the far field (more than 10 centimeters), the signal will not have enough power to induce the necessary charge within the tag’s inlay. Therefore, it has to rely on signal backscattering, a phenomenon where certain metal surfaces scatter and reflect a portion of the radio signal at multiple angles in the opposite direction it came from. The antenna receives this signal and sends it to the reader.
Once a reader receives the signal, it uses a microchip and preprogrammed algorithms to identify the tag signal, isolate it, and convert it into a readable format. Then send the information to the display/computer system for users to read.
Types of RFID Readers Available in the Market
Now we know the principle on which an RFID reader and to a lesser degree an RF system works. Although it may seem simple, these systems can be quite complex. Hence, there are different types of readers available in the market, suitable for different functions.
There are different factors on which you can classify different types of readers.
Reader Portability
Firstly, we will discuss different types of readers based on their portability. Based on these criteria, there are three types of readers available in the market.
(A). Fixed Readers
As the name suggests, these readers offer zero level of mobility. They need to be fixed on a mount, they use an ethernet cable to connect with multiple antennas and create different interrogation zones. Fixed RFID readers like the Zebra FX9600 require a connection to a power source to operate and have the best range due to high power signals.
(B). Handheld Readers
When it comes to portability, there is nothing better than handheld readers. Handheld RFID Readers like Zebra MC3390xR Handheld RFID Reader have ergonomic designs, tailored to provide a comfortable grip and ease of handling. These readers have an incorporated antenna within them and are powered by an internal battery. They have a decent range of reading and are mostly used in situations, where the items are far out of reach and in multiple angles and directions.
(C). Integrated Readers
Lastly, the integrated readers, these readers do not need an outside antenna to operate. Integrated readers like the 12 dBi Integrated UHF RFID Reader have an internal antenna integrated into them. However, due to this, they do have a shorter communication range and less powerful signals. But, most of them have the option to attach a few external antennas using ethernet cables.
Operating Frequency
Another criterion for the classification of readers is the radio frequency at which they operate. Based on this, four types of readers operate on different frequency ranges.
(A). Low Frequency
These readers operate using low-frequency radio signals. Depending on the region, different places will have slightly different frequency standards for LF readers. For example, the majority of Asian and European countries consider 125 kHz as the standard for low-frequency readers. However, most American countries consider the low frequency to be 134 kHz.
The signals from these readers have low power and a very short range of communication. However, they are also most resistant to signal distortions and detuning caused by metallic surfaces inside the interrogation zone.
(B). High Frequency
These types of readers operate on a higher frequency than LF readers. HF readers broadcast signals at 13.56 MHz. Though these readers have a higher frequency, they can still work relatively well in environments with metal surfaces. HF signals have more power and gain than LF signals, and thus, provide better communication coverage. They also have a higher rate of data transfer.
(C). Ultra-High Frequency
As the name suggests, these readers operate at some of the highest frequency ranges available. Similar to LF readers, the frequency of these also depends on the region they are manufactured in. In European and Asian countries, UHF readers operate on an 865 to 868 MHz frequency range. And in American countries, UHF readers operate between 902 to 928 MHz.
Ultra-High Frequency readers provide the fastest data transfer rate and significantly more communication range compared to HF and LF readers.
(D). Active Readers
Lastly, the active readers, these only work with active tags, due to their high-frequency bandwidth. Active tags have an internal battery that allows them to broadcast more powerful and high-frequency signals. Unlike other readers, these systems do not work on signal backscattering. Since the tags have an internal battery, it broadcasts their signal that is picked by the reader.
Active readers operate at 2.4 GHz of the frequency range. They have the highest communication range of any RFID system, due to the signal strength and transfer of data at a very fast rate.
Communication Method
An essential part of an RF system is the database/central computer, etc. These are the components that allow users to interact with an RFID system. The computer receives information from the reader's view physical connection or wireless connection. There are two types of readers based on this.
(A). Cabled Connection
These readers use ethernet cables to transfer data to the systems. The cable can be connected to the components using a different variety of connectors. Different connections offer different advantages and disadvantages. The biggest problem with these readers is the complexity of setting up wires, in case the reader is far away from the system.
(B). Wireless Connection
Unlike cabled readers, these do not need to be connected using an ethernet cable. Rather, they use Wi-Fi connections to communicate with the systems. This allows them to be placed farther away from the central system and spread throughout the facility.
Conclusion
Radio Frequency Identification readers are an essential component of RF systems. It is a device responsible for communicating with RFID tags and the computer system. There are a variety of readers available in the market for users.
Users can select from a variety of readers, depending on their application and needs.
Frequently Asked Questions
Q1. Can mobile read RFID?
Yes, most modern smartphones come with an internal NFC reader. Meaning that they are capable of reading certain types of RFID tags.
Q2. What distance can RFID read from?
The reading distance of an RF system depends on the type of reader and the tags. For example, an NFC reader can only work at a maximum distance of a few inches. On the other hand, an active RFID setup can work a little over 100 meters.
Q3. Where is the RFID reader used?
These readers can be used in a variety of industries like retail, automotive, warehousing, manufacturing, etc. These systems are used for the purpose of item identification & tracking throughout the supply chain.
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