RFID Frequency Range

Radio Frequency Identification (RFID) technology operates across different frequency bands, each offering unique advantages for specific applications. The RFID frequency range directly impacts factors such as read range, data transfer speed, interference resistance, and material penetration capabilities. From low-frequency (LF) systems ideal for short-range animal tracking to ultra-high-frequency (UHF) solutions enabling rapid inventory management, understanding these frequency differences is critical for selecting the right RFID solution. This guide explores the major RFID frequency bands—LF (125-134 kHz), HF (13.56 MHz), UHF (860-960 MHz), and microwave (2.45 GHz & 5.8 GHz)—and their real-world applications in industries like automotive, retail, and logistics.

Speaking of RFID many partners have not heard or heard but not clear what RFID. We check out in the supermarket, the cashier waved a scanning gun to identify the goods; over the high-speed toll booths, without stopping can be automatically deducted; library books, the administrator gently swept on the completion of the registration; these commonplace moments, are hidden with the same “invisible heroes” - -RFID.

RFID has actually been born a long time ago, in all corners of the silent service for all walks of life. RFID is the abbreviation for Radio Frequency Identification, the Chinese name is called radio frequency identification. Simply put, it is a non-contact automatic identification technology, without human intervention can be realized information recognition.

The development of RFID

RFID applications can be traced back to the Second World War, the U.S. military has been used to identify allied aircraft, to avoid mistakenly hitting friendly forces. 1980s began to rise, and gradually mature. In addition to the military, in many other industries, people have to identify the need for various items, which always have to give the items labeled with a lot of labels, labels and to enter a lot of information, it is too much of a waste of time and manpower, and data error rate is relatively high. So people in order to save labor, free hands, they began to look for a way to automatically identify, so RFID came into being. To help people solve the slow speed of manual input, high BER, labor-intensive and simple repetitive work and many other issues, but also to improve the real-time information systems and accuracy, for the work of various industries has brought great convenience.

Composition of RFID

The composition of RFID is very simple, consisting of three components: electronic tags, antennas and read-write. These are integral to the completion of RFID.

Electronic tag

The electronic label is the miniature device which stores the target information (such as ID, attribute data), is equivalent to the “wireless ID card”, and its core function is to receive the energy, analyze the instruction, and feedback the data.

Antenna

The antenna is the physical transmission channel of energy and signal between the reader and the label, the main function is to transmit and receive signals. Read-write

The reader is a digital transceiver, responsible for initiating communication, processing signals, managing data interaction, equivalent to the “wireless card reader”.

The working principle of RFID

The working principle of RFID is not complicated, the language of communication between RFID and read-write is electromagnetic wave. Read-write, antenna, electronic tags through electromagnetic waves to achieve energy transfer and data interaction, its logical relationship can be summarized as follows: read-write under the control of the host to send commands and receive tags return signals, the antenna is responsible for the launch and reception of electromagnetic waves, electronic tags passive or active response and feedback information.

Electronic tags

Electronic tags are equivalent to the RFID “ID card”, there are two main storage areas - ID area stored in the world's only “ID number” (UID), who can not change; user Data area is like a notepad, can write and draw at will, convenient for everyone to store the information they need. Antenna

The antenna is equivalent to the RFID “mouth” and ‘ears’, responsible for sending and receiving electromagnetic signals, so that RFID and read-write can “chat”. Read-write

Read-write is equivalent to the RFID “translator”, read-write first through the antenna send a signal, RFID received the information in the tag through the antenna sent back to the read-write, and finally read-write and then pass the information to the host to complete the identification.

RFID frequency

RFID according to frequency can be divided into four categories: low frequency, high frequency, ultra-high frequency and microwave. Different frequencies, different characteristics, respectively, in different scenarios play a unique role.

Low frequency (125KHz)

Slow “chronic”, speak softly, read-write have to come up to 1.2 meters to hear. But it is penetrating, metal other than the obstacles can not be blocked, suitable for parking lots, access control such as close-range scenarios.

High Frequency (13.56MHz)

Like a “machine gun”, the speed of speech is fast, but the transmission distance is about 1.2 meters. It is often seen in library lending and medical logistics management.

UHF (860-960MHz)

Like “loud voice + fast mouth”, standing 4 meters away can communicate, with its own power (active), suitable for production lines, container management, such as the need for rapid identification of the scene.

Microwave (2.45GHz, 5.8GHz)

Like the “long-distance running champion”, the longest distance can be transmitted more than 100 meters, mobile vehicle identification, remote access control rely on it.

Active vs. Passive

The transmission distance of a message does not only depend on the frequency, but also on many other factors. For example, one of the determining factors is the method of energy supply, which is introduced next. RFID is categorized into two types according to the method of energy supply: active RFID and passive RFID, which corresponds to the active (active) and passive (passive) modes of communication, respectively.

Low Frequency

Low-frequency is generally passive, passive electronic tags do not have their own power supply, lack of energy supply, there is no way to actively open their mouths to speak, need to read and write to them to transmit radio waves, they use the received inductance current in order to tell their own information to read and write, belongs to the passive family. Although the low-frequency speaking speed is slow, small voice, but their voice penetration is strong. General obstacles in addition to metal can not block the communication between them and the reader. But because of their communication distance limitation, they are usually active in pet management, sports and equestrian event management, etc., which do not require high distance.

High frequency

High frequencies are generally passive, and signals can pass through most materials except metal, but these obstacles reduce the distance their sound travels. They are used in places such as automatic parking lot charges, access control in hotels and neighborhoods, and library management.

UHF

UHF is generally passive, UHF signals also can not penetrate the metal, metal on the RFID UHF signal effect is very significant and strong, is the UHF RFID applications in one of the most common sources of interference. UHF workplace is generally in the production line automation aviation parcel management, container management, as well as railroad parcel management and applications such as the transmission speed requirements of higher places.

Microwave

The microwave is generally active, the microwave electronic label owns the power supply, in order to achieve the comparatively high frequency speaking rate, they need to bring their own power supply to provide the energy. Also because of brings the power supply, they may take the initiative to the read-write to send the frequency radiation signal, and brings the power supply may let their signal spreads farther. Microwave RFID is more often used in mobile vehicle identification, electronic remote control and other transmission speed, transmission distance have high requirements of the place. Take the high speed ETC vehicles automatic toll collection to say, because the car starts to move when the speed is fast, so need to speak faster microwave RFID. the vehicle owner puts the microwave electron label pastes in the car, the microwave electron label carries the power supply, at any time through the antenna transmits the electromagnetic wave in order to mark their own position. When the vehicles passes the toll station, the read-write through his antenna sends out the signal to obtain the vehicles information, the microwave electron label passes the vehicles information to the read-write, the read-write receives the information and then according to the car type and the journey calculates needs to pay the expense, then passes the information which has been dealt with (the toll fee) to pass back to the microwave electron label, then the vehicle owner pays the expense after the vehicles can pass. The whole process fastest in 2 seconds, the efficiency is very high.

In short, the simplest way to distinguish between active and passive, you can see whether the electronic label comes with power. The tag with its own power supply belongs to active, and vice versa, the tag without power supply belongs to passive.

Application of RFID

Various industries have gained tremendous benefits from the popularization and application of RFID technology. For example, the traditional retail industry, relying on bar code inventory management, manual scanning, not only inefficient (a 1000 square meters of large supermarket inventory may take hours or even a day), but also easy to miss the scanning, wrong scanning leads to inventory data distortion, which in turn triggers the “out-of-stock” or "backlog " problem. The use of RFID technology, RFID tags can be recorded through the entry of goods, shelves, sales, returns and other full life cycle data, the system updates the inventory status in real time. Stores can accurately grasp “which goods on the shelves, which in the warehouse, which is about to sell out”, to avoid the information lag caused by “false out of stock” (goods actually in the warehouse but not on the shelves) or excessive stockpiling, inventory turnover efficiency by 20% -50%.

(Staff using read-write inventory)

In the warehousing and logistics industry, the goods in and out of the warehouse in the past need to be manually counted through the registration form, which not only consumes a lot of manpower and time. Now using RFID technology, forklift in a plug a unloading between the rapid reading of goods information, and the goods in and out of the warehouse information back to the big data visualization Kanban, factory warehouse managers through the Kanban data on the warehouse operations at a glance.

(Forklift installed with RFID readers)

RFID technology is applied in logistics management and warehouse management system, the correct rate and accuracy are up to or even more than 99%, which is a lot higher than the previous correct rate of manual visual management, and reduces the cost waste and parcel shipment error of the enterprise. All commodity logistics are automatically recorded and generate documents, which makes it easier to further optimize tracking and identification.

In fact, RFID is ubiquitous in our lives, you live in hotels with access cards to open the door, in the company with an employee card punch card, library books when the card, in and out of the parking lot automatically charge, are the magic of RFID at work. After reading the above introduction, is not a deeper knowledge of RFID.