What is RFID?
Radio frequency identification (RFID) is a simple technology that uses radio waves to read and write data. It is a method to identify objects without using physical contact.
We usually see RFID tags on clothing labels. These tags are made up of an antenna and a chip, much like a unique identity card that stores an object’s identification information. To read this “identity information,” a reader is required. The tag and the reader communicate with each other using radio waves. They can read the information already on the RFID tag, and they can also write new data to it. In general, a complete RFID system must include RFID tags, RFID readers, and application software.
Communication Methods of RFID Systems
When chatting on social media, some people prefer texting, while others like sending voice messages. Similarly, RFID tags and readers have two ways of communication: inductive coupling and backscatter coupling.
Inductive coupling tags use passive waterproof transmission and need to get energy (power) from the reader. According to the law of electromagnetic induction, coupling is achieved through a high-frequency alternating magnetic field in space. This method is generally suitable for short-range RFID systems operating at low or high frequencies.
Backscatter coupling, on the other hand, follows the rule of electromagnetic wave propagation. The emitted electromagnetic waves reflect back after hitting the target, carrying the corresponding target information. This method is usually suitable for long-range RFID systems operating at ultra-high frequencies or microwave frequencies.
| Frequency | Wavelength | Energy | Coupling Mode |
|---|---|---|---|
| High | Short | High | Electromagnetic Backscatter Coupling / Electromagnetic Transmission |
| Low | Long | Low | Inductive Coupling / Electromagnetic Induction |
How Are RFID Systems Categorized?
RFID systems are typically categorized based on their operating frequency bands, which determine the size of the radio waves used for communication between system components. Globally, RFID systems operate in three main frequency bands: low frequency (LF), high frequency (HF), and ultra-high frequency (UHF). Each frequency band exhibits unique characteristics, offering specific advantages and drawbacks.
For instance, low-frequency systems have slower data read rates but excel at reading tags near or on metal or liquid surfaces. In contrast, high-frequency systems provide faster data transfer rates and longer read ranges but are more prone to interference from liquids and metals. Ultra-high frequency systems, while offering superior speed and range, were traditionally more sensitive to such interference. However, recent technological advancements have significantly improved their performance in environments with liquids and metals.
Low Frequency (LF) RFID
The LF band operates within frequencies ranging from 30 KHz to 300 KHz, with most LF RFID systems functioning at 125 KHz or occasionally at 134 KHz. This frequency band offers a short read range of about 10 cm and a slower read speed compared to higher frequency bands. However, LF RFID is less susceptible to radio wave interference, making it suitable for specific environments. The LF spectrum is not fully standardized globally due to variations in frequency and power regulations across different regions.
Applications:
Access control (e.g., key cards).
Livestock tracking (e.g., ear tags).
Standards:
LF animal tracking systems comply with ISO 14223 and ISO/IEC 18000-2.
High-Frequency (HF) RFID
The HF band operates between 3 MHz and 30 MHz, with most HF RFID systems working at 13.56 MHz. These systems typically offer read ranges between 10 cm and 1 meter, and they experience moderate sensitivity to interference.
Applications:
Ticketing (e.g., public transport passes).
Payment systems (e.g., contactless credit cards).
Data transfer (e.g., file sharing between devices).
Standards:
ISO 15693: Used for item tracking.
ECMA-340 & ISO/IEC 18092: Standards for Near Field Communication (NFC), enabling short-range data exchange between devices.
ISO/IEC 14443 A & ISO/IEC 14443: Standards for MIFARE technology, widely used in smart cards and proximity cards.
JIS X 6319-4: Standard for FeliCa, a smart card system commonly used in electronic money cards.
Ultra-High Frequency (UHF) RFID
The UHF frequency band spans from 300 MHz to 3 GHz, with NATION RFID systems using the 860 to 960 MHz range, compliant with the GXR Chip Series.
Passive UHF systems offer a read range of up to 12 meters and deliver faster data transfer rates compared to LF and HF systems. While UHF RFID is the most sensitive to interference, advancements in tag, antenna, and reader designs have allowed manufacturers to maintain high performance in a wide variety of applications. Additionally, passive UHF tags are easier and more cost-effective to produce than LF and HF tags.
Applications:
Retail inventory management.
Pharmaceutical anti-counterfeiting.
Wireless device configuration.
UHF RFID is the dominant choice for most new RFID projects, surpassing LF and HF technologies.
Standards:
The UHF band is governed by the global EPCGlobal Gen2 (ISO 18000-63) standard.
Among them, the high-frequency (HF) and ultra-high-frequency (UHF) bands belong to the ISM (Industrial, Scientific, and Medical) frequency range. The ISM band is reserved for industrial, scientific, and medical applications, though different countries may have different regulations. UHF operates within the microwave frequency range, which spans from 300 MHz to 300 GHz.
RFID Frequency Table
| Frequency | Low Frequency (LF) | High Frequency (HF) | Ultra High Frequency (UHF) | Microwave |
|---|---|---|---|---|
| Band | 125kHz, 134.2kHz | 13.56MHz | 433MHz, 860–960MHz | 2.45GHz, 5.8GHz |
| Wavelength | Long wave | Short wave | Decimeter wave | Decimeter & Centimeter wave |
| Identification Distance | Within 60cm | Within 1.5m | 0–200m | 0–150m |
| Application Areas | Access control, animal identification, inventory control | Smart cards, library management, ticket management | Personnel positioning, vehicle positioning | Apparel tracking, jewelry, alcohol anti-counterfeiting, ETC collection systems, community electric vehicle management |
| Operating Mode | Passive | Passive | Active | Passive/Active |
| Environmental Impact | Small | Relatively small | Moderate | Large |
| Data Rate | 1–17Kbits/s | 106Kbits/s, 14443 supports high speed 847.5Kbits/s | 40Kbits/s–640Kbits/s | 250K–1M |
Application Software
As the “leader” of the RFID system, application software is mainly responsible for controlling and setting the reader and managing the information read from the tags.
For example, a bus reader can independently perform simple tasks like ticket validation and fare collection, which doesn’t require the application software to intervene. However, when it comes to a network of multiple readers, the “leader” comes into play. It can effectively integrate data from multiple readers for specific RFID applications, enabling query, historical records, and other management services. Furthermore, through data processing, analysis, and mining, application software can provide a basis for making correct decisions, forming what is known as an information management system and a decision-making system.
Since application software handles a wide range of tasks, it can’t function without some capable assistants. This brings us to the topic of RFID middleware.
RFID Middleware
RFID middleware is responsible for transmitting information from one program to another or to multiple programs. It serves as a bridge between the application system and the RFID system, facilitating the transfer of data. Depending on the application and architecture, RFID middleware can be categorized into two main types:
- Application-Centered: In this approach, the RFID hardware provider offers an API, allowing developers to directly write specific RFID device data adapters through an additive method. These adapters then transmit the data to the backend system’s application or database, achieving integration with the backend system.
- Architecture-Centered: For enterprises using multiple application systems or dealing with high complexity, it may not be feasible to write adapters for each application program in an additive way. Additionally, there could be challenges with other standards. In such cases, companies may need to consider collaborating with middleware providers offering standards or using RFID middleware with standard specifications provided by hardware manufacturers.
RFID Reader
The RFID reader, also known as a reader-writer, is a tool used for reading and writing tag information. Due to its function similar to that of a base station, some people also refer to it as a base station.
In terms of appearance, RFID readers come in various shapes and sizes. In practical applications, they are generally divided into mobile and fixed types.
While different readers may vary significantly in frequency range, communication protocols, and data transmission methods, most readers typically have the following functions:
- Transmitting energy to RFID tags via radio frequency;
- Reading data from RFID tags or writing data to them;
- Processing the read data and enabling interaction with application software.
RFID Tag
The most numerous “members” in an RFID system are RFID tags, commonly known as electronic tags or smart tags. These tags are typically made up of a coupling element and a chip, with each RFID tag having a unique electronic code that attaches to an object to identify the target.
There are three types of RFID tags: passive tags, semi-passive tags, and active tags. The main difference between them lies in their power source.
Passive Tags
These tags have no battery and are “emotionless.” Outside the reader’s range, the tag is inactive. Within the reader’s range, the tag extracts the power it needs from the radio frequency energy emitted by the reader. Most passive tags use inductive coupling.
Semi-Passive Tags
These tags have a battery, but the battery only assists in providing power. It supports the data circuits or provides the voltage needed for the chip’s operation. The tag’s circuit uses very little power and remains in a dormant state. When the tag enters the reader’s range, it is activated by the radio frequency energy from the reader, similar to passive tags, with the energy source for communication still coming from the reader.
Active Tags
These tags are powered entirely by an internal battery, which also partially converts energy into radio frequency energy needed for communication with the reader.
The Technological Origins of RFID
The origin of RFID technology—believe it or not—is closely tied to war.
During World War II, in the Battle of Britain, the German Air Force had 3 air fleets and 2,669 aircraft, with an even split between fighters and bombers. In contrast, Britain only had 700 fighters and 500 bombers, giving Germany a massive advantage. However, in the end, the British forces destroyed 1,733 German aircraft and captured or killed over 6,000 German pilots, costing them 915 aircraft and 414 pilots. This victory in the Battle of Britain was remarkable.
A key factor in this victory was the British use of radio-based Identification Friend or Foe (IFF) systems. These systems worked alongside radar to display information about “friend” or “foe” on radar screens. The IFF system typically consisted of an interrogator and a responder. The interrogator would send out pre-programmed electronic pulse codes, which are essentially the core features of what we now know as RFID technology. This was the origin of RFID technology.
RFID Applications in the Global Market
Since RFID technology originated in developed countries in Europe and the United States, it entered the market application phase earlier than in other regions.
The commercial application of RFID technology began in the late 1960s, with electronic article surveillance (EAS) systems based on “1-bit responders” becoming widely used in shopping malls and supermarkets, primarily for anti-theft purposes, and this system is still in use today.
In the 1980s and 1990s, with the advancement and popularization of chip and electronic technologies, Europe was the first to apply RFID technology in civilian fields such as highway toll collection.
In January 2003, Gillette in the United States announced that it would purchase 500 million RFID tags at a price below 10 cents each and affix them to products for testing. This marked the beginning of RFID applications in the commercial logistics sector. The world’s largest retailer, Walmart, then required all its suppliers to attach RFID tags to product packaging, leading to the purchase of 1 billion RFID tags. In the government procurement sector, the U.S. Department of Defense also promoted the full adoption of electronic tags, requiring suppliers to use RFID tags on transportation boxes, containers, and packages worth $24 billion annually starting in 2005.
In Europe, 4 of the top 10 retail giants announced they would begin using RFID starting in 2004. Tesco, a major retailer in the UK, began using electronic tags on non-food packaging at distribution centers in April 2004, tracking these boxes to various stores. Germany’s Metro, the fifth-largest retailer in the world, announced a large-scale expansion of RFID application trials in November 2004—”The Future Store.” This project tracks the movement of goods from supplier factories to store shelves using RFID tags. The trial involved 100 suppliers, 10 logistics points, and 250 stores across Germany.
In Japan, in October 2003, the Ministry of Economy, Trade and Industry (METI) proposed a strategy for the widespread use of electronic tags and published the country’s product coding standards in May 2004. Japan also formed a technological industry alliance, with around 100 companies participating in the research, development, and pilot applications of RFID technology.
Market Prospects
Footwear and Apparel Industry
China’s manufacturing industry is highly developed, with the footwear and apparel sector holding more than half of the global market share. Additionally, China is one of the largest consumer markets for footwear and apparel worldwide, creating a high demand for RFID technology in this industry.
Several well-known international brands integrated RFID into their operations early on to enhance supply chain management and service efficiency, including Nike, ZARA, Uniqlo, H&M, and Decathlon. In recent years, domestic brands such as Haier, La Chapelle, UR, and Anta have also started adopting RFID technology. However, they focus on different application methods based on their specific needs.
Overall, the use of RFID in the footwear and apparel industry offers the following advantages:
- Improved warehouse logistics and inventory efficiency: It helps reduce inventory levels and cut labor costs.
- Reduced loss and errors in stores: It enhances customer experience by minimizing the chances of missing or incorrect items.
- Anti-counterfeit traceability: RFID plays a crucial role in verifying the authenticity of products, especially in e-commerce, helping to avoid counterfeit goods.
Given the enormous size of the footwear and apparel industry, coupled with its periodic updates and product cycles, the market potential for RFID technology in this sector is vast.
Aviation Industry
Statistics show that globally, approximately 23 million pieces of luggage are mishandled each year. Misrouted luggage not only negatively affects passenger experience but also leads to significant economic losses for airlines. In June 2019, during the 75th annual conference of the International Air Transport Association (IATA), member airlines unanimously voted in favor of deploying RFID technology globally for baggage tracking.
RFID applications in the aviation industry mainly include baggage tracking and aviation maintenance tool management.
In the past year, the Civil Aviation Administration of China (CAAC) has been actively promoting the widespread use of RFID in the aviation sector. Airlines such as China Eastern, Air China, China Southern, Yunnan Airlines, Spring Airlines, and airports like Daxing, Chongqing Jiangbei, Xi’an, and Wuhan Tianhe are all making significant strides in related deployments.
RFID is applied across various stages of baggage handling, including sorting, check-in, and tracking. Given the immense scale of the aviation industry, RFID still has considerable growth potential, and the application of RFID in baggage handling is one of the most promising areas to watch in the near future.
Warehousing and Logistics
For the logistics industry, efficient delivery is the key principle. With giants like SF Express, JD, YTO, ZTO, and Cainiao dominating the landscape, the focus of the logistics sector has shifted from large-scale competition to a balance between scale and refined management. In this process, technologies like 5G, RFID, the Internet of Things (IoT), cloud computing, and artificial intelligence have been continuously integrated, gradually forming a more efficient and intelligent logistics system.
Given RFID’s significant advantages in wireless identification, the logistics industry has long adopted this technology. RFID applications in logistics include:
- Anti-counterfeit traceability for high-value products (such as jewelry, wine, etc.).
- Improved warehouse turnover efficiency, leading to better supply chain management.
- Digital management transformation, contributing to the development of smart logistics.
The parcel logistics sector holds great potential for ultra-high-frequency (UHF) RFID technology. China’s express parcel consumption exceeds 60 billion annually, and RFID is currently applied in small-scale areas like warehouse turnover. However, achieving widespread adoption will require further push to address cost issues. Given the high market concentration in the express parcel sector, once RFID is widely implemented, the speed of market adoption will accelerate rapidly.
Library Management
In recent years, domestic libraries in China have increasingly adopted RFID technology to accelerate their digital transformation. As economic development and national reading demand continue to grow, the number of libraries in China has also increased. With a vast collection of books and high circulation rates, the challenges and costs of managing these libraries have risen. As a result, libraries need to introduce more efficient management systems, and RFID technology, which is highly suitable for this scenario, has naturally become the top choice.
RFID technology significantly improves the information management level and processing efficiency of library systems. It enables the automation of book borrowing, returning, shelving, searching, and inventory management, making these processes smarter and more efficient.
Currently, Chinese libraries consume around 500 million RFID tags annually. Of these, more than half are ultra-high-frequency (UHF) RFID tags, with the remainder being high-frequency (HF) RFID tags. This represents a significant and growing market.
Smart Healthcare
RFID in smart healthcare utilizes advanced Internet of Things (IoT) technologies to achieve seamless communication between patients, healthcare professionals, medical institutions, and medical equipment, thereby enhancing the level of informatization in the healthcare system. The application of RFID technology in the medical field can improve medical workflows, enhance the quality of care, and increase the efficiency and accuracy of medical tasks. This, in turn, helps safeguard patient safety and reduces the occurrence of medical disputes.
RFID applications in healthcare are diverse and cater to different objects and scenarios, as shown in the table below:
| Label/Object | Typical Applications |
|---|---|
| Patients and Visitors |
|
| Medical Supplies |
|
| Medical Staff |
|
As technology continues to develop and new solutions are introduced, RFID applications in healthcare extend far beyond what is listed here. In recent years, driven by national policies and technological advancements, the demand for smart healthcare in China has been growing rapidly, leading to a swift expansion of the market. As RFID becomes more widespread in healthcare, people are benefiting from more efficient, smarter, and more reliable medical services.
Automotive Industry
Driven by market demand and technological advancements, the automotive industry is moving towards greater intelligence, connectivity, and integration. In the process of automotive electrification, RFID technology has been integrated into various aspects of car manufacturing, driving experience, safety monitoring, and traffic management.
| Application Areas | Typical Applications |
|---|---|
| Production & Manufacturing | Parts identification management; RFID electronic vehicle label; Welding, painting, assembly seat pressure sensor labels |
| Driving Experience | Smart car key; Seat temperature sensor label; ETC non-stop toll collection |
| Safety Monitoring | Tire pressure & temperature monitoring; Liquid level monitoring electronic label |
| Traffic Management | RFID electronic license plate; IoT warehouse |
| Production Line Control | Process control in assembly line |
Currently, with the continuous improvement of 5G technology, autonomous driving, electric vehicle technologies, as well as RFID and sensor technologies, alongside the need for lean production control by manufacturing companies, the application of RFID tags in automobiles is bound to become increasingly widespread.
Power Industry
The development trend in the power industry is the creation of smart grids. One of the most common RFID applications here is power inspection management. In the past, power equipment inspections relied on manual checks and handwritten records, a method that had numerous drawbacks:
- Insufficient inspections, missed checks, or untimely maintenance.
- Low efficiency and error-prone results from manual reporting.
- Difficulty for management to promptly and accurately understand the status of power lines.
By integrating RFID technology, the digitization of power equipment inspections is significantly enhanced, ensuring the safety and reliability of power equipment.
In addition, asset management is another major RFID application focus in the power industry. By associating RFID tags with power assets, utility companies can achieve visualized management of their equipment, improving efficiency and accuracy.
Anti-Counterfeiting and Traceability
RFID plays a pivotal role in anti-counterfeiting and traceability, with its applications most commonly seen in high-value products such as alcohol, jewelry, and food safety tracking. To combat counterfeiting tactics like reused packaging or product forgery, RFID tags often feature tamper-evident and non-transferable designs.
Beyond just authentication, RFID/NFC technology records the entire product circulation process, offering companies valuable insights into their market distribution and supply chain management.
Given the frequent food safety incidents, establishing a robust management and traceability system is no longer optional — it’s a necessity. RFID technology provides comprehensive tracking of meat products, covering all critical stages, including production, farming, slaughter, and sales. This full-chain visibility helps ensure food safety and accountability, offering a true technological solution to a global concern.
Beyond the industries mentioned above, RFID technology continues to expand into a wide array of sectors. Its versatility makes it indispensable for numerous innovative applications.
As the Internet of Things (IoT) continues its rapid integration into society, new RFID products and applications are emerging at a remarkable pace. The future of RFID promises to touch even more aspects of our daily lives, bringing unprecedented levels of convenience, efficiency, and connectivity.
