A brief analysis of different types of RFID tags and their application scenarios

RFID technology is a technology that uses radio signals for data transmission and identification. According to the different characteristics and application scenarios of the tags, RFID tags can be divided into many types. The following will introduce different types of RFID tags and their application scenarios in detail.

1. With or without power battery

1.1 Active RFID tags

Active RFID tags have built-in batteries, which provide energy. The communication distance between them and RFID Readers is relatively long, which can reach tens of meters or even hundreds of meters.

Advantages: long communication distance, suitable for scenarios that require long-distance identification and tracking.

Disadvantages: large size, high cost, and the use time is limited by battery life. The ideal indicator of manufacturers is 7-10 years, but due to the number of times each card is used per day and the environment, in actual projects, some cards can only be used for a few months, and some cards can be used for more than 5 years.

Application scenarios: logistics tracking, vehicle management, animal tracking, etc.

1.2 Passive RFID tags

Passive RFID tags do not contain batteries. They get their power from RFID readers. When the passive RFID tags are close to the RFID readers, the antenna of the passive RFID tags converts the received electromagnetic wave energy into electrical energy, activates the chip in the RFID tags, and sends out the data in the RFID chip.

Advantages: small size, light weight, low cost, and service life of more than 10 years.

Disadvantages: limited communication distance, generally within a few tens of centimeters.

Application scenarios: inventory management, Access Control systems, Asset MANAGEMENT, etc.

2. Timing of sending signals

2.1 Active RFID tags

Active RFID tags rely on their own batteries and other energy sources to actively send data outward.

Application scenarios: Intelligent transportation systems, remote monitoring, etc.

2.2 Passive RFID tags

Passive RFID tags get energy from the electromagnetic waves sent by the received RFID readers, and can only send data outward after activation.

Application scenarios: logistics tracking, inventory management, access control systems, etc.

2.3 Semi-active RFID tags

Semi-active RFID tags have built-in energy sources such as batteries, which are only used by the circuits in the RFID tags and do not actively send data signals.

Application scenarios: environmental monitoring, smart medical care, etc.

III. Data read and write types

3.1 Read-only RFID tags

The content of read-only RFID tags can only be read, not written. According to whether they are programmable, they can be divided into read-only tags, one-time programmable read-only tags and reprogrammable read-only tags.

Read-only tags have data written in them when they leave the factory and cannot be modified.

One-time programmable read-only tags write data through programming before use and cannot be modified after reading.

Reprogrammable read-only tags can erase data and reprogram and write.

Application scenarios: anti-counterfeiting traceability, commodity management, etc.

3.2 Read-write RFID tags

The content of read-write RFID tags can be read and written, and random access memory (RAM) or electrically erasable programmable read-only memory (EEROM) is used internally.

Some tags have two or more memory blocks, and the reader can program and write content to different memory blocks separately.

Application scenarios: Logistics Management, inventory management, asset tracking, etc.

4. Signal frequency band

According to the operating frequency of RFID tags, they can be classified into four categories: low frequency, medium and high frequency, ultra-high frequency and microwave. Different operating frequencies directly affect the design of RFID tags, antenna design, working mode, working distance and reader installation requirements. Therefore, understanding the characteristics of RFID tags at different operating frequencies is crucial for designing RFID application systems.

4.1 Low-frequency RFID tags

The typical operating frequency of low-frequency tags is 125kHz to 134.2kHz. Low-frequency tags are usually passive tags. They obtain working energy from the radiation near field of the coupling coil of the reader through inductive coupling. Their reading and writing distance is generally less than 1 meter.

The chip manufacturing cost of low-frequency tags is low, and they are suitable for applications with short distance, low transmission rate and small data volume, such as access control, attendance, electronic billing, electronic wallet and parking fee management. Since low-frequency tags have a low operating frequency and can penetrate water, organic tissue and wood, their appearance can be designed as earrings, collars, pills or injections, which are suitable for the identification of animals such as cattle, pigs, and pigeons.

4.2 Medium and high frequency RFID tags

The common operating frequency of medium and high frequency tags is 13.56MHz. Its working principle is basically the same as that of low frequency tags, and it is also a passive tag. The tag obtains working energy from the radiation near field of the coupling coil of the reader through inductive coupling, and its reading and writing distance is generally less than 1 meter.

Medium and high frequency tags can be easily designed into card form. Typical applications include electronic identity recognition, electronic tickets, and identity cards for campus cards and access control systems. my country's second-generation ID Card is embedded with a 13.56MHz RFID chip that complies with the ISO/IEC14443B standard.

4.3 High-frequency and microwave RFID tags

UHF and microwave band RFID tags are usually called "microwave tags", where the operating frequency range of UHF is 860MHz to 928MHz, and the operating frequency range of microwave band is 2.45GHz to 5.8GHz. Microwave tags are mainly divided into two categories: passive tags and active tags. The operating frequency of microwave passive tags is mainly between 902MHz and 928MHz, and the operating frequency of microwave active tags is mainly between 2.45GHz and 5.8GHz. Microwave tags work in the far field area radiated by the reader antenna.

Since an important feature of electromagnetic waves in the UHF and microwave bands is line-of-sight transmission, their radio wave diffraction ability is weak, and there must be no objects blocking the transmitting antenna and the receiving antenna. Therefore, the reader antenna for UHF and microwave band RFID tags is designed as a directional antenna. Only the electronic tags within the directional beam range of the antenna can be read and written. The reader antenna radiation field provides energy for the passive tag. The working distance of the passive tag is greater than 1 meter, and the typical value is 4 to 7 meters. The RFID reader antenna sends read and write instructions to the active tag, and the active tag sends the identification information Stored in the tag to the reader. The maximum working distance of the active tag can exceed 100 meters.

Microwave tags are usually used for long-distance identification and identification of fast-moving objects. For example, in the fields of short-range communication and industrial control, logistics, railway transportation identification and management, and non-stop electronic toll collection (ETC) systems on highways.

V. Package type style

5.1 Sticker RFID tag

Sticker RFID tags are usually composed of a surface layer, a chip and antenna circuit layer, a glue layer and a bottom layer. This type of label is cheap and has a sticky function. It can be directly attached to the identified object. The surface layer can usually print text and is often used for factory packaging box labels, asset tags, clothing and item tags, etc.

5.2 Plastic RFID Tags

Plastic-encapsulated RFID tags use specific processes and plastic substrates (such as ABS, PVC, etc.) to encapsulate the chip and antenna into tags of different shapes. The plastic that encapsulates the RFID tag can be of different colors, and the encapsulation material usually has the characteristics of high temperature resistance.

5.3 Glass RFID Tags

Glass-encapsulated RFID tags encapsulate the chip and antenna in glass containers of different shapes to form glass-encapsulated RFID tags. This tag can be implanted in animals for animal identification and tracking, as well as the management of pets such as precious fish, dogs, and cats. In addition, it can also be used for the identification of firearms, helmets, wine bottles, molds, Jewelry or key chains.

5.4 Anti-metal RFID Tags

Anti-metal RFID tags are based on RFID electronic tags and add a layer of anti-metal material. This layer of material can avoid the failure of the tag after being attached to a metal object. The anti-metal material is an electronic tag encapsulated by a special anti-magnetic wave-absorbing material. It technically solves the problem that the electronic tag cannot be attached to the metal surface. It has the characteristics of waterproof, acid-proof, alkali-proof and collision-proof, and can be used outdoors.