First, low frequency (from 125KHz to 134KHz).
In fact, RFID technology was first widely used and popularized at low frequency. This frequency mainly works through inductive coupling, that is, there is transformer coupling between the reader coil and the RFID tag coil. The voltage induced by the alternating field of the reader in the antenna is rectified and can be used as the power supply voltage. The magnetic field area can be well defined, but the field strength drops too fast.
Features:
1. Generally, the working frequency of a card reader working at low frequency is between 120KHz and 134KHz, and the working frequency of TI is134.2kHz. The wavelength of this frequency band is about 2500m.
2. Generally speaking, except the influence of metal materials, low frequency can pass through any material without reducing its reading distance.
3. There are no special licensing restrictions for readers working at low frequency in the world.
4. Low-frequency products have different packaging forms. A good packaging form is too expensive, but it has a service life of more than 10 years.
5. Although the magnetic field area of this frequency drops rapidly, it can produce a relatively uniform reading and writing area.
6. Compared with RFID readers in other frequency bands, the data transmission speed in this frequency band is relatively slow.
7. The price of card reader is more expensive than other frequency bands.
Main applications:
1, animal husbandry management system
2. The application of automobile anti-theft and keyless door opening system.
3. Application of Marathon Running System
4. Automatic parking charge and vehicle management system
5, the application of automatic refueling system
6. The application of hotel door lock system
7, access control and safety management system
Meet international standards:
A) application of iso11784 RFID in animal husbandry-coding structure
B) application of iso11785 RFID in animal husbandry-technical theory
C) application of iso14223-1RFID in animal husbandry-air interface
D) application of iso14223-2 RFID in animal husbandry-protocol definition
E) ISO 18000-2 defines the physical layer, anti-collision and low-frequency communication protocols.
F) DIN 30745 is mainly the European standard for waste management application definition.
Second, high frequency (working frequency is 13. 56 MHz)
At this frequency, the card reader no longer needs to wind the coil, and the antenna can be made by etching and printing. The card reader usually works by load modulation. That is to say, the voltage on the antenna of the reader is changed by turning on and off the load resistor on the reader, and the amplitude modulation of the antenna voltage is realized by using the remote reader. If people control the on-off of load voltage through data, then these data can be transmitted from the card reader to the card reader.
Features:
1, the working frequency is 13.56MHz, and the wavelength of this frequency is about 22m.
2. Except for metal materials, the wavelength of this frequency can pass through most materials, but it often reduces the reading distance. The reader antenna needs to be far away from the metal.
This frequency band is recognized all over the world, and there is no special restriction.
4. Sensors are usually in the form of electronic tags.
5. Although the magnetic field area of this frequency drops rapidly, it can produce a relatively uniform reading and writing area.
6. The system has anti-collision characteristics and can read multiple electronic tags at the same time.
7. You can write some data information into the label.
8. Data transmission rate is faster than low frequency, and the price is not very expensive.
Main applications:
1, the application of books and archives management system
2. Management and use of gas cylinders
3. Management and application of garment production line and logistics system.
4. Three-meter prepayment system
5. Management and application of hotel door locks
6, large conference personnel channel system
7. Logistics and supply chain management solutions
8. Pharmaceutical Logistics and Supply Chain Management
9. Intelligent shelf management
Meet international standards:
A) ISO/IEC 14443 is a tightly coupled IC card with a maximum reading distance of 10cm.
B) ISO/IEC 15693 loosely coupled IC card, maximum reading distance1m.
C) ISO/IEC 18000-3 This standard defines the physical layer, anti-collision algorithm and communication protocol of 13.56MHz system.
D) 13.56MHz ISM band Class 1 definition 13.56MHz conforms to the interface definition of EPC.
Third, ultra-high frequency (working frequency is between 860 MHz and 960 MHz)
Ultra-high frequency system transmits energy through electric field, and the energy of electric field will not drop quickly, but the reading area is not well defined. The reading distance of this frequency band is relatively long, and the passive frequency can reach about 10m. It is mainly realized by capacitive coupling.
Features:
1. This frequency band is defined differently all over the world-the frequency defined in Europe and parts of Asia is 868MHz, the frequency defined in North America is between 902 and 928 MHz, and the recommended frequency band in Japan is between 950 and 956. The wavelength of this frequency band is about 30cm.
2. At present, the power output of this frequency band is uniformly defined (defined as 4W in the United States and 500mW in Europe). Maybe the limit in Europe will rise to 2W EIRP.
3.UHF radio waves can't pass through many materials, especially water and metals, and suspended particles such as dust and fog will also have an impact. Compared with high-frequency electronic tags, electronic tags in this frequency band do not need to be separated from metals.
4. The antenna of electronic tag is usually long and tag-shaped. The antenna has two designs of linear polarization and circular polarization to meet the needs of different applications.
5. This frequency band has a good reading distance, but it is difficult to define the reading area.
6. It has a high data transmission rate and can read a large number of electronic tags in a short time.
Main applications:
1, Logistics and Supply Chain Management Solutions
2. Management and application of production line automation
3. Management and application of air parcels
4, container management and application
5. Management and application of railway parcels
6, the application of logistics management system
Meet international standards:
A) ISO/IEC 18000-6 defines the physical layer and communication protocol of UHF; The air interface defines two parts: type A and type B; Supports both readable and writable operations.
B) EPCglobal defines the structure of electronic article coding, UHF air interface and communication protocol. For example: class 0, 1 class, UHF Gen2.
C) Ubiquitous ID Japan organization, which defines UID coding structure and communication management protocol.
There is no doubt that UHF products will be widely used in the future.