Radio Frequency Identification (Radio Frequency Identification, abbreviated RFID), radio frequency identification technology is an automatic identification technology began to rise in the 1990s, radio frequency identification technology is a use of radio frequency signals through the spatial coupling (alternating magnetic field or electromagnetic field) to achieve contactless information transfer and through the information transmitted to achieve the Recognition of the purpose of the technology.
From the basic principle of information transfer, radio frequency identification technology in the low-frequency band based on the transformer coupling model (primary and secondary energy transfer and signal transfer), in the high-frequency band based on the radar to detect the target spatial coupling model (radar launch electromagnetic wave signal after encountering the target to return to the radar receiver with the target information).
In 1948, Harry Stockman published the "use of reflected power communication" laid the theoretical foundation of RFID radio frequency identification technology.
The development of RFID technology can be divided into ten-year periods as follows:
1940-1950: the improvement and application of radar gave birth to the RFID technology, 1948 laid the theoretical foundation of RFID technology.
1950-1960: early RFID exploration phase, mainly in the laboratory experimental research.
1960-1970: the theory of radio frequency identification technology has been developed, began some application attempts.
1970-1980: RFID technology and product development is in a period of great development, a variety of RFID technology testing has been accelerated.
Some of the earliest RFID applications appeared.
1980-1990: RFID technology and products into the commercial application stage, a variety of large-scale applications began to appear.
1990-2000: RFID standardization issues are increasingly being paid attention to, RFID products are widely used, RFID products gradually become part of people's lives.
2000 years later: the standardization of the problem of increasing attention to people, radio frequency identification product categories are richer, active electronic tags, passive electronic tags and semi-passive electronic tags have been developed, the cost of electronic tags continue to reduce the scale of the application industry to expand.
So far, the theory of RFID has been enriched and improved.
Single chip tags, multi-tag reading, wireless read-write, passive tags, long-distance recognition, adapt to high-speed moving objects, radio frequency identification technology and products are becoming a reality and towards the application.
RFID working frequency guide and typical applications
RFID products in different frequency bands will have different characteristics, the following details passive inductor in different operating frequency products and the characteristics of the main applications.
At present, the working frequency of RFID products is defined as low-frequency, high-frequency and ultra-high-frequency frequency range in line with the different standards of different products, and different frequency bands of RFID products will have different characteristics.
One of the inductor has a passive and active two ways, the following details passive inductor in different operating frequencies and the characteristics of the product and the main applications.
First, low-frequency (from 125KHz to 134KHz)
In fact, RFID technology was first widely used in low-frequency applications and promotion.
The frequency is mainly through the inductive coupling of the way to work, that is, in the reader coil and the inductor coil between the presence of transformer coupling. The voltage induced in the inductor antenna by the alternating field of the reader is rectified and used as the supply voltage. The magnetic field region can be well defined, but the field strength drops too quickly.
Characteristics:
1. working in the low frequency inductor general operating frequency from 120KHz to 134KHz, TI's operating frequency of 134.2KHz.
The wavelength of the band is about 2500m.
2. except for the effect of metal materials, the general low-frequency can be passed through the items of any material without reducing the reading distance. reading distance.
3. There are no special licensing restrictions worldwide for readers operating at low frequencies.
4. Low-frequency products are available in different packages.
A good package is one that is too expensive, but has a life expectancy of more than 10 years.
5. Although the frequency of the magnetic field area falls very quickly, but can produce a relatively uniform read-write area.
6. Relative to other frequency bands of RFID products, the frequency band data transfer rate is relatively slow.
7. The price of the inductor is more expensive than other frequency bands.
Main applications:
1. Livestock management system
2. Automotive anti-theft and keyless entry system
3. Marathon running system
4. Automatic parking lot charging and vehicle management system
5. Automatic refueling system
6. Hotel lock system
7. Application of hotel locking system
7. Access control and security management system
Conformity with international standards:
a) ISO 11784 RFID animal husbandry application - coding structure
b) ISO 11785 RFID animal husbandry application - technical theory
c) ISO 14223-1 RFID Livestock Applications-Air Interface
d) ISO 14223-2 RFID Livestock Applications-Protocol Definitions
e) ISO 18000-2 Defines the physical layer, impingement and communication protocols for low frequency
f) DIN 30745 Primarily a European standard defining waste management applications
II. High Frequency (Operating Frequency 13.56 MHz)
At this frequency sensors no longer require coils to be wound, and antennas can be made by etching alive printing.
Inductors generally work by load modulation.
That is, through the inductor on the load resistance on and off to prompt the reader antenna voltage changes to realize the long-distance sensor on the antenna voltage amplitude modulation.
If one controls the turn-on and turn-off of the load voltage with data, then the data can be transmitted from the inductor to the reader.
Characteristics:
1. operates at a frequency of 13.56MHz, which has a wavelength of roughly 22m.
2. the wavelength of the frequency can pass through most materials except metals, but tends to reduce the read range.
The sensor needs to be some distance away from the metal.
3. The frequency band is recognized worldwide and has no special restrictions.
4. The sensor is usually in the form of an electronic tag.
5. Although the magnetic field area at this frequency falls off very quickly, it can produce a relatively uniform read/write area.
6. The system has anti-collision properties and can read multiple tags at the same time.
7. Some data information can be written into the tag.
8. The data transmission rate is faster than low frequency and not very expensive.
Main applications:
1. Library management system applications
2. Gas cylinder management applications
3. Garment production line and logistics system management and applications
4. Three-meter pre-fee system
5. Hotel locks management and applications
6. Large-scale conference personnel access system
7. Fixed assets management system 7.7. Fixed asset management system
8. Management and application of pharmaceutical logistics system
9. Intelligent shelf management
Conforms to international standards:
a) ISO/IEC 14443 close-coupled IC card, the maximum reading distance of 10cm.
b) ISO/IEC 15693 sparse-coupled IC card, the maximum reading distance of 10 cm.
b) ISO/IEC 15693 sparse-coupled IC card, the maximum reading distance of 10cm. b) ISO/IEC 15693 Sparsely coupled IC cards, with a maximum read distance of 1m.
c) ISO/IEC 18000-3 This standard defines the physical layer, anti-collision algorithms, and communication protocols for 13.56MHz systems.
d) 13.56MHz ISM Band Class 1 This standard defines the interface definition for 13.56MHz compliant EPC.
iii. UHF (operating between 860MHz and 960MHz)
UHF systems transmit energy through an electric field.
The energy of the electric field does not fall very quickly, but the area of reading is not very well defined.
The frequency band reads a relatively long distance, passive up to about 10m.
It is mainly realized by capacitive coupling.
Characteristics:
1. In this band, the global definition is not quite the same - Europe and part of Asia define the frequency of 868MHz, North America defines the band between 902 and 905MHz, and in Japan the proposed band is between 950 and 956.
The wavelength of this band is about 30cm.
2. Currently, the power output of this band is currently defined uniformly (4W in the US and 500mW in Europe).
It is possible that the European limit will rise to 2W EIRP.
3. UHF band waves cannot pass through many materials, especially water, dust, fog and other suspended particles material.
Compared to the high frequency electronic tags, the frequency band electronic tags do not need to be separated from the metal.
4. The antenna of the tag is generally long and tag-like.
The antenna has two designs, linear and circular polarization, to meet the needs of different applications.
5. The band has a good reading distance, but it is difficult to define the reading area.
6. It has high data transmission rate, and can read a large number of electronic tags in a very short time.
Main applications:
1. supply chain management and application
2. production line automation management and application
3. air parcel management and application
4. container management and application
5. railroad parcel management and application
6. Logistics management system application
6.
Conform to international standards:
a) ISO/IEC 18000-6 defines the physical layer of UHF and communication protocols; air interface defines Type A and Type B parts; and supports readable and writable operations.
b) EPCglobal defines the structure of the Electronic Article Code (EAC) and the VHF air interface and protocols for communication.
Examples: Class 0, Class 1, UHF Gen2.
c) Ubiquitous ID Japanese organization that defines the UID coding structure and protocols for communication management.
In the future, UHF will be used in a large number of applications.
For example, WalMart, Tesco, the U.S. Department of Defense, and Metro Supermarkets will all be using RFID in their supply chains.
Active RFID technology (2.45GHz, 5.8G)
Active RFID has a low transmit power, long communication distance, large amount of transmitted data, high reliability and good compatibility, etc., and passive RFID compared to the advantages of the technology is very obvious.
It is widely used in highway toll collection, harbor freight management and other applications.
As an emerging automatic identification technology, RFID has great potential for development in China.
RFID (Radio Frequency Identification) is actually the specific application and development of automatic identification technology (AEI, Automatic Equipment Identification) in radio technology.
The basic idea of the technology is that, through the use of some advanced technical means, to realize the people of all kinds of objects or equipment (people, goods) in different states (mobile, static or harsh environment) under the automatic identification and management.
Radio Frequency Identification (RFID) band guidance:
The current definition of RFID products operating frequency has a low-frequency, high-frequency and very high-frequency frequency range in line with the different standards of different products, and different frequency bands of RFID products will have different characteristics.
One of the inductor has a passive and active two ways, the following details passive inductor in different operating frequencies and the characteristics of the product and the main applications.
First, low-frequency (from 125KHz to 134KHz)
In fact, RFID technology is first widely used in low-frequency applications and promotion.
The frequency is mainly through the inductive coupling of the way to work, that is, in the reader coil and the inductor coil between the presence of transformer coupling. The voltage induced in the inductor antenna by the alternating field of the reader is rectified and used as the supply voltage. The magnetic field region can be well defined, but the field strength drops too quickly.
Characteristics:
1. working in the low-frequency inductor's general operating frequency from 120KHz to 134KHz, TI's operating frequency is 134.2KHz.
The wavelength of the frequency band is about 2500m.
2. In addition to the influence of metal materials, the general low-frequency is able to pass through the items of any material without decreasing the reading distance. reading distance.
3. There are no special licensing restrictions worldwide for readers operating at low frequencies.
4. Low-frequency products are available in different packages.
A good package is one that is too expensive, but has a life expectancy of more than 10 years.
5. Although the frequency of the magnetic field area falls very quickly, but can produce a relatively uniform read-write area.
6. Relative to other frequency bands of RFID products, the frequency band data transfer rate is relatively slow.
7. The price of the inductor is more expensive than other frequency bands.
Main applications:
1. Livestock management system
2. Automotive anti-theft and keyless entry system applications
3. Marathon running system applications
4. Automated parking lot charging and vehicle management system
5. Automated refueling system applications
6. Hotel locking system applications
6. Application of hotel locking system
7. Access control and security management system
Conformity with international standards:
a) ISO 11784 RFID animal husbandry application - coding structure
b) ISO 11785 RFID animal husbandry application - technical theory
c) ISO 14223-1 RFID Livestock Applications-Air Interface
d) ISO 14223-2 RFID Livestock Applications-Protocol Definitions
e) ISO 18000-2 Defining Physical Layer, Impact Prevention, and Communication Protocols for Low Frequency
f) DIN 30745 Primarily a European standard defining waste management applications
II. High Frequency (Operating Frequency 13.56MHz)
At this frequency sensors no longer require coils to be wound, and antennas can be made by etching alive printing.
Inductors generally work by means of load modulation.
That is, through the inductor on the load resistance on and off to prompt the reader antenna voltage changes to realize the long-distance sensor on the antenna voltage amplitude modulation.
If one controls the turn-on and turn-off of the load voltage with data, then the data can be transmitted from the inductor to the reader.
Characteristics:
1. operates at 13.56MHz, which has a wavelength of roughly 22m.
2. the wavelength of the frequency passes through most materials except metals, but tends to reduce the read range.
The sensor needs to be some distance away from the metal.
3. The frequency band is recognized worldwide and has no special restrictions.
4. The sensor is usually in the form of an electronic tag.
5. Although the magnetic field area at this frequency falls off very quickly, it can produce a relatively uniform read/write area.
6. The system has anti-collision properties and can read multiple tags at the same time.
7. Some data information can be written into the tag.
8. The data transmission rate is faster than low frequency and not very expensive.
Main applications:
1. Application of library management system
2. Management of gas cylinders
3. Management and application of garment production line and logistics system
4. Three-meter pre-fee charging system
5. Management and application of hotel locks
6. Personnel access system for large-scale conference
7. Fixed assets management system8.
7. Fixed asset management system
8. Management and application of pharmaceutical logistics system
9. Management of intelligent shelves
Conformity with international standards:
a) ISO/IEC 14443 close-coupled IC card, with a maximum reading distance of 10cm.
b) ISO/IEC 15693 sparse-coupled IC card, with a maximum reading distance of 10 cm.
b) ISO/IEC 15693 sparse-coupled IC card, with a maximum reading distance of 10 cm. b) ISO/IEC 15693 Sparsely coupled IC cards, with a maximum read distance of 1m.
c) ISO/IEC 18000-3 This standard defines the physical layer of the 13.56MHz system, the anti-collision algorithms and the communication protocols.
d) 13.56MHz ISM Band Class 1 This defines the interface definition for 13.56MHz compliance with EPC.
iii. VHF (operating between 860MHz and 960MHz)
VHF systems transmit energy through an electric field.
The energy of the electric field does not fall very quickly, but the area of reading is not well defined.
The band reads over a relatively long distance, up to about 10m passively.
It is mainly realized by capacitive coupling.
Characteristics:
1. In this band, the global definition is not quite the same - Europe and part of Asia define the frequency of 868MHz, North America defines the band between 902 and 905MHz, and in Japan the proposed band is between 950 and 956.
The wavelength of this band is about 30cm.
2. Currently, the power output of this band is currently defined uniformly (4W in the US and 500mW in Europe).
It is possible that the European limit will rise to 2W EIRP.
3. VHF band waves cannot pass through many materials, especially water, dust, fog and other suspended particles material.
Compared to the HF electronic tags, the electronic tags in this band do not need to be separated from the metal.
4. The antenna of the tag is generally long and tag-like.
The antenna has two designs, linear and circular polarization, to meet the needs of different applications.
5. The band has a good reading distance, but it is difficult to define the reading area.
6. It has high data transmission rate, and can read a large number of electronic tags in a very short time.
Main applications:
1. supply chain management and application
2. production line automation management and application
3. air parcel management and application
4. container management and application
5. railroad parcel management and application
6. logistics management system application
6.
International standards:
a) ISO/IEC 18000-6 defines the physical layer and communication protocols of VHF; the air interface defines Type A and Type B parts; and supports readable and writable operations.
b) EPCglobal defines the structure of the Electronic Article Code (EAC) and the VHF air interface and protocols for communication.
Examples: Class 0, Class 1, UHF Gen2.
c) Ubiquitous ID Japanese organization that defines the UID coding structure and protocols for communication management.
We have no doubt that in the future, VHF products will be used in a large number of applications.
For example, WalMart, Tesco, the U.S. Department of Defense, and Metro Supermarkets are all using RFID in their supply chains.
RFID
What is RFID?
RFID stands for Radio Frequency Identification, commonly known as an electronic tag.
What is RFID technology?
RFID radio frequency identification is a non-contact automatic diagnosis technology, it is through the radio frequency signal automatically identify the target object and obtain the relevant data, identification work without human intervention, can work in a variety of harsh environments.
RFID technology can recognize high-speed movement of objects and can identify multiple tags at the same time, the operation is fast and convenient.
RFID is a simple wireless system with only two basic devices, which are used to control, detect and track objects.
The system consists of one interrogator (or reader) and many transponders (or tags).
What are the basic components of RFID?
Tags (Tag): by the coupling element and chip composition, each tag has a unique electronic code, attached to the object to identify the target object;
Readers (Reader): read (and sometimes write) tag information equipment, can be designed as a hand-held or stationary;
Antennas (Antenna): in the tags and reader between the transmission of radio frequency signals. Transmission of radio frequency signals between the tag and the reader.
What is the basic working principle of RFID technology?
The basic working principle of RFID technology is not complicated: the tag into the magnetic field, receive the radio frequency signal sent by the decoder, by virtue of the inductive current of the energy gained to send out the product information stored in the chip (Passive Tag, passive tags or passive tags), or take the initiative to send a certain frequency of the signal (Active Tag, active tags or active tags); The decoder reads the information and decodes it, and then sends it to the central information system for relevant data processing.
A complete RFID system, by the reader (Reader) and electronic tags (TAG) is also known as the transponder (Transponder) and the application software system consists of three parts, the principle of operation is that the Reader emits a specific frequency of radio wave energy to the Transponder, to drive the Transponder circuit will be the internal Transponder circuitry sends the internal data out, at which point the Reader receives and interprets the data in sequence and sends it to the application program to do the corresponding processing.
To RFID card reader and tag communication and energy sensing way to see can be divided into, inductive coupling (Inductive Coupling) and backscatter coupling (Backscatter Coupling) two kinds of general low-frequency RFID most of the first kind of style, and the higher frequency most of the second kind of way.
Reader according to the use of different structures and technologies can be read or read / write device, is the RFID system information control and processing center.
The reader is usually composed of a coupling module, transceiver module, control module and interface unit.
The reader and transponder generally use half-duplex communication between the information exchange, while the reader through the coupling to the passive transponder to provide energy and timing.
In practical applications, the collection, processing, and remote transmission of object recognition information can be further realized through Ether or WLAN and other management functions.
The transponder is the information carrier of the RFID system, and most of the transponders are composed of coupling elements (coils, microstrip antennas, etc.) and microchips to form a passive unit.
What makes retailers so excited about RFID?
Retail analysts at Sanford C. Bernstein estimate that Walmart could save $8.35 billion annually by adopting RFID, mostly due to labor cost savings from not having to manually look at incoming barcodes.
While other analysts think the $8 billion figure is overly optimistic, there is no doubt that RFID can help solve two of retail's biggest problems: merchandise out-of-stocks and shrinkage (lost product due to theft and supply chain disruption), and right now Walmart loses almost $2 billion a year on theft alone, which would be a lot of money if a legitimate business with that kind of turnover could be in the top 1,000 U.S. stores. figure, it would rank 694th on the list of America's 1,000 largest companies.
Research organizations estimate that this RFID technology can help reduce theft and inventory levels by 25%.
What are the typical applications of RFID technology?
Logistics and supply management
Manufacturing and assembly
Airline baggage handling
Mail/express parcel handling
Document tracking/library management
Animal identification
Sports timing
Access control/electronic ticketing
Automated toll collection on roads
RFID reading and writing.
RFID Read/Write Devices
RFID is only useful if there are read/write devices.
RFID read-write devices have RFID readers, RFID read-write modules, etc., currently on the market more cost-effective YW-201 and YW-601U and YW-601R and so on.
These devices can read or write RFID data, and do a good job encrypting.