What is RFID technology?

What is radio frequency identification technology?

Radio frequency recognition technology (RFID), is a kind of data stored in electronic data carrier (such as integrated circuit), and through the magnetic field or electromagnetic field in wireless way transponder/tag and interrogator/reader ( Interrogator/Reader) two-way communication between the emerging technology, so as to achieve the identification purpose and exchange data the technology can achieve multi-target identification and motion target identification; has resistance to harsh environments, high accuracy, security, flexibility and scalability and many other advantages; easy to achieve item tracking and logistics management through the Internet, and therefore widely concerned. Therefore, RFID is recognized as one of the 10 most promising technologies in this century.
Radio frequency identification technology through radio waves without contact rapid information exchange and storage technology, through wireless communication combined with data access technology, and then connected to the database system, and to achieve non-contact two-way communication, so as to achieve the purpose of identification, for data exchange, in tandem with an extremely complex system. In the recognition system, through the electromagnetic wave realization electronic label read-write and the communication. According to the communication distance, may divide into the near field and the far field, for this reason reads/writes the equipment and the electronic label between the data exchange method also correspondingly is divided into the load modulation and the backscatter modulation.
The radio’s signal is through the electromagnetic field which tunes into the radio frequency, transmits the data from the label which attaches to the article, in order to automatically recognize and trace the article. Some tags can get energy from the electromagnetic field emitted by the identifier during identification and do not need batteries; there are also tags that have their own power source and can actively emit radio waves (electromagnetic fields tuned to radio frequencies). The tag contains electronically stored information and can be recognized within several meters. Unlike bar codes, RFID tags do not need to be in the line of sight of the identifier and can be embedded within the object being tracked.

RFID refers to the transmission of digital IDs and other data between RFID tags and readers via electromagnetic waves in a wireless or non-contact manner. Tagging physical objects allows businesses, organizations and consumers to identify, verify, track, detect and interact with each item seamlessly through a unique digital ID (digital twin). 
Unlike other automatic identification technologies such as optical QR codes, RFID can read tags within a line of sight range of a few centimeters to more than 20 meters, depending on the type of RFID system. Typical examples are using a fixed reader door mounted behind a door in the shipping area to read hundreds of tagged products in totes on pallets, or scanning store shelves with a handheld reader to count inventory in seconds, or using a smartphone to scan a luxury wallet to verify authenticity and sign up for a membership, for example.

How RFID technology works

The basic working principle of RFID technology is not complicated: after the tag enters the reader, it receives the RF signal from the reader and sends out the product information stored in the chip (PassiveTag, passive tag) by virtue of the energy obtained from the induction current, or the tag actively sends a signal of a certain frequency (ActiveTag, active tag), and the reader After reading the information and decoding, it is sent to the central information system for relevant data processing.
A complete RFID system is composed of three parts: the reader, the electronic tag, the so-called transponder, and the application software system. The working principle is that the reader (Reader) emits a specific frequency of radio wave energy to drive the circuit to send out the internal data, at which time the Reader will receive and decode the data in sequence and send it to the application to do the corresponding processing.
To RFID card reader and electronic tags between the communication and energy induction method can be roughly divided into: induction coupling and backward scattering coupling two. General low-frequency RFID mostly use the first way, while the higher frequency mostly use the second way.

Readers 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. Readers are usually composed of coupling module, transceiver module, control module and interface unit. Half-duplex communication is generally used between the reader and the tag for information exchange, while the reader provides energy and timing to the passive tag through coupling. In practical applications, management functions such as collection, processing and remote transmission of object identification information can be further realized through Ethernet or WLAN.

Technology and performance parameters of RF identification tags

The radio frequency recognition label is the key of the current radio frequency recognition technology. The radio frequency recognition label may store the certain capacity information and has the certain information processing function, the read-write equipment may exchange the information with the label through the radio signal with the certain data transmission rate, the action distance may vary from several centimeters to 1 kilometer according to the technology used.
Identification label form factor mainly by the antenna decision, and the antenna and depends on the working frequency and to the role of the distance requirements. There are currently four frequencies in which tags are more common in use. They are divided according to their radio frequency: low frequency tags (125 or 134.2kHz), high frequency tags (13.56MHz), UHF tags (868~956MHz) and microwave tags (2.45GHz). Since no global specifications have been developed for the use of UHF tags, such tags are not yet able to be used globally in a uniform manner. The application of UHF tags has received the most attention, and these tags are mainly used in the logistics field. The higher the frequency, the greater the action distance, the higher the data transmission rate, the identification tag form factor can be made smaller, but also the higher the cost. The current consumer-oriented identification tag form factor requirements are generally based on credit card or commodity bar codes.
At the beginning of 2005 each label price is still in 30 euro cent or so, the large quantity (one billion pieces above) produces the radio frequency recognition label price in 2011 already in 10 euro cent or below.
In view of the label and read-write equipment does not need to establish mechanical or optical contact between, the cryptographic technology in the whole radio frequency recognition technology field the status will certainly be increasing. Along with the radio frequency recognition popularization, the compatibility between the different manufacturers’ label and read-write equipment will also become the problem worthy of attention.
In addition, the service life, the use environment and the reliability are also important parameters.
Radio frequency identification technology also includes a set of information technology infrastructure, including.
The radio frequency recognition label, also called the radio frequency label, the electronic label, mainly by has the recognition code large-scale integrated line chip and the transceiver antenna constitutes, at present mainly for the passive type, uses when the electric energy takes from the antenna receives the radio wave in the energy.
The radio frequency recognition read-write equipment as well as with the corresponding information service system, such as into the inventory sales system networking and so on.
Will radio frequency category technology and the bar code technology to compare with each other, the radio frequency category has many advantages, such as:

• Can accommodate more capacity.
• Communication distance is long.
• Difficult to replicate.
• High tolerance to environmental changes.
• Multiple tags can be read simultaneously.

The relative disadvantage is that it is expensive to build. However, through the mass use of this technology, the production cost can be significantly reduced.

Components RFID systems

The complete RFID system by the Read-write Reader, electronic tag, antenna and data management system four components.
RFID radio frequency recognition is a kind of non-contact automatic diagnosis technology, it through the radio frequency signal automatically identifies the target object and obtains the relevant data, the recognition work without human intervention, can work in all kinds of harsh environment. RFID technology can identify the high speed movement object and can simultaneously identify multiple tags, the operation is fast and convenient.
Electronic tag: by the coupling components and chip composition, each tag has a unique electronic code, attached to the object identification target object. The electronic label is similar to the barcode in the barcode system, and its internal integration of a chip that can be erased and written for storing information. According to whether with battery, the electronic label is divided into active and passive two kinds. The active electronic label with battery, compared with the passive electronic label, can read the distance is longer.
Reader: read (sometimes can also write) label information equipment, can be designed for handheld rfid read-write (such as: C5000W) or fixed read-write; used to read the electronic label data and transmitted to the upper computer application software system; some can also write data to the electronic label.
Antenna: Transmits the radio frequency signal between the label and the reader.
Data management system: PC or PLC based software system, used to process the data sent by the reader.

RFID electronic tags

RFID tags have a variety of shapes and sizes, can be “passive”, can also be “active”. But the most common is passive tags, which means they do not need an integrated power supply such as batteries. Passive tags are usually composed of RFIDinlay and a housing to prevent physical damage. inlay consists of a small silicon microchip that stores digital IDs and other data and is affixed to an antenna on a thin substrate such as paper or plastic (PET) film. The passive label antenna receives the radio wave from the reader and transmits it to the microchip, the microchip collects the energy and is used to send the wireless signal back to the reader.
The Inlay’s thin size makes it easy to embed into a traditional tag, making it a smart tag, or into very strong plastic (hard tags) or biocompatible glass (glass tags) for use in extremely harsh environments or for injection into animals.
RFID tags use electronics to store messages on a permanent storage area with a miniature radio wave transceiver in the middle of the tag. The reader sends out an encoded radio signal to “interrogate” the RF tag, and the tag receives the signal and sends out its own identification message in response. The identification message can be either the serial number of the tag itself, or other information about the product, such as the material number, production date, batch or lot number, or other specific information.
RF identification tags include passive tags (passive tags), active tags (active tags), and battery-assisted passive tags. Active (active) tags have a built-in battery that periodically emits an identification signal. Battery-assisted passive (BAP) tags have a small battery built in and are only triggered in the vicinity of the RF reader. Passive tags do not have a battery; they are cheaper and smaller because they use the energy from the radio waves coming from the reader to supply their own power. However, in order to make the passive tag work, it must be exposed to about three times the energy level of the signal transmission, which leads to interference and radiation problems.
Tags can be read-only or read-write: read-only tags, the factory set out a serial number, as a password to log into the item’s database; read-write tags, the system user can write specific data about an item into the tag. Field programmable tags are single write multiple read (WORM), where the user can write the product’s electronic code into a blank tag. A tag without a serial number is often in danger of being manipulated.
Radio frequency identification tag has at least two parts: one is an integrated circuit to store and process information, modulation and demodulation of a section of radio frequency signal, from the reader to collect DC energy in the signal, etc.; the second is an antenna to collect the signal transmission signal. Tag information is stored in the non-volatile memory. The radio frequency identification tag includes a logic integrated chip or a programmed or programmable data processor to process and transmit sensor data respectively.
The electronic tag consists of a transceiver antenna, an AC/DC circuit, a demodulation circuit, a logic control circuit, a memory and a modulation circuit.

• (1) Transceiver antenna: receives the signal from the reader and sends the requested data back to the reader.
• (2) AC/DC circuit: Using the electromagnetic field energy emitted by the reader, the output of the voltage regulator circuit provides a stable power supply for other circuits.
• (3) Demodulation circuit: removes the carrier wave from the received signal and demodulates the original signal.
• (4) Logic control circuit: decode the signal from the reader and send back the signal according to the reader’s requirements.
• (5) Memory: As the location for system operation and storage of identification data.
• (6) Modulation circuit: the data sent by the logic control circuit is loaded to the antenna after the modulation circuit to send to the reader.

RFID reader

The RFID reader sends out an encrypted wireless signal to interrogate the tag. The tag receives the signal and responds to it with its own serial number and other information. This may be a unique tag serial number or specific information related to the product like storage quantity, share, lot number, production date.
A reader is a device that reads the information from the label or writes the information that the label needs to store to the label. Depending on the structure and technology used, the reader can be a read/write device and is the information control and processing center of the RFID system. In RFID system operation, an electromagnetic field is formed by the reader sending RF energy in a region, the size of which depends on the transmitting power. The tag in the reader coverage area is triggered to send the data stored in it, or modify the data stored in it according to the reader’s instructions, and can communicate with the computer network through the interface. The basic components of the reader usually include: transceiver antenna, frequency generator, phase-locked loop, modulation circuit, microprocessor, memory, demodulation circuit and peripheral interface.

• (1) Transceiver antenna: send RF signal to the tag, and receive the response signal and tag information returned by the tag.
• (2) Frequency generator: generates the operating frequency of the system.
• (3) Phase-locked loop: generates the required carrier signal.
• (4) Modulation circuit: the signal sent to the tag is loaded to the carrier and sent out by the RF circuit.
• (5) Microprocessor: Generate the signal to be sent to the tag, while the signal returned by the tag is decoded, and the decoded data is returned to the application, if the system is encrypted, the decryption operation is also required.
• (6) Memory: store the user program and data.
• (7) Demodulation circuit: demodulate the signal returned by the tag and give it to the microprocessor for processing.
• (8) Peripheral interface: to communicate with the computer.

RFID frequency bands (Data from: wikipedia.org).

There are several ways of signal propagation between the reader and the tag. These methods are not compatible with each other, but depends on the frequency bands used by the tag. Tags that operate on short-wave and long-wave are very close to the reader’s antenna (shorter than a wavelength distance). In the near-field area, the tag is electronically coupled closely to the transmitter in the reader. The tag can modulate the electric field generated by the reader by varying the electrical load represented by the tag. By switching between lower and higher relative loads, the tag produces changes that can be detected by the reader. At UHF and higher frequencies, the tag has more than one radio wavelength of the reader. The tag can feed back signals. Active tags can contain functionally separate transmitter and receiver, the tag does not have to respond to the reader to interrogate the frequency of the signal.

Electronic product code

Electronic Product Code (EPC) is a common type of data stored in the tag. When written to by an RFID tag printer, the tag contains a 96-bit data string. The first 8 bits are a header that identifies the version of the protocol. The next 28 bits identify the organization that manages the data for this tag; the organization’s number is assigned by the EPCglobal association. The next 24 bits are the object classification, used to identify what category of product it is, and the last 36 bits are the unique serial number of this tag. These last two fields are set by the organization that issued the label. Unlike the URL, the total electronic product code number can be used as a key to access the global database, which uniquely identifies a specific product [8].

Typically, there will be multiple tags responding to the tag reader at the same time, for example, many individual products with tags attached may be shipped in a common box or on a common pallet. Conflict detection is very important when such data can be read. Two different types of protocols are used to “recognize” a label, enabling its data to be read from many similar labels. In the slottedAloha system, the reader issues an initialization command and a parameter, and the tags alone are used to pseudo-randomly delay their responses. When using the “adaptive binary tree” protocol, the reader sends an initialization symbol and then sends the ID data one bit at a time, and only tags matching that one bit respond, so that only one tag matches the entire ID string.
An example of the binary tree method used to identify RFID tags.
These two methods have disadvantages when used for multiple tags or multiple overlapping readers.

Electronic product code information system

RFID tags in the EPC information, can be stored and controlled by the background information system EPICS, EPCIS (EPCInformationService) is GS1 in its EPCglobal (page archive backup, stored in the Internet Archive) Network architecture in an important standard, it is responsible for the storage of EPC and its related dynamic information, each It is responsible for storing EPC and its related dynamic information, each piece of information is called Event, and provides a query interface according to the authority.
The EPC events stored in EPCIS contain various states of the EPC at a certain time and place, and are summarized into 4W (What/When/Where/Why), and each participating unit can query the status of the item with its own authority.

• What – The identification code is 12345.
• When – March 1, 2012 at 10:00 am.
• Where – Factory A, is read.
• Why-Shipping and its subsequent status is in-transit.

The EPCIS standard is open and free of charge, and any manufacturer who wishes can download the specification from GS1EPCglobal and develop the implementation. If the stored and queried information is transnational, it is recommended to use standard EPC codes, standard commercial character codes and standard data formats in order to have a consistent interpretation of commodity information. In practice, manufacturers can also rent a centralized EPCIS system instead of building their own, for example, Tristar’s (page archive backup, stored in the Internet Archive) system.

Classification of radio frequency identification technology

RFID system in fact has existed and developed for decades, from the power supply state can be divided into “active” and “passive” two categories; from the working frequency point of view, can be divided into low frequency (125KHz ~ 135KHz), high frequency ( 13.56MHz), ultra-high frequency, microwave (2.45GHz, 5.8GHz) and other major categories. The hardware price difference of different RFID system is huge, and the characteristics of the system itself are also different, and the maturity of the system is also different. Many questions, even the industry personnel can’t easily give a clear answer therefore the user often feels at a loss when choosing the radio frequency identification technology. The author combined with their own development and application experience, at the same time in reference to the relevant application information and technical data on the basis of, through this paper to try to give the reader a more comprehensive and objective understanding, hope to be able to give the user in the choice of the appropriate frequency of radio frequency identification system to provide some help.
Radio frequency identification technology according to its tag power supply can be divided into three categories, namely passive RFID, active RFID, and semi-active RFID.

Passive RFID

In the three types of RFID products, passive RFID appears the earliest time, the most mature, its application is also the most extensive. In the passive RFID, electronic tags through the acceptance of radio frequency identification reader transmission to the microwave signal, as well as through the electromagnetic induction coil to obtain energy to their own brief power supply, so as to complete this information exchange. Because the power supply system is omitted, so the volume of passive RFID products can reach the centimeter scale or even smaller, and their own structure is simple, low cost, low failure rate, and long service life. But as a price, passive RFID’s effective recognition distance is usually shorter, generally used for close contact identification. Passive RFID mainly works in the lower frequency band 125KHz, 13.56MKHz, etc. Its typical applications include: bus cards, second generation ID cards, canteen meal cards, etc.

Active RFID

Active RFID emerged not long, but has been in various fields, especially in the highway electronic non-stop toll collection system plays an indispensable role. Active RFID through the external power supply, active to send signals to the radio frequency identification reader. Its volume is relatively large. But also therefore has a long transmission distance and high transmission speed. A typical active RFID tag can establish contact with the RFID reader from a hundred meters away, and the reading rate can reach 1,700read/sec. Active RFID mainly works in 900MHz, 2.45GHz, 5.8GHz and other higher frequency bands, and has the function that can identify multiple tags at the same time. Active RFID’s long range, high efficiency, making it in some need of high performance, a large range of radio frequency identification applications in essential.

Semi-active RFID

Passive RFID does not power itself, but the effective recognition distance is too short. Active RFID recognition distance is long enough, but need external power supply, the volume is larger. And semi-active RFID is for this contradiction and the product of compromise. Semi-active RFID is also called low-frequency activation trigger technology. Under normal circumstances, semi-active RFID products in a dormant state, only the tag to maintain data in the part of the power supply, so power consumption is small, can be maintained for a long time. When the tag enters the RFID reader recognition range, the reader first now with 125KHz low frequency signal in a small range of precise activation of the tag to make it enter the working state, and then through the 2.4GHz microwave and its information transmission. That is to say, the first use of low frequency signal precise positioning, and then use high frequency signal fast transmission data. The usual application scenario is that multiple low-frequency readers are placed at different locations for activating semi-active RFID products in a wide range that can be covered by a high-frequency signal. This accomplishes both positioning and information collection and transmission.
According to the different radio frequencies, RFID systems can be divided into four types of low frequency, high frequency, UHF and microwave.

• Low frequency systems (LF): RFID radio wave frequency below 134 KHz system, following the ISO/IEC18000-2 standard.
• High frequency system (HF): RFID radio wave frequency in 13.56MHz system, following ISO/IEC15693 (compatible with ISO/IEC18000-3), ISO14443 standard.
• UHF systems (UF): systems with RFID radio wave frequencies between 860 and 960 MHz, following the ISO/IEC18000-6B/C standard.
• Microwave systems (Microwave): systems with RFID radio wave frequencies between 2.4 GHz, following the ISO/IEC18000-4 standard.

Different frequency band RFID technology characteristics

Low Frequency (Low Frequency)

The use of the frequency band range of 10KHz ~ 1MHz, the common main specifications are 125KHz, 135KHz, etc.. Generally this frequency band of electronic tags are passive, through the inductive coupling method for energy supply and data transmission. The biggest advantage of the low frequency is its label close to the metal or liquid on the item when the label is affected by the smaller, at the same time the low frequency system is very mature, read-write equipment price is low. But the disadvantage is to read the distance is short, can’t simultaneously carry on the multi-tag reading (anti-conflict) and the information quantity is low, the general storage capacity in 128 bit to 512 bit. Mainly used in access control systems, animal chips, car immobilizers and toys, etc. Although the low-frequency system is mature, read-write equipment is inexpensive, but because of its low resonant frequency, the tag needs to produce inductance value is very large wire-wound inductor, and often need to package off-chip resonant capacitor, the cost of its tags rather than other frequency bands high. Compared with UHF and HF, LF system data transmission rate and read distance is lower, but low-frequency system suitable for use in harsh environments. 

High Frequency (HF)

The use of the frequency band range from 1MHz to 400MHz, the common main specifications for 13.56MHz this ISM band. The tags in this band are still mainly passive, also through the inductive coupling method for energy supply and data transmission. The biggest application in this band is the contactless smart card that we are familiar with. Compared to lower frequencies, the transmission speed is faster, usually above 100kbps, and multiple tags can be identified (international standards have proven anti-collision mechanisms). The system in this band benefits from the application and popularity of contactless smart cards, and the system is also more mature, with lower prices for reading and writing devices. The products are the most abundant, with storage capacities ranging from 128 bits to more than 8K bytes, and can support a high level of security features, from the simplest write locking, to stream encryption, and even cryptographic coprocessors are integrated. The general applications are in identification, library management, product management, etc. RFID applications with high security requirements, this band is currently the only choice.

Near Field Communication (NFC)

NFC RFID systems operate in the 13.56 MHz band, with a read range ranging from near contact to 50 cm. Typical applications include library media management, automated manufacturing, gaming chip management, ID cards, contactless payments for NFC payment cards or smartphone applications, and consumer interaction. HF tags require special readers, while NFC tags can be read by virtually any smartphone at a distance of a few centimeters. 
With billions of NFC-enabled smartphones on the market today and more and more consumers getting used to contactless payments, there is a great future for consumer interaction and other new consumer-centric applications using NFC tags.

Ultra High Frequency (UHF)

The frequency band used ranges from 400MHz to 1GHz, and the main common specifications are 433MHz, 868~950MHz. this band transmits energy and information by means of electromagnetic waves. Active and passive applications in this band are very common, passive tag reading distance of about 3 ~ 10m transmission rate is faster, generally can also reach about 100kbps, and because the antenna can be manufactured by etching or printing, so the cost is relatively low. Because of the reading distance, information transmission rate is faster, and can be read and identified at the same time a large number of tags, so especially suitable for logistics and supply chain management and other fields. However, this frequency band’s disadvantage is in the metal and the liquid article’s application is not ideal at the same time the system is not mature, read-write equipment’s price is very expensive, the application and the maintenance cost is also very high. In addition, the security characteristics of this frequency band is general, not suitable for the application field of high security requirements. Compared with HF and LF, UHF system support longer reading range, can achieve a variety of sizes and shapes of cost-effective inlay and tags, and can quickly read the bulk, but more vulnerable to metal or conductive materials or liquid radio wave interference.

Microwave

The use of the frequency range of 1GHz or more, common specifications are 2.45GHz, 5.8GHz. microwave band characteristics and applications and UHF band similar to the reading distance of about 2 meters, but the sensitivity to the environment is higher. Because its frequency is higher than UHF, the size of the tag can be made smaller than UHF, but the water attenuation of the signal in this band is higher than UHF, while the working distance is also smaller than UHF.
It is generally used in baggage tracking, item management, supply chain management…etc.

The characteristics of the radio frequency identification technology

Generally speaking, the radio frequency identification technology has the following characteristics.

1. Applicability: RFID technology relies on electromagnetic waves and does not require physical contact between the connecting parties. This makes it able to ignore dust, fog, plastic, paper, wood and all kinds of obstacles to establish connection and complete communication directly.
2. High efficiency: RFID system read and write speed is extremely fast, a typical RFID transmission process is usually less than 100 milliseconds. High frequency band RFID readers can even identify and read the contents of multiple tags at the same time, greatly improving the efficiency of information transmission.
3. Uniqueness: each RFID tag is unique, through the RFID tag and product one-to-one correspondence, you can clearly track the subsequent circulation of each product.
4. Simplicity: RFID tag structure is simple, high recognition rate, the required reading equipment is simple. Especially with the gradual popularization of NFC technology on smart phones, each user’s cell phone will become the simplest RFID reader.

The advantages and disadvantages of RFID technology

The advantages of RFID technology

RF identification technology can be widely applied to a number of industries and fields, there is bound to be its “superiority”.
In terms of its external manifestation, radio frequency identification technology carrier is generally to have waterproof, anti-magnetic, high temperature resistance and other characteristics, to ensure that radio frequency identification technology in the application of stability. In terms of its use, radio frequency identification has advantages in real-time update data, storage information volume, service life, work efficiency, security and so on. Radio frequency identification can reduce the human material and financial resources under the premise, more convenient update the existing information, make the work more convenient; radio frequency identification technology based on the computer and so on to store information, the maximum can reach several megabytes, can store the information volume is large, guarantee the smooth progress of work; radio frequency identification technology has a long service life, as long as the staff pay attention to the protection when using, it can carry on the repeated use; radio frequency identification Technology has changed the former to the information processing inconvenience, realized the multi-target simultaneously to be recognized, greatly improved the working efficiency; And the radio frequency recognition at the same time has the password protection, is not easy to be forged, the security is high. The technology similar to the radio frequency identification technology is the traditional bar code technology, the traditional bar code technology in the update data, the storage information quantity, the service life, the efficiency, the security and so on are poorer than the radio frequency identification technology, can’t adapt well to our country’s current social development demand, also difficult to meet the industry as well as the related field needs.
RFID is an easy to manipulate, simple and practical and especially suitable for automation control flexibility application technology, identification work without human intervention, it can support both read-only work mode can also support read-write work mode, and no contact or targeting; can work freely in a variety of harsh environments: short-distance RF products are not afraid of oil, dust pollution and other harsh environments, can replace the bar code, for example, used in the factory Flow line to track objects; Long distance RF products are mostly used in traffic, recognition distance can reach tens of meters, such as automatic charging or identification of vehicle identity, etc. Radio frequency identification system has the following main system advantages.
1. Anti-interference superb
It has one of the most important advantages is non-contact identification, it can be in the sharp harsh environment can work, can and penetration is extremely strong, can quickly identify and read the tag.
2. The data capacity of RFID tags is very large
It can be expanded to 10k according to the user’s needs, much higher than the capacity of 2725 digits of the 2D bar code.
3. It can be dynamically manipulated
Its tag data can be dynamically modified using programming, and can be dynamically tracked and monitored as long as the object to which the RFID tag is attached appears within the effective recognition range of the decoder.
4. Long service life
Because of its strong resistance to interference, RFID tags are not easily damaged and have a long service life.
5. Anti-Collision
It can read multiple RFID tags at the same time within the effective recognition range of the decoder.
6. High security
RFID tags can be attached to the product in any form, and can encrypt the tag data with a password to improve security.
7. Fast identification speed
As soon as the RFID tag enters the effective recognition range of the decoder, it immediately starts to read the data, and in general less than 100 milliseconds to complete the recognition.
Of course, every technology has its advantages and disadvantages, RFID technology development to today, there will be defects, that is, the technology of the UHF band is not widely enough used, the technology is not mature enough, the relevant products are expensive, stability is not high, the international community has not developed a unified standard.
At present, RFID technology has been closely related to our daily life, in the current era of the Internet of things, if RFID technology is improved, RFID UHF technology is mature, RFID UHF market development is widely used, then the development of the Internet of things will also be pushed to a new height.

The disadvantages of RFID technology

• (1) The technology maturity is not enough. RFID technology appears time is short, in technology is not very mature. Because of the UHF RFID electronic tag has the reverse reflectivity characteristic, makes its application in the metal, liquid and other commodities more difficult.
• (2) High cost. RFID tags relative to ordinary bar code tags are more expensive, dozens of times the ordinary bar code tags, if the use of large quantities, it will cause the cost is too high, to a large extent, reducing the market enthusiasm for the use of RFID technology.
• (3) Security is not strong enough. RFID technology faces security problems are mainly manifested in the RFID electronic tag information is illegally read and malicious tampering.
• (4) Technical standards are not uniform.
• (5) RFID UHF (UHF) tags due to electromagnetic backscatter (Backscatter) characteristics of metals and liquids and other environments are more sensitive, which can lead to this working frequency passive tags (Passivetag) difficult to work in objects with metal surfaces or liquid environment, but such problems have been completely solved with the development of technology.
• (6) As RFID tags do not need to contact directly with the transceiver, the user will be unaware of the situation by others to read the information stored in the tag, posing security concerns.

Top ten issues and threats of RFID security

Like other security devices, the security of RFID devices is not perfect. Although RFID devices are widely used, they pose security threats that need to be addressed before the device is deployed. The following article will focus on several RFID-related security issues.
01. RFID forgery
Based on computing power, RFID can be divided into three categories.

• 1. Ordinary tags;
• 2. Tags using symmetric keys;
• 3. Tags using asymmetric keys.

Among them, ordinary tags do not do any cryptographic operation, which can be easily forged. However, ordinary tags are widely used in logistics management and tourism, and an attacker can easily write information into a blank RFID tag or modify an existing tag to gain access to the corresponding authentication system using RFID tags. For common tags attackers can do the following three things.
According to the computing power, RFID can be divided into three categories.

• 1. Modify the data in an existing tag to make an invalid tag valid, or conversely, to make a valid tag invalid. For example, it is possible to modify the contents of a tag of an item and then purchase an expensive item at a lower price.
• 2. Also modify the label, but the content of one label is modified to the content of another label, that is, the civet.
• 3. Create a label of your own based on the content of someone else’s label that you have obtained.
• So, when want to use RFID tags in some systems that deal with sensitive information such as ID cards, be sure to use encryption technology. However, if you have to use ordinary tags, make sure that they are equipped with appropriate security specifications, monitoring and auditing procedures to detect any abnormal behavior in the RFID system.

02. RFID Sniffing
RFID sniffing is a major problem in RFID systems. RFID readers always send authentication requests to tags, and when the reader receives the authentication information from the tag, it uses the back-end database to verify the legitimacy of the tag’s authentication information.
But unfortunately, most RFID tags do not authenticate the RFID reader’s legitimacy. Then the attacker can use his own reader to snare the tag’s content.
03. Tracking
By reading the content on a tag, an attacker can track the movement of an object or person. When a tag comes within the reader’s readable range, the reader can identify the tag and record the tag’s current location.
Whether or not the communication between the tag and the reader is encrypted, there is no escaping the fact that the tag is being tracked. An attacker can use a mobile bot to track the tag’s location.
04. Denial of Service
When the reader receives an authentication message from the tag, it compares the authentication information with the information in the back-end database. Both the reader and the back-end database are vulnerable to denial-of-service attacks.
When there is a denial of service attack, the reader will not be able to complete the authentication of the tag and cause the interruption of other corresponding services. Therefore, it is important to ensure that there are corresponding mechanisms to prevent denial-of-service attacks between the reader and the back-end database.
05. Spoofing
In a spoofing attack, the attacker often fakes himself as a legitimate user. Sometimes, the attacker will fake himself as the administrator of the back-end database. If the fake is successful, then the attacker can do whatever he wants, such as: corresponding invalid requests, changing RFID identifiers, denying normal services or simply planting malicious code in the system directly.
06. Denial
Denial is when a user refuses to acknowledge that he has done an operation after it has been performed. When a denial is sent, there is no way for the system to verify whether the user has performed the operation or not.
In the use of RFID, there are two possible denials: one is that the sender or receiver may deny having performed an operation, such as sending an RFID request, when we do not have any evidence to prove whether the sender or receiver has sent an RFID request; the other is that the owner of the database may deny that they have given any tag to an item or person.
07. Insertion Attack
In this attack, the attacker attempts to send a system command to the RFID system instead of the normal data content. One of the simplest examples is when an attacker inserts an attack command into the normal data stored by the tag.
08. Retransmission Attack
By intercepting the communication between the tag and the reader, the attacker records the tag’s reply to the reader’s authentication request and later retransmits this information to the reader. An example of a retransmission attack is where the attacker records the information used for authentication between the tag and the reader.
09. Physical Attacks
Physical attacks are sent when an attacker has physical access to the tag and tampers with the tag’s information. There are various ways of physical attacks, such as using microprobes to read and modify tag contents, using X-rays or other rays to destroy tag contents, and using electromagnetic interference to disrupt the communication between the tag and the reader.
In addition, anyone can easily use a knife or other tool to artificially damage the tag so that the reader cannot recognize the tag.
10. Virus
Like other information systems, RFID systems are susceptible to virus attacks. In most cases, viruses target the back-end database. RFID viruses can destroy or leak the tag contents stored in the back-end database and deny or interfere with the communication between the reader and the back-end database. To protect the back-end database, it is important to patch database vulnerabilities and other risks in a timely manner.
Although RFID systems are often the target of attacks, the low cost of RFID systems has made them widely used in many fields. So when preparing to deploy RFID systems, be sure to pay more attention to their security, especially the first four attacks described in this paper: forgery, sniffing, tracking, and denial-of-service attacks.

Application areas of RF identification technology

(1) Expressway charging and intelligent transportation system
At present China’s highway development is very fast, the regional economic development prerequisite is to have convenient transportation conditions, but the highway toll but there are some problems, one is traffic jam, in the toll station entrance, many vehicles to stop queue to pay the toll, become a traffic bottleneck problem; Second, a few unlawful toll collectors embezzle the collected toll, so that the country suffered a loss of financial revenue.
RFID technology applied to the highway automatic toll collection can fully reflect the advantages of the technology. In the vehicle through the toll station at high speed at the same time automatically complete payment, solve the bottleneck problem of traffic, improve the speed of traffic, to avoid congestion, improve the efficiency of the toll calculation, and at the same time can solve the problem of toll collectors to embezzle the collected toll.
(2) Automation and process control of production
RFID technology has many applications in production process control because of its strong resistance to harsh environments, non-contact identification and other characteristics. By using RFID technology in automated production lines of large factories, material tracking and automatic control and monitoring of production processes are realized, which improves production efficiency, improves production methods and reduces costs.
In the automation and process control of production lines, BMW of Germany has applied RFID systems to car assembly lines in order to ensure that cars are accurately assembled at each location on the assembly line. And Motoro 1 a has adopted the automatic identification process control system of RFID technology to meet the special requirements of semiconductor production on the environment, while improving production efficiency.
(3) Automatic identification of vehicles and theft prevention
Through the establishment of the automatic vehicle number recognition system which adopts the radio frequency identification technology, it can understand the running situation of the vehicle at any time, not only realizes the automatic tracking management of the vehicle, but also can greatly reduce the possibility of the accident, and can effectively verify the owner of the vehicle through the radio frequency identification technology, prevent the theft of the vehicle from occurring, and can effectively find the lost vehicle after the vehicle is lost.
Using radio frequency identification technology can be real-time monitoring, statistics, scheduling of road traffic flow, but also can be used as vehicles running red light record alarm, stolen (suspicious) vehicle alarm and tracking, special vehicle tracking, hit-and-run vehicle exclusion, etc.. Reportedly, the United Kingdom plans to install radio frequency chip in the car, driving over speed will be automatically “reported”.
(4) Electronic ticket
Use the electronic label to replace all kinds of “card”, realize the non-cash settlement, solved the cash transaction inconvenient also unsafe as well as the previous kinds of magnetic card, IC card easily damaged and so on. At the same time the electronic label uses convenient, quick, also may simultaneously recognize several electronic labels, parallel charge.
Radio frequency recognition system, especially the non-contact IC card (electronic label) application potential one of the biggest fields is the public transportation field. Using the electronic label as the electronic ticket, has the advantage that the use is convenient, can shorten the transaction time, reduces the operation cost and so on.
In January 1996 South Korea in Seoul 600 public vehicles installed radio frequency recognition system for electronic monthly ticket, realized the non-cash settlement, convenient the public travel. And the German Lufthansa airline begins the trial radio frequency card (electronic label) as the airplane ticket, changed the traditional air ticket purchase and sale method, simplified the airport entry procedure.
(5) Cargo tracking management and monitoring
The radio frequency recognition technology for the cargo tracing management and the monitoring has provided the convenient, the quick, the accurate automatic technical method.
The automatic identification of container with radio frequency identification technology as the core has become the largest cargo tracking management application in the world. Will record has the container position, the item category, the quantity and so on data electronic label installs in the container, by means of the radio frequency recognition technology, may determine the container in the freight yard the exact position. The system can also identify the container movement which is not allowed, which is beneficial to management and security.
In the cargo tracking, the management and the monitoring aspect, Australia and the British Heathrow airport will radio frequency recognition technology application in the passenger baggage management, greatly improved the sorting efficiency, reduced the error rate. In a few years ago, the European Community requested from 1997 onwards the production of new models must have the anti-theft system based on the radio frequency identification technology. At present our country railroad department also plans to promote the line baggage automatic tracking management system, but the real application will take time.
(6) Storage, distribution and other logistics links
The radio frequency identification system is used in the intelligent warehouse goods management, can effectively solve the management of the information related to the flow of goods in the warehouse, monitor the goods information, real-time understanding of the inventory situation, automatic identification of goods, determine the location of goods.
(7) Automatic sorting system for mail and postal packages
Radio frequency identification technology has been successfully applied to the automatic sorting system of postal parcels in the postal field. The system has the characteristics of non-contact and non-line-of-sight data transmission, so the directionality of the parcels can be disregarded in the parcel transmission. In addition, when multiple targets enter the recognition area at the same time, they can be recognized at the same time, which greatly improves the goods sorting capacity and processing speed. In addition, because the electronic label may record all the characteristic data of the parcel, is more conducive to improve the accuracy of the parcel sorting.
(8) Animal tracking and management
The radio frequency recognition technology may use in the animal tracking and the management. Will use the small glass package electronic label planted in the animal skin, may identify the livestock, monitors the animal health condition and other important information, provides the reliable technical method for the ranch management modernization. In the large farm, may through the use radio frequency recognition technology to establish the breeding file, the preventive inoculation file and so on, achieves the high efficiency, the automation management livestock the purpose, at the same time provides the guarantee for the food safety.
In animal tracking and management, many developed countries use radio frequency identification technology, through the livestock individual identification, to ensure that the livestock large-scale disease outbreak during the effective tracking of the infected and the uninfected isolation control.
(9) Access control security
The future access control security system all can apply the electronic label, one card can be multi-purpose, such as do work card, the access card, the parking card, the hotel accommodation card and even the travel passport and so on. Use the electronic label can effectively identify the personnel, carry on the security management as well as the high efficiency charge, simplified the access procedure, improved the working efficiency, and effectively carried on the security protection. The system will automatically recognize the identity when the personnel enter and leave, and there will be an alarm when the illegal entry. Where the security level is high, other identification methods can be combined, and fingerprints, palm prints or facial features can be stored in the electronic tag.
(10) Anti-counterfeiting
The forgery problem is a headache in all over the world, the present application of anti-counterfeiting technology such as holographic anti-counterfeiting will be forged by the wrongdoer as well. Will the radio frequency recognition technology application in the anti-counterfeiting domain has its own technical advantage, it has the low cost but also very difficult to forge the advantage. The cost of the electronic label is relatively cheap, and the manufacture of the chip requires an expensive factory, which discourages forgers. The electronic label itself has a memory, can store, modify the data related to the product, and facilitate the authentication of authenticity. Using this technology does not need to change the existing data management system, the unique product identification number can be fully compatible with the database system already in use.
(11) Footwear field
All clothing stores need to take an inventory of clothing every once in a while in order to make decisions on the promotion of old products and the purchase of new ones. For a large clothing store with 100,000 pieces of clothing, the inventory may take 2 to 3 days to complete if it relies on manual counting one piece at a time or sweeping one piece at a time with a code gun. In addition, the reader installed in the fitting room can record the types of clothes that are tried on the most times, and the recorded data is uploaded to the cloud data, which can form valuable data analysis.
(12) Restaurant industry
Core tray intelligent settlement model. The so-called core plate intelligent settlement mode, is in the bottom of each tableware implanted RFID chip, tableware into the dining table settlement area (RF antenna induction area), through the bottom of the tableware RFID chip to read and write operations, with the help of the computer and its communication technology, to achieve the bottom of the tableware RFID chip communication and management, to achieve rapid settlement.
Intelligent dinner plate not only appearance and ordinary tableware no difference, in the application also greatly improve the settlement speed. Under the application of this tableware, customers only need to use the billing card or third-party payment, they can complete the settlement in 2 to 3 seconds, avoiding long queues and reducing the waiting time. As for the operator, the adoption of the core plate intelligent settlement mode will make it take the initiative and have a convenient scientific management with higher efficiency than the traditional dining mode.

Selecting the right frequency band RFID technology according to the application

How to choose the appropriate radio frequency identification technology?

• First, the cost of a radio frequency identification system, including hardware cost, software cost and integration cost, etc.. And hardware cost not only includes read-write and label cost, but also includes the installation cost. Very often, the application and data management software and integration is the main cost of the whole application. If you consider from the cost, must be based on the overall cost of the system, not just limited to the hardware, such as the price of the tag. Here, we will not discuss and analyze this part further, but the reader needs to have an understanding and awareness of this. In the following, we will mainly discuss how to choose the right frequency band from the technical aspect.
• Secondly, we know that even the communication distance of RFID system in the same frequency band is also very different. Because the communication distance usually depends on the antenna design, the read-write output power, the label chip power consumption and the read-write receiving sensitivity and so on. We can’t simply think that a certain frequency band’s radio frequency recognition system’s working distance is greater than another frequency band’s radio frequency recognition system.
• Third, although the ideal radio frequency recognition system is the long working distance, the high transmission rate and the low power consumption. However, the reality of the situation this kind of ideal radio frequency system is not exist, the high data transmission rate can only be achieved under the relatively close distance. Conversely, if the communication distance is to be increased, the data transmission rate needs to be reduced. So we must sacrifice the communication rate if we want to choose the radio frequency identification technology with long communication distance. The process of choosing the frequency band is often a kind of compromise process.
• Fourth, in addition to consider the communication distance, when we choose a radio frequency system, usually also have to consider the memory capacity, security characteristics and other factors. According to these application requirements, only then can we determine the suitable RF identification frequency band and solution. From the existing solution point of view, the UHF and microwave radio frequency recognition system has the biggest operation distance (can reach 3 to 10 meters) and has the faster communication rate, but in order to reduce the power consumption and complexity of the tag chip, and does not realize the complex security mechanism, is limited to write lock and password protection and other simple security mechanism. Moreover, the electromagnetic wave energy of the frequency band in the water attenuation serious, so for tracking animals (body contains more than 50% of water), containing liquid medicine, etc. is not suitable. Low-frequency and high-frequency system read-write distance is small, usually not more than one meter. The high frequency band is used by technically mature contactless smart cards, which can support large memory capacity and complex security algorithms. As mentioned earlier, the operating distance of contactless smart cards is typically around 10 cm due to the communication rate and security requirements. The ISO15693 specification in the high-frequency band increases the communication distance by reducing the communication rate, and the working distance can reach more than 1 meter with large antennas and high-power readers. Low frequency band because the carrier frequency is low, more than 100 times lower than the high frequency 13.56MHz, so the communication rate is the lowest, and usually does not support the reading of multiple tags.

Case study of RF identification technology

Animal tracking management

The animal tracking and the management traditionally is uses the low frequency frequency band radio frequency recognition technology, and has the international specification specification code and the space signal interface, the corresponding international specification is ISO11784 and the ISO11785 respectively. because the high frequency and the low frequency radio frequency recognition technology each has the advantage and the disadvantage, so now the international frequency band about the animal tracking management also has the debate. The reasons supporting the adoption of low-frequency technology solution are mainly.
(1) The fact that the existence of international norms, compatibility requirements.
(2) If use single antenna solution, usually low frequency system than high frequency system read and write distance to 20% to 30%. Because the low-frequency system data rate is low, so the power consumption of the tag chip can be done below micro-watt.
(3) Although the low-frequency system data transmission rate is low, but in view of its signal robustness, in the actual application of reading efficiency is not low.
(4)The low frequency system can penetrate the animal tissue, is the only frequency choice for the implantable electronic tag. And support high-frequency technology program mainly for the following reasons.

• (1)The international standard ISO11784 animal coding method can completely realize in the high frequency and ultra-high frequency band solution, in the application and the system level does not seem to exist difference.
• (2) Due to the frequency difference, low frequency tags require winding wire-wound inductors to form the tag antenna, and the cost of making the tag is higher than that of high frequency tags. High-frequency tags usually only have to be wound about 3 turns for credit card size and can be printed using a low-cost printing process. The overall cost of HF tags is much lower. This is an accepted fact.
• (3) If the realization is reasonable, the high frequency system also can obtain and the low frequency system equivalent read-write distance. And the high frequency read-write can through the door type antenna to control the role range, facilitates the accurate and fast realization data acquisition.
• (4) complete anti-collision mechanism, can quickly and accurately realize multi-target reading. Efficiency and accuracy are higher than using low-frequency handhelds for data acquisition.
• (5) The frequency use of high frequency has become a unified global norm, and the adoption of high frequency systems will not face compatibility problems around the world. The editors are more supportive of the technical solution of using HF in the tracking management of animals that do not require RFID implantation, such as pigs. The main reason is based on the cost of the system considerations. The price and profit margin of agricultural products in China are very low, and the cost of hardware consumption in animal tracking management such as hogs is mainly from the tags. High frequency technology should be used from reducing this part of cost. At the same time, taking into account the pig breeding and other production units usually do not have broadband connection electronic tags may not only store a tag number information, but also may store certain related data. And high-frequency solutions in common storage space can reach more than 1k bits. Second, at present, our main RFID infrastructure is based on high-frequency technology, the use of compatible technology systems in terms of installation costs and reliability are advantageous. High-frequency technology from the chip, tag packaging, read-write machine, system integration and other links, China has hundreds of suppliers, which is not comparable to low-frequency technology. In addition, in the pig management and other applications, does not need to implantable electronic tag, can use the animal ear tag form. Of course, in animal tracking management using high frequency technology program and the traditional high frequency radio frequency system is still different, need to reduce the environment on the operating distance, special read-write equipment development to carry out research and development work, make the high frequency technology in the operating distance and reliability to achieve the system requirements.

Medicine management

Even today, experts still think in the field of consumer goods to achieve the item level tracking management or a need 3 to 5 years to be possible to achieve the goal. However, the adoption of RFID technology for single-item management of relatively high-value pharmaceutical products is already a reality that is happening. The U.S. Food and Drug Administration (FDA) requires that the entire process of tracking and management of pharmaceutical products be achieved in 2007, from raw materials to home medicine box. For the single product management of drug management, it seems that the use of high frequency technology currently has more comprehensive advantages, specifically.

• (1) HF and UHF both realize energy and signal transmission through electromagnetic field, UHF is energy and signal transmission through electric field, the system generally works in the far field, for the single item in close proximity, the label detuning will cause the label (item) to miss reading. The high-frequency system is working in the near-field range (that is, the electromagnetic field is still bound inside the system, and did not form electromagnetic waves emitted) energy and signal is carried out through the magnetic field, for the system inside the tag can be accurately identified (of course, the role of the distance is only within 1 meter), there is better resistance to electromagnetic interference ( ElectromagneticInterference, EMI) ability.
• (2) The influence of liquid and metal. High-frequency signal than the UHF in terms of attenuation in water is small, more suitable for use in containers containing liquid, and a significant part of the drug is in liquid form.
• (3) Storage capacity, the storage capacity of high frequency tags can reach 8K bytes, so you can store more information on the tag to achieve a “mobile database” rather than just an electronic number. This in the current UHF solution has not such a large capacity of the electronic label.
• (4) The high frequency 13.56MHz is the international common ISM band, there is no compatibility problem. And the UHF so far global not all areas have the corresponding radio frequency recognition label band can use. Our country’s UHF band is in the process of development.

Each band of RFID technology has its own characteristics. Even in the same frequency band of the radio frequency identification system, its communication distance is also very different. We can’t simply think that a certain frequency band’s RFID system’s working distance is greater than another frequency band’s RFID system. And in the actual selection of radio frequency system, need to consider the overall cost of an RFID system, as well as memory capacity, security characteristics and other factors, according to these to comprehensive selection of suitable RFID frequency band.

The development trend of radio frequency identification technology

Trend of radio frequency identification tag

With the development of standards, the wide range of application fields, the increase in the number of applications, the continuous improvement of the process, the rapid progress of technology (such as in books, in the cover or copyright page with conductive ink directly in the printing of radio frequency identification antenna), its cost will be lower; secondly, the recognition distance is farther, even passive radio frequency identification tags can reach tens of meters; volume will also be smaller.

High frequency

UHF radio frequency identification system and low frequency system, compared with the recognition distance is far, data exchange speed is faster, forgery difficulty is higher, the outside world’s anti-interference ability is stronger, the volume is small, and with the reduction of manufacturing cost and high frequency technology further improvement, the application of UHF system will be more extensive.

Networking

Some applications need to unify the data collected by different systems (or multiple readers), and then provide users with the use, such as we use the second generation ID card in the automatic ticket machine to take train tickets, which requires the network management of radio frequency identification system, to achieve remote control and management of the system.

Multifunctionalization

With the continuous improvement and popularization of mobile computing technology, the development trend of RFID reader design and manufacturing is to multi-function, multi-interface, multi-format, and to modular, miniaturization, portable, embedded direction; at the same time, multi-reader coordination and networking technology will become one of the future development direction.

Difference between RFID card and IC card

1. Difference in meaning
IC card is made by embedding microelectronic chip into card base conforming to ISO 7816 standard. The communication mode between IC card and reader can be contact or non-contact.
RFID card, namely radio frequency identification technology. It is a kind of automatic identification technology. It carries out non-contact two-way data communication through radio frequency, and uses radio frequency to read and write recording media (electronic tag or radio frequency card), so as to achieve the purpose of identification and data exchange. It is considered to be one of the most potential information technologies in the 21st century.
2. Difference in working principle
The working principle of IC card is that the RF reader sends a set of fixed frequency electromagnetic waves to the IC card. Under the excitation of electromagnetic waves, the LC resonant circuit resonates, so that there is charge in the capacitor. The unidirectional conduction electronic pump connected at the other end of the capacitor sends the capacitor charge to another capacitor for storage. When the accumulated charge reaches 2V, the capacitor provides voltage for other circuits to transmit the data in the card or receive the data of the reader / writer.
The working principle of RFID technology is that after the tag enters the reader, it receives the RF signal sent by the reader and sends the product information (passive tag or passive tag) stored in the chip with the energy obtained by the induced current, or the tag actively sends the signal of a certain frequency (active tag or active tag). After the reader reads and decodes the information, Send to the central information system for relevant data processing.

Difference between active RFID and passive RFID

The two concepts are different:

• 1. Active RFID, also known as active RFID, is the type of electronic tag divided by different power supply modes of electronic tag. It usually supports long-distance identification. Electronic tags can be divided into active electronic tags, passive electronic tags and semi passive electronic tags.
• 2. Passive RFID, that is, passive RF tags adopt frequency hopping working mode and have anti-interference ability. Users can customize reading and writing standard data, which is more efficient in special application systems, and the reading distance can reach more than 10 meters.

They work differently:

• 1. Active electronic tag means that the energy of the tag is provided by the battery. The battery, memory and antenna together form an active electronic tag. Different from the activation mode of passive RF, it always sends out information through the set frequency band before battery replacement.
• 2. The performance of passive RFID tag is greatly affected by tag size, modulation form, circuit Q value, device power consumption and modulation depth. The passive RF tag has 1024 bits memory capacity and ultra wide working frequency band, which not only meets the relevant industry regulations, but also can carry out flexible development and application, and can read and write multiple tags at the same time. Passive RF tag design, no battery, memory can be rewritten more than 100000 times.

The principle of the two batteries is different:

• 1. The active electronic tag supports the built-in battery.
• 2. Passive RF tags do not support built-in batteries.

The price and service life of the two are different:

• 1. Active RFID: high price and relatively short battery life.
• 2. Passive RFID: the price is cheaper than active RFID, and the battery life is relatively long.

Source: China RFID Tags Manufacturer – Actility Technologies Company Limited (www.tractility.com)