Radio frequency technology (RF) is an abbreviation for Radio Frequency. The more common applications are wireless radio frequency identification (Radio Frequency Identification, RFID), often referred to as inductive electronic chip or proximity card, proximity card, non-contact card, electronic tags, electronic barcode, etc.. The principle of the scanner by transmitting a specific frequency of radio wave energy to the receiver, used to drive the receiver circuit will be the internal code sent out, this time the scanner will receive the code.
What is RFID?Radio frequency identification (RFID) technology is also known as electronic label, is a wireless communication technology, can through the radio signal recognition specific target and read and write related data, without recognition system and the establishment of a specific target between the mechanical or optical contact, so it is a kind of non-contact automatic diagnosis technology. Radio frequency recognition system mainly by the electronic label, read-write and antenna and other parts of the composition
radio frequency technology (RF) the main application is what? Compared with the bar code what are its advantagesRadio frequency technology (RF) is a kind of radio communication technology, its basic principle is the electromagnetic theory, the use of radio waves on the record media read and write.RFID system by the signal transmitter (radio frequency tags), signal receivers (readers), transmitting and receiving antenna and other parts of the components.RF technology applications have penetrated into the commercial, industrial, transportation industry, logistics management, RFID technology has penetrated into many fields such as commerce, industry, transportation, logistics management, medical insurance, finance and teaching, etc. 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 tickets, and automated road toll collection. == Please refer to RF and barcode advantages compared to: large information capacity; reusable, long life, can be used in harsh environments; strong penetration; label content can be dynamically changed, the write time is shorter than the printing of barcodes. RF shortcomings: transmitting and receiving devices are expensive; the transmitter life is short ---
Radio Frequency is a technologyWhat is RFID
Radio Frequency is the English "RFID", which is a technology that can be used in a wide range of applications, such as mobile phones, mobile phones, mobile phones and other mobile devices. RFID is the English "Radio Frequency Identification" acronym, known as radio frequency identification, inductive electronic chip or proximity card, proximity card, contactless card ... and so on. And so on, is a kind of non-contact automatic identification technology. According to a study by Pira UK, it is likely to have a significant impact on packaging, printing and paper in the next few years. According to Pira research, one of the important impacts on packaging, printing and paper in the next few years is RFID (Radio Frequency Identification); Forrester Research says data centers adopting Linux, offshore outsourcing, and RFID (Radio Frequency Identification) will be the four major IT trends in 2004; Ares puts RFID in the top 10 technologies to watch for in 2003; and it has been a long time since we have seen such an exciting new technology. seen such exciting new technology" is the ITRI planning team leader Wu Pai-cheng's description of RFID; wireless identification system will replace the bar code - RFID will make ten million checkout clerks out of work (93/12/01 China Times); the old technology RFID has become a new generation of killer applications, the global retail industry, one hundred and twenty-two trillion dollars of merchandise class revolution (833 issue of the Business Week). These are all descriptions of RFID. In fact RFID technology has existed as early as World War II, when the UK used to confirm whether or not the aircraft coming into the airport were their own, in order to avoid accidental attacks.
The simplest RFID system is made up of three parts: the label (Tag), the reader (Reader) and the antenna (Antenna): when the label enters the magnetic field area, the reader receives a signal to send out a signal, by virtue of the inductive current of energy gained by sending out the product information stored on the chip (Passive Tag, unpowered labeling, or passive labeling), or actively send a signal at a certain frequency (Passive Tag), or actively send out a signal at a certain frequency (Passive Tag). Or actively send a certain frequency of the signal (Active Tag, with power roll-up tag or active roll-up tag); reader reads the information and decodes it, and sends it to the central information system for the relevant processing, but in practical applications require other hardware and software support.
According to the United States Retail Chain Industry Alliance estimates, the United States several major retailers, a year because of poor goods management and suffered losses of up to 70 billion U.S. dollars. ProcterGamble (ProcterGamble) former vice president of marketing Kevin Ashton have personal pain, in 1997, ProcterGamble's Ou Lei moisturizing lotion on the market, the commodity is a big bestseller, but too bestseller, many stores shelves are often empty, due to too many commodities, and too slow to check and fill in the speed, "we watched the money from the shelves one minute at a time to lose. Ashton said. It took him two years to find the answer, which is to replace the current bar code with RFID, which becomes an excellent transmitter of information about retail merchandise and can be used in hundreds of different applications and management methods. In the treasure base company (PG) and Gillette company (Gillette) under the sponsorship of the United States Massachusetts Institute of Technology (MIT) two research and development of RFID application technology professors Sanjay Sarma and David Brock, set up the automatic ID center (Auto-ID Center), specializing in the study of RFID electronic merchandise bar code, the establishment of the date 1999 October 1, 1999 was the 25th anniversary of the bar code. In addition to the headquarters at the School of Engineering, MIT, there are branches in the United Kingdom (Cambridge University), Switzerland (St. Gallen University), Australia (University of Adelaide), Japan (Keio University), China (Fudan University) (). .
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What is RF?Question 1: What does RF mean? What is Radio FrequencyRadio Frequency Radio Frequency Technology, abbreviated as RF. radio frequency is radio frequency current Radio Frequency Technology, which is a high-frequency alternating variations of electromagnetic waves. An alternating current that changes less than 1,000 times per second is called a low-frequency current, and one that changes more than 10,000 times per second is called a high-frequency current.
Radio frequency technology classification:
Automatic identification technology
Automatic equipment identification technology is currently the international development of a new technology, the English name for Automatic Equipment Identification, referred to as AEI. The basic idea of the technology is to use some advanced technical means to achieve The basic idea of this technology is to use some advanced technical means to realize the automatic identification and management of all kinds of objects or equipments (personnel, goods) in different states (mobile, static or bad environment).
Currently the most widely used automatic identification technology can be broadly divided into two aspects: optical technology and radio technology. One of the optical technology commonly used products are: bar code and camera two categories. These two types of products have been widely used in people's daily lives, and has been known to people. For example: bar code for commodity management, camera used to capture illegal vehicles and so on.
Radio frequency identification technology
Radio frequency identification technology according to its frequency can be divided into two categories of low-frequency system and high-frequency system; According to the electronic label is equipped with battery power supply, can be divided into two categories of active and passive system; From the electronic label to save the information injected into the way can be divided into the integrated circuit curing type, on-site wired rewrite type and on-site wireless Rewrites three big categories; According to reads the electronic label data the technical realization method, may divide it into the broadcasting transmits the type, the frequency multiplication type and the reflection modulation type three big categories.
1.low frequency system generally refers to its working frequency is less than 30MHz, the typical working frequency has: 125KHz, 225KHz, 13.56MHz and so on, these frequency points apply the radio frequency recognition system generally has the corresponding international standard to support. The basic characteristics of the electronic tag is the lower cost, the amount of data saved in the tag is less, reading distance is shorter (passive case, the typical reading distance of 10cm) electronic tag shape is diverse (card, ring, button, pen), reading antenna directionality is not strong, and so on.
2. High-frequency system generally refers to its operating frequency is greater than 400MHz, the typical working frequency band: 915MHz, 2450MHz, 5800MHz and so on. High-frequency systems are also supported by numerous international standards in these frequency bands. The basic characteristics of the high-frequency system are electronic tags and reader costs are higher, the tag to save a larger amount of data, reading distance (up to a few meters to a dozen meters), to adapt to high-speed movement of the object performance is good, the shape of the general card, reading antenna and electronic tag antenna have a strong directionality.
3. Active tags are equipped with batteries, generally have a longer reading distance, the shortcomings of the battery life is limited (3 ~ 10 years); passive tags without batteries, it receives the reader (readout device) issued by the microwave signals, will be part of the microwave energy converted into direct current for their own work, generally can do maintenance-free. Compared with the active system, the passive system in the reading distance and adapts to the object movement speed the slight limitation ......
Question 2: What is the meaning of radio frequency electric waves need to be emitted, must be high frequency to a certain extent, such as the current GSM 900MHZ and 1800MHZ. the frequency of sound is very low, only 20HZ-20KHZ, this frequency of the signal can not be directly emitted, it must be modulated to a high frequency is also that is the radio frequency to be able to emit, which is the meaning of the RF.
For Radio Frequency Technology to achieve good communication between cell phones and base stations, the radio frequency emitted by the cell phone must be strong enough to work, when the cell phone and the base station distance is close, you can use less power to maintain communication, when the cell phone and the base station distance is very far away, the cell phone must increase its own transmit power to maintain a good level of communication. Therefore, the power of the RF in the cell phone is automatically adjustable.
Since nowadays cell phones for the appearance of small, many of the antenna integrated inside the phone, which has a certain impact on the RF emission, in order to achieve good results, the phone had to further increase the RF power to maintain normal operation, sometimes, this power exceeds the value of the national standard regulations, it will have a certain impact on the human body.
Receiver characteristics are also important for the entire cell phone system. Poor receiver characteristics can cause the user to receive very low quality sound signals, or even cause the user to lose base station information and cause termination of the call. Poor receiver sensitivity is often caused by internal noise and spurious signals emitted by the transmitter feeding back into the receiver. For this reason, the CTIA standard requires that receiver sensitivity be measured at the transmitter's maximum transmit power.
Question 3: What does RF mean?RF stands for Radio Frequency. In the theory of electronics, the current flows through the conductor, the conductor around the formation of a magnetic field; alternating current through the conductor, the conductor around the formation of an alternating electromagnetic field, known as electromagnetic waves. When the frequency of electromagnetic wave is lower than 100khz, the electromagnetic wave will be absorbed by the ground and cannot form an effective transmission, but when the frequency of electromagnetic wave is higher than 100khz, the electromagnetic wave can be propagated in the air.RF refers to high-frequency tactile magnetic wave with the ability to transmit over long distances, and the radio frequency technology has been widely used in the field of wireless communication.
Question 4: What is the radio frequency line RF, that is, can be directly through the transmitting device into the frequency of radio waves. The so-called radio frequency line, is able to transmit this kind of communication signal cable! Generally have (soft, hard) coaxial bile cable, waveguide, etc.
Question 5: What is the RF service in the cell phone ah GSM Global System for Mobile Communications , the second generation of digital mobile communications system.
GPRS established on the GSM network, can provide cell phone Internet, MMS and other new services of a network.
WIFI A technology that allows personal computers, handheld devices (such as PDAs and cell phones) and other terminals to connect to each other wirelessly.
RF Radio Frequency (RF) technology, a technology that allows interactive communication through inductive means.
Mobile phone amplifier A functional module inside the main board of a cell phone circuit that is used to place the received wireless signal.
Question 6: What is the meaning of cosmetic RF? Cosmetic RF generally refers to radiofrequency beauty.
Radiofrequency cosmetic positioning tissue heating, prompting subcutaneous collagen contraction and tightening, while the skin surface cooling measures, the dermis is heated while the epidermis to maintain a normal temperature, this time will produce two reactions: one is the dermis layer of the skin thickened, the wrinkles with shallow or disappear; two is the form of subcutaneous remodeling of the collagen, the production of new collagen, the skin in the Lido after a treatment to become tighter.
Question 7: What is the difference between high-frequency and radio frequency "high-frequency" refers to a range of frequencies
"Radio frequency" refers to the radio frequency circuitry generated by the specific frequency of the modulation wave.
Question 8: Is radio frequency is high frequency radio frequency "radio" means what? Indicates that the electromagnetic frequency can be radiated into space, the frequency range from 300KHz to 300GHz. Radio frequency is short for RF radio frequency is radio frequency current, it is a high-frequency alternating electromagnetic waves. The alternating current that changes less than 1,000 times per second is called low-frequency current, and the one that changes more than 10,000 times per second is called high-frequency current, and radio frequency is such a high-frequency current. High frequency (greater than 10K); radio frequency (300K-300G) is the higher frequency band of high frequency; microwave band (300M-300G) is again the higher frequency band of radio frequency.
Question 9: What is RF front-end equipment? RF front-end is the part of the communication system between the antenna and the IF (or baseband) circuit. In this segment signals are transmitted in RF form. For wireless receivers, the RF front-end typically includes: amplifiers, filters, inverters, and some RF connectivity and matching circuitry.
Question 10: What is the radio frequency card radio frequency card (RF card for short) is a wireless transmission of data set of terrier circuit card, it has data processing and security authentication functions and other unique advantages.
The basic principle of radio frequency technologyThe basic principle of radio frequency technology refers to the electromagnetic wavelength of the processing signal and the circuit or device size is in the same order of magnitude of the circuit, at this time due to the size of the device size and the size of the wire, the circuit needs to be processed with the theory related to the distribution parameters.
These circuits can all be considered as radio frequency circuits, which do not have strict requirements on their frequency, such as long-distance transmission of AC transmission lines (50 or 60 Hz) sometimes have to be processed with the correlation theory of RF.
A system model of a wireless communication transceiver that contains a transmitter circuit, a receiver circuit, and a communication antenna. This transceiver can be used in personal communications and wireless local area networks.
In this system, the digital processing part is mainly to process the digital signal, including sampling, compression, coding, etc.; and then through the A/D converter converter into analog form into the analog signal circuit unit.
The analog signal circuit is divided into two parts: the transmitting part and the receiving part. The main role of the transmitting part is: digital - analog conversion output of low-frequency analog signals and local oscillator to provide high-frequency carrier frequency through the mixer up-converted into RF modulation signal, RF signal through the antenna radiation into the space.
Receiving part of the main role is: space radiation signal through the antenna coupled to the receiving circuit, the received weak signal through the low noise amplifier is amplified with the local oscillator signal through the mixer down-converted into a signal containing intermediate frequency signal component.
The role of the filter is to filter out the useful intermediate frequency signal into the analog-to-digital converter into a digital signal, and then into the digital processing part of the processing.