CN201429849Y - Radio frequency identification reader-writer - Google Patents
Radio frequency identification reader-writer Download PDFInfo
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- CN201429849Y CN201429849Y CN2009201319146U CN200920131914U CN201429849Y CN 201429849 Y CN201429849 Y CN 201429849Y CN 2009201319146 U CN2009201319146 U CN 2009201319146U CN 200920131914 U CN200920131914 U CN 200920131914U CN 201429849 Y CN201429849 Y CN 201429849Y
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- frequency identification
- identification reader
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Abstract
The utility model discloses a radio frequency identification reader-writer, which comprises a microprocessor circuit, a transmitting circuit, a receiving circuit, an antenna circuit and an interface circuit. The microprocessor circuit controls the transmitting circuit and the receiving circuit and is communicated with a host machine through the interface circuit; the transmitting circuit produceshigh frequency transmitted energy, activates an electronic lag via the antenna circuit, supplies energy for the electronic lag, modulates transmitted signals and transmits data to the electronic lag through the antenna circuit; the receiving circuit receives and demodulates radio frequency signals from the electronic lag through the antenna circuit; the microprocessor circuit, the transmitting circuit and the receiving circuit are all formed by universal chips and individual elements. Compared with using a special reader-writer chip, the radio frequency identification reader-writer can reducecost by more than a half so as to guarantee lower product prices of the reader-writer and is favorable for wider application of radio frequency identification technology.
Description
[technical field]
The utility model relates to REID, relates in particular to a kind of radio-frequency identification reader/writer.
[background technology]
REID (RFID) is to rise an automated wireless that also constantly moves to maturity the eighties in last century to discern and data acquisition technology.Compare with automatic identification technologies such as traditional bar code, magnetic cards, the RFID technology all has significant advantage at aspects such as operating distance, confidentiality, intellectuality and adaptives capacity to environment thereof, and can discern a plurality of high-speed moving objects simultaneously, and vast potential for future development is arranged.
Rfid system is made up of electronic tag, antenna circuit, read write line three parts.Read write line by antenna circuit send, received signal, contactlessly read with identification label in the data of being preserved, and information be sent to host computer further handle, thereby reach the purpose of Target Recognition.This shows that read write line is the core of RFID technology.
Frequency of operation that RFID adopts has 125K, 13.56M, and 433M, 915M, 2.4G, frequency ranges such as 5.8G, the 13.56M passive RFID system that wherein is used for closely discerning is one of present most widely used radio-frequency recognition system.13.56M radio-frequency (RF) identification be widely used in personnel's work attendance, electronic entrance ticket, city all-purpose card, fields such as file management.At present, there is TI in the producer that produces the 13.56M electronic tag, companies such as Philips, these companies also produce core component---the read write line integrated chip of 13.56M read write line simultaneously, the processing of these chips are general integrated radio frequency physical channel and part air interface protocol.Domestic 13.56M read write line generally all adopts these chips.At present, the price of this chip is added microprocessor and other interface circuits generally about 30 yuan of Renminbi, and the least cost of read write line is about 40 yuan.Though this price has been the read write line product well below UHF or microwave frequency band, with present application surface, this cost price is further developing in restriction read write line market.
[summary of the invention]
The technical problems to be solved in the utility model provides the comparatively cheap radio-frequency identification reader/writer of a kind of cost.
In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is, a kind of radio-frequency identification reader/writer, comprise microcontroller circuit, radiating circuit, receiving circuit, antenna circuit and interface circuit, described microcontroller circuit is controlled radiating circuit, receiving circuit, and communicates by interface circuit and main frame; Described radiating circuit produces the high-frequency emission energy, by antenna circuit active electron label, for it provides energy, and modulates transmitting, and transfers data to electronic tag by antenna circuit; Described receiving circuit receives also demodulation from the radiofrequency signal of electronic tag by antenna circuit; Described microcontroller circuit, radiating circuit and receiving circuit are formed by general-purpose chip and discrete component.
Above-described radio-frequency identification reader/writer, described microcontroller circuit comprises single-chip microcomputer and crystal oscillating circuit, and described crystal oscillating circuit provides clock signal to single-chip microcomputer, and described single-chip microcomputer provides baseband signal to radiating circuit.
Above-described radio-frequency identification reader/writer, in radiating circuit, from the local oscillation signal of described crystal oscillator with enter diode together from the baseband signal of single-chip microcomputer and carry out mixing, again through the low pass filter filters out higher hamonic wave, the signal of process filtering inserts antenna circuit and outwards sends modulated signal after the mixing after two-stage amplifier amplifies.
Above-described radio-frequency identification reader/writer, in described two-stage amplifier, first order amplifier is 1 paraphase Schmidt trigger, second level amplifier is made of the parallel connection of a plurality of paraphase Schmidt trigger.
Above-described radio-frequency identification reader/writer, second level amplifier is made of the parallel connection of 5 paraphase Schmidt triggers, and paraphase Schmidt trigger in the first order amplifier and second level amplifier belong to 1 integrated circuit (IC) chip by 5 paraphase Schmidt triggers.
Above-described radio-frequency identification reader/writer, in described receiving circuit, from the radiofrequency signal of electronic tag after detector diode detection, filter capacitor filtering high-frequency signal, capacitance remove direct current, carrying out signal by the two-stage in-phase amplifier amplifies, signal after the amplification is through RC low pass filter filters out noise, enter the in-phase input end of comparer then, the inverting input of comparer is a threshold voltage.The output signal of comparer enters single-chip microcomputer and handles.
Above-described radio-frequency identification reader/writer comprises 1 operational amplifier integrated circuit (IC) chip, and described operational amplifier integrated circuit (IC) chip comprises 3 operational amplifiers.Wherein 2 operational amplifiers are as described two-stage in-phase amplifier,, 1 operational amplifier is as described comparer in addition.
Above-described radio-frequency identification reader/writer, described antenna circuit comprise EMC low-pass filter, antenna circuit match circuit and antenna circuit coil.
Above-described radio-frequency identification reader/writer, described interface circuit comprise USB interface and USART conversion chip, and described USB interface is communicated by letter with chip microcontroller by the USART conversion chip; Described USB interface provides low-tension supply to each circuit of radio-frequency identification reader/writer.。
The microcontroller circuit of the utility model radio-frequency identification reader/writer, radiating circuit and receiving circuit are formed by general-purpose chip and discrete component, can be than the cost that uses read-write machine dedicated chip to reduce by more than 50, product price with the assurance read write line is cheaper, helps the widespread use of REID.
[description of drawings]
Below in conjunction with the drawings and specific embodiments the utility model is described in further detail.
Fig. 1 is the theory diagram of the utility model radio-frequency identification reader/writer embodiment.
Fig. 2 is the circuit diagram of the utility model radio-frequency identification reader/writer embodiment microcontroller circuit.
Fig. 3 is the circuit diagram of the utility model radio-frequency identification reader/writer embodiment radiating circuit.
Fig. 4 is the circuit diagram of the utility model radio-frequency identification reader/writer embodiment receiving circuit.
Fig. 5 is the circuit diagram of the utility model radio-frequency identification reader/writer embodiment antenna circuit.
Fig. 6 is the circuit diagram of the utility model radio-frequency identification reader/writer embodiment interface circuit.
[embodiment]
The embodiment of the utility model radio-frequency identification reader/writer as shown in Figure 1 comprises microcontroller circuit, radiating circuit, receiving circuit, antenna circuit and interface circuit, microcontroller circuit is controlled radiating circuit, receiving circuit, and communicates by interface circuit and main frame; Radiating circuit produces the high-frequency emission energy, by antenna circuit active electron label, for it provides energy, and modulates transmitting, and transfers data to electronic tag by antenna circuit; Receiving circuit receives also demodulation from the radiofrequency signal of electronic tag by antenna circuit; Microcontroller circuit in the present embodiment, radiating circuit and receiving circuit are formed by general-purpose chip and discrete component.
As shown in Figure 2, microcontroller circuit comprises AVR series monolithic MEGA88 and the crystal oscillating circuit as the single-chip microcomputer atmel corp of microprocessor (MCU).Because what rfid system adopted is 13.56M frequency range radiofrequency signal, therefore the dominant frequency with MCU is made as 13.56M, with synchronized transmission and the reception that makes things convenient for signal.MCU adopts the 13.56M external crystal-controlled oscillation that the clock source is provided, and when fuse bit disposes external crystal-controlled oscillation is configured to full width of cloth vibration, and the radio-frequency transmissions circuit is supplied with in this clock source simultaneously.Because MEGA88 has the auto-reset function of powering on, so do not need to add other reset circuits, causes exceptional reset for preventing external electromagnetic interference, need add a 10K pull-up resistor on reset pin.The transmission of label signal and reception pin can be selected arbitrarily.Present embodiment selects PB.0 for sending pin, and PD.3 is for receiving pin.
As shown in Figure 3, the local oscillation signal of radiating circuit picks up from the 13.56M crystal oscillator, adopts diode mixer circuit to carry out the signal modulation.The ASK baseband signal of modulation is produced by single-chip microcomputer.PB.0 pin by single-chip microcomputer produces square-wave modulation signal, and the carrier wave that process resistance R 1 back and crystal oscillator insert enters schottky diode D1 together and carries out mixing.Modulated signal after the mixing adopts Schmidt trigger to increase drive current, promptly carries out power amplification.Integrated chip 74HCT14 contains 6 paraphase Schmidt triggers, will be wherein 1 amplify as the first order, other 5 are together in parallel and amplify as the second level.Signal after the amplification is through the low-pass filter of inductance L 1 and capacitor C 4 compositions, and the cutoff frequency of wave filter is designed to 20M, with the filtering higher hamonic wave.The signal of process wave filter promptly inserts antenna circuit and sends.
Receiving circuit as shown in Figure 4, the tag reflection signal is equivalent to amplitude-modulated signal, demodulation method is selected the method for diode envelope detection.Select for use schottky diode D2 as detector diode.By capacitor C 13 filtering high-frequency signals, after process capacitor C 14 is removed direct current, enter operational amplifier and carry out the signal amplification after the detection.Operational amplifier chip model is LM2902, and it comprises the operational amplifier of 4 separate units.Adopt wherein 2 to make the two-stage in-phase amplifier, every grade of Amplifier Gain is designed to 10 times, and two-stage is amplified totally 100 multiplication benefits.Signal after the amplification enters the in-phase input end of the 3rd operational amplifier then through RC low pass filter filters out noise.The 3rd operational amplifier be the device circuit as a comparison, and inverting input is a threshold voltage.Entering single-chip microcomputer after the comparer output handles.
As shown in Figure 5, present embodiment uses the directly antenna of coupling.Match circuit and aerial coil comprising EMC wave filter, antenna itself.The EMC wave filter adopts the LC low-pass filter, effectively suppresses three times, five times and the higher hamonic wave of 13.56MHZ.When the coil of antenna and the coil of electronic tag intercouple, electric current I in the card reader antenna coil produces magnetic flux, part magnetic flux passes the coil of label, coil at label produces induction electromotive force, this voltage is by rectification, when reaching the operating voltage of label, label is activated, thereby realizes the communication between card reader and the label.
As shown in Figure 6, present embodiment provides UART to change USB interface, uses the CP2102 switching bridge of SiliconLab company, USB interface selection standard MiniUSB joint, and each circuit of whole card reader is powered by USB interface, and supply voltage is 5V, and electric current is 100mA.
In the present embodiment, the microprocessor ATMEGA48 price of selecting for use is about 5 yuan, Schmidt trigger 74HCT14 and operational amplifier LM2902 price are all below 1 yuan, add other interface chips and discrete component, the components and parts cost of read write line can be controlled at below 15 yuan, has reduced half cost of having a surplus than the scheme of using the read write line chip like this.Chip used and components and parts are general-purpose device, are fit to produce in enormous quantities.
The read write line that this project is designed, base band signal process such as data transmit-receive, encoding and decoding are finished by software fully, can support IS015693 and IS014443A/B agreement, can also expand the agreement of other types, are fit to the application demand in different regions and field.
Claims (9)
1. radio-frequency identification reader/writer, it is characterized in that, comprise microcontroller circuit, radiating circuit, receiving circuit, antenna circuit and interface circuit, described microcontroller circuit is controlled radiating circuit, receiving circuit, and communicates by interface circuit and main frame; Described radiating circuit produces the high-frequency emission energy, by antenna circuit active electron label, for it provides energy, and modulates transmitting, and transfers data to electronic tag by antenna circuit; Described receiving circuit receives also demodulation from the radiofrequency signal of electronic tag by antenna circuit; Described microcontroller circuit, radiating circuit and receiving circuit are formed by general-purpose chip and discrete component.
2. radio-frequency identification reader/writer according to claim 1, it is characterized in that, described microcontroller circuit comprises single-chip microcomputer and crystal oscillating circuit, and described crystal oscillating circuit provides clock signal to single-chip microcomputer, and described single-chip microcomputer provides baseband signal to radiating circuit.
3. radio-frequency identification reader/writer according to claim 2, it is characterized in that, in radiating circuit, from the local oscillation signal of described crystal oscillator with enter diode together from the baseband signal of single-chip microcomputer and carry out mixing, again through the low pass filter filters out higher hamonic wave, the signal of process filtering inserts antenna circuit and outwards sends modulated signal after the mixing after two-stage amplifier amplifies.
4. radio-frequency identification reader/writer according to claim 3 is characterized in that, in described two-stage amplifier, first order amplifier is 1 paraphase Schmidt trigger, and second level amplifier is made of the parallel connection of a plurality of paraphase Schmidt trigger.
5. radio-frequency identification reader/writer according to claim 4, it is characterized in that, second level amplifier is made of the parallel connection of 5 paraphase Schmidt triggers, and paraphase Schmidt trigger in the first order amplifier and second level amplifier belong to 1 integrated circuit (IC) chip by 5 paraphase Schmidt triggers.
6. according to the described radio-frequency identification reader/writer of arbitrary claim in the claim 2 to 5, it is characterized in that, in described receiving circuit, from the radiofrequency signal of electronic tag after detector diode detection, filter capacitor filtering high-frequency signal, capacitance remove direct current, carrying out signal by the two-stage in-phase amplifier amplifies, signal after the amplification is through RC low pass filter filters out noise, enter the in-phase input end of comparer then, the inverting input of comparer is a threshold voltage, and the output signal of comparer enters single-chip microcomputer and handles.
7. radio-frequency identification reader/writer according to claim 6, it is characterized in that, comprise 1 operational amplifier integrated circuit (IC) chip, described operational amplifier integrated circuit (IC) chip comprises 3 operational amplifiers, wherein 2 operational amplifiers are as described two-stage in-phase amplifier, and 1 operational amplifier is as described comparer in addition.
8. according to the described radio-frequency identification reader/writer of arbitrary claim in the claim 1 to 5, it is characterized in that described antenna circuit comprises EMC low-pass filter, antenna circuit match circuit and antenna circuit coil.
9. according to the described radio-frequency identification reader/writer of arbitrary claim in the claim 1 to 5, it is characterized in that described interface circuit comprises USB interface and USART conversion chip, described USB interface is communicated by letter with chip microcontroller by the USART conversion chip; Described USB interface provides low-tension supply to each circuit of radio-frequency identification reader/writer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009201319146U CN201429849Y (en) | 2009-05-18 | 2009-05-18 | Radio frequency identification reader-writer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009201319146U CN201429849Y (en) | 2009-05-18 | 2009-05-18 | Radio frequency identification reader-writer |
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| Publication Number | Publication Date |
|---|---|
| CN201429849Y true CN201429849Y (en) | 2010-03-24 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2009201319146U Expired - Lifetime CN201429849Y (en) | 2009-05-18 | 2009-05-18 | Radio frequency identification reader-writer |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103310170A (en) * | 2012-03-16 | 2013-09-18 | 上海复旦微电子集团股份有限公司 | RFID (Radio Frequency Identification Device) card reader for identifying card entrance by non-responding manner and identification method |
| CN104392193A (en) * | 2014-11-12 | 2015-03-04 | 广州中大微电子有限公司 | Card reader and method for filtering received signals of RFID card reader |
| CN104598852A (en) * | 2015-01-08 | 2015-05-06 | 福建鑫诺通讯技术有限公司 | Discrete element circuit and method for realizing low-frequency RFID (radio frequency identification devices) label decoding |
| CN107292373A (en) * | 2017-06-22 | 2017-10-24 | 深圳逗号互联科技有限公司 | One kind miniaturization hyperfrequency read/write circuit module |
| CN110503168A (en) * | 2019-08-19 | 2019-11-26 | 杭州檀木科技有限公司 | Electronic mark read-and-write device and data processing method |
-
2009
- 2009-05-18 CN CN2009201319146U patent/CN201429849Y/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103310170A (en) * | 2012-03-16 | 2013-09-18 | 上海复旦微电子集团股份有限公司 | RFID (Radio Frequency Identification Device) card reader for identifying card entrance by non-responding manner and identification method |
| CN104392193A (en) * | 2014-11-12 | 2015-03-04 | 广州中大微电子有限公司 | Card reader and method for filtering received signals of RFID card reader |
| CN104392193B (en) * | 2014-11-12 | 2017-05-31 | 广州中大微电子有限公司 | Method and card reader that signal is filtered are received to RFID card reader |
| CN104598852A (en) * | 2015-01-08 | 2015-05-06 | 福建鑫诺通讯技术有限公司 | Discrete element circuit and method for realizing low-frequency RFID (radio frequency identification devices) label decoding |
| CN107292373A (en) * | 2017-06-22 | 2017-10-24 | 深圳逗号互联科技有限公司 | One kind miniaturization hyperfrequency read/write circuit module |
| CN110503168A (en) * | 2019-08-19 | 2019-11-26 | 杭州檀木科技有限公司 | Electronic mark read-and-write device and data processing method |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20100324 |