CN112202477A - 4G wireless transmission RFID read-write system - Google Patents
4G wireless transmission RFID read-write system Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
- H04B5/70—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes
- H04B5/77—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes for interrogation
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K17/00—Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
- G06K17/0022—Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations arrangements or provisions for transferring data to distant stations, e.g. from a sensing device
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Abstract
A4G wireless transmission RFID read-write system comprises a micro antenna, a signal coupling module, a radio frequency module, a main control processor, a first 4G wireless transmission module, a server and a display terminal; the signal coupling module is used for processing and distributing radio frequency signals, the miniature antenna is connected with the signal coupling module, and the signal coupling module is connected with the radio frequency module; the radio frequency module is connected with the main control processor; the first 4G wireless transmission module is used for transmitting electronic tag information, the main control processor is connected with the first 4G wireless transmission module, and the first 4G wireless transmission module is connected with the server; according to the 4G wireless transmission RFID read-write system designed by the scheme, the signal coupling module is additionally arranged between the miniature antenna and the radio frequency module, and radio frequency signals are distributed and processed, so that the anti-interference capability of external signals is improved; meanwhile, the 4G wireless transmission module is arranged, so that the immediacy of electronic tag information transmission is ensured, and remote transmission can be realized.
Description
Technical Field
The invention belongs to the technical field of radio frequency identification, and particularly relates to a 4G wireless transmission RFID read-write system.
Background
Radio Frequency Identification (RFID) is a non-contact automatic identification technology. The task and purpose of automatic identification is to provide personal, animal, goods, merchandise and graphics information. The system can be applied to various occasions such as an intelligent management system of a library, food quality and safety supervision and the like. The electronic tag is similar to an object identity card in the invention, and has the characteristics of uniqueness, high safety, easy verification, long storage period and the like.
The principle of the technology is that information exchange is carried out on the basis of radio frequency signals through space coupling (alternating magnetic field) and transmission characteristics, and automatic identification of an object is achieved. A general RFID system architecture is composed of a reader/writer, an electronic tag, middleware, and application software, which are collectively referred to as an application system. Wherein the reader reads or writes the electronic tag data; the electronic tag is attached to a target object and used as an identifier of the target object; the application system is application layer software, and the collected data is extracted, analyzed and processed for various purposes such as trajectory tracking and the like.
At present, the current state of the RFID technology industry is at home and abroad, the United states is a positive driver and a practicer of the application of the RFID technology, the industry standard is established at the earliest time, and software and hardware are in the forefront of the world by means of strong technical reserves. The european RFID standard follows the american leading EPCglobal, and its technical and application maturity is comparable to that of the united states in closed system applications. Although the UID standard is proposed in japan, the range of application is limited to domestic manufacturers. Mature RFID products are available in the United states, British, Germany, Switzerland and the like.
The existing RFID technical problems have some defects, firstly, an article attached to a label is also a medium, which can generate certain influence on electromagnetic signals, and particularly, the shielding of the electromagnetic wave signals by a metal medium can interfere the transmission of radio frequency signals to a certain extent; meanwhile, most of RFID adopts Bluetooth equipment when transmitting electronic tag information, and the Bluetooth equipment has short transmission distance and has certain delay in transmission.
Therefore, it is necessary to design a 4G wireless transmission RFID read/write system to solve the above technical problems.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention aims to provide a 4G wireless transmission RFID read-write system.
In order to achieve the above objects and other related objects, the present invention provides the following technical solutions: A4G wireless transmission RFID read-write system comprises a micro antenna, a signal coupling module, a radio frequency module, a main control processor, a first 4G wireless transmission module, a server and a display terminal; the signal coupling module is used for processing and distributing radio frequency signals and comprises a power amplifier, a low-pass filter, an attenuator and a balun circuit; the radio frequency module is used for generating, transmitting and receiving radio frequency signals; the radio frequency module comprises a radio frequency oscillator, a radio frequency processor and a radio frequency receiver; the radio frequency oscillator is connected with the radio frequency processor, the radio frequency processor is connected with the power amplifier through the balun circuit, the power amplifier is connected with the low-pass filter, the low-pass filter is connected with the miniature antenna, the miniature antenna is simultaneously connected with the attenuator, the attenuator is connected with the radio frequency receiver through the balun circuit, and the radio frequency receiver is connected with the main control processor; the first 4G wireless transmission module is used for transmitting electronic tag information processed by the main control processor, the first 4G wireless transmission module comprises a 4GL/LTE unit, a 4G antenna and an SIM card unit, the main control processor is connected with the 4GL/LTE unit, and input pins and output pins of the 4GL/LTE unit are respectively connected with the 4G antenna and the SIM card unit; meanwhile, the first 4G wireless transmission module is connected with the server, and the server is connected with the display terminal.
Preferably, a second 4G wireless transmission module is further arranged between the server and the display terminal, the server is connected with the second 4G wireless transmission module, the second 4G wireless transmission module is connected with the display terminal, and the structure of the 4G wireless transmission module is the same as that of the first 4G wireless transmission module.
Preferably, the main control processor is further connected with a power management module, an interface module and a storage module.
Preferably, the interface module is provided with an RS232/485 interface and a USB interface.
Preferably, the master control processor is an ARM processor.
Preferably, the master control processor is connected with the 4GL/LTE unit through a serial communication bus
Preferably, the first 4G wireless transmission module is connected to the server through a 4G wireless network link.
Preferably, the second 4G wireless transmission module is connected to the server through a 4G wireless network link.
Preferably, the second 4G wireless transmission module is connected with the display terminal through a data bus
Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:
according to the 4G wireless transmission RFID read-write system designed by the scheme, the signal coupling module is additionally arranged between the miniature antenna and the radio frequency module, so that radio frequency signals are distributed and processed, and the anti-interference capability of external signals is improved; meanwhile, the 4G wireless transmission module is arranged, so that the immediacy of electronic tag information transmission is ensured, and remote transmission can be realized.
Drawings
Fig. 1 is a schematic view of the overall structure of the present invention.
In the above figures, the micro antenna 1, the signal coupling module 2, the radio frequency module 3, the master control processor 4, the first 4G wireless transmission module 5, the server 6, the second 4G wireless transmission module 7, the display terminal 8, the low pass filter 21, the attenuator 22, the power amplifier 23, the balun circuit 24, the radio frequency processor 31, the radio frequency oscillator 32, the radio frequency receiver 33, the 4GL/LTE unit 51, the 4G antenna 52, the SIM card unit 53, the power management module 9, the interface module 10, the storage module 11, the 4G wireless network link 12, the data bus 13, and the serial communication bus 14.
Detailed Description
The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.
Please refer to fig. 1. It should be understood that in the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship which the product of the present invention is usually placed in when used, which is only for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance. The terms "horizontal", "vertical", "overhang" and the like do not imply that the components are required to be absolutely horizontal or overhang, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.
In the description of the present invention, it should be further noted that, unless otherwise specifically stated or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may include, for example, a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, and a communication between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
As shown in fig. 1, a 4G wireless transmission RFID read-write system includes a micro antenna 1, a signal coupling module 2, a radio frequency module 3, a main control processor 4, a first 4G wireless transmission module 5, a server 6, and a display terminal 8; the signal coupling module 2 is used for processing and distributing radio frequency signals, the miniature antenna 1 is connected with the signal coupling module 2, and the signal coupling module 2 is connected with the radio frequency module 3; the signal coupling module 2 comprises a power amplifier 23, a low-pass filter 21, an attenuator 22 and a balun circuit 24; the radio frequency module 3 is used for generating, transmitting and receiving radio frequency signals; the radio frequency module 3 is connected with the main control processor 4; the radio frequency module 3 comprises a radio frequency oscillator 32, a radio frequency processor 31 and a radio frequency receiver 33; the first 4G wireless transmission module 5 is used for transmitting the electronic tag information processed by the main control processor 4, the main control processor 4 is connected with the first 4G wireless transmission module 5, the first 4G wireless transmission module 5 is connected with the server 6, and the server 6 is connected with the display terminal 8; the first 4G wireless transmission module 5 comprises a 4GL/LTE unit 51, a 4G antenna 52 and a SIM card unit 53; the specific connection mode of components in each module of the RFID electronic tag reader-writer based on the 4G wireless transmission device is as follows: the radio frequency oscillator 32 is connected with the radio frequency processor 31, the radio frequency processor 31 is connected with the power amplifier 23 through the balun circuit 24, the power amplifier 23 is connected with the low-pass filter 21, the low-pass filter 21 is connected with the miniature antenna 1, the miniature antenna 1 is simultaneously connected with the attenuator 22, the attenuator 22 is connected with the radio frequency receiver 33 through the balun circuit 24, the radio frequency receiver 33 is connected with the main control processor 4, the main control processor 4 is connected with the 4GL/LTE unit 51, and meanwhile, input and output pins of the 4GL/LTE unit 51 are respectively connected with the 4G antenna 52 and the SIM card unit 53; for sending information to be transmitted to the 4G antenna 52 and the master processor 4 and for receiving information received by the 4G antenna; the first 4G wireless transmission module 5 is connected with the server 6, and the server 6 is connected with the display terminal 8; according to the RFID electronic tag reader-writer based on the 4G wireless transmission device, the signal coupling module 2 is additionally arranged between the micro antenna 1 and the radio frequency module 3, radio frequency signals are distributed and processed, and the anti-interference capability of external signals is improved; meanwhile, the 4G wireless transmission module is arranged, so that the immediacy of electronic tag information transmission is ensured, and remote transmission can be realized.
Preferred embodiments:
a second 4G wireless transmission module 7 is also arranged between the server 6 and the display terminal 8, and the structure of the 4G wireless transmission module is the same as that of the first 4G wireless transmission module 5.
The main control processor 4 is also connected to a power management module 9, an interface module 10 and a storage module 11.
The interface module 10 is provided with an RS232/485 interface and a USB interface.
The master processor 4 is an ARM processor.
The main control processor 4 is connected with the 4GL/LTE unit 51 through a serial communication bus 14;
the first 4G wireless transmission module 5 is connected to the server 6 via a 4G wireless network link 12.
The second 4G wireless transmission module 7 is connected to the server 6 via a 4G wireless network link 12.
The second 4G wireless transmission module 7 is connected with the display terminal 8 through a data bus 13
The scheme comprises the following steps of selecting each module and introducing detailed parameters:
a processor based on ARM9 kernel of S3C2416 treater of selecting in this design, its operating rate can reach 667MHz, and inside has abundant interface certainly, including LCD screen interface, USB, UART, SPI, IIC, camera and ethernet interface etc. its basic parameter is:
(1) the ARM926EJ core is manufactured by adopting a 65nmCMOS process, and the dominant frequency can reach 400 MHz;
(2) the 64M Byte DDR II memory and the 256M Byte SLC NandFlash have good operation in a high-low temperature operation test within the range of minus 10 ℃ to plus 70 ℃.
The best RFID read-write chips are mainly two, one is R1000/R2000 series products of Impinjndy company, and the other is AS 3991/AS 3992 series products of Austria microelectronics company. They account for almost more than 80% of the total market. The R1000/R2000 series chip has better performance in receiving sensitivity, but the power consumption is larger and reaches 1.35W, so that the battery pressure of the radio frequency identification device is larger, and the radio frequency identification device is not suitable for the development of remote transmission requirements. And the internal registers are more, and the development difficulty is higher. The AS 3991/AS 3992 has relatively low receiving sensitivity, but the performance can also meet various application occasions, the power consumption is only 0.5W, the number of registers is small, and the development difficulty is low. Therefore, the AS 3991/AS 3992 scheme is more suitable for the use of the invention, and the main parameters are AS follows:
(1) a 64 pin QFN package, size 9mm9 mm;
(2) the receiving sensitivity reaches 86dB, and the antenna works in a 915MHz frequency band;
(3) the communication protocol of ISO/IEC 18000-6C/6B is supported, and ASK or PR-ASK signal modulation can be adopted;
(4) and 8-bit parallel or 4-wire serial communication between the MCU and the MCU is supported.
In the selection of the 4G wireless transmission module, the characteristics that an ARM controller supports the communication interface, the modularized integration is required to be met, excessive circuit design is not needed, the performance is high, multi-frequency and multi-mode are supported, and the like are supported, so the scheme selects the 4G module of the USR-LTE-7S4 model, adopts an industrial standard, can simultaneously support the 4G network of China Mobile, China telecom and China Unicom, and supports the working mode, the network transmission mode and the HTTPD mode of TCP and UDP. The module is internally designed by adopting development based on a Linux system, and has the characteristics of high reliability and high integration level.
JTAG interface circuit and RS232/485 interface circuit; the JTAG interface and the RS232/485 interface are interfaces that must be used for ARM-based program development. In the aspect of JTAG interface, the basic bootstrap program and the driver program are mainly programmed, and the initial program programming part of the system is provided. JTAG interface signals are relatively fixed, but in terms of interface forms, the JTAG interface signals are of different types, such as a 14PIN interface, a 20PIN interface and the like, the increased PIN number is mainly reflected in the ground level signals, and according to past conclusion, when the ground level is low, the anti-interference performance of the signals is reduced, and errors are caused in the long-distance transmission process. Therefore, a 20pin interface pin mode is adopted in the design; the RS232/485 interface circuit adopts a standard MAX3232 chip which is commonly used and has higher performance, and is a chip widely used in the field of embedded development. Debugging information of the program can be printed out through the serial port, the execution position of the program is monitored, and system development is facilitated. JTAG and RS232/485 serial port circuit.
SD memory cell circuit design: the SD card storage design mainly considers two functions, one is the expansion of system storage, and if a small-sized database system is required to be added on the intelligent inspection terminal, the original FLASH storage cannot meet the requirements. Secondly, upgrading the system; in the process of upgrading system software, the system can be upgraded from the SD card by setting the mode that the system is started from the SD card first. The upgrading operation avoids the adoption of an upgrading mode of JTAG burning in a system development scheme, and simplifies the use of the system. The system is provided with an 8G SD memory card, and the storage capacity of the SD memory card can be increased when the system function is required.
The radio frequency circuit filtering technology comprises the following steps: in the process of designing the schematic diagram, a pi-type filter matching circuit is designed between the rear end of the directional isolator and the MMCX antenna connector, and a pi-type filter matching circuit is also added between the balun and a radio frequency power amplifier 23 SKY77181 chip and consists of two 3.6pF capacitors and one 9.1nH inductor.
The antenna of the reader-writer adopts circularly polarized antenna with gain of 12dBi, the radio frequency module 3 of the reader-writer adopts the maximum transmitting power of 27dBm at the front end of 840-960MHz radio frequency which is researched and developed by self, and the E41-B type label of Impinj company is adopted under the protocol test label ISO18000-6C protocol.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (9)
1. The utility model provides a 4G wireless transmission RFID reading and writing system which characterized in that: the system comprises a micro antenna, a signal coupling module, a radio frequency module, a main control processor, a first 4G wireless transmission module, a server and a display terminal;
the signal coupling module is used for processing and distributing radio frequency signals and comprises a power amplifier, a low-pass filter, an attenuator and a balun circuit;
the radio frequency module is used for generating, transmitting and receiving radio frequency signals; the radio frequency module comprises a radio frequency oscillator, a radio frequency processor and a radio frequency receiver; the radio frequency oscillator is connected with the radio frequency processor, the radio frequency processor is connected with the power amplifier through the balun circuit, the power amplifier is connected with the low-pass filter, the low-pass filter is connected with the miniature antenna, the miniature antenna is simultaneously connected with the attenuator, the attenuator is connected with the radio frequency receiver through the balun circuit, and the radio frequency receiver is connected with the main control processor;
the first 4G wireless transmission module is used for transmitting electronic tag information processed by the main control processor, the first 4G wireless transmission module comprises a 4GL/LTE unit, a 4G antenna and an SIM card unit, the main control processor is connected with the 4GL/LTE unit, and input pins and output pins of the 4GL/LTE unit are respectively connected with the 4G antenna and the SIM card unit; meanwhile, the first 4G wireless transmission module is connected with the server, and the server is connected with the display terminal.
2. The 4G wireless transmission RFID read-write system according to claim 1, characterized in that: the server is connected with the second 4G wireless transmission module, the second 4G wireless transmission module is connected with the display terminal, and the structure of the 4G wireless transmission module is the same as that of the first 4G wireless transmission module.
3. The 4G wireless transmission RFID read-write system according to claim 1, characterized in that: the main control processor is also connected with a power supply management module, an interface module and a storage module.
4. The 4G wireless transmission RFID read-write system according to claim 3, characterized in that: and the interface module is provided with an RS232/485 interface and a USB interface.
5. The 4G wireless transmission RFID read-write system according to claim 1, characterized in that: the master control processor is an ARM processor.
6. The 4G wireless transmission RFID read-write system according to claim 1, characterized in that: the main control processor is connected with the 4GL/LTE unit through a serial communication bus.
7. The 4G wireless transmission RFID read-write system according to claim 1, characterized in that: the first 4G wireless transmission module is connected with the server through a 4G wireless network link.
8. The 4G wireless transmission RFID read-write system according to claim 2, characterized in that: and the second 4G wireless transmission module is connected with the server through a 4G wireless network link.
9. The 4G wireless transmission RFID read-write system according to claim 2, characterized in that: and the second 4G wireless transmission module is connected with the display terminal through a data bus.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101542929A (en) * | 2007-06-08 | 2009-09-23 | Lg伊诺特有限公司 | Wireless communication device |
| WO2010075645A1 (en) * | 2008-12-31 | 2010-07-08 | 中兴通讯股份有限公司 | A method and device for improving the linearity of a radio frequency power amplifier |
| US20160164474A1 (en) * | 2014-05-13 | 2016-06-09 | Skyworks Solutions, Inc. | Systems and methods related to linear and efficient broadband power amplifiers |
| CN208781280U (en) * | 2018-04-16 | 2019-04-23 | 惠州市超人盒子网络科技有限公司 | A kind of commodity self-service payment system applied to unattended shop |
| CN209182836U (en) * | 2019-01-15 | 2019-07-30 | 南宁职业技术学院 | RFID reader |
| CN210955099U (en) * | 2019-12-20 | 2020-07-07 | 苏州希格玛科技有限公司 | RFID electronic tag reader-writer based on 4G transmission and 4G wireless transmission device |
-
2020
- 2020-09-30 CN CN202011065198.3A patent/CN112202477A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101542929A (en) * | 2007-06-08 | 2009-09-23 | Lg伊诺特有限公司 | Wireless communication device |
| WO2010075645A1 (en) * | 2008-12-31 | 2010-07-08 | 中兴通讯股份有限公司 | A method and device for improving the linearity of a radio frequency power amplifier |
| US20160164474A1 (en) * | 2014-05-13 | 2016-06-09 | Skyworks Solutions, Inc. | Systems and methods related to linear and efficient broadband power amplifiers |
| CN208781280U (en) * | 2018-04-16 | 2019-04-23 | 惠州市超人盒子网络科技有限公司 | A kind of commodity self-service payment system applied to unattended shop |
| CN209182836U (en) * | 2019-01-15 | 2019-07-30 | 南宁职业技术学院 | RFID reader |
| CN210955099U (en) * | 2019-12-20 | 2020-07-07 | 苏州希格玛科技有限公司 | RFID electronic tag reader-writer based on 4G transmission and 4G wireless transmission device |
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Application publication date: 20210108 |