CN214475020U

CN214475020U - Radio frequency identification system

Info

Publication number: CN214475020U
Application number: CN202120533928.1U
Authority: CN
Inventors: 王冬生; 黄毅然; 王斌
Original assignee: Shenzhen Yingda Information Technology Co ltd
Current assignee: Shenzhen Yingda Information Technology Co ltd
Priority date: 2021-03-15
Filing date: 2021-03-15
Publication date: 2021-10-22
Anticipated expiration: 2031-03-15

Abstract

The application provides a radio frequency identification system, which comprises at least one passive electronic tag; the activation device is arranged beside the passive electronic tag and is used for emitting continuous waves to activate the passive electronic tag; the reader is used for receiving the radio frequency signal emitted after the passive electronic tag is activated and is provided with a band-pass filter used for filtering continuous waves emitted by the activation device.

Description

Radio frequency identification system

Technical Field

The present invention relates to rfid systems, and more particularly to rfid systems with separate transmit and receive functions.

Background art:

the traditional ultrahigh frequency reader-writer is a passive backscatter reader-writer, and the information sent to the tag by the reader-writer is realized by modulating a radio frequency signal within the range of 860-960 MHz. The tag receives both the energy and the information transmitted by the radio frequency signal. The tag is passive, that is to say it extracts all the energy it needs to operate from the radio frequency signal it receives from the reader/writer. When receiving information from the label, the reader-writer sends a continuous radio frequency signal to the label, and the label modulates the reflection coefficient of the antenna of the label and scatters the label information to the reader-writer. The mode is that the reader-writer speaks first, that is, the label modulates the reflection coefficient of the antenna with the information signal stored in the label, and the modulation is only completed according to the requirement of the command after receiving the command designation sent by the reader-writer. The reader and the tag do not require simultaneous talking, but rather the communication is performed in a half-duplex manner, i.e. the tag is in a receiving (listening) state when the reader sends a command, and the reader is in a receiving (listening) state when the tag responds in return.

Under the condition of multiple labels, when the number of the labels is more than 400 and the arrangement is disordered, the phenomenon of reading missing can occur due to shielding and interference among the labels; in the case of long-distance identification, it is difficult to read when the distance between the reader/writer and the tag is greater than 15 meters or even 10 meters.

The present application addresses the above problems by providing a new radio frequency identification system that employs new methods and techniques to address these problems.

SUMMERY OF THE UTILITY MODEL

In view of the problems faced by the background art, the present application was created to provide a separate transceiving rfid system.

In order to achieve the purpose, the following technical means are adopted in the application:

the present application provides a radio frequency identification system, characterized by comprising: at least one passive electronic tag; the activation device is arranged beside the passive electronic tag and is used for emitting continuous waves to activate the passive electronic tag; the reader is used for receiving the radio frequency signal emitted after the passive electronic tag is activated and is provided with a band-pass filter used for filtering continuous waves emitted by the activation device.

Optionally, a plurality of said passive electronic tags are provided around said activation device.

Optionally, a plurality of the activation devices are arranged around the reader, and the continuous waves emitted by the activation devices have the same frequency.

Optionally, the frequency of the continuous wave emitted by the activation device is staggered with the frequency of the radio-frequency signal emitted by the passive electronic tag, and the band-pass filter allows the radio-frequency signal emitted by the passive electronic tag to pass through.

Optionally, the continuous wave emitted by the activation device is used only to power the passive electronic tag and not for communication.

Optionally, the activation device is configured to continuously emit continuous waves.

Optionally, the passive electronic tag receives continuous waves through the same antenna and transmits radio frequency signals through the same antenna.

Optionally, the passive electronic tag has a plurality of antennas, and the plurality of antennas are used for receiving the continuous wave and transmitting the radio frequency signal.

Optionally, the frequency of the continuous wave is between 860 MHz and 900 MHz.

Optionally, the operating frequency of the reader is between 902 and 928 MHz.

Compared with the prior art, the method has the following beneficial effects:

the radio frequency identification system activates the passive electronic tag by emitting continuous waves through the activation device, the reader is only used for receiving radio frequency signals emitted by the activated passive electronic tag, the reader filters the continuous waves emitted by the activation device through the band-pass filter, interference of the continuous waves is avoided, and further disc total rate and reading distance of the reader are increased.

Drawings

FIG. 1 is a schematic view of a radio frequency identification system of the present application showing a plurality of activation devices;

fig. 2 is another schematic view of the rfid system of the present application, showing only one activation device. Detailed description of the embodiments reference is made to the accompanying drawings in which:

reader 1

Band-pass filter 2

Activation device 3

Passive electronic tag 4

Antenna 5

Detailed Description

For a better understanding of the objects, structure, features, and functions of the present application, reference should be made to the drawings and detailed description that follow.

The traditional reader-writer based on the ISO18000-6C protocol needs to emit electromagnetic waves to deactivate the tag, after the tag is activated, the tag modulates information carried by the tag into electromagnetic waves with the same frequency to emit the electromagnetic waves to the reader-writer, and the reader-writer receives and decodes the information of the tag. Electromagnetic waves emitted by the reader-writer can cause interference to the reader-writer, and the interference can be relieved through a carrier cancellation technology. However, when the density of the tags is increased or the tags are far from the reader-writer, the reader-writer needs to emit stronger electromagnetic waves, so that all the tags or the tags far away can acquire enough energy to be activated; however, emitting stronger electromagnetic waves means stronger self-interference, and even if the tag is activated, the reader/writer does not have sufficient sensitivity to recognize the signal returned by the tag.

The radio frequency identification system well solves the self-interference problem of the reader 1, so that the reader 1 has ultrahigh sensitivity.

As shown in fig. 1 and 2, the rfid system mainly includes an activation device 3, a passive electronic tag 4, and a reader 1.

The reader 1 has a band-pass filter 2, which is dedicated to filter the continuous wave emitted by the activation device 3, and allow the radio frequency signal emitted by the passive electronic tag 4 to pass through, for example, the band-pass filter 2 filters out the continuous wave between 860 and 900MHz, and allows the radio frequency signal between 902 and 928MHz to pass through, so as to avoid adjacent channel interference caused by the continuous wave. Specifically, the reader 1 receives an electromagnetic wave through a receiving module (not shown, the same applies below), filters a continuous wave transmitted by the activation device 3 through the band-pass filter 2, separates a radio frequency signal transmitted by the passive electronic tag 4 from the received electromagnetic wave, and further decodes the radio frequency signal.

The activation device 3 omnidirectionally emits Continuous Waves (CW) to power the surrounding passive electronic tag 4, the frequency of the Continuous waves is set according to the operating frequency of the passive electronic tag 4, for example, the passive electronic tag 4 can be activated by electromagnetic waves with a frequency of 860-. In this embodiment, since the continuous wave emitted by the activation device 3 only needs to supply power to the passive electronic tag 4, the continuous wave may not carry information; in other embodiments, the continuous wave emitted by the activation device 3 may be modulated as needed to carry a signal, so that the activation device 3 may also communicate with the passive electronic tag 4, but this may increase the cost.

One or more of the activating devices 3 can be arranged in an area where the passive electronic tags 4 are densely arranged, one or more of the activating devices 3 can be additionally arranged in another area where the passive electronic tags 4 are densely arranged, and the continuous waves emitted by a plurality of the activating devices 3 have the same frequency; in other embodiments, a plurality of said activation devices 3 may emit continuous waves of different frequencies.

Because the distance between the activation device 3 and the passive electronic tag 4 is very close, the power of the continuous wave emitted by the activation device 3 does not need to be very high, and all the electronic tags around the activation device 3 can be activated, so that the interference of the too strong continuous wave to the reader 1 is avoided, and the disk total rate of the reader 1 can be improved. And because the reader 1 does not need to emit electromagnetic waves to deactivate the passive electronic tag 4, but only needs to receive the radio frequency signal emitted after the passive electronic tag 4 is activated, self-interference is avoided, so that the sensitivity of the reader 1 can be improved, the disk total rate of the reader 1 is increased, and the reader 1 can recognize the passive electronic tag 4 at a longer distance, for example, a traditional reader-writer can only read tags within 10 meters generally, and the reader 1 can recognize the passive electronic tags 4 beyond 10 meters, even 15 meters, so that the reader is suitable for some long-distance reading environments. And the reader 1 has better cruising ability because continuous waves do not need to be transmitted.

The passive electronic tag 4 is provided with more than two antennas 5, each antenna 5 is used for receiving the continuous wave transmitted by the activation device 3 and obtaining energy therefrom, and each antenna 5 is used for transmitting a radio frequency signal, so that the passive electronic tags 4 in different postures can receive the energy provided by the continuous wave from different angles and transmit the radio frequency signal towards different angles; since the continuous wave does not include information and only provides energy, each antenna 5 of the passive electronic tag 4 can continuously obtain energy (because the antenna 5 does not need to obtain information from the continuous wave, only needs to obtain energy), and can emit radio frequency signals outwards while obtaining energy.

In one embodiment, the reader 1 and the activation device 3 communicate wirelessly to achieve command synchronization and improve reading efficiency, and the communication frequency of the activation device 3 and the reader 1 is staggered from the frequency of the continuous wave emitted by the activation device 3, so as to avoid interference, for example, the activation device 3 and the reader 1 may communicate via a wireless lan or a wireless communication network.

The radio frequency identification system of the application has the following beneficial effects:

the radio frequency identification system of this application, through 3 passive electronic tags 4 of continuous wave activation of activation device, reader 1 only is used for receiving the radio frequency signal of passive electronic tags 4 postactivation transmission, and reader 1 has filtered the continuous wave of 3 launches of activation device through band pass filter 2, avoids the interference of continuous wave, and then increases reader 1's dish percentage of wholeness and reading distance.

The above detailed description is only for the purpose of illustrating the preferred embodiments of the present application, and not for the purpose of limiting the scope of the present application, therefore, all technical changes that can be made by applying the present specification and the drawings are included in the scope of the present application.

Claims

1. A radio frequency identification system, comprising:

at least one passive electronic tag;

the activation device is arranged beside the passive electronic tag and is used for emitting continuous waves to activate the passive electronic tag;

the reader is used for receiving the radio frequency signal emitted after the passive electronic tag is activated and is provided with a band-pass filter used for filtering continuous waves emitted by the activation device.

2. The radio frequency identification system of claim 1, wherein: the activation device has a plurality of the passive electronic tags around it.

3. The radio frequency identification system of claim 1, wherein: and a plurality of activation devices are arranged around the reader, and the continuous waves emitted by the activation devices have the same frequency.

4. The radio frequency identification system of claim 1, wherein: the frequency of the continuous wave emitted by the activation device is staggered with the frequency of the radio-frequency signal emitted by the passive electronic tag, and the band-pass filter allows the radio-frequency signal emitted by the passive electronic tag to pass through.

5. The radio frequency identification system of claim 1, wherein: the continuous wave emitted by the activation device is used only to power the passive electronic tag and not for communication.

6. The radio frequency identification system of claim 1, wherein: the activation device is used to continuously emit continuous waves.

7. The radio frequency identification system of claim 1, wherein: the passive electronic tag receives continuous waves through the same antenna and transmits radio frequency signals through the same antenna.

8. The radio frequency identification system of claim 1, wherein: the passive electronic tag is provided with a plurality of antennas, and the antennas are used for receiving continuous waves and transmitting radio frequency signals.

9. The radio frequency identification system of claim 1, wherein: the frequency of the continuous wave is between 860 MHz and 900 MHz.

10. The radio frequency identification system of claim 1, wherein: the operating frequency of the reader is between 902 and 928 MHz.