CN103020557B - A kind of centreless RFID tag and recognition methods thereof - Google Patents

A kind of centreless RFID tag and recognition methods thereof Download PDF

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CN103020557B
CN103020557B CN201210496905.3A CN201210496905A CN103020557B CN 103020557 B CN103020557 B CN 103020557B CN 201210496905 A CN201210496905 A CN 201210496905A CN 103020557 B CN103020557 B CN 103020557B
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张文梅
闫丽云
马润波
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Shanxi University
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Abstract

The present invention relates to RFID tag design, be specially a kind of centreless RFID tag based on space angle information coding.Label is made up of the radiating element with space angle characteristic, such as bar shaped or v-shaped structure.The identification to label angle information is realized by the reverse scattering electric field again measured in horizontal and vertical two polarised directions.Also use multiple scattered field to remove the interference of neighbourhood noise in tag recognition process, tag recognition effect can be improved.Label construction is simple, and cost of manufacture is low; During labeling task, band occupancy is narrower, substantially increases the availability of frequency spectrum, thus reduces the cost of whole radio-frequency recognition system.

Description

A kind of centreless RFID tag and recognition methods thereof
Technical field
The present invention relates to technical field of RFID, specifically belong to a kind of centreless RFID tag based on space angle information coding and recognition methods thereof.
Background technology
REID RFID(Radio Frequency Identification) be a kind of technology utilizing rf wave to carry out wireless data acquisition, it is one of the most popular current intelligent identification technology, also be one of core technology being subject to the Internet of Things that the whole society greatly pays close attention to, will very wide application prospect be had in the field such as logistics, retail.But the high price of RFID tag, limits its application.The high cost of label produces primarily of the expense of chip and encapsulation.In passive label, emerging centreless RFID tag is that the cost reducing electronic tag provides solution.For this reason, centreless RFID tag becomes a focus of research at present.
Chinese scholars has done more research work in centreless electronic tag, and current centreless RFID tag can be divided three classes: based on Time Domain Reflectometry type, based on spectrum signature type and the backscatter type based on amplitude/phase.The subject matter that current centreless RFID tag exists is: the codified bit number based on the centreless RFID tag of Time Domain Reflectometry is limited and require that reader possesses radio-frequency front-end at a high speed, in addition, the increase of time delay can make the amplitude of the time-domain signal of reception diminish, and brings difficulty to detection; Based on the centreless RFID tag of frequency-region signal, belong to scalar measurement method in essence, to multipath transmisstion and interference ratio more responsive, be difficult to realize jumbo coding, and mostly adopt radio ultra wide band system, the availability of frequency spectrum is low, and reader system cost is high; The placed angle of centreless RFID tag to the polarised direction of reader antenna label in other words based on the backscattered modulation of amplitude/phase is more responsive, when polarised direction changes, will produce error code, and can not identify even completely.
Summary of the invention
The object of the invention is to design a kind of centreless RFID tag of saving frequency spectrum resource, low cost.
The object of the invention is to be reached by following measure:
A kind of centreless RFID tag, be made up of medium and radiating element, described radiating element is bar shaped paster, and it becomes α angle with the polarised direction of field wave, 0 °≤α < 180 °.The resonance frequency of label is determined by the length of bar shaped paster.
A kind of recognition methods of centreless RFID tag:
1, without under label condition, the S on the horizontal and vertical direction of measurement environment 21, be expressed as S 21-XBwith S 21-YB;
2, placement is identified label, measures and is identified label S in the horizontal and vertical directions 21, be expressed as S 21-XTwith S 21-YT;
3, label S in the horizontal and vertical directions will be identified 21with environment S in the horizontal and vertical directions 21the interference that subtraction of vector removes neighbourhood noise is carried out respectively by formula (1) (2);
S 21-X=S 21-XT-S 21-XB(1)
S 21-Y=S 21-YT-S 21-YB(2)
4, according to S 21-Xwith S 21-Yphase relation judge that α is acute angle or obtuse angle: both homophases, α is acute angle, and both are anti-phase, and α is obtuse angle;
5, in resonance frequency, angle [alpha] is obtained by formula (3) or (4), thus identification label,
α=180°×arctg(|S 21-Y|/|S 21-X|)/π(α<90°)(3)
α=180°–180°×arctg(|S 21-Y|/|S 21-X|)/π(α>90°)(4)。
A kind of centreless RFID tag, be made up of medium and radiating element, described radiating element itself has obvious space angle characteristic, be the V-arrangement paster be made up of the two arms of same size, wherein one arm is fixed arm, consistent with the polarised direction of field wave, another arm is pivot arm, α angle is become, 0 ° of < α≤180 °, preferably 60 °≤α≤180 ° with fixed arm.The resonance frequency of label is determined by the brachium of V-arrangement paster.
A kind of recognition methods of centreless RFID tag:
1, without under label condition, the S on the horizontal and vertical direction of measurement environment 21, be expressed as S 21-XBwith S 21-YB;
2, placement is identified label, measures and is identified label S in the horizontal and vertical directions 21, be expressed as S 21-XTwith S 21-YT;
3, label S in the horizontal and vertical directions will be identified 21with environment S in the horizontal and vertical directions 21the interference that subtraction of vector removes neighbourhood noise is carried out by formula (1) (2);
4, the label selecting fixed arm and pivot arm in 90 ° as reference label, witness mark label S in the horizontal direction 21, be expressed as S 21-XR, and do decyclization border noise processed, as shown in formula (5);
S 21-XR′＝S 21-XR-S 21-XB(5)
5, according to being identified label and reference label S in the horizontal direction 21size relatively judge that α is acute angle or obtuse angle: if | S 21-X| <|S 21-XR' |, then α <90 °; If | S 21-X| >|S 21-XR' |, then α >90 °;
6, according to 5 result, select formula (6) or (7), will the S of label be identified 21the amplitude of horizontal component | S 21-X| with the S of reference label 21the amplitude of horizontal component | S 21-XR' | subtract each other, to remove the impact of fixed arm;
|S 21-X′|=|S 21-XR′|-|S 21-X|(α<90°)(6)
|S 21-X′|=|S 21-X|-|S 21-XR′|(α>90°)(7)
7, in resonance frequency, angle [alpha] is obtained by formula (8) or (9), thus identification label,
α=180°×arctg(|S 21-Y|/|S 21-X′|)/π(α<90°)(8)
α=180°-180°×arctg(|S 21-Y|/|S 21-X′|)/π(α>90°)(9)。
Centreless RFID tag based on space angle information coding of the present invention, adopts the radiating element with angular characteristics, utilizes the backscattering electric field in horizontal and vertical two polarised directions to carry out angle recognition.This label not only makes simply, cost is low, and because the label of equal length is under different coding state, the frequency band taken is identical, and the frequency band therefore shared by labeling task is very narrow, improve the availability of frequency spectrum, thus reduce the cost of whole radio-frequency recognition system; This label also adopts multiple scattered field to remove the interference of neighbourhood noise, and improve the recognition effect of label, therefore the practicality of label is high.
Accompanying drawing explanation
Fig. 1 is the structural representation of bar shaped label of the present invention;
Fig. 2 is the structural representation of V-arrangement label of the present invention;
Fig. 3 is measurement environment S in the horizontal direction 21schematic diagram;
Fig. 4 is measurement environment S in vertical direction 21schematic diagram;
Fig. 5 is witness mark label S in the horizontal direction 21schematic diagram;
Fig. 6 measures to be identified label S in the horizontal direction 21schematic diagram;
Fig. 7 measures to be identified label S in vertical direction 21schematic diagram.
Embodiment
Below in conjunction with accompanying drawing citing, more detailed description is done to the present invention:
Fig. 1 is a kind of embodiment of the present invention---the structural representation of bar shaped label.This label is single layer structure, and its radiating element is 60 × 2mm 2bar shaped paster, medium for Rogers 4350(specific inductive capacity be 3.43 ~ 3.53, average 3.48), dielectric thickness is 0.8mm.The resonance frequency of label is determined by the length of bar shaped paster.Angle between the polarised direction of bar shaped paster and field wave is α, and this angle information α is as the coded message of label.
The linear polarization plane wave of horizontal direction is adopted to impinge perpendicularly on this label, its backscattering electric field component Exs in the horizontal direction and component Ey in vertical direction srespectively as shown in formula (10) (11), wherein k is scale-up factor, E ifor incident field intensity.
Ex s=k×E i×cosα×cosα(10)
Ey s=k×E i×cosα×sinα(11)
Can find out, the horizontal component Ex of backscattering electric field swith vertical component Ey sbe proportional to cos α cos α and cos α sin α, so the ratio Ey of these two components of scattered field respectively s/ Ex sequal tg α, as shown in formula (12).
Ey s/Ex s=tgα(12)
From theoretical analysis above, according to the vertical of the backscattering electric field of label and horizontal component, the angle α between the polarised direction that just can obtain bar shaped paster on label and field wave, namely identifies this label.The result that table 1 emulates above-mentioned bar shaped label for adopting CST2011.
The simulation result of table 1 bar shaped patch label
The angle α of bar shaped paster and horizontal direction 0° 15° 30° 45° 60° 75° 105° 120° 135° 150° 165°
Resonance frequency/GHz 1.95 1.95 1.95 1.95 1.95 1.95 1.95 1.95 1.95 1.95 1.95
Identification angle [alpha] '/° 0.000015 15.12 30.12 44.97 59.67 73.03 106.97 120.33 135.03 149.88 164.88
Error/° 0.000015 0.12 0.12 0.03 0.33 1.97 1.97 0.33 0.03 0.12 0.12
Fig. 2 is another kind of embodiment of the present invention---the structural representation of V-arrangement label.This label is single layer structure, and its radiating element adopts the V-arrangement paster with obvious angle character, and one of them arm is fixed, parallel with the polarised direction of field wave, in x direction, another arm rotates, and the angle between fixed arm is α, and two-arm is measure-alike, be all 30 × 2mm 2.Angle α between pivot arm and fixed arm is as the coded message of label.The resonance frequency of label is determined by the length of two-arm.The backscattering electric field that fixed arm produces is main in the horizontal direction, and pivot arm will produce the scattered field of horizontal and vertical directions, the scattered field of this both direction is directly proportional to cos α and sin α respectively, if can remove the scattered field that fixed arm produces, then the ratio by the both direction scattered field produced by pivot arm obtains angle [alpha].
During actual discriminating label, we select α to be that the V-arrangement label of 90 ° is as reference label, remove the scattered field that fixed arm produces, reason is as follows: when the linear polarization plane wave of horizontal direction impinges perpendicularly on 90 ° of reference label, pivot arm and polarised direction orthogonal, the part produced by pivot arm in the horizontal component of therefore its scattered field is very little, if ignored, can think that the horizontal component of this label scattered field all produced by fixed arm.In addition, by analyzing direction of current during V-arrangement patch resonant, can also find, when α is less than 90 °, the direction of the horizontal component of the scattered field of fixed arm and pivot arm is contrary, and the scattered field of pivot arm and fixed arm balances out a part; When α is greater than 90 °, both directions are identical, and pivot arm will superpose with the scattered field of fixed arm.Therefore, for V-arrangement label, identify the formula of the angle [alpha] of V-arrangement paster, needing according to α is acute angle or obtuse angle, is modified to
Ey s-tag/(Ex s-tag90°-Ex s-tag)=tgα(α<90°)(13)
Ey s-tag/(Ex s-tag-Ex s-tag90°)=tg(180°-α)(α>90°)(14)
Wherein Ex s-tagand Ey s-tagbe respectively the horizontal and vertical component of the backscattering electric field of V-arrangement label, Ex s-tag90 °it is the horizontal component of the backscattering electric field of 90 ° of reference label.The result that table 2 emulates above-mentioned V-arrangement label for adopting CST2011.
The simulation result of table 2V shape patch label
Bookmark name Label 1 Label 2 Label 3 Label 4 Label 5 Label 6 Label 7 Label 8 Label 9
V-arrangement angle [alpha] 60° 75° 90° 105° 120° 135° 150° 165° 180°
Resonance frequency/GHz 2.66 2.41 2.31 2.31 2.31 2.31 2.31 2.31 2.31
Resolution α '/° 64.21 76.33 88.75 108.41 122.52 136.45 151.06 165.65 180.00
Error/° 4.21 1.33 1.25 3.41 2.52 1.45 1.06 0.65 0
Fig. 3-7 is to the second embodiment of the present invention---the system chart that V-arrangement label is measured.In order to verify the practicality of label, during measurement, do not adopt darkroom, but carry out in physical environment.Be utilize the backscattering electric field of horizontal and vertical directions to obtain angle during tag recognition designed by the present invention, vector network analyzer therefore can be adopted as reader, utilize the S that it measures in horizontal and vertical directions 21obtain angle information.The electromagnetic horn 1 be connected with the port one of vector network analyzer is as the emitting antenna of reader, and the plane wave of emission level polarization, the electromagnetic horn 2 be connected with port 2 is as the receiving antenna of reader, and what receive label oppositely answers scattered field signal.Two loudspeaker are just the same.The identification step of described V-arrangement label is as follows:
1, arrange accordingly vector network analyzer: emissive power is set to-10dBm, swept frequency range is set to 1-3GHz, and frequency sweep is counted and is set to 201 points, and frequency interval is 10MHz;
2, to the S of environment 21measure: do not place label, vertically placed by loudspeaker 1, loudspeaker 2 are also vertically placed, and as shown in Figure 3, measure, the S now recorded 21as environment S 21horizontal component S 21-XB; Then vertically placed by loudspeaker 1, loudspeaker 2 horizontal positioned, as shown in Figure 4, measures, the S now recorded 21as vertical component S 21-YB;
3, to the S of reference label 21horizontal component measure: 90 ° of reference label are placed on two in the middle of loudspeaker and distance loudspeaker 1m places, vertically placed by loudspeaker 1, loudspeaker 2 are also vertically placed, and as shown in Figure 5, measure, the S now recorded 21as the S with reference to label 21horizontal component S 21-XR;
4, to the S being identified label 21measure: will be identified label and be placed in the middle of two loudspeaker and distance loudspeaker 1m place, vertically placed by loudspeaker 1, loudspeaker 2 are also vertically placed, and as shown in Figure 6, measure, the S now recorded 21as the S being identified label 21horizontal component S 21-XT; Then vertically placed by loudspeaker 1, loudspeaker 2 horizontal positioned, as shown in Figure 7, measures, the S now recorded 21as the S being identified label 21vertical component S 21-YT;
5, the interference of neighbourhood noise is removed: label S in the horizontal and vertical directions will be identified 21with background environment S in the horizontal and vertical directions 21carry out subtraction of vector by formula (1) (2), the horizontal component comprising reference label also needs to do same process, as formula (5):
S 21-X=S 21-XT-S 21-XB(1)
S 21-Y=S 21-YT-S 21-YB(2)
S 21-XR′＝S 21-XR-S 21-XB(5)
6, judge that the angle α being identified V-arrangement paster on label is acute angle or obtuse angle: according to being identified label and reference label S in the horizontal direction 21size relatively judge that α is acute angle or obtuse angle, if | S 21-X| <|S 21-XR' |, then α <90 °; If | S 21-X| >|S 21-XR' |, then α >90 °;
7, remove the impact of fixed arm: according to the result of step 6, select formula (6) or (7) to be identified the S of label 21the amplitude of horizontal component | S 21-X| with the S of reference label 21the amplitude of horizontal component | S 21-XR' | subtract each other;
|S 21-X′|=|S 21-XR′|-|S 21-X|(α<90°)(6)
|S 21-X′|=|S 21-X|-|S 21-XR′|(α>90°)(7)
8, derivation angle [alpha] value: according to S 21maximal value judge tuning-points, and obtain angle [alpha] at tuning-points place by formula (8) or (9), thus identification label,
α=180°×arctg(|S 21-Y|/|S 21-X′|)/π(α<90°)(8)
α=180°-180°×arctg(|S 21-Y|/|S 21-X′|)/π(α>90°)(9)。
Table 3 is for the second embodiment of the present invention---V-arrangement label measure by above-mentioned steps after result.As can be seen from the table, utilize the backscattering electric field in horizontal and vertical two polarised directions, the label of different angles can be identified, and identification error is less than 5 °.
Table 3 reading result
Label 1 Label 2 Label 3 Label 4 Label 5 Label 6 Label 7 Label 8 Label 9
V-arrangement angle [alpha] 60° 75° 90° 105° 120° 135° 150° 165° 180°
Resonance frequency/GHz 2.06 2 2.01 1.95 1.92 1.91 1.83 1.82 1.81
Identification angle [alpha] '/° 63.97 75.06 88.22 105.01 122.04 136.27 153.66 167.86 176.81
Error/° 3.97 0.06 1.78 0.01 2.04 1.27 3.66 2.86 3.19
Label designed by the present invention uses identical frequency spectrum under different encoding states, this rfid system can be operated on narrower frequency band, substantially increase the utilization factor of frequency, also reduce system cost.In addition, label uses multiple scattered field to remove the interference of neighbourhood noise in identifying, and improve recognition effect, identification error is less than 5 °.
Certainly; the present invention can also have other various embodiments; when not deviating from the present invention's spirit and essence thereof, those of ordinary skill in the art can make various corresponding distortion according to the present invention, but these change accordingly and are out of shape the protection domain that all should belong to claim of the present invention.

Claims (3)

1. a recognition methods for centreless RFID tag, is characterized in that, step is:
1), without under label condition, the S on the horizontal and vertical direction of measurement environment 21, be expressed as S 21-XBwith S 21-YB;
2), place be identified label, measure be identified label S in the horizontal and vertical directions 21, be expressed as S 21-XTwith S 21-YT;
3), label S in the horizontal and vertical directions will be identified 21with environment S in the horizontal and vertical directions 21the interference that subtraction of vector removes neighbourhood noise is carried out respectively by formula (1) (2);
S 21-X＝S 21-XT-S 21-XB(1)
S 21-Y＝S 21-YT-S 21-YB(2)
4), according to S 21-Xwith S 21-Yphase relation judge that α is acute angle or obtuse angle: both homophases, α is acute angle, and both are anti-phase, and α is obtuse angle;
5), in resonance frequency angle [alpha] is obtained by formula (3) or (4), thus identification label; If α is <90 °, select formula (3), if α is >90 °, select formula (4),
α＝180°×arctg(|S 21-Y|/|S 21-X|)/π (3)
α＝180°–180°×arctg(|S 21-Y|/|S 21-X|)/π (4)；
Described centreless RFID tag, is made up of medium and radiating element, and described radiating element is bar shaped paster, and it becomes α angle with the polarised direction of field wave, 0 °≤α < 180 °.
2. a recognition methods for centreless RFID tag, is characterized in that, step is:
1), without under label condition, the S on the horizontal and vertical direction of measurement environment 21, be expressed as S 21-XBwith S 21-YB;
2), place be identified label, measure be identified label S in the horizontal and vertical directions 21, be expressed as S 21-XTwith S 21-YT;
3), label S in the horizontal and vertical directions will be identified 21with environment S in the horizontal and vertical directions 21the interference that subtraction of vector removes neighbourhood noise is carried out by formula (1) (2);
S 21-X＝S 21-XT-S 21-XB(1)
S 21-Y＝S 21-YT-S 21-YB(2)
4), the label of selecting fixed arm and pivot arm in 90 ° as reference label, witness mark label S in the horizontal direction 21, be expressed as S 21-XR, and do decyclization border noise processed, as shown in formula (5);
S 21-XR′＝S 21-XR-S 21-XB(5)
5), according to being identified label and reference label S in the horizontal direction 21size relatively judge that α is acute angle or obtuse angle: if | S 21-X| <|S 21-XR' |, then α <90 °; If | S 21-X| >|S 21-XR' |, then α >90 °;
6), according to 5) result, label S will be identified 21the amplitude of horizontal component | S 21-X| with the S of reference label 21the amplitude of horizontal component | S 21-XR' | subtract each other, to remove the impact of fixed arm, if α is <90 °, select formula (6), if α is >90 °, select formula (7);
|S 21-X′|＝|S 21-XR′|-|S 21-X| (6)
|S 21-X′|＝|S 21-X|-|S 21-XR′| (7)
7), in resonance frequency angle [alpha] is obtained by formula (8) or (9), thus identification label, if α is <90 °, select formula (8), if α is >90 °, select formula (9)
α＝180°×arctg(|S 21-Y|/|S 21-X′|)/π (8)
α＝180°-180°×arctg(|S 21-Y|/|S 21-X′|)/π (9)；
Described centreless RFID tag, be made up of medium and radiating element, described radiating element is the V-arrangement paster be made up of the two arms of same size, wherein one arm is fixed arm, consistent with the polarised direction of field wave, another arm is pivot arm, becomes α angle with fixed arm, 0 ° of < α≤180 °.
3. the recognition methods of a kind of centreless RFID tag according to claim 2, is characterized in that, described α angle is 60 °≤α≤180 °.
CN201210496905.3A 2012-11-28 2012-11-28 A kind of centreless RFID tag and recognition methods thereof Expired - Fee Related CN103020557B (en)

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CN103950309B (en) * 2014-04-14 2017-01-04 西安交通大学 Electromagnetic anti-counterfeiting application for printing analog radio frequency tag under standard printing process
CN103983184B (en) * 2014-05-22 2016-09-28 山西大学 A kind of angular transducer of internet of things oriented
CN104567948B (en) * 2015-01-19 2017-01-25 山西大学 Resistor type sensor adopting radio frequency technology for recognition
CN109543805A (en) * 2018-12-14 2019-03-29 华南理工大学 A kind of chipless RFID label for angular transducer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070221729A1 (en) * 2004-12-09 2007-09-27 Somark Innovations, Inc. Microwave readable dielectric barcode
CN101111852A (en) * 2004-06-22 2008-01-23 伍比克公司 Rfid system utilizing parametric reflective technology
CN102544749A (en) * 2010-12-21 2012-07-04 财团法人工业技术研究院 Device and method for compensating polarization rate of radio frequency tag test antenna

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101111852A (en) * 2004-06-22 2008-01-23 伍比克公司 Rfid system utilizing parametric reflective technology
US20070221729A1 (en) * 2004-12-09 2007-09-27 Somark Innovations, Inc. Microwave readable dielectric barcode
CN102544749A (en) * 2010-12-21 2012-07-04 财团法人工业技术研究院 Device and method for compensating polarization rate of radio frequency tag test antenna

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
phase-encoded chipless RFID transponder for large-scale low-cost applications;Isaac Balbin et al;《IEEE microwave and wireless components letters》;20090807;第19卷(第8期);第509-511页 *

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