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CN101465468A - Radio frequency identification electronic label antenna with EBG structure - Google Patents

Radio frequency identification electronic label antenna with EBG structure Download PDF

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Publication number
CN101465468A
CN101465468A CNA2009100366549A CN200910036654A CN101465468A CN 101465468 A CN101465468 A CN 101465468A CN A2009100366549 A CNA2009100366549 A CN A2009100366549A CN 200910036654 A CN200910036654 A CN 200910036654A CN 101465468 A CN101465468 A CN 101465468A
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CN
China
Prior art keywords
copper sheet
antenna
radiation patch
ebg structure
groove part
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Pending
Application number
CNA2009100366549A
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Chinese (zh)
Inventor
胡斌杰
王辰
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South China University of Technology SCUT
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South China University of Technology SCUT
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Application filed by South China University of Technology SCUT filed Critical South China University of Technology SCUT
Priority to CNA2009100366549A priority Critical patent/CN101465468A/en
Publication of CN101465468A publication Critical patent/CN101465468A/en
Pending legal-status Critical Current

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Abstract

The invention discloses a radio frequency identification electronic tag antenna with an EBG structure, comprising three T-shaped radiating patch antennas and an EBG structure; the three T-shaped radiating patch antennas are arranged at the upper end of the EBG structure, left radiating patches and right radiating patches of the three T-shaped radiating patch antennas are arranged on the upper surface of an upper dielectric layer and are separated by a T-shaped slit which is a reversed T-shaped gap which is arranged on the upper surface of the upper dielectric layer, and a left T-shaped slit and a right T-shaped slit are respectively arranged at two sides of the gap; the EBG structure on the lower layer comprises an upper-layer medium and a lower-layer medium, and 3*4 of square copper plates are uniformly arranged on the upper surface of the upper-layer medium in interval, and 4*5 of the square copper plates are uniformly arranged on the middle interlayer of the upper-layer medium and the lower-layer medium; the antenna bandwidth is wide, therefore, the antenna not only can work on a nonmetallic surface, but also the antenna can be conveniently applied to a metallic surface; the radio frequency identification electronic tag antenna has the characteristics of wide band, low environment sensitivity and far reading distance.

Description

The frequency identification electronic label antenna that has the EBG structure
Technical field
The present invention relates to a kind of frequency identification electronic label antenna, specifically relate to a kind of can be applicable in hyper band (UHF) scope, North America (866-869MHz) and European frequency range (902-928MHz) can be worked in simultaneously, and the frequency identification electronic label antenna under the multiple environment can be conveniently be applied to.
Background technology
Radio-frequency (RF) identification (RFID) technology is a kind ofly to carry out contactless bidirectional data communication by wireless radio frequency mode, target is discerned and obtained the automatic identification technology of relevant information.REID (RFID) was promoted rapidly in recent years, the occasion that is widely used in the article identification in logistics, warehouse etc., help the information of such industrial application of information technology, high speed collection, management article, to realize high efficiency management and scheduling to article.Radio-frequency recognition system mainly is made up of reader, middleware and electronic tag three parts.Electronic tag is made up of on-chip antenna and integrated chip, carries out exchanges data by electromagnetic wave and reader, has intelligent read and encrypted communication function.Antenna is received and dispatched front-end radiofrequency signal power with the electromagnetic wave form, is the interface device in circuit and space, is used for realizing the conversion of guided wave and free space wave energy.In rfid system, electronic label antenna is born the effect of received energy, and whole rfid system is played a crucial role.The periodic wave guide structure refers to that identical inhomogeneities periodically appears in boundary condition along the direction of propagation, be widely used in many microwave components, as filter, antenna, amplifier etc.People are incorporated into microwave circuit with the bandgap structure of optical field, i.e. electro-magnetic bandgap (EBG, electromagnetic band-gap) structure.Can not propagate in this periodic structure because the topmost feature of EBG periodic structure is the ripple in a certain frequency range, just there be " forbidden band " in this kind structure itself.Therefore, have the surface wave of inhibition when EBG is used for microstrip antenna and suppress harmonic wave, the gain that improves antenna and bandwidth, can weaken surrounding environment to effects such as antenna influences simultaneously.
There are three big difficult points in microwave current section RFID label antenna in design with in using.The first, all parts of the world district is to the regulation difference of UHF RFID frequency band, for example 840MHz~845MHz (China), 920MHz~925MHz (China), 866MHz~869MHz (Europe), 902MHz~928MHz (U.S.) etc.Along with the development of global logistics, labeing the article of RFID and will discerned easily in the world, just necessarily require the RFID label antenna self to possess the characteristic that can cover the wide operational frequency bandwidth of above-mentioned each frequency band.But the input impedance of RFID label chip has very big condensance and less resistance usually, has constituted the high Q value effect at resonant frequency point place.So, be designed to the RFID label antenna can overcome this high Q value effect and characteristic with wide operational frequency bandwidth is the difficult problem of a bad solution.The second, the RFID label can be glued to the surface of the various article of different dielectric properties in actual applications.The different dielectric properties of article can produce deterioration in various degree to the performance of RFID label antenna.Especially the mis-behave that metal brought is particularly serious, can cause the RFID label to be identified, and has reduced the recognition success rate of rfid system to article.And traditional flexible board antenna can't be worked in the metal surface, and this just needs design can work and the antenna RF ID label antenna of metal surface, creationary the RFID antenna is combined the tender subject that then can solve environment with the EBG structure.The 3rd, because the complexity of environment has caused reducing of electronic tag reading distance.In order to increase the effective reading distance of electronic tag, be necessary to improve the gain of label antenna so that satisfy the demand.Present used microstrip antenna, though can work in the metal surface, the gain of antenna is low, its reading distance is shorter.Therefore be necessary that the higher antenna of designing gain satisfies actual needs.
Summary of the invention
The objective of the invention is to overcome the shortcoming of prior art, the requirement that can touch the mark of a kind of gain that makes entire antenna and reading distance is provided, can be applied in the hyperfrequency frequency range radio-frequency recognition system reader, and can work in the frequency identification electronic label antenna that has the EBG structure under the multiple environment.
Purpose of the present invention is achieved through the following technical solutions:
The frequency identification electronic label antenna that has the EBG structure comprises three T type radiation patch antenna and EBG structures, and three T type radiation patch antennas are positioned at EBG structure upper end; The upper surface that the left radiation patch of described three T type radiation patch antennas and right radiation patch are positioned at dielectric layer is separated by a T groove part crack, and about T groove part crack symmetry; Left side radiation patch and right radiation patch are connected to the first copper sheet floor by left short-circuit piece and right short-circuit piece respectively; Left side short-circuit piece and right short-circuit piece lay respectively at the left and right sides, the first copper sheet floor; T groove part crack is an inverted T shape breach that is positioned at the upper surface of dielectric layer, the left and right sides of breach is respectively equipped with left T groove part crack and right T groove part crack, T groove part crack lower central is provided with the copper sheet matching network, left side radiation patch and right radiation patch are connected to the copper sheet matching network by left microstrip line and right microstrip line respectively, and the copper sheet matching network is provided with antenna input port.
The EBG structure of described lower floor comprises top dielectric and layer dielectric, upper surface in top dielectric is interval with 3 * 4 square copper sheets equably, be interval with 4 * 5 square copper sheets equably in top dielectric and the two-layer intermediate course of layer dielectric, the center that is centered close to per four the square copper sheets of interlayer of a square copper sheet at top dielectric upper surface place; The lower surface of layer dielectric posts the second copper sheet floor, and the square copper sheet of top dielectric all is connected with the second copper sheet floor by via hole with the square copper sheet of layer dielectric.
For further realizing the object of the invention, described left radiation patch and right radiation patch are preferably copper sheet.
Described three T type radiation patch antennas are preferably placed at EBG structure upper end 1-2mm.
The length of side of described square copper sheet and square copper sheet all is preferably 25mm-30mm.
Vertical barbed portion width in described T groove part crack is 5mm-10mm.
Compared with prior art, the present invention has following advantage and good effect:
(1) label antenna is placed on the EBG structure, utilize the reflection characteristic of EBG structure, can reduce the influence of metal surface, thereby make the antenna that places on the EBG structure not only can well work in free space antenna performance, also can operate as normal in the metal surface.
(2) the EBG structure has the characteristic of high impedance surface, thereby can reduce the surface wave loss, has improved the gain of antenna.
(3) the present invention can be used in the radio-frequency recognition system of hyperfrequency (UHF) frequency range, can contain the radio-frequency recognition system of 902~928MHz of the radio-frequency recognition system of 866~869MHz in Europe and North America simultaneously, all reach more than 6 meters at free space and metal surface reading distance.
(4) three T groove part cracks that form on the paster of the label antenna the superiors.Two copper sheet short circuits lay respectively at top, the left and right sides, the first copper sheet floor and symmetrical.Copper sheet matching network, gap size satisfy the impedance of electronic label antenna and the label chip impedance phase coupling that links to each other.The EBG structure comprises periodic two-layer square-shaped metal paster and floor and the medium between them.This structure makes antenna reduce the susceptibility of metal environment, therefore can work in simultaneously in free space and two kinds of environment of metal.
Description of drawings
Fig. 1 has the structural representation of the frequency identification electronic label antenna of EBG structure for the present invention.
Fig. 2 is the vertical view of paster antenna among Fig. 1.
Fig. 3 is an elementary cell structural representation of the EBG of lower floor structure among Fig. 1.
Fig. 4 is the EBG of a lower floor structure among Fig. 1.
Embodiment
The present invention is further detailed explanation below in conjunction with accompanying drawing, but embodiments of the present invention are not limited thereto.
As shown in Figure 1, 2, the frequency identification electronic label antenna that has the EBG structure comprises three T type radiation patch antenna and EBG structures, and three T type radiation patch antennas are positioned at EBG structure upper end, between the two for the interval that is provided with 1 to 2 millimeter easy to process.Wherein, three T type radiation patch antennas comprise dielectric layer 1, following dielectric layer 2, the first copper sheet floor 3, the left radiation patch 4 that has 3 T groove part cracks and pair net, right radiation patch 5, left short-circuit piece 6 and right short-circuit piece 7.Left side radiation patch 4 and right radiation patch 5 are copper sheet, are positioned at the upper surface of dielectric layer 1, separate by a big T groove part crack 18, and about T groove part crack 18 symmetries; Left side radiation patch 4 and right radiation patch 5 are connected to the first copper sheet floor 3 by left short-circuit piece 6 and right short-circuit piece 7 respectively; Left side short-circuit piece 6 and right short-circuit piece 7 lay respectively at 3 left and right sides, the first copper sheet floor.T groove part crack 18 is an inverted T shape breach that is positioned at the upper surface of dielectric layer 1, the left and right sides of breach is respectively equipped with a little left T groove part crack 16 and right T groove part crack 17, T groove part crack 18 lower central are provided with copper sheet matching network 8, left side radiation patch 4 and right radiation patch 5 are connected to copper sheet matching network 8 by left microstrip line 19 and right microstrip line 20 respectively, copper sheet matching network 8 is provided with antenna input port 9, and the chip of RFID antenna is affixed on antenna input port 9.Vertical barbed portion width in the T groove part crack 18 between left side radiation patch 4 and the right radiation patch 5 is 5mm-10mm (being the T-shape vertical line partial width in T groove part crack 18), this width plays the effect of regulating centre frequency and regulating the real part coupling, when this width changed in the 5-10mm scope, centre frequency also changed about 915MHz thereupon.Breach is wide more, and centre frequency is high more, and real part is more little; Otherwise breach is narrow more, the centre frequency skew of turning left of naming a person for a particular job, and real part is big more.By regulating the coupling of antenna and chip, can increase the bandwidth of antenna, thereby make it the radio-frequency recognition system of 902~928MHz of the radio-frequency recognition system of the complete 866~869MHz that covers Europe and North America.The effect that increases the electric current electrical length is played in T groove part crack 16, a left side and right T groove part crack 17, shows on the overall performance of antenna, i.e. the return loss of bandwidth of Kuo Daing and reduction.Can also regulate the input impedance of entire antenna by regulating the size of matching network 8, the impedance that makes it and be placed on the chip at port 9 places reaches coupling.
Shown in Fig. 3,4, the EBG structure of lower floor comprises top dielectric 10 and layer dielectric 11, upper surface in top dielectric 10 is interval with 3 * 4 square copper sheets 12 equably, be interval with 4 * 5 square copper sheets 13 equably in top dielectric 10 and layer dielectric 11 two-layer intermediate courses, the center that is centered close to per four the square copper sheets of interlayer of a square copper sheet 12 at top dielectric 10 upper surface places.The lower surface of layer dielectric 11 posts the second copper sheet floor 14, and the square copper sheet 12 of top dielectric 10 all is connected with the second copper sheet floor 14 by via hole with the square copper sheet 13 of layer dielectric 11.By adjusting the size of square copper sheet 12 and square copper sheet 13, and the dielectric constant of top dielectric 10 and layer dielectric 11 two layer medium plates is regulated the centre frequency of EBG structure.The length of side of square copper sheet 12 and square copper sheet 13 is 25mm-30mm.This structure of EBG makes it have the characteristic of high surface impedance, the EBG structure makes the ripple in a certain particular frequency range not propagate in this structure, thereby suppresses surface wave, improves the performance of antenna, and reduced the influence of metal pair antenna, antenna is worked in the multiple environment.Simultaneously, because the effect that increases the electric current electrical length is played in the existence in three T groove part cracks, shows on the overall performance of antenna, promptly the return loss of bandwidth of Kuo Daing and reduction has increased reading distance simultaneously, and antenna is all reached more than 6 meters at free space and metal surface reading distance.
When receiving the electromagnetic wave signal that the rfid interrogator antenna launches, the left radiation patch 4 of two mirror image symmetries and the surface of right radiation patch 5 have been energized the CURRENT DISTRIBUTION of symmetrical balance, this electric current is through the shunting and the corrective action of copper sheet matching network 8, make the input impedance conjugate impedance match of antenna feed impedance with the RFID label chip that is connected at antenna input port 9 places, the information energy that finally makes this label antenna and received is with farthest the feed input of RFID label chip of the form of electric current, to activate the RFID label chip and to make it work.To rfid interrogator antenna transmission electromagnetic wave signal the time, reply rfid interrogator with backscattered communication mode, the no modulated carrier signal that label antenna modulation reflection rfid interrogator antenna transmission is come, central RFID label chip comes the short circuit and the impedance conjugate impedance match state of control antenna input port 9 according to the response message that will send, the no modulated carrier signal that the short-circuit condition of antenna input port 9 makes left radiation patch 4 and 5 pairs of rfid interrogator antenna transmission of right radiation patch presents high reflective condition, the no modulated carrier signal that the impedance conjugate impedance match state of antenna input port 9 makes left radiation patch 4 and 5 pairs of rfid interrogator antenna transmission of right radiation patch presents low reflective condition, by this two states, label antenna is realized the amplitude shift key modulation of the different modulating degree of depth to the carrier signal that reflects back, and the rfid interrogator antenna receives this modulated signal that reflects.Be positioned on the metal for general antenna, because electromagnetic wave incides the reflected wave that the metal environment can produce 180 ° of phase shifts, this reflected wave can influence the radiation mode and the resonance frequency of antenna, thereby makes the antenna cisco unity malfunction under our needed pattern.And below three t-antennas, have after the EBG structure, because the EBG structure is in certain band limits, has-180 °-180 ° reflected phase will, promptly can be by regulating the size of EBG structure, make it in our needed band limits, realize 0 ° phase shift, promptly eliminate of the influence of below metal environment antenna.Simultaneously, because the high-impedance behavior of EBG structure has reduced the loss that the surface wave transmission is brought, thereby has finally reached high-gain, the characteristics of reading distance far away.
The present invention can be used in the radio-frequency recognition system of hyperfrequency (UHF) frequency range, can contain simultaneously Europe The radio-frequency recognition system of the radio-frequency recognition system of 866~869MHz and 902~928MHz of North America is read distance From reaching more than 6 meters. The present invention can reliably conveniently be applied to the metal surface, and it is low to have a loss, The advantages such as reading distance is far away.

Claims (5)

1, the frequency identification electronic label antenna that has the EBG structure is characterized in that comprising three T type radiation patch antenna and EBG structures, and three T type radiation patch antennas are positioned at EBG structure upper end; The upper surface that the left radiation patch of described three T type radiation patch antennas and right radiation patch are positioned at dielectric layer is separated by a T groove part crack, and about T groove part crack symmetry; Left side radiation patch and right radiation patch are connected to the first copper sheet floor by left short-circuit piece and right short-circuit piece respectively; Left side short-circuit piece and right short-circuit piece lay respectively at the left and right sides, the first copper sheet floor; T groove part crack is an inverted T shape breach that is positioned at the upper surface of dielectric layer, the left and right sides of breach is respectively equipped with left T groove part crack and right T groove part crack, T groove part crack lower central is provided with the copper sheet matching network, left side radiation patch and right radiation patch are connected to the copper sheet matching network by left microstrip line and right microstrip line respectively, and the copper sheet matching network is provided with antenna input port.
The EBG structure of described lower floor comprises top dielectric and layer dielectric, upper surface in top dielectric is interval with 3 * 4 square copper sheets equably, be interval with 4 * 5 square copper sheets equably in top dielectric and the two-layer intermediate course of layer dielectric, the center that is centered close to per four the square copper sheets of interlayer of a square copper sheet at top dielectric upper surface place; The lower surface of layer dielectric posts the second copper sheet floor, and the square copper sheet of top dielectric all is connected with the second copper sheet floor by via hole with the square copper sheet of layer dielectric.
2, the frequency identification electronic label antenna that has the EBG structure according to claim 1 is characterized in that: described left radiation patch and right radiation patch are copper sheet.
3, the frequency identification electronic label antenna that has the EBG structure according to claim 1 is characterized in that: described three T type radiation patch antennas are positioned at EBG structure upper end 1mm-2mm.
4, the frequency identification electronic label antenna that has the EBG structure according to claim 1 is characterized in that: the length of side of described square copper sheet and square copper sheet all is 25mm-30mm.
5, the frequency identification electronic label antenna that has the EBG structure according to claim 1 is characterized in that: vertical barbed portion width in described T groove part crack is 5mm-10mm.
CNA2009100366549A 2009-01-14 2009-01-14 Radio frequency identification electronic label antenna with EBG structure Pending CN101465468A (en)

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102004937A (en) * 2010-11-29 2011-04-06 四川新源现代智能科技有限公司 Small-size remote passive electronic tag capable of being adhered to surface of metal
CN101593866B (en) * 2009-06-30 2013-07-10 华南理工大学 Dielectric resonance UHF RFID label antenna provided with T-shaped matching network
CN103985958A (en) * 2014-04-01 2014-08-13 杭州电子科技大学 Small metal resistance type UHF tag antenna based on EBG structure
CN104577287A (en) * 2015-01-23 2015-04-29 广东顺德中山大学卡内基梅隆大学国际联合研究院 Harmonic suppression broadband patch coupler and method of adjusting power-dividing ratio and method of simultaneously achieving suppression broadband and second harmonics
CN108741462A (en) * 2018-05-08 2018-11-06 上海应用技术大学 A kind of bracelet
CN108776829A (en) * 2018-06-15 2018-11-09 袁涛 Medical detection ultra-high frequency RFID label
CN111916900A (en) * 2019-05-09 2020-11-10 杭州海康威视数字技术股份有限公司 Integrated directional antenna
CN112417905A (en) * 2019-08-23 2021-02-26 菜鸟智能物流控股有限公司 Radio frequency tag identification system and method
CN114865284A (en) * 2022-05-18 2022-08-05 上海英内物联网科技股份有限公司 Annular UHF RFID label antenna capable of adapting to various environments
CN117875352A (en) * 2023-12-12 2024-04-12 南京航空航天大学 High-coding-density RFID chipless tag

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101593866B (en) * 2009-06-30 2013-07-10 华南理工大学 Dielectric resonance UHF RFID label antenna provided with T-shaped matching network
CN102004937A (en) * 2010-11-29 2011-04-06 四川新源现代智能科技有限公司 Small-size remote passive electronic tag capable of being adhered to surface of metal
CN102004937B (en) * 2010-11-29 2013-05-22 四川新源现代智能科技有限公司 Small-size remote passive electronic tag capable of being adhered to surface of metal
CN103985958A (en) * 2014-04-01 2014-08-13 杭州电子科技大学 Small metal resistance type UHF tag antenna based on EBG structure
CN103985958B (en) * 2014-04-01 2017-02-15 杭州电子科技大学 Small metal resistance type UHF tag antenna based on EBG structure
CN104577287A (en) * 2015-01-23 2015-04-29 广东顺德中山大学卡内基梅隆大学国际联合研究院 Harmonic suppression broadband patch coupler and method of adjusting power-dividing ratio and method of simultaneously achieving suppression broadband and second harmonics
CN108741462A (en) * 2018-05-08 2018-11-06 上海应用技术大学 A kind of bracelet
CN108776829A (en) * 2018-06-15 2018-11-09 袁涛 Medical detection ultra-high frequency RFID label
CN111916900A (en) * 2019-05-09 2020-11-10 杭州海康威视数字技术股份有限公司 Integrated directional antenna
CN111916900B (en) * 2019-05-09 2023-02-28 杭州海康威视数字技术股份有限公司 Integrated directional antenna
CN112417905A (en) * 2019-08-23 2021-02-26 菜鸟智能物流控股有限公司 Radio frequency tag identification system and method
CN114865284A (en) * 2022-05-18 2022-08-05 上海英内物联网科技股份有限公司 Annular UHF RFID label antenna capable of adapting to various environments
CN117875352A (en) * 2023-12-12 2024-04-12 南京航空航天大学 High-coding-density RFID chipless tag

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Application publication date: 20090624