CN101752648B - Broadband RFID UHF antenna and tag and manufacturing method of tag - Google Patents

Abstract

The invention discloses a broadband RFID UHF antenna, which is used for connecting a RFID chip; the characteristics are as follows: the antenna comprises a near-field antenna and a far-field antenna which are connected in cascade, and the near-field antenna and the far-field antenna are two separated parts which cling to each other to form the UHF antenna. Meanwhile, the invention also provides a RF tag using the antenna and a manufacturing method of the RF tag. The using of the RF antenna and the RF tag provided by the invention can obtain the following benefits: the working distance range of the antenna comprises the near-field range or the far-field range, and the working frequency range can cover the entire RFID UHF frequency band, therefore, the invention has wide range of adaptability. Meanwhile, in the range of the frequency band, the impedance value is stable, and good omni-directivity is provided at xz direction in the working frequency band.

Description

Broadband RFID UHF antenna and label with and manufacture method

Technical field

The present invention relates to the transponder in radio-frequency (RF) identification (RFID) technology, particularly relate to RFID ultra-high frequency antenna and electronic tag in the transponder.

Background technology

Need not physical contact between the transponder of rfid system and the read write line and just can finish identification, so RFID there is the advantage of not replacing than bar code: the first, single very concrete object can be identified, rather than as bar code, a type objects can only be identified; The second, adopt radio frequency, can pass through the exterior material reading out data, and bar code must lean on the laser reading information; The 3rd, can distinguish a plurality of objects simultaneously, and bar code can only be read singly.In addition, the amount of information of tag storage is much bigger than bar code.

The main distinction feature of radio-frequency recognition system comprises the operating distance of the physical coupling method and system between operating frequency, read write line and the transponder of read write line.Wherein hyperfrequency (UHF) passive RFID tags is because its operating frequency is high, read-write distance need not external power source, low cost of manufacture, become at present one of emphasis direction of RFID research, might become the in the near future main product in RFID field.

Working method according to rfid system is different, and electronic label antenna generally can be divided near field induction coil antenna and far-field radiation antenna.So-called near field and far field are to break away from antenna according to electromagnetic field to divide as the position that electromagnetic wave enters the space, the near field that namely is called antenna from antenna to the scope that forms electromagnetic field, be called the far field from leaving antenna to being completed into electromagnetic scope, the boundary of the two is apart from antenna λ/2 π, wherein, λ is the electromagnetic wavelength of aerial radiation.

The near field induction coil antenna is comprised of the multiturn inductance coil usually, and the far-field radiation antenna mainly comprises electric field dipole antenna, doublet antenna and microstrip antenna.The far-field radiation antenna is resonant mode normally, and general length is taken as half-wavelength.Therefore, the size of operating frequency is determining the size of antenna size; The size of antenna is usually determining again to use the size of the RFID tag of this antenna/card; Higher operating frequency can realize less radio-frequency (RF) identification card size.

In general, the RFID label comprises semiconductor chip and high frequency antenna, and data can be programmed and again be write in the semiconductor chip.Semiconductor chip and high frequency antenna direct-coupling (for example by wire-bonded (wirebounding), flip-chip (Flip Chip) encapsulation), or be installed to high frequency antenna as SMD (surface mount) device (for example TSSOP, thin-type small-size encapsulation).Semiconductor chip and high frequency antenna are arranged on the carrier substrate, and this carrier substrate can be made by plastic material.This system also can be manufactured on the printed circuit board (PCB).

A good RFID tag application system should consider following problem: the characteristic of marker (tray, container, single product, wrapper, metal, liquid etc.); Great space is arranged between the label; The local statues that the label need of work is observed; The relative position of reading and writing device antenna and marker (distance, installation position, radiation field direction) etc., above each side characteristic, can assess with following parameters: label is in the sensitivity on different medium surface; Frequency sensitivity; The space performance.

About antenna and the antenna design method of RFID, have many patents this to be studied in the prior art, but the antenna of these prior aries all can only be applied to single working method, namely its sphere of action can only be one of far field or near field.This has just greatly limited the scope of application of radio frequency transponder.Simultaneously, even the antenna of prior art its operating frequency range in simple near field range also is confined to a narrower interval.

And, because for passive balise, its energy is fully from the energy that receives from reader of antenna, even to active balise, the energy that the used energy of its communication also receives from reader from antenna, therefore, the impedance matching of antenna receives most important for energy, and the impedance matching effect of the antenna of prior art in wider operating frequency range is also undesirable.

Summary of the invention

The objective of the invention is provides a kind of and can be operated in the wider frequency range in order to overcome the above-mentioned shortcoming of prior art, and can work in distance of near field scope and also can work in the far field distance range, and the good radio-frequency antenna of impedance matching.

For this reason, a kind of broadband RFID UHF antenna is used for being connected with the RFID chip, it is characterized in that, described antenna comprises a cascade near field antenna and a far field antenna together, and described near field antenna and described far field antenna to be that two discrete parts are bonded to each other form described ultra-high frequency antenna.

The present invention also provides the electronic tag that uses above-mentioned broadband RFID UHF antenna; the diaphragm that it comprises transponder antenna, the transponder chips that is electrically connected with it and coats described transponder antenna and transponder chips; it is characterized in that; described transponder antenna comprises the level near field antenna and the far field antenna that are linked togather, and described far field antenna forms electric connection with the applying of described near field antenna.

Meanwhile, the manufacture method that the invention provides a kind of above-mentioned electronic tag may further comprise the steps:

S1: preparation RFID chip;

S2: make the closed induction coil as near field antenna, carry out flip-chip at closed induction coil;

S3: closed induction coil is cut lamination;

S4: the dipole antenna as far field antenna is made cross cutting;

S5: carry out the electronic tag printing;

S6: electronic tag compound makes it cascade with near field antenna and far field antenna in the mode of fitting and is electrically connected.

Use radio-frequency antenna of the present invention and label can obtain following beneficial effect: (1) antenna operating distance of the present invention scope comprises near field or far-field range, and the scattering parameter that its operating frequency range just can cover in the whole RFIDUHF frequency range (830MHz-950MHz) is all very little, the change in gain curve is very steady, can undistorted radiation signal, therefore have widely adaptability.(2) in frequency band range, resistance value is very stable, and this antenna can be complementary with the chip of multiple impedance, so just there is no need to be specially certain chip design antenna, can reduce greatly workload in real work.(3) material of label antenna and thickness are very little to the performance impact of UHF antenna.When producing the UHF product, can select as required the cost of suitable antenna thickness, control antenna material like this, and not worry to cause the change of antenna performance.

Make this electronic tag then because " closing coil " is fixed with chip nation first with method of the present invention; " far field antenna " then can adopt the mode of cross cutting, directly obtains the arbitrarily size and dimension of design from large rolls of aluminum foil/Copper Foil coating material.Then closing coil and " gain amplifier " are fitted in one, the energy of closing coil is coupled on " gain amplifier " by electromagnetic induction in Z-direction.Reduce by this method existing nation and decided a lot of accurate control steps such as position accuracy demand, conducting resinl curing temperature and dosage, pressure and time etc. harsh in the technique; And various materials and step are simple and convenient, easily realize, have reduced the processing threshold of existing RFID, reduce and optimized similar semi-conductive processing industry chain and production technology.

Description of drawings

Below in conjunction with accompanying drawing above and other features and advantages of the present invention are elaborated:

Fig. 1 is the structural representation of RFID antenna of the present invention;

Fig. 2 is half-wavelength folded doublet structure one embodiment schematic diagram;

Fig. 3 is the gain curve of antenna of the present invention in the 830MHz-950MHz frequency range;

When Fig. 4 a-4c was frequency shift, antenna of the present invention was at the far field normalization antenna pattern of xz face and yz face, and Fig. 4 a is 915MHz, and Fig. 4 b is 830MHz, and Fig. 4 c is 950MHz;

Fig. 5 is that the reflection coefficient of half-wavelength folded doublet is with the curve of frequency change;

Fig. 6 is the change curve of impedance in 830MHz-950MHz of half-wavelength folded doublet;

Fig. 7 is the equivalence two port match lattice network schematic diagrames of electronic tag;

Fig. 8 a, 8b are for increasing the impedance variation schematic diagram of serpentine front and back antenna, and Fig. 8 a is imaginary part, and Fig. 8 b is real part;

Fig. 9 a, 9b are for increasing the impedance variation schematic diagram of little ring front and back antenna, and Fig. 9 a is imaginary part, and Fig. 9 b is real part;

Figure 10 is the reflection coefficient curve through the coupling aft antenna;

Figure 11 is the impedance of chip when getting different value, the comparison curves of reflection coefficient;

Figure 12 a, 12b are the thickness of antenna material when getting different value, and the comparison curves of its impedance, Figure 12 a are real part, and Figure 12 b is imaginary part;

Figure 13 is independent inductance coil and the gain comparison schematic diagram of antenna of the present invention;

Figure 14 is the structure of closing coil;

Figure 15 shows that the reflection loss curve of closing coil and spill antenna;

Figure 16 A and 16B are that closing coil and the gain of spill antenna in the 830MHz-950MHz frequency range are compared;

Figure 17 is the each several part structure cutaway view of RFID label;

Figure 18 is the technological process of production schematic diagram of RFID label in the prior art;

Figure 19 is RFID technological process of production schematic diagram of the present invention.

Embodiment

The embodiment of a kind of broadband RFID UHF antenna of the present invention can know from figure and find out as shown in Figure 1, and this antenna comprises a cascading near field antenna and a far field antenna together.By combination realizes near field, the two kinds of different working methods in far field with near field antenna with the far field.Wherein, preferably, near field antenna is induction coil 2, and described far field antenna is dipole antenna 1.And, for the impedance matching of realization with the RFID chip, being connected in parallel to the line that crawls between the induction coil of described RFID ultra-high frequency antenna and the dipole antenna, an end of serpentine is connected with induction coil 2, and the other end is connected with the stub 4 of dipole antenna.

Wherein, the size of dipole antenna is relevant with its operating frequency, for example, the half wavelength dipole antenna length that is operated in 915MHz is 164mm, and is for reducing the shared volume of antenna, generally folding two arms of dipole antenna, for example, a kind of way of realization of folded doublet as shown in Figure 2.Its every characteristic such as Fig. 3 are to shown in Figure 6.

Fig. 3 is the gain curve of dipole antenna in the 830MHz-950MHz frequency range.As shown in Figure 3, in whole working band, the gain of antenna can reach maximum 1.88dBi all greater than 1.5dBi at 890MHz.In whole working band, the variation spoke degree of gain is in 0.4dB, and curvilinear motion is very steady, so antenna can undistorted transmitted signal.As seen from Figure 3, in working frequency range, along with the rising of frequency, the antenna pattern of antenna is undistorted.Antenna has good omni-directional at the xz mask, can omnidirectional radiation.So when engineering construction and the field, read write line is installed along the xz face of antenna, can guarantee that just system has good readwrite performance.

When Fig. 4 a-4c was frequency shift, dipole antenna was at the far field normalization antenna pattern of xz face and yz face, and Fig. 4 a is 915MHz, and Fig. 4 b is 830MHz, and Fig. 4 c is 950MHz.By Fig. 4 a-4c as seen, folded doublet is 866MHz-926MHz less than the working range of-10dB, and impedance bandwidth is 60MHz.

Fig. 5 is that the reflection coefficient of half-wavelength folded doublet is with the curve of frequency change; Fig. 6 is the change curve of impedance in 830MHz-950MHz of half-wavelength folded doublet.By Fig. 5, Fig. 6 as seen, this moment, antenna reached resonance in this frequency range, and the Q value is larger, in order to increase impedance bandwidth, will reduce the Q value, and makes antenna and chip impedance conjugate impedance match.

The below is Philip NXP chip with what establish antenna nation fixed (bounding); the impedance of chip is that 20-j151 is that the example explanation is according to the designing impedance matching of antenna of the present invention; but be not to limit to according to this scope of the present invention; antenna is in conjunction with any designing impedance matching of other RFID chip, only otherwise exceed thought of the present invention and scope all should be considered as falling into protection scope of the present invention.

In general, because the impedance of chip is 20-j151, for reaching impedance matching.Making the impedance of antenna in wide frequency band range is 20+j151.

By the frequency simulation calculation, above-mentioned dipole antenna is 43+j19 (ohm) in the impedance of 915MHz, differs larger with chip impedance, obviously needs further coupling.Its mode is the equiva lent impedance realization by the induction coil 2 that designs with it cascade.About equiva lent impedance in parallel be calculated as the general general knowledge of prior art, do not add at this and give unnecessary details.

And the mode of the accurate impedance matching of a kind of preferred realization is, adds the matched impedance network.Circuit overall schematic behind the adding impedance network as shown in Figure 7.Wherein, the passive matching network of two ports makes antenna end and IC end all satisfy the conjugate impedance match condition.For example, according to a preferred embodiment of the present invention, matching network comprises serpentine 3 and induction coil 2, as shown in Figure 1.Below for sake of convenience, induction coil 2 is called again " little ring ".

Wherein, the real part of the input impedance of little ring comprises radiation resistance R _RadiationConduction loss R with little ring _LossTwo parts.The radiation resistance of little ring can be determined by following formula:

$R_{\mathrm{rediation}}=31171{\left(\frac{A}{{\mathrm{\&lambda;}}^2}\right)}^2={20\mathrm{\&pi;}}^2\frac{{\mathrm{<figure-callout\; id="4"\; label="C"\; filenames="H2008102278270E00011.png,H2008102278270E00052.png"\; state="\{\{state\}\}">C</figure-callout>}}^4}{{\mathrm{\&lambda;}}^4}=197C_{\mathrm{\&lambda;}}^4---\left(1\right)$

In the formula, A is the area of little ring, and C is the girth of little ring, C _λIt is the little ring girth with wavelength tolerance.By formula (1) as seen, antenna resistance is mainly determined by the area of ring.

The inductance L of little ring _AWith the relation of the size of little ring as shown in the formula:

$L_A={\mathrm{\&mu;}}_0\frac{A_c}{l_m}---\left(2\right)$

In the formula, A _cBe the area of little ring, 1 _mLength for little ring.

Can be got by formula (1), the anti-real part of little loop resistance is approximately 0, and little ring is equivalent to a pure inductance element, by regulating the length and width size of little ring, can adjust its inductance value size.Serpentine is equivalent to an electric capacity, by regulating number, spacing, the live width of serpentine, can change its capacitance size.

By regulating little ring in parallel and serpentine in parallel, can adjust accordingly the size of shunt inductance and shunt capacitance, thereby by adjusting match circuit, finally realize antenna and chip impedance coupling.

Describe below in conjunction with the effect of accompanying drawing to little ring and the line that crawls.Fig. 8 a, 8b are for increasing the impedance variation schematic diagram of serpentine front and back antenna, and Fig. 8 a is imaginary part, and Fig. 8 b is real part.Shown in Fig. 8 a, 8b, when not adding serpentine, the real part of the impedance of antenna and imaginary part have in frequency range than great fluctuation process, are difficult to guarantee all mate with chip impedance in whole frequency range.

Fig. 9 a, 9b are for increasing the impedance variation schematic diagram of little ring front and back antenna, and Fig. 9 a is imaginary part, and Fig. 9 b is real part.As shown in Figure 9, when not adding little ring, the real part of the impedance of antenna and imaginary part are all very large, and very large fluctuation is arranged, and add little ring, have been equivalent to an inductance element in parallel, can become Low ESR to the high impedance of antenna, thereby well mate with chip.

Figure 10 is the reflection coefficient curve through the coupling aft antenna.Comparison diagram 5 and Figure 10 as seen, add matching network after, the impedance of antenna all has good coupling with chip in the broadband of 830MHz-950MHz, reflection loss all very little (＜-25dB), can reach minimum value-33dB at 890MHz.As seen antenna of the present invention and chip have good impedance matching performance, and, only needing nation's fixed point between chip and antenna, its working range just can cover whole RFID uhf band.

Figure 11 is the impedance of chip when getting different value, the comparison curves of reflection coefficient; As shown in figure 11, the antenna of the present embodiment is in operating frequency range, and when nation's constant impedance was the chip of 20-j151, scattering parameter is minimum, and was namely best with the coupling of antenna.Impedance is that the coupling of the chip of 40-j190 and 59-j242 and antenna is slightly poor, but scattering parameter in frequency range also all less than-10dB, this is acceptable in actual applications.This antenna can be complementary with the chip of multiple impedance, so just there is no need to be specially certain chip design antenna, can reduce greatly workload in real work.

Simultaneously; the present invention also provides a kind of broadband RFID UHF radio-frequency (RF) tag; the diaphragm that it comprises transponder antenna, the transponder chips that is electrically connected with it and coats described transponder antenna and transponder chips; can be installed on this diaphragm by silk screen printing or the etching technique antenna with transponder; manufacture method about radio-frequency (RF) tag is touched upon in the prior art, just repeats no more at this.The difference of itself and existing RFID label is, described transponder antenna comprises a near field antenna and the far field antenna that level is linked togather.Be that described broadband RFID UHF radio-frequency (RF) tag is used the related various antennas of the invention described above.

The realization of antenna of the present invention can be etched on the PET substrate that covers aluminium for antenna nearly, and far field antenna is made separately, and the two is discrete, and electrically links by the mode of fitting.When making label, then label sizes respectively increases by 3-5mm in the basic surrounding of antenna size.

Figure 12 a, 12b are the thickness of antenna material when getting different value, and the comparison curves of its impedance, Figure 12 a are real part, and Figure 12 b is imaginary part.As shown in figure 12, the thickness of antenna material is got 5um, 10um, and during 15um, real part and the imaginary part of their impedance all are consistent substantially, so the thickness of antenna material is very little on the impact of UHF label antenna performance.When producing the UHF product, can select as required the cost of suitable antenna thickness, control antenna material, and not worry to cause the change of antenna performance like this.

Because the thickness of antenna material is very little to the performance impact of UHF antenna.This selects the cost of suitable antenna thickness, control antenna material that good theoretical the support is provided when producing UHF.Simultaneously show that also antenna material thickness is limited on the impact of antenna performance, with adopting what chip to mate binding, concern also little.

Figure 13 is independent inductance coil and the gain comparison schematic diagram of antenna of the present invention.See from Figure 13, in operating frequency range, closing coil is very little in the gain in far field, only have-10dBi about.After adding dipole antenna, gain is brought up to about 1.6dBi, has improved 10dB.For closing coil, peripheral dipole is equivalent to one " gain amplifier ", can improve greatly whole gain.

Simultaneously, label of the present invention can be closing coil and the far field antenna that nation decided chip and combines.Nation has decided the closing coil of chip can work in the near field, and after the far field antenna that adds as gain amplifier, the energy of closing coil is coupled on the gain amplifier by Z-direction induction, and energy to far-field radiation, thereby the realization label antenna is worked in the far field.Antenna just can must be realized far and near work flexibly like this.

" closing coil " is near field UHF, is used for the solution of single grade sign; Add behind the gain amplifier it is far field UHF, be used for the solution of 830-940MHz frequency range INLAY or intelligent label.

The RFID label processing producer closing coil of can getting ready the goods at ordinary times, then according to actual application environment and demand, the design of carrying out separately gain amplifier get final product, and is reliable and flexible, possesses good environmental suitability.

Below, the performance of RFID label according to the present invention is described.

The scope that label reads can be calculated with following Frills formula:

$r=\frac{\mathrm{\&lambda;}}{4\mathrm{\&pi;}}\sqrt{\frac{P_t{G}_t{G}_r\mathrm{\&tau;}}{P_{\mathrm{th}}}}---\left(3\right)$

Wherein: λ is operation wavelength, changes P with frequency _tBe read write line transmitting power, G _tGain for the read write line transmitting antenna; G _rBe the gain of label antenna, P _ThIndispensable power for the minimum of the sufficient energy of (tag sensitivity) provisioning RFID label chip; τ is power transmission factor, establishes chip impedance and is expressed as Z _c=R _c+ jX _c, antenna impedance is expressed as Z _a=R _a+ jX _a, then

$\begin{array}{cc}\mathrm{\&tau;}=\frac{{4R}_c{R}_a}{{|Z_a+Z_c|}^2},& 0\&le;\mathrm{\&tau;}\&le;1\end{array}---\left(4\right)$

For example, NXP chip sensitivity P _Th=-14dBm (40uw), according to formula (4), can be in the working band scope, τ ≈ 0.9,

By diagram as can be known, the gain of antenna is about 1.8dBi (1.51), therefore, as follows in the antenna parameters in different frequency interval:

1) during 902-928MHz, EIRP=4w

$\sqrt{902\&times;928}=915\mathrm{MHz}$

${\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="H2008102278270E00011.png,H2008102278270E00032.png"\; state="\{\{state\}\}">r</figure-callout>}}_1=\frac{\mathrm{\&lambda;}}{4\mathrm{\&pi;}}\sqrt{\frac{\mathrm{EIRP}\&CenterDot;G_r\mathrm{\&tau;}}{P_{\mathrm{th}}}}=0.0261\sqrt{\frac{4\&times;1.51\&times;0.9}{4\&times;{10}^{-5}}}=9.73m$

2) during 866-868MHz, ERP=2w

$\sqrt{866\&times;868}=867\mathrm{MHz}$

${\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="H2008102278270E00011.png"\; state="\{\{state\}\}">r</figure-callout>}}_2=\frac{\mathrm{\&lambda;}}{4\mathrm{\&pi;}}\sqrt{\frac{\mathrm{ERP}\&times;1.67\&CenterDot;G_r\mathrm{\&tau;}}{P_{\mathrm{th}}}}=0.02755\&times;\sqrt{\frac{2\&times;1.67\&times;1.51\&times;0.9}{4\&times;{10}^{-5}}}=9.31m$

3) during 860-960MHz, ERP=1w

$\sqrt{860\&times;960}=908.6\mathrm{MHz}$

${\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="H2008102278270E00011.png,H2008102278270E00022.png"\; state="\{\{state\}\}">r</figure-callout>}}_3=\frac{\mathrm{\&lambda;}}{4\mathrm{\&pi;}}\sqrt{\frac{\mathrm{ERP}\&times;1.67\&CenterDot;G_r\mathrm{\&tau;}}{P_{\mathrm{th}}}}=0.0263\&times;\sqrt{\frac{1\&times;1.67\&times;1.51\&times;0.9}{4\&times;{10}^{-5}}}=6.27m$

So this RFID label can be worked in the 830MHz-960MHz broadband, can meet the standard of a plurality of countries.North America 902-928MHz, Japanese 957-958MHz, Chinese 840-845MHz, 920-925MHz, European 860-930MHz.Therefore label of the present invention adapts to each major area frequency standard of the world, and reads distance and also satisfy the various places application fully.

The nation of can getting ready the goods at ordinary times of RFID label processing producer has decided " closing coil " of chip, such as the label of need near field work, directly carries out compoundly just can using; Such as the label of need far field work, only need according to actual application environment and demand, carry out separately the design of " gain amplifier ", then it is added on the existing closing coil.Label just can must be realized far and near work flexibly like this, has good environmental suitability.Waiting time is ripe, it is also conceivable that direct employing " on-chip antenna (carrying the chip of antenna) " and " gain amplifier " directly make up future.

Closing coil of the present invention, when being operated in the near-field region of read write line as single grade application, the UHFG2 label is placed in the liquid or sticks on the metal, can work.This is because liquid and metal can affect the far-field characteristic of UHF label, but except the near field.In liquid was used, UHF G2 label not only can in liquid surface work, also can be worked in the liquid the inside.

The extensive application of single grade sign RFID technology is subject to the impact of a plurality of process segments and processing cost thereof to a great extent, and above design means the change of UHF lot of materials cost.The present invention has not only proposed the intelligent label manufacturing value chain of optimizing, but also is UHF label production solution brand-new and novelty.The present invention so in fact improved the rate of finished products of processing, has correspondingly also improved the successful read rate ROI of system because adopted the method for stack " gain amplifier ".Simultaneously the difficulty of Antenna Design is reduced to the design of gain amplifier, and the coupling of more concern and practical application; The difficulty of processing technology is reduced to the control of applying, more pays close attention to the reduction of cost and the control of product percent of pass.

According to broadband RFID UHF electronic tag of the present invention; the diaphragm that it comprises transponder antenna, the transponder chips that is electrically connected with it and coats described transponder antenna and transponder chips; and described transponder antenna comprises the level near field antenna and the far field antenna that are linked togather, and described far field antenna forms electric connection with the applying of described near field antenna.Preferably mode is, described near field antenna is induction coil, and described far field antenna is folded doublet, is connected in parallel to the line that crawls between described induction coil and the dipole antenna.

The main distinction of itself and existing RFID electronic tag is to have simultaneously near field antenna and far field antenna, and the two is to make respectively then to fit to form, and is not one etching or printing.In order to construct electronic tag of the present invention, also needing has the manufacture method different from existing electronic tag.

Figure 14 is the structure of the closing coil of near field antenna of the present invention; Figure 15 shows that the reflection loss curve of closing coil and spill antenna; Figure 16 A and 16B are that closing coil and the gain of spill antenna in the 830MHz-950MHz frequency range are compared; Above-mentioned illustrating increased the variation that brings to antenna performance as behind the dipole of " gain amplifier ".

Below in conjunction with Figure 17-19 explanation electronic tag manufacture method of the present invention.Figure 17 is the each several part structure cutaway view of RFID label; As seen from the figure, closing coil can be etching or be printed on the base material, and is separated by by base material between dipole antenna and the closing coil.

Figure 18 is the technological process of production schematic diagram of RFID label in the prior art; In general, the manufacturing of RFID label comprises preparation RFID chip; Manufacturing is carried out flip-chip as closed induction coil and/or the dipole antenna of antenna at antenna; The antenna band is cut lamination; Carry out the electronic tag printing; And electronic tag is compound.

Figure 19 is RFID technological process of production schematic diagram of the present invention.The main distinction of itself and prior art is, two parts as antenna are not once to prepare simultaneously, for example, not as a global pattern etching or printing on base material, the 2nd, prepare first near field antenna, flip-chip afterwards, and in addition separately preparation of far field antenna, the near field antenna that will finish at last flip-chip and the far field antenna for preparing are to fit or other simple connected mode is electrically connected.Its process is specific as follows:

S1: prepare the RFID chip, prepare chip at wafer; This step is also chosen existing RFID chip;

S2: make the closed induction coil as near field antenna, carry out the RFID flip-chip at closed induction coil;

S3: closed induction coil is cut lamination, and this step is same as the prior art;

S4: the dipole antenna as far field antenna is made cross cutting; Near field antenna and far field antenna are electrically connected, and make it to be mutual cascade;

S5: carry out the electronic tag printing, this step is same as the prior art;

S6: electronic tag compound, this step is same as the prior art.

Preferably, to make cross cutting be the dipole antenna that cuts out required form and size at the aluminium foil patrix to described dipole antenna.

The present invention adopts the mode of two parts subdivision and stack to realize producing." closing coil " nation has chip surely, is bonded on the heat-sensitive paper (viscosity silicone oil paper); " gain amplifier " can adopt the mode of cross cutting, directly obtains the arbitrarily size and dimension of design from large rolls of aluminum foil/Copper Foil coating material.Then closing coil and " gain amplifier " are fitted in one, the energy of closing coil is coupled on " gain amplifier " by electromagnetic induction in Z-direction.Reduce by this method existing nation and decided a lot of accurate control steps such as position accuracy demand, conducting resinl curing temperature and dosage, pressure and time etc. harsh in the technique; Can also avoid simultaneously loosening in the welding process, and various material and step are simple and convenient, easily realize, have reduced the processing threshold of existing RFID, reduce and optimized similar semi-conductive processing industry chain and production technology.

The above description of this invention is illustrative, and nonrestrictive, and those skilled in the art is understood, and can carry out many modifications, variation or equivalence to it within spirit that claim limits and scope, but they will fall within the scope of protection of the present invention all.

Claims (4)

1. broadband RFID UHF antenna, be used for being connected with the RFID chip, it is characterized in that, described antenna comprises a cascade near field antenna and a far field antenna together, and to be that two discrete parts are bonded to each other form described ultra-high frequency antenna for described near field antenna and described far field antenna, described near field antenna is induction coil, described far field antenna is folded doublet, be connected in parallel to the line that crawls between the induction coil of described RFID ultra-high frequency antenna and the dipole antenna, described line and the induction coil composition matched impedance network of crawling.

2. broadband RFID UHF electronic tag; it comprises transponder antenna; the transponder chips that is electrically connected with it and coat the diaphragm of described transponder antenna and transponder chips; it is characterized in that; described transponder antenna comprises a near field antenna and the far field antenna that level is linked togather; and described far field antenna and described near field antenna are fitted and are formed electric connection; described near field antenna is induction coil; described far field antenna is folded doublet; be connected in parallel to the line that crawls between described induction coil and the dipole antenna, described line and the induction coil composition matched impedance network of crawling.

3. the manufacture method of a broadband RFID UHF electronic tag is characterized in that, may further comprise the steps:

S1: preparation RFID chip;

S2: make the closed induction coil as near field antenna, carry out flip-chip at closed induction coil;

S3: closed induction coil is cut lamination;

S4: the dipole antenna as far field antenna is made cross cutting, near field antenna and far field antenna are made it the cascade electric connection in the mode of fitting;

S5: carry out the electronic tag printing;

S6: electronic tag compound.

4. method according to claim 3 is characterized in that, it is the dipole antenna that cuts out required form and size at the aluminium foil patrix that described dipole antenna is made cross cutting.

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