CN101750541B - Radio frequency identification electronic label antenna complex impedance test device and method - Google Patents
Radio frequency identification electronic label antenna complex impedance test device and method Download PDFInfo
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- CN101750541B CN101750541B CN2009100919551A CN200910091955A CN101750541B CN 101750541 B CN101750541 B CN 101750541B CN 2009100919551 A CN2009100919551 A CN 2009100919551A CN 200910091955 A CN200910091955 A CN 200910091955A CN 101750541 B CN101750541 B CN 101750541B
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- 238000005859 coupling reaction Methods 0.000 claims description 9
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- 229910000906 Bronze Inorganic materials 0.000 claims description 3
- 239000010974 bronze Substances 0.000 claims description 3
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 claims description 3
- 229910001220 stainless steel Inorganic materials 0.000 claims description 3
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- 230000005684 electric field Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
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- 238000012545 processing Methods 0.000 description 2
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- 238000013459 approach Methods 0.000 description 1
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- 230000007812 deficiency Effects 0.000 description 1
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Abstract
The invention relates to a radio frequency identification electronic label antenna complex impedance test device and a method. A cable is respectively and electrically connected with a vector network analyzer and a second metal plate, the second metal plate is embedded inside a first metal plate, a core of a switching port is electrically connected with a feed port of a semi-arm electronic label antenna, and a sheath of the switching port is connected with the second metal plate in a short-circuit way. By utilizing the principle of an image method and testing the impedance of the semi-arm antenna port, the test difficulty for the balance feed-form antenna can be solved. Compared with the steps of a balance/imbalance converter and a matching network required for testing the balance feed-form antenna impedance, the test procedure of the device is simple and convenient, and the device has economic benefit while ensuring the test precision.
Description
Technical field
The invention belongs to electronic information technical field, relate generally to a kind of radio frequency identification (RFID) system electronic label antenna impedance measurement device and method.
Background technology
Electronic label antenna generally all belongs to the balanced feeding form, if use coaxial cable feed, need between antenna and cable, add balance/imbalance converter, just usually said Ba Lun.In addition; The complex impedance measurement of electronic label antenna also need add a matching network earlier before Ba Lun, be the impedance conversion of antenna 50 ohm, could realize the accurate measurement to electronic label antenna; The routine measurement mode is complex steps not only; Cost dearly, and since around test component to the influence of antenna port, make precision of test result have much room for improvement.
In the measuring process of miniature antenna, connect the potato masher antenna radiation field that the cable each several part of antenna and network analyzer can not ignore, the practical operation difficulty of getting up is very big.Particularly when the unconventional feed of antenna, directly embed small-sized radiator situation like chip, an interference is extremely serious.Therefore, need special metering system to obtain abundance test data accurately.The test of rfid system electronic label antenna is that engineering technical personnel show off a difficult problem to be solved always.
Because non-50 ohm of the electronic label antenna port Impedance to be measured of prior art, electronic label antenna port to be measured can not directly join through concentric cable and vector network analyzer in the test process.Because electronic label antenna port to be measured is the balanced feeding mode, and concentric cable is the unbalanced feed mode, accurately test electronic label antenna port parameter to be measured must be by means of balance/imbalance conversion process, i.e. barron device spare.In addition, be set to complex impedance under the port general work frequency of electronic label antenna to be measured, have impedance mismatching, have a strong impact on precision of test result with concentric cable.General test device for electronic label antenna to be measured is: at port loaded impedance match circuit and barron device spare, test structure is complicated and the result had the influence that difference is ignored.
Summary of the invention
In order to solve the deficiency of prior art, the purpose of this invention is to provide a kind of method of radio frequency identification system electronic label antenna complex impedance test device.
In order to reach said purpose, first aspect of the present invention the present invention proposes the proving installation of a kind of radio-frequency recognition system electronic tag port to be measured complex impedance, and described proving installation comprises:
Vector network analyzer, first sheet metal, second sheet metal, concentric cable, converting interface and half arm electronic label antenna; Wherein:
Cable is electrically connected with the vector network analyzer and second sheet metal respectively, and second sheet metal is embedded in first sheet metal, and the feed port of the core of converting interface and half arm electronic label antenna is electrically connected, and the crust of converting interface is connected with the second sheet metal short circuit.
To achieve these goals, another aspect of the present invention has proposed a kind of preparation method of measurement mechanism of electronic label antenna port complex impedance, and the step of this measuring method comprises:
Step S1: be embedded into first sheet metal central authorities greater than the second sheet metal area to second sheet metal, both are electrically connected;
Step S2: cut the electronic label antenna to be measured that is symmetrically distributed about two arm directions symmetry, get the half the of electronic label antenna length to be measured, the half arm electronic label antenna that obtains being symmetrically distributed;
Step S3: be connected the two-port of the coupling annulus of half arm electronic label antenna with the second sheet metal short circuit;
Step S4: the crack foam is handled on the limit, two ends of half arm electronic label antenna, is used for fixing half arm electronic label antenna;
Step S5:, and link to each other with vector network analyzer through coaxial cable with the feeding point of half arm electronic label antenna and the core short circuit of converting interface;
Step S6: the calibration vector network analyzer, and accomplish initial setting up;
Step S7: in the vector network analyzer operator scheme, select Smith chart, the port Impedance of double arm electronic label antenna is tested, and obtains the port Impedance of half arm electronic label antenna;
Step S8: preserve the port Impedance test result of half arm electronic label antenna, and divide record port Impedance data;
Step S9: the port Impedance test result of half arm electronic label antenna multiply by 2, then obtain electronic label antenna port Impedance to be measured.
Beneficial effect of the present invention: the present invention is directed to the electronic label antenna of structural symmetry, proposed a kind of proving installation of image method.Since the radio RF recognition technology own characteristic, electronic label antenna port to be measured and unconventional 50 ohm or 100 ohm of feeds, and antenna port can not directly be connected with testing tool.And in order to obtain the impedance of electronic label antenna port to be measured; Usually need convert electronic label antenna port Impedance to be measured to 50 ohm; And through the balance/imbalance converter, be electronic label antenna port translation to be measured uneven feeding classification, could link to each other with testing tool.This process is comparatively loaded down with trivial details, and the adding of matching network and balance/imbalance converter, and the radiation of electronic label antenna to be measured is caused unnecessary influence, then, has influence on precision of test result.The present invention is through simply being divided into two electronic label antenna symmetrical structure to be measured; Utilize desirable ground plane to replace the electric field E face of electronic tag radiation field to be measured; Electronic label antenna formal transformation to be measured is the monopole form; Thereby electronic label antenna to be measured can directly join with testing tool, has effectively solved the drawback of electronic tag port balanced feeding to be measured.
Whole electronic label antenna can regard as half arm antenna structure and its about the image antenna of second sheet metal symmetry and form.The impedance that this device is used image antenna is the half the of its whole antenna impedances, if obtain the impedance of entire antenna, only need record its image antenna impedance, and twice gets final product then.Of the present invention through test half arm antenna port impedance; Solved the test difficult problem of balanced feeding type of antenna; Than the required balance/imbalance converter of balanced feeding type of antenna testing impedance and the design procedure of matching network; Simple testing process of the present invention when guaranteeing measuring accuracy, has economic benefit.Whole test process control element of the present invention is simply effective, and controlling schemes has higher feasibility, and the design of control system is prone to row.
Description of drawings
Fig. 1 is an electronic label detection of RFID system antenna complex impedance method of testing process flow diagram of the present invention;
Fig. 2 among the present invention as a typical miniaturized electronic label antenna structure of illustration;
Fig. 3 is image method half an arm electronic label antenna proving installation structure of the present invention;
Fig. 4 is antenna processing mode on the sheet metal of the present invention;
Fig. 5 is a test structure structure of the present invention;
Fig. 6 is that emulation of the present invention and electronic label antenna test result to be measured compare, and wherein solid line is a test result, and dotted line is a simulation result.
Embodiment
For making the object of the invention, technical scheme and advantage clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, to further explain of the present invention.Below, we measure electronic label antenna complex impedance device to be measured with an example explanation image method.
Radio-frequency recognition system electronic label antenna to be measured vertically stands near a slice conductor, be reflected towards the energy of radiation of conductors, and synthetic field be exactly ground wave and reflection wave vector and.Can think also that the latter is not produced by reflection, but by below the conductive surface image antenna produced.1/4 wavelength antennas by end fed cooperates with its image antenna, just in time forms a half-wave dipole antenna, but because its lower half-space no reflection events field, the aerial radiation general power is the half the of common half-wave dipole antenna.And its radiation resistance also only is the half the of common half-wave antenna radiation resistance.
Like Fig. 1 electronic label detection of RFID system antenna complex impedance method of testing process flow diagram of the present invention is shown, the step of this method comprises:
Step S1: be embedded into first sheet metal, 2 central authorities greater than second sheet metal, 3 areas to second sheet metal 3, both are electrically connected;
Step S2: cut the electronic label antenna to be measured that is symmetrically distributed about two arm directions symmetry, get the half the of electronic label antenna length to be measured, the half arm electronic label antenna 6 that obtains being symmetrically distributed;
Step S3: be connected the two-port of the coupling annulus 62 of half arm electronic label antenna 6 with 3 short circuits of second sheet metal;
Step S4: the crack foam is handled on the limit, two ends of half arm electronic label antenna 6, is used for fixing half arm electronic label antenna 6;
Step S5:, and link to each other with vector network analyzer 1 through coaxial cable with the feeding point of half arm electronic label antenna 6 and the core short circuit of converting interface 5;
Step S6: calibration vector network analyzer 1, and accomplish initial setting up;
Step S7: in vector network analyzer 1 operator scheme, select Smith (Smith) circle diagram, the port Impedance of double arm electronic label antenna 6 is tested, and obtains the port Impedance of half arm electronic label antenna 6;
Step S8: preserve the port Impedance test result of half arm electronic label antenna 6, and divide record port Impedance data;
Step S9: the port Impedance test result of half arm electronic label antenna 6 multiply by 2, then obtain electronic label antenna port Impedance to be measured.
Shown in Figure 2 is a miniaturization electronic label antenna to be measured; The structure of this electronic label antenna to be measured is about straight line aa ' symmetry; Coupling annulus 62 makes electronic label antenna to be measured and electronic label chip impedance conjugation, and electronic label antenna two arms to be measured are that the spiral fashion bending has reduced the antenna shapes size greatly.
In the measuring process of common electronically small antenna, cable 4 each several parts that connect antenna and vector network analyzer 1 have the potato masher antenna radiation field of can not ignore, and the practical operation difficulty of getting up is very big.Particularly when the unconventional feed of antenna, directly embed small-sized radiator situation like electronic label chip, an interference is extremely serious.Therefore, need special metering system to obtain abundance test data accurately.
In order to overcome this difficulty, be different from the measurement entire antenna, the conductive metal sheet of bigger electric size replaces the electric field E plane of symmetry; Measure half hitch structure antenna impedance, the present invention as shown in Figure 3 is the electronic label detection of RFID system antenna complex impedance test device, comprising: vector network analyzer 1; First sheet metal 2; Second sheet metal 3, concentric cable 4, converting interface 5, half arm electronic label antenna 6; Wherein: cable 4 is electrically connected with the vector network analyzer 1 and second sheet metal 3 respectively; Second sheet metal 3 is embedded in first sheet metal 2; The feed port 61 of the core of converting interface 5 and half arm electronic label antenna 6 is electrically connected, and the crust 51 of converting interface 5 is connected with 3 short circuits of second sheet metal.Said second sheet metal 3 overlaps with first sheet metal, 2 geometric centers, each limit respective parallel, and both are electrically connected.The area of said second sheet metal 3 is less than the area 2 of first sheet metal.Said half arm electronic label antenna 6 is a symmetrical structure, and half arm electronic label antenna 6 is corresponding half the after the two arms symmetry of electronic label antenna to be measured is cut, and the port Impedance of whole electronic label antenna 6 to be measured is the twice of institute's geodesic structure test result.First port 621 and second port 622 of electronic label antenna to be measured coupling annulus 62 itself weld together with second sheet metal 3 respectively, can the part that coupling annulus 62 cuts be regarded as with desirable ground plane short circuit thus and join.First sheet metal 2 is the stainless steel metal plate; Second sheet metal 3 is bronze sheet metals.Cable 4 is 50 Europe concentric cable.Converting interface 5 is the SMA converting interface.
Be divided into two electronic label antenna structure to be measured along straight line aa '; Like Fig. 4; First port 621, second port 622 and second sheet metal 3 of electronic label antenna to be measured coupling annulus 62 weld together; 61 termination SMA converting interfaces 5 of half arm electronic label antenna 6, and link to each other with vector network analyzer 1.For fixing half arm configuration electronic label antenna 6, we are the processing of crack foam at the two ends of half arm electronic label antenna 6, so that half arm electronic label antenna 6 to be measured is fixing.Because the specific inductive capacity of foam approaches atmosphere, so the electromagnetic interference (EMI) of introducing thus can be ignored.Fig. 5 is the back side diagrammatic sketch of test structure, and converting interface 5 is embedded in the geometric center of first sheet metal 2, and the core 51 of converting interface can be connected vector network analyzer 1 with after cable 4 docks.Fig. 6 is for emulation and test this electronic label antenna port Impedance curve to be measured; Wherein the simulation calculation result that representes of dotted line can find out that test result and result of calculation are identical basically, at the 915MHz Frequency point; The electronic label antenna port Impedance of calculating gained is 12.5+j414Ohm; And measured value is 12.6+j418Ohm, and both are more approaching, and this method of testing is reliable.
The description of front is to be used to realize preferred exemplary of the present invention, and scope of the present invention should not described by this and limits.Scope of the present invention is limited accompanying claims.
Claims (6)
1. a radio-frequency recognition system electronic label antenna complex impedance test device to be measured is characterized in that, comprising: vector network analyzer (1); First sheet metal (2); Second sheet metal (3), 50 Europe concentric cable (4), converting interface (5), half arm electronic label antenna (6); Wherein:
50 Europe concentric cable (4) are electrically connected with vector network analyzer (1) and second sheet metal (3) respectively; Second sheet metal (3) is embedded in first sheet metal (2); The core (51) of converting interface (5) is electrically connected with the feed port (61) of half arm electronic label antenna (6), and the crust of converting interface (5) is connected with second sheet metal (3) short circuit;
Used second sheet metal (3) overlaps with first sheet metal (2) geometric center, each limit respective parallel, and both are electrically connected; Said half arm electronic label antenna (6) itself has coupling annulus (62), and first port (621) of this coupling annulus (62) is connected with second sheet metal (3) respectively with second port (622), and this short circuit that is connected to desirable ground plane is joined.
2. according to the described proving installation of claim 1, it is characterized in that the area of said second sheet metal (3) is less than the area of first sheet metal (2).
3. according to the described proving installation of claim 1, it is characterized in that said half arm electronic label antenna (6) is a symmetrical structure.
4. according to the described proving installation of claim 1, it is characterized in that first sheet metal (2) is the stainless steel metal plate; Second sheet metal (3) is bronze sheet metal.
5. according to the described proving installation of claim 1, it is characterized in that converting interface (5) is the SMA converting interface.
6. radio-frequency recognition system electronic label antenna complex impedance to be measured method of testing is characterized in that the step of this method comprises:
Step S1: be embedded into first sheet metal central authorities greater than the second sheet metal area to second sheet metal, both are electrically connected;
Step S2: cut the electronic label antenna to be measured that is symmetrically distributed about two arm directions symmetry, get the half the of electronic label antenna length to be measured, the half arm electronic label antenna that obtains being symmetrically distributed;
Step S3: be connected the two-port of the coupling annulus of half arm electronic label antenna with the second sheet metal short circuit;
Step S4: the crack foam is handled on the limit, two ends of half arm electronic label antenna, is used for fixing half arm electronic label antenna;
Step S5:, and link to each other with vector network analyzer through coaxial cable with the feeding point of half arm electronic label antenna and the core short circuit of converting interface;
Step S6: the calibration vector network analyzer, and accomplish initial setting up;
Step S7: in the vector network analyzer operator scheme, select Smith chart, the port Impedance of double arm electronic label antenna is tested, and obtains the port Impedance of half arm electronic label antenna;
Step S8: preserve the port Impedance test result of half arm electronic label antenna, and write down the port Impedance data respectively;
Step S9: the port Impedance test result of half arm electronic label antenna multiply by 2, then obtain electronic label antenna port Impedance to be measured.
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Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103091556B (en) * | 2011-10-31 | 2016-03-30 | 国民技术股份有限公司 | A kind of measuring method of electronic tag matched impedance and system |
| EP2978069B1 (en) | 2014-07-24 | 2023-11-01 | Ignion, S.L. | Slim radiating systems for electronic devices |
| CN104297566B (en) * | 2014-10-23 | 2017-10-27 | 西安电子科技大学 | Antenna impedance measuring method on super high frequency radio frequency identification electronic tag |
| CN104297567B (en) * | 2014-10-23 | 2017-02-15 | 西安电子科技大学 | Clamp for measuring antenna impedance on ultrahigh-frequency radio frequency identification tag |
| CN108107339B (en) * | 2016-11-25 | 2020-05-22 | 四川华大恒芯科技有限公司 | Method for testing chip impedance and sensitivity of ultrahigh frequency RFID (radio frequency identification) tag |
| CN106680587A (en) * | 2016-12-15 | 2017-05-17 | 无锡科睿坦电子科技股份有限公司 | System and method for measuring resistance value of RFID high frequency antenna |
| CN107026325B (en) * | 2017-06-06 | 2023-10-03 | 中国电子技术标准化研究院 | Impedance matching connection device for radio frequency identification tag antenna |
| CN109444547B (en) * | 2018-11-22 | 2020-12-15 | 北京智芯微电子科技有限公司 | RFID chip impedance measuring method and device based on two-port network |
| CN111416204B (en) * | 2019-01-07 | 2023-04-07 | 北京京东乾石科技有限公司 | Ultrahigh frequency electronic tag and radio frequency identification system comprising same |
| CN112394227B (en) * | 2020-10-30 | 2023-10-27 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | RFID tag antenna impedance testing method |
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