CN117638474A - UHF tag test near field antenna and system based on electric field coupling - Google Patents
UHF tag test near field antenna and system based on electric field coupling Download PDFInfo
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Abstract
The invention discloses a UHF tag test near field antenna and a system based on electric field coupling, comprising: the device comprises a grounding metal layer, a first insulating layer, a dielectric layer, a second insulating layer and an electrode layer. The electrode layer includes a first strip electrode and a second strip electrode arranged in order along a first direction with a gap therebetween. The first strip electrode has a dimension in the first direction that is greater than a dimension in the second direction, and the second strip electrode has a dimension in the first direction that is greater than a dimension in the second direction. The first end of the first strip electrode, which is far from the second strip electrode, is used for being electrically connected with external equipment, and the first end of the second strip electrode, which is far from the first strip electrode, is used for being electrically connected with external equipment. The near field antenna designed by the embodiment of the invention only acts on the UHF tag in a short-distance range, so that the distance from the test antenna to the UHF tag can be shortened, and the interference of the activation of the UHF tag which is not to be tested on the measurement of the UHF tag to be tested is avoided.
Description
Technical Field
The embodiment of the invention relates to the technical field of antenna measurement, in particular to a UHF tag test near field antenna and a UHF tag test near field antenna system based on electric field coupling.
Background
An ultra-high frequency (Ultra High Frequency, UHF) tag is an electronic tag based on radio frequency identification (Radio Frequency Identification Digital, RFID) technology, and the UHF tag is widely applied to the fields of retail, logistics, factory automation and non-motor vehicle management. In the UHF label production process, the sensitivity of the UHF label is required to be measured and screened out to obtain a label with poor sensitivity, so that the label with poor sensitivity is prevented from flowing into the market.
The boundary of the near field and far field of an antenna is defined as follows:wherein D is the maximum size of the antenna, lambda is the wavelength, and the distance is greater than R ff When the distance is less than R, the distance is less than R ff And belongs to the near field of the antenna.
In the prior art, UHF tags are typically measured using a far field antenna, i.e., the UHF tag is placed in the far field of the antenna for measurement. In general, the larger the far-field antenna size, the better the radiation direction, the more concentrated the radiation, the narrower the beam width, and the higher the antenna gain. But the larger the far field antenna size, the greater the distance of its far field will increase with the square of the antenna size. If a small-sized antenna is used, the far-field antenna gain is reduced, and the beam bandwidth is wider, although the far-field distance is reduced, the non-UHF tag around the far-field antenna may be activated, thereby interfering with the measurement of the tag to be measured.
Disclosure of Invention
The embodiment of the invention provides a near field antenna and a system for testing UHF labels based on electric field coupling, which only act on UHF labels in a near range, can reduce the proportion of far field radiation power to input power, is beneficial to shortening the distance between a test antenna and the UHF labels, and avoids the interference of activation of non-to-be-tested UHF labels on measurement of the to-be-tested UHF labels.
In a first aspect, an embodiment of the present invention provides a near field antenna for testing a UHF tag based on electric field coupling, including: the grounding metal layer, the first insulating layer, the dielectric layer, the second insulating layer and the electrode layer are sequentially stacked;
the electrode layer comprises a first strip electrode and a second strip electrode which are sequentially arranged along a first direction, and a gap is reserved between the first strip electrode and the second strip electrode; the first strip electrode has a dimension in the first direction that is greater than a dimension in the second direction, and the second strip electrode has a dimension in the first direction that is greater than a dimension in the second direction;
the first end of the first strip electrode, which is far from the second strip electrode, is used for being electrically connected with external equipment, and the first end of the second strip electrode, which is far from the first strip electrode, is used for being electrically connected with external equipment.
Optionally, the dielectric layer is an air layer or an insulating layer.
Optionally, the dielectric layer, the first insulating layer and the second insulating layer are made of the same material.
Optionally, the first and second strip electrodes have a dimension in the second direction that is greater than the width of the UHF tag.
Along the first direction, the total length of the first strip electrode, the second strip electrode, and the gap is greater than the length of the UHF tag.
Optionally, the dimensions of the first strip electrode and the second strip electrode in the second direction meet the following condition:
wherein c is the speed of light, f max Is the maximum operating frequency of the UHF tag.
Optionally, the first strip electrode and the second strip electrode are the same size.
In a second aspect, an embodiment of the present invention provides a UHF tag testing system, including: the balun and the UHF tag test near field antenna based on electric field coupling provided by any embodiment of the invention;
the UHF tag based on electric field coupling tests that a first end of a first strip electrode of the near-field antenna is connected with a first end of the balun through a coaxial line, and a first end of a second strip electrode is connected with a second end of the balun through the coaxial line; and the two coaxial radio frequency wires have the same length, material and caliber.
Optionally, the UHF tag test system further comprises: a shield shell having an opening;
the UHF tag test near field antenna based on electric field coupling is fixedly arranged in the shielding shell, and the first strip electrode and the second strip electrode are exposed at the opening.
Optionally, the UHF tag test system further comprises: a matching circuit;
the first end of the matching circuit and the third end of the balun are connected by a coaxial line, and the second end of the matching circuit is used for being connected with the RF port of the test equipment by the coaxial line.
Optionally, the UHF tag test system further comprises: an insulating support layer;
the insulation supporting layer is arranged on the surfaces of the first strip electrode and the second strip electrode and is used for arranging UHF labels to be tested;
the thickness of the insulating support layer is less than half the thickness of the UHF tag test near field antenna based on electric field coupling.
The embodiment of the invention provides a UHF tag test near field antenna based on electric field coupling, which comprises the following steps: the grounding metal layer, the first insulating layer, the dielectric layer, the second insulating layer and the electrode layer are sequentially stacked. The electrode layer includes a first strip electrode and a second strip electrode arranged in order along a first direction with a gap therebetween. The first strip electrode has a dimension in the first direction that is greater than a dimension in the second direction, and the second strip electrode has a dimension in the first direction that is greater than a dimension in the second direction. The first end of the first strip electrode, which is far from the second strip electrode, is used for being electrically connected with external equipment, and the first end of the second strip electrode, which is far from the first strip electrode, is used for being electrically connected with external equipment. The near field antenna designed by the embodiment of the invention only acts on the UHF tag in a close range, can reduce the proportion of far field radiation power to input power, is beneficial to shortening the distance from the test antenna to the UHF tag, and avoids the interference of activation of the UHF tag which is not to be tested on the measurement of the UHF tag which is to be tested.
It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the invention or to delineate the scope of the invention. Other features of the present invention will become apparent from the description that follows.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a top view of a structure of a UHF tag test near field antenna based on electric field coupling according to an embodiment of the present invention;
fig. 2 is a front view of a structure of a UHF tag test near field antenna based on electric field coupling according to an embodiment of the present invention;
fig. 3 is an equivalent circuit schematic diagram of a near field antenna for testing a UHF tag based on electric field coupling according to an embodiment of the present invention;
fig. 4 is an electric field distribution diagram of a section of a UHF tag test near field antenna based on electric field coupling according to an embodiment of the present invention;
FIG. 5 is a diagram of a dipole antenna electric field profile;
fig. 6 is a schematic structural diagram of a UHF tag to be tested according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of a UHF tag testing system according to an embodiment of the present invention.
Detailed Description
In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or apparatus.
Fig. 1 is a top view of a UHF tag test near field antenna structure based on electric field coupling according to an embodiment of the present invention. Fig. 2 is a front view of a structure of a UHF tag test near field antenna based on electric field coupling according to an embodiment of the present invention. Fig. 3 is an equivalent circuit schematic diagram of a near field antenna for testing a UHF tag based on electric field coupling according to an embodiment of the present invention. Fig. 1-2 show a schematic structural diagram of a UHF tag test near field antenna based on electric field coupling. Referring to fig. 1 and 2, the electric field coupling-based UHF tag test near field antenna includes a ground metal layer 6, a first insulating layer 5, a dielectric 4 layer, a second insulating layer 3, and an electrode layer, which are sequentially stacked. The electrode layer includes a first strip electrode 1 and a second strip electrode 2 arranged in order along a first direction with a gap between the first strip electrode 1 and the second strip electrode 2. The first strip electrode 1 has a dimension in the first direction that is larger than a dimension in the second direction, and the second strip electrode 2 has a dimension in the first direction that is larger than a dimension in the second direction. The first end B of the first strip electrode 1 remote from the second strip electrode 2 is for electrical connection with an external device, and the first end a of the second strip electrode 2 remote from the first strip electrode 1 is for electrical connection with an external device.
The ground metal layer 6 and the electrode layer 1 may be copper layers, and the first insulating layer 5 and the second insulating layer 3 may be FR4 layers. The dielectric layer 4 may be made of the same material as the first insulating layer 5 and the second insulating layer 3, and the dielectric layer 4 may be an air layer. The gap between the first and second strip electrodes 1 and 2 is gap, the second direction dimension of the first and second strip electrodes 1 and 2 is W, and the sum of the first direction dimensions of the first and second strip electrodes 1 and 2 and the gap between the first and second strip electrodes 1 and 2 is L.
Specifically, when the near field antenna for testing the UHF tag based on electric field coupling is used for testing the UHF tag, the UHF tag to be tested needs to be placed above the first strip electrode 1 and the second strip electrode 2 in parallel, differential excitation signals are loaded on two ports of the first strip electrode 1 and the second strip electrode 2, and capacitive coupling is formed between gaps of the first strip electrode 1 and the second strip electrode 2. The excitation current may flow from the first end a of the first strip electrode 1 to the first end B of the second strip electrode 2, or the first end B of the second strip electrode 2 to the first end a of the first strip electrode 1, at the gap between the first strip electrode 1 and the second strip electrode 2, the excitation current is converted into a displacement current. When differential excitation signals are loaded on the first end a of the first strip electrode 1 and the first end B of the second strip electrode 2, an equivalent circuit diagram of a near field antenna based on UHF tag test of electric field coupling is shown in fig. 3, the middle of the gap between the first strip electrode 1 and the second strip electrode 2 is equivalent to a short-circuit surface of a virtual circuit, three capacitances are formed by the gap between the first strip electrode 1 and the second strip electrode 2, the first strip electrode 1 and the ground metal layer 6, and the second strip electrode 2 and the ground metal layer 6, and the electrode layer 1, the dielectric layer 4 and the ground metal layer 6 form a microstrip transmission line.
Fig. 4 is a schematic diagram of a section electric field distribution diagram of a near field antenna for testing a UHF tag based on electric field coupling according to an embodiment of the present invention. Referring to fig. 1 and 4, exemplary, the arrow indicates the distribution of the electric field intensity, the thicker the arrow indicates the larger the electric field intensity, if the excitation signals at the first end a of the first electric strip electrode 1 and the second end B of the second strip electrode 2 of the UHF tag test near field antenna based on electric field coupling are +vs, -Vs, the adjacent ports of the first electric strip electrode 1 and the second strip electrode 2 are in open circuit, the electric field intensity is maximum, and the polarities are opposite, but because the two ports of the first strip electrode 1 and the second strip electrode 2 are close, the magnetic field excited by the displacement current is bound in the near field region of the antenna under the action of the grounded metal layer 6, the far field transmission capability is reduced, the radiation capability is greatly weakened, and the electric field generated by the displacement current at the adjacent two ports of the first strip electrode 1 and the second strip electrode 2 is strongest, so that the coupling between the electric field of the UHF tag test near field antenna based on electric field coupling and the UHF tag can be increased, and the UHF tag can be better tested.
Fig. 5 is a dipole antenna electric field distribution diagram. Referring to fig. 5, the dipole antenna operates on the following principle: the dipole antenna is composed of a first section of straight conductor 9 and a second section of straight conductor 10, excitation signals are loaded at two adjacent end points of the two sections of straight conductors, the strongest electric field distribution is generated at the end points far away from each other, and the strongest electric field distribution is converted into displacement current, and when the dipole antenna is far away from each other, the displacement current excites a magnetic field, and the magnetic field in turn excites an electric field, so that radiation and propagation of electromagnetic waves are formed. The magnetic field of the UHF tag test near field antenna based on electric field coupling provided by the embodiment of the invention is limited in the near field region of the near field antenna under the action of the grounding metal layer, the electric field generated by the displacement current at two adjacent ports of the first strip electrode and the second strip electrode is strongest, the coupling between the electric field of the UHF tag test near field antenna based on electric field coupling and the UHF tag can be increased, and compared with a dipole antenna, the UHF tag can be better tested by the antenna of the embodiment of the invention.
In the embodiment of the invention, the near-field antenna comprises a grounding metal layer 6, a first insulating layer 5, a dielectric layer 4, a second insulating layer 3 and an electrode layer which are sequentially stacked. The electrode layer comprises a first strip electrode 1 and a second strip electrode 2 which are sequentially arranged along a first direction, a gap is reserved between the first strip electrode 1 and the second strip electrode 2, the size of the first strip electrode 1 along the first direction is larger than that along the second direction, the size of the second strip electrode 1 along the first direction is larger than that along the second direction, a first end B of the first strip electrode 1, which is far away from the second strip electrode 2, is used for being electrically connected with external equipment, and a first end A of the second strip electrode 1, which is far away from the first strip electrode 1, is used for being electrically connected with the external equipment. The near field antenna designed by the embodiment of the invention has the advantages that the magnetic field is limited in the near field region of the near field antenna under the action of the grounding metal layer 6, and the displacement current is strongest at the electric fields generated by the two adjacent ports of the first strip electrode 1 and the second strip electrode 2, so that the near field antenna designed by the embodiment of the invention only acts on UHF labels in a short range, the proportion of far field radiation power to input power can be reduced, the distance from the test antenna to the UHF labels is favorably shortened, and the interference of activation of the non-to-be-tested UHF labels on measurement of the to-be-tested UHF labels is avoided.
Referring to fig. 2, the dielectric layer 4 is an air layer or an insulating layer, as an option, based on the above embodiment.
With continued reference to fig. 2, the dielectric layer 4, the first insulating layer 6 and the second insulating layer 3 may be made of the same material, as an alternative to the above embodiments.
The materials adopted by the dielectric layer 4, the first insulating layer 6 and the second insulating layer 3 can be FR4 dielectric.
Fig. 6 is a schematic structural diagram of a to-be-tested UHF tag according to an embodiment of the present invention, and referring to fig. 6, a tested UHF tag minimum system is composed of an RFID chip and a tag antenna. The RFID tag chip contains differential RF pins that are connected to the feed point of the tag antenna. The tag antenna is similar to a dipole antenna.
Referring to fig. 1 and 4, alternatively, the dimension W of the first strip electrode 1 and the second strip electrode 2 in the second direction is larger than the width H2 of the UHF tag on the basis of the above-described embodiment;
in the first direction, the total length L of the first strip electrode 1, the second strip electrode 2 and the gap is greater than the length L2 of the UHF tag.
By the arrangement, the magnetic field formed by the first strip electrode 1 and the second strip electrode 2 can be weakened, meanwhile, the UHF tag is covered by the electric field, the electric field coupling is increased, and the UHF tag is better measured.
On the basis of the above-described embodiment, optionally, the dimensions W of the first and second strip electrodes in the second direction satisfy the following condition:
wherein c is the speed of light, f max Is the maximum operating frequency of the UHF tag.
By the arrangement, the longitudinal current component can be reduced, electromagnetic field radiation to space is weakened, energy loss is reduced, and electric field intensity is further increased.
With continued reference to fig. 1, on the basis of the above-described embodiment, optionally, the first strip electrode 1 and the second strip electrode 2 are the same size.
The first strip electrode 1 and the second strip electrode 2 are arranged in the same size, so that the generation of asymmetric electric field distribution caused by the different sizes of the first strip electrode 1 and the second strip electrode 2 can be avoided, and the influence on the electric field coupling of the antenna and the UHF tag is further avoided.
Fig. 7 is a schematic structural diagram of a UHF tag testing system according to an embodiment of the present invention, referring to fig. 7, the UHF tag testing system includes: balun 7 and the UHF tag test near field antenna based on electric field coupling provided by any embodiment of the invention. The UHF tag test near field antenna based on electric field coupling has the advantages that the first end A of the first strip electrode 1 of the near field antenna is connected with the first end of the balun 7 through a coaxial line, the first end B of the second strip electrode 2 is connected with the second end of the balun 7 through the coaxial line, and the lengths of the two coaxial radio frequency cables are equal, and the materials and the calibers are the same. Wherein the first end and the second end are balance ports of the balun. The UHF tag test near field antenna based on electric field coupling is provided with a radio frequency connector at each of the first end A of the first strip electrode 1 and the first end B of the second strip electrode 2, wherein the radio frequency connector can be an SMA connector or an N-type connector. Balun 7 is a piece of hardware for converting a single-ended signal into a differential signal, and balun 7 may be of the LC lumped type or of the transformer type. The balanced port impedance of the balun 7 formed by the first and second ends is 100Ohm, i.e. the impedance of the first and second ends to ground is 50Ohm, respectively.
Specifically, the rf connector at the first end of the first strip electrode 1 is electrically connected to the first end a of the balun 7 by a coaxial rf cable, and the rf connector at the first end B of the second strip electrode 2 is electrically connected to the second end of the balun 7 by a coaxial rf cable, and the lengths of the two coaxial rf cables should be equal to avoid phase imbalance.
When the single-ended signal enters the balun 7, the balun 7 converts the single-ended signal into a differential signal and then transmits the differential signal from the first and second ends of the balun 7 to the first and second strip electrodes 1 and 2 of the near field antenna, respectively.
In the embodiment of the invention, the balun can convert the single-ended signal into the differential signal, thereby facilitating the measurement of the UHF tag by the UHF tag test near-field antenna based on electric field coupling.
Based on the above embodiment, optionally, the UHF tag test system further includes: and a shield case having an opening. The UHF tag test near field antenna based on electric field coupling is fixedly arranged in the shielding shell, and the first strip electrode and the second strip electrode are exposed at the opening.
Specifically, the UHF tag test near field antenna based on electric field coupling is placed in a shielding shell with metal on the periphery and the bottom surface, and only the top surface opening is exposed without metal shielding. Two insulators can be arranged on the metal wall, the first insulating layer and the grounding metal layer can be fixed on the metal wall through the insulators, meanwhile, the radio frequency connectors at two ends of the near-field antenna can be replaced by through-wall connectors which are assembled on two opposite metal walls of the shielding shell, and pins of the radio frequency connectors pass through the metal wall through holes and are welded at a feed position of the near-field antenna.
In the embodiment of the invention, the UHF tag test near field antenna based on electric field coupling is fixed in the shielding shell, so that the interference of surrounding electromagnetic environment can be reduced.
With continued reference to fig. 7, in addition to the above embodiment, optionally, the UHF tag testing system further includes: and a matching circuit 8. The first end of the matching circuit 8 is connected to the third end of the balun 7 by a coaxial line and the second end of the matching circuit 8 is adapted to be connected to the RF port of the test device by a coaxial line.
Wherein the matching circuit 8 is arranged to match the input impedance of the third terminal of the balun 7 to 50Ohm. The test equipment is used for outputting signals and measuring response signals of the labels to be tested. The matching circuit 8 is assembled with the balun 7 on a circuit board which is then mounted in a metal shield, drilled in the side walls of the shield, and fitted with a radio frequency connector. And the coaxial line is connected with a radio frequency connector of two sections of the UHF tag test near field antenna based on electric field coupling.
In the embodiment of the invention, the input impedance of the third end of the balun 7 can be matched to 50Ohm by arranging the matching circuit 8, so that the connection with the measuring equipment is convenient.
Based on the above embodiment, optionally, the UHF tag test system further includes: an insulating support layer. The insulating supporting layer is arranged on the surfaces of the first strip electrode and the second strip electrode, and the insulating supporting layer is used for setting UHF labels to be tested. The thickness of the insulating support layer is less than half the thickness of the UHF tag test near field antenna based on electric field coupling.
The material of the insulating supporting layer can be white foam, glass and ceramic.
Specifically, when the UHF tag is measured, the supporting insulating layer is disposed on the first strip electrode 1 and the second strip electrode 2, the UHF tag is disposed on the supporting insulating layer and faces the positions of the first strip electrode 1 and the second strip electrode 2 on the supporting insulating layer, the distance between the UHF tag and the first strip electrode 1 and the second strip electrode 2 is the thickness of the supporting insulating body, if the distance between the UHF tag and the first strip electrode 1 and the second strip electrode 2 is too small (for example, the UHF tag is closely attached to the near field antenna), the coupling between the first strip electrode and the second strip electrode of the near field antenna and the UHF tag changes the resonance state, and the sensitivity of the UHF tag is deviated, so that the distance between the UHF tag and the first strip electrode and the second strip electrode should ensure that the resonance frequency of the UHF tag is not affected by the proximity of the electrode layer. I.e. the thickness of the insulating support layer is less than half the thickness of the UHF tag test near field antenna based on electric field coupling.
In the embodiment of the invention, the thickness of the supporting insulator can not only prevent the resonance frequency of the UHF tag from being affected by the proximity of the near-field antenna, but also ensure that the near-field antenna has enough power to couple to the UHF tag.
The embodiment of the invention also provides a specific example of a UHF tag test system, and the UHF tag test system comprises a balun, a matching circuit and a UHF tag test near-field antenna based on electric field coupling. The UHF tag test near field antenna based on electric field coupling is characterized in that the first insulating layer and the second insulating layer are both RF4 plates, the medium layer is an air medium, the thickness of the air medium is 15mm, and the thickness of the FR4 plates is 1.6mm. The widths of the first and second strip electrodes were 12mm, the gap between the first and second strip electrodes was 4mm, and the total length of the first, second and first and second strip electrodes was 115mm. Due to the use of air media, FR4 needs to be secured to the metal side wall of the shield. In the configuration of 15mm in air medium thickness and 1.6mm in thickness of the fr4 board, if the balun is in the form of a transformer, the transformation ratio becomesThe impedance of the third end of the balun can be matched to 50Ohm with a coaxial line length of 10cm, and the matching circuit can be omitted. When the UHF label is tested, white foam with the thickness of 5mm is placed on the first strip electrode and the second strip electrode, and the label is placed at the position opposite to the electrode on the foam, so that the sensitivity of the UHF label can be measured.
It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present invention may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present invention are achieved, and the present invention is not limited herein.
The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.
Claims (10)
1. A UHF tag test near field antenna based on electric field coupling, comprising:
the grounding metal layer, the first insulating layer, the dielectric layer, the second insulating layer and the electrode layer are sequentially stacked;
the electrode layer comprises a first strip electrode and a second strip electrode which are sequentially arranged along a first direction, and a gap is reserved between the first strip electrode and the second strip electrode; the first strip electrode has a dimension in a first direction greater than a dimension in a second direction, and the second strip electrode has a dimension in the first direction greater than a dimension in the second direction;
the first end of the first strip electrode, which is far away from the second strip electrode, is used for being electrically connected with an external device, and the first end of the second strip electrode, which is far away from the first strip electrode, is used for being electrically connected with the external device.
2. An antenna according to claim 1, characterized in that:
the dielectric layer is an air layer or an insulating layer.
3. An antenna according to claim 2, characterized in that:
the dielectric layer, the first insulating layer and the second insulating layer are made of the same material.
4. An antenna according to claim 1, characterized in that:
the dimensions of the first and second strip electrodes along the second direction are greater than the width of the UHF tag;
along the first direction, the total length of the first strip electrode, the second strip electrode, and the gap is greater than the length of the UHF tag.
5. An antenna according to claim 1, characterized in that:
the dimensions of the first and second strip electrodes in the second direction satisfy the following conditions:
wherein c is the speed of light, f max Is the maximum operating frequency of the UHF tag.
6. An antenna according to claim 1, characterized in that:
the first and second strip electrodes are the same size.
7. A UHF tag test system, comprising:
a balun and the electric field coupling based UHF tag test near field antenna of any one of claims 1-6;
the UHF tag test near field antenna based on electric field coupling is characterized in that a first end of a first strip electrode is connected with a first end of the balun through a coaxial line, and a first end of a second strip electrode is connected with a second end of the balun through a coaxial line; and the two coaxial radio frequency cables have the same length, material and caliber.
8. The system of claim 6, further comprising:
a shield shell having an opening;
the UHF tag test near field antenna based on electric field coupling is fixedly arranged in the shielding shell, and the first strip electrode and the second strip electrode are exposed at the opening.
9. The system of claim 7, further comprising:
a matching circuit;
the first end of the matching circuit is connected with the third end of the balun through a coaxial line, and the second end of the matching circuit is used for being connected with an RF port of the testing device through the coaxial line.
10. The system of claim 7, further comprising:
an insulating support layer;
the insulation supporting layer is arranged on the surfaces of the first strip electrode and the second strip electrode and is used for setting UHF labels to be tested;
the thickness of the insulating supporting layer is smaller than half of the thickness of the UHF tag test near field antenna based on electric field coupling.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311672267.0A CN117638474A (en) | 2023-12-06 | 2023-12-06 | UHF tag test near field antenna and system based on electric field coupling |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311672267.0A CN117638474A (en) | 2023-12-06 | 2023-12-06 | UHF tag test near field antenna and system based on electric field coupling |
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| Publication Number | Publication Date |
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| CN117638474A true CN117638474A (en) | 2024-03-01 |
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| CN202311672267.0A Pending CN117638474A (en) | 2023-12-06 | 2023-12-06 | UHF tag test near field antenna and system based on electric field coupling |
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| Country | Link |
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| CN (1) | CN117638474A (en) |
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