Ultrahigh frequency dielectric resonator tag antenna and electronic tag

Abstract

The invention discloses an ultrahigh-frequency dielectric resonator tag antenna and an electronic tag in the field of antennae, and the ultrahigh-frequency dielectric resonator tag antenna comprises a single-layer dielectric sheet, a metal pattern printed on the surface of the single-layer dielectric sheet and a square dielectric resonator block, a horizontal strip-shaped belt, two inverted-V-shaped belts and two special-shaped hook belts which are in bilateral symmetry are sequentially arranged on the inner side of the special-shaped annular belt from top to bottom, and tooth-shaped belts are arranged on the outer side of the special-shaped annular belt in bilateral symmetry; two parasitic special-shaped metal sheets are arranged below the special-shaped annular belt in a bilateral symmetry mode. The top of the special-shaped annular belt is provided with a top notch, and the left and right outer sides of the special-shaped annular belt are provided with side notches. The metal patterns printed on the surface of the single-layer dielectric sheet are compact in structure, the antenna profile height and the overall size are reduced while the performance of the antenna is achieved, the antenna impedance and the antenna resonance center frequency are easy to adjust by adjusting the distribution of the structures of the metal patterns, and efficient impedance matching and performance adjustment are achieved.

Description

Technical Field

[0001] The present invention relates to the field of antennas, and in particular, to a UHF dielectric resonator tag antenna and an electronic tag. Background Art

[0002] Since it was proposed in the early 1950s, radio frequency identification technology (RFID) has experienced rapid development, giving rise to a variety of electronic tags. RFID, the abbreviation of Radio Frequency Identification, is the synonym of radio frequency identification technology. In this field, multiple frequency standards coexist, and the frequency range of the ultra-high frequency band (UHF) covers 860 to 960 MHz. A UHF RFID electronic tag consists of a tag antenna and a chip in the ultra-high frequency band, and the size of the tag antenna directly determines the overall size of the electronic tag. In recent years, with the continuous development of the Internet of Things technology, the research on ultra-high frequency (UHF) tag antennas has received increasing attention. The half-wave bent dipole tag antenna is commonly used in UHF RFID technology, and the length is shortened by bending the antenna arms to achieve miniaturization. However, the size of the tag antenna is still relatively large, which to a certain extent limits the application of the technology. Dielectric resonator UHF tag antennas have gradually become a research hotspot due to their advantages such as miniaturization and high performance. In order to further reduce the volume of UHF RFID electronic tags to meet the requirements of technology applications, small UHF RFID electronic tags have become the focus of research. Summary of the Invention

[0003] The purpose of the present invention is to provide a UHF dielectric resonator tag antenna and an electronic tag, and the overall volume of the antenna is reduced by the compact arrangement of each structure on the metal pattern.

[0004] To solve the above technical problems, the following technical solutions are adopted: In a first aspect, the present invention provides a UHF dielectric resonator tag antenna, including a single-layer dielectric sheet, a metal pattern printed on the surface of the single-layer dielectric sheet, and a dielectric resonator. The dielectric resonator is connected to the side of the single-layer dielectric sheet printed with the metal pattern. The metal pattern includes an unclosed special-shaped ring belt. Inside the special-shaped ring belt, horizontally strip-shaped belts that are symmetric left and right, two inverted V-shaped belts, and two special-shaped hook belts are arranged in sequence from top to bottom. On the outer side of the special-shaped ring belt, tooth-shaped belts are symmetrically arranged on the left and right; Two parasitic special-shaped metal sheets are symmetrically arranged on the left and right below the special-shaped ring belt. The parasitic special-shaped metal sheet includes an arc ring belt and a vertical strip-shaped belt extending upward from the end of the arc ring belt; A top notch is provided at the top of the special-shaped ring belt, and side notches are provided on the left and right outer sides.

[0005] Optionally, the horizontal strip includes a first horizontal band, a second horizontal band, and a third horizontal band. The first horizontal band is disposed below the top notch and crosses the shaped annular band; the second horizontal band is connected to the tips of the two inverted V-shaped bands and crosses the shaped annular band; the two ends of the third horizontal band are respectively connected to the side edges of the open ends of the two inverted V-shaped bands.

[0006] Optionally, the inverted V-shaped band is formed by the crossing of the thin ends of two metal strips that are thick at one end and thin at the other end. The tip of the inverted V-shaped band penetrates through the second horizontal band and then is connected to the shaped annular band.

[0007] Optionally, the second horizontal band includes two horizontal bands on the same straight line, with a gap therebetween. Each horizontal band is connected to the tip of one of the inverted V-shaped bands. The second horizontal band on both sides of the gap straddles the label chip.

[0008] Optionally, the toothed band is disposed on the outer side of the shaped annular band and includes a plurality of square toothed bands with different lengths. The edge profiles of the plurality of square toothed bands are consistent with the outer contour of the shaped annular band.

[0009] Optionally, the toothed band is located on the outer side of the shaped annular band corresponding to the shaped hook band.

[0010] Optionally, the shaped hook band is an open ellipse shape with an opening in an inverted U shape. The two ends of the shaped annular band are respectively connected to one end of the two shaped hook bands. The other end of the shaped hook band forms a tip that is aligned with but not connected to one end of the arc-shaped annular band.

[0011] Optionally, the dielectric resonator is of a square structure.

[0012] In a second aspect, the present invention provides an electronic tag, which includes a label chip and further includes the ultra-high frequency dielectric resonator tag antenna according to any one of the first aspect. The label chip is connected to the metal pattern.

[0013] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: 1. The metal pattern printed on the surface of the single-layer dielectric sheet in the present invention has a compact structure. While achieving various antenna performances, it reduces the antenna profile height and the overall volume. By adjusting the distribution of each structure of the metal pattern, it is easy to adjust the antenna impedance and the antenna resonance center frequency, thereby achieving efficient impedance matching and performance adjustment.

[0014] 2. The tag antenna provided by the present invention can be used on a metal surface and has a high antenna gain. Description of the Drawings

[0015] Figure 1It is a schematic diagram of the overall structure of the ultra-high frequency dielectric resonator tag antenna in the embodiment of the present invention; Figure 2 It is the frequency characteristic curve of the input impedance of the ultra-high frequency dielectric resonator tag antenna in the embodiment of the present invention; Figure 3 It is the gain plane pattern of the ultra-high frequency dielectric resonator tag antenna placed on the metal surface in the embodiment of the present invention; Figure 4 It is the simulation result diagram of the three-dimensional gain pattern of the ultra-high frequency dielectric resonator tag antenna in the embodiment of the present invention.

[0016] Description of the reference numerals: 1. Single-layer dielectric sheet; 2. Metal pattern; 21. Irregular ring-shaped band; 22. Inverted V-shaped band; 23. First horizontal band; 24. Second horizontal band; 25. Third horizontal band; 26. Parasitic irregular metal sheet; 211. Irregular hook-shaped band; 212. Tooth-shaped band; 3. Dielectric resonator block. Detailed implementation manners

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use.

[0018] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more. In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances. Embodiment 1

[0019] This embodiment provides a ultra-high frequency dielectric resonator tag antenna, which includes a single-layer dielectric sheet 1, a metal pattern 2 printed on the surface of the single-layer dielectric sheet 1, and a dielectric resonator 3. The dielectric resonator 3 is connected to the side of the single-layer dielectric sheet 1 printed with the metal pattern 2. The metal pattern 2 not only feeds the dielectric resonator 3 but also participates in the external radiation of the antenna. By adjusting the structural arrangement and size of the metal pattern 2, the input impedance of the antenna can be changed, the current path can be extended, and the size of the tag antenna can be reduced.

[0020] The metal pattern 2 designed in this embodiment includes an irregular ring-shaped band 21 that is not closed. The inner side of the irregular ring-shaped band 21 is sequentially provided with horizontally symmetric strip-shaped bands, two inverted V-shaped bands 22, and two irregular hook-shaped bands 211 from top to bottom. The outer sides of the irregular ring-shaped band 21 are symmetrically provided with toothed bands 212 on the left and right.

[0021] Two parasitic irregular metal sheets 26 are symmetrically provided on the left and right below the irregular ring-shaped band 21. The parasitic irregular metal sheet 26 includes an arc-shaped ring band and a vertical strip-shaped band extending upward from the end of the arc-shaped ring band. The top of the irregular ring-shaped band 21 is provided with a top notch, and the left and right outer sides are provided with side notches.

[0022] The non-closed special-shaped annular band 21 serves as a radiation element, receiving and transmitting radio frequency signals. The horizontal strip 24 serves as a feeder line and is connected to the tag chip to ensure signal transmission from the chip to the radiation element. Structures for adjusting the antenna impedance, improving the directivity and radiation efficiency of the antenna, etc. are arranged within the special-shaped annular band 21, making the metal pattern 2 compact in structure, with the antenna impedance being easily adjustable to meet the technical requirements of ultra-high frequency radio frequency identification while reducing the overall volume of the antenna. Embodiment 2

[0023] Based on Embodiment 1, this embodiment provides an ultra-high frequency dielectric resonator tag antenna.

[0024] There are three horizontal strips on the metal pattern 2, namely the first horizontal strip 23, the second horizontal strip 24, and the third horizontal strip 25. By adjusting the widths, lengths, and the spacing between the three horizontal strips, the adjustment of antenna impedance matching is achieved.

[0025] The first horizontal strip 23 is located below the top notch of the special-shaped annular band 21. The two ends of the first horizontal strip 23 penetrate and extend to the outside of the special-shaped annular band 21. The lateral notches on both sides outside the special-shaped annular band 21 are located below the first horizontal strip 23. The second horizontal strip 24 is located below the first horizontal strip 23. The two ends of the second horizontal strip 24 also penetrate and extend to the outside of the special-shaped annular band 21 and are located below the lateral notches. The middle of the second horizontal strip 24 is disconnected, forming two horizontal strips on the same straight line. Inverted V-shaped bands 22 are respectively connected below the two horizontal strips. The tip of the inverted V-shaped band 22 is connected to the second horizontal strip 24. The two ends of the third horizontal strip 25 are respectively connected to the two inverted V-shaped bands 22. The middle of the second horizontal strip 24 is disconnected and connected to the tag chip. The second horizontal strip 24 transmits the signal in the chip to the special-shaped annular band 21 serving as the radiation element, and through the special-shaped annular band 21 and the structures thereon, signal reception and transmission are realized.

[0026] The inverted V-shaped band 22 is composed of two metal strips that gradually become thinner from thick to thin, and the two thin ends cross. The tip of the inverted V-shaped band penetrates through the second horizontal strip 24 and is then connected to the special-shaped annular band 21. The inverted V-shaped band 22 opens downward. The third horizontal strip 25 is located on the side of the opening, connecting the two inverted V-shaped bands 22. Below the inverted V-shaped band 22 is the special-shaped hook band 211, and the special-shaped hook band 211 opens downward. On the premise that the inverted V-shaped band 22 is not connected to the special-shaped hook band 211, increasing the height of the inverted V-shaped band 22 can lower the resonant center frequency of the antenna.

[0027] The special-shaped hook belt 211 is in the shape of an open ellipse with a U-shaped opening facing downwards; one end of a special-shaped hook belt 211 is connected to one end of the special-shaped ring belt 21, and one end of the other special-shaped hook belt 211 is connected to the other end of the special-shaped ring belt 21. The end not connected to the special-shaped ring belt 21 forms a tip that aligns with but is not connected to the vertical strip on the parasitic special-shaped metal sheet 26.

[0028] The tooth-shaped belts 212 arranged symmetrically on the left and right include several square tooth belts with different lengths. The lengths of the square tooth belts shorten from top to bottom, and the outer edge contours of the square tooth belts with different lengths are consistent with the outer edge of the special-shaped ring belt 21. The tooth-shaped belts 212 are located on the outer side corresponding to the special-shaped hook belts 211 provided on the special-shaped ring belt 21.

[0029] The two parasitic special-shaped metal sheets 26 symmetrically arranged on the left and right below the special-shaped ring belt 21 include an arc belt and a vertical strip. The parasitic special-shaped metal sheets 26 are not connected to the special-shaped ring belt 21 and its upper structures, and there is a gap between the two parasitic special-shaped metal sheets 26. When the length of the vertical strip becomes longer, the antenna resonance center frequency decreases.

[0030] The dielectric resonator 3 is square and is located below the metal pattern 2. The dielectric resonator 3 is made of a material with a high dielectric constant. When used on the metal surface, the dielectric resonator 3 contacts the metal surface to isolate the interference on the metal surface and ensure the antenna performance.

[0031] For the tag antenna provided in this embodiment, the high dielectric constant characteristic of the square dielectric resonator 3 reduces the resonance frequency of the tag antenna, thereby reducing the antenna size at the same frequency; the metal pattern 2 printed on the surface of the dielectric sheet not only feeds the square dielectric resonator 3 but also participates in the external radiation of the antenna. By adjusting multiple structural parameters of the metal pattern 2, it plays a role in changing the antenna input impedance, extending the current path, and reducing the tag antenna size; adjusting the length of the first horizontal band 23 in the metal pattern 2 can change the antenna impedance without changing the resonance frequency; the length of the square tooth belt in the tooth-shaped belt 212 can be made longer, so that the antenna resonance center frequency decreases; adjusting the spacing and position of the second horizontal band 24 and the third horizontal band 25 can play a role in impedance matching adjustment; adjusting the size and width of the special-shaped ring belt 21 and the special-shaped hook belt 211 will have an obvious impact on the input impedance and gain of the antenna; on the premise that the inverted V-shaped belt 22 is not connected to the special-shaped hook belt 211, increasing the height of the inverted V-shaped belt 22 can make the antenna resonance center frequency decrease; making the length of the vertical strip longer, the antenna resonance center frequency decreases. Embodiment 3

[0032] This embodiment provides an electronic tag, which includes a tag chip and the ultra-high frequency dielectric resonator tag antenna provided in the second embodiment. The tag chip is connected to the second horizontal strip 24, and the signal in the tag chip is transmitted to the antenna radiation unit through the second horizontal strip 24, and the signal received by the antenna enters the tag chip for identification.

[0033] Determine the dimensions and materials of each component of the tag antenna, the dimensions within the metal pattern 2, and the specifications and models of the tag chip for simulation testing. Specifically: When the single-layer dielectric sheet 1 of the antenna is made of PET material with a thickness of 0.102 mm (relative dielectric constant εr = 3.5, tanδ = 0.0032 in the simulation model), Al2_O3_ceramic ceramic material with a side length of 24.6 mm and a height of 3 mm is selected as the square dielectric resonator material (relative dielectric constant εr = 9.8, tanδ = 0 in the simulation model). After optimizing the design of the antenna structure dimensions using the simulation software HFSS, the overall dimensions of the antenna are 24.6 mm in length, 24.6 mm in width, and 3.102 mm in height. Then, the following parameters are adopted for the dimensions of the metal pattern 2 printed on the single-layer dielectric sheet 1: The length L1 of the first horizontal strip 23 = 14.2 mm (width is 1 mm), the length (including the gap in the middle) L2 of the second horizontal strip 24 = 20 mm (width is 0.8 mm), the length L3 of the third horizontal strip 25 = 3.6 mm (width is 0.8 mm); the width W1 of the irregular ring-shaped strip 21 = 3 mm; the inner hole width W2 of the irregular hook-shaped strip 211 = 2.7 mm; the distance L4 at the maximum opening at the bottom of the inverted V-shaped strip 22 = 2.7 mm, the height L5 from the bottom of the inverted V-shaped strip 22 to the second horizontal strip 24 = 4.2 mm; the thinnest width W3 of the metal strip from thick to thin on the inverted V-shaped strip 22 = 1.4 mm, the thickest width W4 = 1.56 mm; the length L6 of the vertical strip on the parasitic irregular metal sheet 26 = 3 mm (width is 0.5 mm), the distance L7 between the two end arc strips = 4 mm; the overall length L8 of the distribution of several square-tooth strips = 6 mm, the overall width W5 of the distribution = 2.7 mm; the spacing S1 between the first horizontal strip and the second horizontal strip = 1.2 mm, the spacing S2 between the second horizontal strip 24 and the third horizontal strip 25 = 0.7 mm; the length L9 of the top notch above the irregular ring-shaped strip 21 = 1.5 mm (notch width is 2.2 mm); the upper side length L10 of the side notch at the left and right ends outside above the irregular ring-shaped strip 21 = 0.8 mm, the lower side length L11 = 3.3 mm (notch width is 1.2 mm).

[0034] In addition, the width of each square tooth belt in the toothed belt 212 is 0.4 mm, the outer radius of the special-shaped annular belt 21 is 12.1 mm; the ratio of the short axis to the long axis of the outer periphery of the special-shaped hook belt 211 is 0.86; the long axis of the outer periphery of the special-shaped hook belt 211 is 3.8 mm; the size of the metal surface for placing the electronic tag is 131 mm × 131 mm.

[0035] In the embodiment of the present invention, the U9 chip is used as the tag chip. This chip is a ultra-high frequency (UHF) RFID tag chip launched by NXP (NXP Semiconductors) company, which has excellent performance and broad application prospects and is widely used in the field of radio frequency identification.

[0036] As Figure 2 shown, it is the frequency characteristic curve of the input impedance of the tag antenna provided by this embodiment. Figure 2 The solid line and the dotted line in

[0037] are respectively the real part and the imaginary part of the input impedance obtained by simulating the tag antenna of this embodiment. The impedance at 915 MHz is 13 + j236 ohms, while the impedance of the U9 chip at 915 MHz is 15 - j231 ohms, thus basically meeting the requirement that the impedance of the RFID tag antenna needs to be conjugate-matched with the impedance of the used tag chip. Figure 3 As Figure 4 shown, it is the gain plane pattern of the tag antenna provided by this embodiment.

[0038] Figure 3 And Figure 4

[0039] show that the tag antenna of the present invention shows directional radiation in the space above the metal surface where the antenna is placed vertically. The antenna gain is 4.68 dBi, which can meet the requirement of reading information from all directions in the space above the metal surface in the application. The overall size of the tag antenna provided by this embodiment is 24.6 mm in length, 24.6 mm in width, and 3.102 mm in height. Compared with the existing antenna, it has a simple structure, a low profile, and a small volume, reducing the volume of the conventional ultra-high frequency RFID electronic tag. The antenna impedance is easy to adjust, meeting the requirements of ultra-high frequency radio frequency identification technology.

[0040] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A ultra-high frequency dielectric resonator tag antenna, comprising a single-layer dielectric sheet, a metal pattern printed on the surface of the single-layer dielectric sheet, and a dielectric resonator, wherein the dielectric resonator is connected to the side of the single-layer dielectric sheet with the metal pattern printed thereon, characterized in that, The metal pattern includes an irregular ring-shaped belt that is not closed. Inside the irregular ring-shaped belt, there are horizontally strip-shaped belts that are symmetric left and right, two inverted V-shaped belts, and two irregular hook-shaped belts arranged in sequence from top to bottom. On the outer side of the irregular ring-shaped belt, there are tooth-shaped belts symmetrically arranged on the left and right. On the left and right sides symmetrically below the irregular ring-shaped belt, there are two parasitic irregular-shaped metal pieces. Each parasitic irregular-shaped metal piece includes an arc-shaped ring belt and a vertical strip-shaped belt extending upward from the end of the arc-shaped ring belt. At the top of the irregular ring-shaped belt, there is a top notch, and on the left and right outer sides, there are side notches.

2. The ultra-high frequency dielectric resonator tag antenna according to claim 1, characterized in that The horizontally strip-shaped belt includes a first horizontal belt, a second horizontal belt, and a third horizontal belt. The first horizontal belt is arranged below the top notch and crosses the irregular ring-shaped belt. The second horizontal belt is connected to the tips of the two inverted V-shaped belts and crosses the irregular ring-shaped belt. The two ends of the third horizontal belt are respectively connected to the side edges of the open ends of the two inverted V-shaped belts.

3. The ultra-high frequency dielectric resonator tag antenna according to claim 2, wherein The inverted V-shaped belt is composed of the thin ends of two metal strips that are thick at the top and thin at the bottom crossing each other. The tip of the inverted V-shaped belt passes through the second horizontal belt and is connected to the irregular ring-shaped belt.

4. The ultra-high frequency dielectric resonator tag antenna according to claim 2, characterized in that The second horizontal belt includes two horizontal belts on the same straight line, and there is a gap between the two horizontal belts. Each horizontal belt is connected to the tip of one of the inverted V-shaped belts, and the second horizontal belts on both sides of the gap straddle the label chip.

5. The ultra-high frequency dielectric resonator tag antenna according to claim 1, characterized in that The tooth-shaped belt is arranged on the outer side of the irregular ring-shaped belt and includes several square tooth belts with different lengths. The edge contours of the several square tooth belts are consistent with the outer contour of the irregular ring-shaped belt.

6. The ultra-high frequency dielectric resonator tag antenna according to claim 5, characterized in that, The tooth-shaped belt is located on the outer side of the irregular ring-shaped belt corresponding to the side where the irregular hook-shaped belt is provided.

7. The ultra-high frequency dielectric resonator tag antenna according to claim 1, characterized in that The irregular hook-shaped belt is an open elliptical shape with an inverted U-shaped opening. The two ends of the irregular ring-shaped belt are respectively connected to one end of the two irregular hook-shaped belts. The other end of the irregular hook-shaped belt forms a tip that is aligned with one end of the arc-shaped ring belt and is not connected.

8. The ultra-high frequency dielectric resonator tag antenna according to claim 1, wherein The dielectric resonator is a square structure.

9. An electronic tag, comprising a tag chip, characterized in that, It further includes the ultra-high frequency dielectric resonator tag antenna according to any one of claims 1-8, and the label chip is connected to the metal pattern.

Images