Ultrathin RFID sensing tag antenna for new energy battery temperature detection

Abstract

The invention relates to the field of radio frequency antennas, in particular to an ultrathin RFID sensing tag antenna for new energy battery temperature detection. The tag antenna in the design is of a complete plane structure so as to be convenient to process, in the practical application process, due to the flexible and ultra-thin characteristics, the tag antenna can be inserted between two adjacent batteries in a new energy battery pack for temperature monitoring and sensing, the tag antenna is tightly attached to the batteries so that the tag antenna cannot occupy too large space, and the tag antenna is not prone to damage due to the fact that the tag antenna is of a slotted structure. Good conjugate impedance matching between the antenna and the chip is realized, and the antenna has wide bandwidth. The method has remarkable technical advantages and application prospects in the field of monitoring and sensing of new energy batteries, and further development of related safety monitoring and sensing technologies can be promoted.

Description

Technical Field

[0001] The present invention belongs to the field of radio frequency antennas, and in particular relates to an ultra-thin RFID sensor tag antenna for detecting the temperature of a new energy battery. Background Art

[0002] At present, with my country's increasing emphasis on sustainable development, the new energy vehicle market is growing rapidly. As its key components, new energy batteries are constantly being developed and promoted. In this process, the safety monitoring of new energy batteries has become particularly important and indispensable, especially the temperature monitoring of new energy batteries during operation. In order to obtain more accurate and timely information data, the temperature monitoring and sensing effect between two adjacent batteries in the new energy battery pack is significant. RFID tag chips have the ability to collect relevant signal data, and RFID technology can be used for wireless monitoring and sensing. As an important part of the RFID system, the performance of the RFID tag antenna will directly affect the application of the entire RFID system and the effect of sensor monitoring.

[0003] The performance of RFID tags is greatly affected by the application environment. When ordinary tags are attached to the surface of metal objects, the reading distance of the tags will become shorter or even fail. This is because the metal object destroys the impedance matching between the tag antenna and the chip. Tag antennas are generally made of thick hard materials, and anti-metal tag antennas mostly face metal objects on one side. New energy batteries are commonly square aluminum shells. The two batteries in the battery pack are adjacent to each other, and the gap between them is very small. If ordinary anti-metal tags are used between adjacent batteries, the thickness will become a limitation. In addition, since the chip needs to perform temperature sensing between two adjacent batteries, the presence of aluminum shells on both sides will cause the electromagnetic energy to be unable to be transmitted, the tag to fail, and normal monitoring and sensing cannot be performed. Summary of the invention

[0004] Purpose of the invention: In view of the above problems, the present invention proposes an ultra-thin RFID sensor tag antenna for temperature detection of new energy batteries. This tag antenna can be used between two adjacent batteries in a new energy battery pack, and can realize sensing monitoring in an extremely narrow environment with metal on both sides. The new energy battery is wrapped with a battery blue film to avoid direct contact between the antenna and the metal aluminum surface. Then, one end of the tag antenna on the chip is inserted into the middle of the two batteries. The inserted length is half of the antenna length, and the other half of the tag is attached to the side wall of the battery, thereby realizing temperature detection. At the same time, the tag antenna substrate is ultra-thin, has good bending performance, good impedance matching effect, and has a wide working bandwidth.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] An ultra-thin RFID sensor tag antenna for new energy battery temperature detection, characterized in that the antenna includes a top metal patch layer, an intermediate dielectric layer and a bottom metal ground layer;

[0007] The top metal layer of the tag antenna includes a radiation patch body, a first slot structure, a second slot structure, a matching bump, a first metal wire, and a second metal wire;

[0008] The middle dielectric layer of the tag antenna is a Rogers 5880 material with a thickness of 0.254 mm, and the bottom metal ground layer is the grounding part;

[0009] The tag is characterized in that the base of the antenna top patch is a rectangular patch plus a bump, and then there is a long rectangular metal wire, the end of which is bent, and there is a rectangular slit before the bending point, which is the chip installation place;

[0010] The tag is characterized in that the rectangular patch portion in the antenna top patch is slotted, the slot structure is rectangular, and an "L"-shaped slot is loaded on its side;

[0011] Furthermore, the tag antenna is characterized in that a large range of impedance matching adjustment is performed by adjusting the overall position of the rectangular slot and the "L"-shaped slot, and a small range of impedance matching adjustment is performed by changing the length and width of the metal bump near the center of the tag antenna, ultimately achieving conjugate impedance matching between the chip and the antenna.

[0012] Furthermore, the tag is characterized in that the bottom layer of the antenna is a grounding layer, the grounding layer is a fully covered rectangular metal patch, and the antenna itself has a metal floor, which can effectively reduce the impact of the metal surface on it.

[0013] Furthermore, the dielectric layer has a thickness of 0.254 mm, which can be inserted between two adjacent batteries. The substrate is made of Rogers 5880 material with a dielectric constant of 2.2, a loss tangent value of 0.009, and has good bending performance at a thickness of 0.254 mm.

[0014] Furthermore, the ultra-thin RFID sensor tag antenna for new energy battery temperature detection is characterized in that the antenna size is 170mm×26mm×0.254mm, and the length is sufficient. One end of the antenna on the chip can be inserted between two adjacent batteries, and the insertion length is half the length of the antenna.

[0015] The advantages of the present invention are:

[0016] 1. The present invention is an ultra-thin RFID sensor tag antenna for detecting the temperature of new energy batteries. The antenna can realize sensing monitoring in an extremely narrow environment with metal on both sides. Temperature detection is achieved by inserting half of the length of the tag antenna on the chip between two batteries and attaching the other half to the side wall of the battery.

[0017] 2. The present invention is an ultra-thin RFID sensor tag antenna for new energy battery temperature detection, which can generate a wider bandwidth band in the ultra-high frequency band, from 902MHz to 928MHz, fully covering my country's latest UHF RFID band 920MHz-925MHz, and has a certain amount of excess bandwidth. It ensures the adaptability, stability and feasibility of energy transmission in actual use.

[0018] 3. The present invention is an ultra-thin RFID sensor tag antenna for new energy battery temperature detection. The antenna has a reflection coefficient lower than -10dB in the frequency band of 902MHz to 928MHz. The lowest reflection coefficient in this frequency band is -37.24dB. The center frequency is 920MHz, which ensures that most of the energy and signal power of the antenna are well transmitted. It also shows that the antenna impedance is well matched, ensuring stability in actual use.

[0019] 4. The present invention is an ultra-thin RFID sensor tag antenna for new energy battery temperature detection. The antenna structure is a completely planar structure, which is easy to process and realize. Through the position of the slotted structure, the impedance of the tag antenna can be easily adjusted to achieve good impedance matching.

[0020] 5. The present invention is an ultra-thin RFID sensor tag antenna for detecting the temperature of new energy batteries. The maximum gain of the antenna when sensing between adjacent batteries is -12.73dBi, and the maximum gain in free space is -3.42dBi. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The three-dimensional structure schematic diagram of an ultra-thin RFID sensor tag antenna for new energy battery temperature detection according to the present invention.

[0022] Figure 2 This is a schematic diagram of the practical application of an ultra-thin RFID sensor tag antenna for new energy battery temperature detection in a new energy battery pack according to the present invention.

[0023] Figure 3 This is a top-level plan view of an ultra-thin RFID sensor tag antenna for detecting temperature of new energy batteries according to the present invention.

[0024] Figure 4The bottom plane schematic diagram of an ultra-thin RFID sensor tag antenna for new energy battery temperature detection according to the present invention.

[0025] Figure 5 This is a specific structural diagram of the top slotted patch of an ultra-thin RFID sensor tag antenna for new energy battery temperature detection in the present invention.

[0026] Figure 6 This is a specific structural diagram of the top-layer feeding portion of an ultra-thin RFID sensor tag antenna for detecting temperature of new energy batteries according to the present invention.

[0027] Figure 7 This is a simulation diagram of the reflection coefficient of 860MHz-950MHz of an ultra-thin RFID sensor tag antenna for new energy battery temperature detection in the present invention.

[0028] Figure 8 This is an impedance matching simulation diagram of an ultra-thin RFID sensor tag antenna 860MHz-960MHz for new energy battery temperature detection in the present invention.

[0029] Fig. 9 This is the radiation pattern of the 920MHz E-plane antenna of the ultra-thin RFID sensor tag antenna used for new energy battery temperature detection when sensing between batteries.

[0030] Fig.10 The present invention discloses a 920MHz H-plane antenna radiation pattern when an ultra-thin RFID sensor tag antenna for new energy battery temperature detection senses between batteries. DETAILED DESCRIPTION

[0031] The present invention is an ultra-thin RFID sensor tag antenna for detecting the temperature of a new energy battery. The present invention will be described in more detail below in conjunction with the accompanying drawings and technical solutions.

[0032] This invention is an ultra-thin RFID sensor tag antenna for new energy battery temperature detection. Its three-dimensional structure diagram is as follows: Figure 1 As shown, the top floor plan diagram is as follows Figure 3 As shown, the specific structure of the top slotted patch is as follows Figure 5 The bottom floor plan is shown in Figure 4As shown; the tag antenna includes a top metal patch layer (100), an intermediate dielectric layer (200) and a bottom metal grounding layer (300) from top to bottom; the top metal layer is based on a rectangular patch, including a radiation patch body (101), a first slot structure (102), a second slot structure (103), a matching bump (104), a first metal wire (105), and a second metal wire (106); the intermediate dielectric layer (200) is a Rogers 5880 material with a thickness of 0.254 mm; and the bottom metal grounding layer is a rectangular patch (301).

[0033] The tag antenna is characterized by: Figure 3 As shown, the basis of the patch is a rectangular patch (101) on which a slotting operation is performed; Figure 5 As shown, the first slot structure (102) is rectangular, and there is an "L"-shaped second slot structure (103) on its side, which generates a large inductance for the antenna, thereby achieving impedance matching of the tag antenna; close to the rectangular patch is a rectangular matching bump (104), and the antenna impedance can be adjusted in a small range by adjusting its size. Connecting the bump is a very long first metal wire (105), and at the end there is a second metal wire (106) that is bent 6 times, and its main function is to increase the antenna bandwidth to a certain extent. The specific structure of the feeder is shown in the figure. Figure 6 As shown, there is a rectangular slit near the bending point, which is where the chip is installed.

[0034] like Figure 4 As shown, the tag is characterized in that the antenna grounding layer is a fully covered rectangular patch (301) and has a metal floor, which can effectively reduce the impact of the metal surface on it.

[0035] The size of the intermediate dielectric layer (200) of the tag antenna is 170 mm×26 mm×0.254 mm, and the material used is Rogers 5880 material with a dielectric constant of 2.2 and a loss tangent value of 0.0009. Figure 2 As shown, at a thickness of 0.254 mm, half of the length of the tag antenna on the chip is inserted between two adjacent batteries, and because of its good bending performance, the other half can be folded and attached to the side wall of the battery, thereby realizing temperature detection.

[0036] like Figure 7 As shown, the antenna can generate a -10dB bandwidth from 902MHz to 928MHz, fully covering my country's latest UHF RFID frequency band 920MHz-925MHz, and has a certain amount of excess bandwidth, ensuring the adaptability, stability and feasibility of energy transmission in actual use.

[0037] like Figure 7As shown, the tag antenna has a minimum reflection coefficient of -37.24dB in this frequency band, and a center frequency of 920MHz, which ensures that most of the antenna's energy and signal power are transmitted well. It also shows that the antenna impedance is well matched, ensuring stability in actual use.

[0038] like Figure 8 As shown, the impedance of the tag antenna at 920MHz is 9.6+125i, the conjugate impedance is well matched, and it is easy to adjust.

[0039] The maximum gain of the tag antenna when performing temperature detection between adjacent batteries is -12.73dBi, and the maximum gain in free space is -3.42dBi.

[0040] like Fig. 9 As shown, at a frequency of 920 MHz, the E-plane radiation pattern of the tag antenna when sensing between batteries exhibits a semicircular distribution, indicating that its radiation direction is quite directional.

[0041] like Fig.10 As shown, at a frequency of 920 MHz, the H-plane radiation pattern of the tag antenna when sensing between batteries presents a slightly distorted "8"-like shape.

[0042] From the simulation results analysis:

[0043] 1. Within the range of S11 coefficient below -10dB, the tag antenna can produce a wider bandwidth frequency band from 902MHz to 928MHz. This frequency band covers my country's latest UHF RFID frequency band from 920MHz to 925MHz, and has a certain amount of excess bandwidth, ensuring the adaptability, stability and feasibility of energy transmission in actual use.

[0044] 2. The tag antenna impedance at 920MHz is 9.6+125i, which matches the chip impedance well, and the impedance is easy to adjust through the slot and bump structure.

[0045] 3. The lowest reflection coefficient in this frequency band is -37.24dB, and the center frequency is 920MHz, which ensures that most of the energy and signal power of the antenna are transmitted well. It also shows that the antenna impedance is well matched, ensuring stability in actual use.

[0046] 4. The maximum gain of the tag when sensing between adjacent batteries is -12.73dBi, and the maximum gain in free space is -3.42dBi, and it has a good directional radiation direction, ensuring the reading of the tag antenna.

[0047] The above embodiments should be understood as being only used to illustrate the present invention and not to limit the protection scope of the present invention. After reading the contents of the present invention, technicians can make various changes or modifications to the present invention. These equivalent changes and modifications also fall within the scope defined by the claims of the present invention.

Claims

1. An ultra-thin RFID sensor tag antenna for detecting the temperature of a new energy battery, wherein the tag antenna is composed of a top metal patch layer, an intermediate dielectric layer and a bottom metal grounding layer from top to bottom; the top metal layer includes a radiation patch body, a feeding structure, a feeding port, and a rectangular slot; the intermediate dielectric layer is a Rogers 5880 material with a thickness of 0.254 mm, the bottom metal grounding layer is the grounding part, and the feeding port is between the top long straight metal wire and the curved metal wire, which is also the chip installation location of the RFID tag antenna; insert one end of the tag antenna on the chip into the middle of two batteries, the inserted length is half of the antenna length, and the other half of the tag is attached to the side wall of the battery, the reader uses a radio frequency signal to provide energy to the tag, and the chip collects information data after being activated, and then uses the tag antenna to feed back the stored information to the reader, thereby realizing temperature detection.

2. The ultra-thin RFID sensor tag antenna for new energy battery temperature detection according to claim 1 is characterized in that: The tag is characterized in that the basis of the antenna top patch is a rectangular patch plus a bump, which can adjust the antenna impedance in a small range. There is also a long rectangular metal wire with a bend at the end to increase a certain bandwidth. There is a rectangular slit in front of the bending point, which is where the chip is installed. A slotting operation is performed on the rectangular patch, and the main slotting structure is rectangular. At the same time, an "L"-shaped slot is loaded on its side, thereby adjusting the impedance matching of the tag antenna.

3. The ultra-thin RFID sensor tag antenna for new energy battery temperature detection according to claim 1 is characterized in that: The tag antenna structure is a completely planar structure, which is easy to process and realize, has good directional radiation performance, and can be used for temperature detection between two adjacent batteries in a new energy battery pack.

4. The ultra-thin RFID sensor tag antenna for new energy battery temperature detection according to claim 1, characterized in that: The dielectric layer of the antenna has a size of 170 mm×26 mm×0.254 mm, and is made of Rogers 5880 material with a dielectric constant of 2.2 and a loss tangent value of 0.0009.

5. The ultra-thin RFID sensor tag antenna for new energy battery temperature detection according to claim 1, characterized in that: In the UHF band, a wider bandwidth band can be generated, from 902MHz to 928MHz, which fully covers my country's latest UHF RFID band 920MHz-925MHz, and has a certain amount of excess bandwidth, ensuring the adaptability, stability and feasibility of energy transmission in actual use.

6. The ultra-thin RFID sensor tag antenna for new energy battery temperature detection according to claim 1, characterized in that: The antenna has a reflection coefficient lower than -10dB in the frequency band of 902MHz to 928MHz. The lowest reflection coefficient in this frequency band is -37.24dB with a center frequency of 920MHz, which ensures that most of the energy and signal power of the antenna are transmitted well. It also shows that the antenna impedance is well matched, ensuring stability in actual use.

7. The ultra-thin RFID sensor tag antenna for new energy battery temperature detection according to claim 1, characterized in that: The antenna has a maximum gain of -12.73 dBi when sensing between adjacent batteries and a maximum gain of -3.42 dBi in free space, and has a radiation direction with good directivity, ensuring the reading of the tag antenna.

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