CN115117628B

CN115117628B - Dual-frenquency point temperature measurement RFID tag antenna

Info

Publication number: CN115117628B
Application number: CN202210651119.XA
Authority: CN
Inventors: 刘珂炫; 姜菲; 华昌洲; 吴凯晟; 符宇航; 方礼昀; 叶康平; 陈益; 许高明
Original assignee: Ningbo University
Current assignee: Ningbo University
Priority date: 2022-06-10
Filing date: 2022-06-10
Publication date: 2023-05-12
Anticipated expiration: 2042-06-10
Also published as: CN115117628A

Abstract

The invention discloses a dual-frequency point temperature measurement RFID tag antenna, which comprises an antenna main body structure, a radio frequency tag chip and a temperature measurement circuit, wherein the antenna main body structure comprises a radiation structure, a feed structure, a bonding pad structure, a connection structure, a dielectric substrate, a first layer of FR4 board and a second layer of FR4 board, the radiation structure respectively enables the tag antenna to generate two resonance frequency points by arranging eleven rectangular metal blocks and arranging a plurality of rectangular grooves on the first rectangular metal blocks, return loss values of the two resonance frequency points are below-10 dB, and the impedance value of the tag antenna and the impedance value of the tag chip realize conjugate matching; the advantage is can be used for the operational environment that needs to cover two frequency channels independently, and overall dimension is lower, and the cost is lower, and can not appear disturbing phenomenon, and label identification accuracy and temperature detection accuracy are all higher.

Description

Dual-frenquency point temperature measurement RFID tag antenna

Technical Field

The invention relates to an RFID tag antenna, in particular to a dual-frequency point temperature measurement RFID tag antenna.

Background

The radio frequency identification (RFID, radio Frequency Identification) technology is a non-contact automatic identification technology using a radio frequency technology, and has advantages of low cost, long identifiable distance, multi-target identification, good environmental adaptability, etc., which is widely used in a plurality of industries and fields of logistics, transportation, supply chain management, automatic production, and temperature sensors.

The radio frequency identification system mainly comprises a reader, an RFID electronic tag and a data management system, wherein the RFID electronic tag is an important component in the radio frequency identification system and is responsible for receiving and transmitting signals. The RFID tag antenna is a transponder antenna of an RFID electronic tag, is a communication induction antenna, and is generally combined with an RFID chip to form the finished RFID electronic tag. RFID systems can be classified into low frequency (125-134.2 KHz), high frequency (13.56 MHz), ultra-high frequency (840-960 MHz) and microwave (2.45-5.8 GHz) RFID systems according to the operating frequency. The frequency ranges allowed by the RFID system are different in different countries, for example, 902-928MHz is used in the United states, canada and the like, 868-870MHz is used in Europe, and 840-845MHz and 920-925MHz are used in China.

The RFID technology and the temperature sensor are combined, so that not only can target identification be realized, but also the acquisition of temperature data can be realized, and further, the temperature is observed in real time. Along with the development of radio frequency identification technology and sensor technology, the current temperature sensor combined with an RFID tag antenna for realizing temperature measurement has two main research directions, the first is that a temperature sensing material is integrated into an internal structure of the RFID tag antenna for realizing temperature measurement, wherein the temperature sensing material is generally integrated into an antenna structure or a medium substrate and then is provided with an external sensor component, but the temperature measurement RFID tag antenna has large size and high cost; the second is that the integrated IC circuit of the RFID tag antenna realizes the temperature-measuring RFID tag antenna, the size and the cost of the temperature-measuring RFID tag antenna are reduced compared with the first, and the temperature-measuring RFID tag antenna is one of the current research directions.

In the research of the temperature measuring RFID tag antenna of the existing RFID tag antenna integrated IC circuit, most of the temperature measuring RFID tag antennas are designed aiming at a certain frequency range, the frequency band is single, and more than two frequency bands can not be independently met. When the working environment of the temperature measuring RFID tag antenna needs to cover a plurality of frequency ranges, the temperature measuring RFID tag antenna combination with a plurality of different frequencies is required to work, the overall size is large, the cost is high, in addition, mutual interference can be generated between the temperature measuring RFID tag antennas to a certain extent, tags cannot be identified easily, and the temperature detection is inaccurate.

Disclosure of Invention

The invention aims to solve the technical problem of providing the dual-frequency point temperature measurement RFID tag antenna which can be independently used for working environments needing to cover two frequency bands, has the advantages of lower overall size and lower cost, does not generate interference phenomenon, and has higher tag identification accuracy and temperature detection accuracy.

The technical scheme adopted for solving the technical problems is as follows: the dual-frequency point temperature measurement RFID tag antenna comprises an antenna main body structure, a radio frequency tag chip and a temperature measurement circuit for measuring temperature, wherein the radio frequency tag chip is respectively connected with the temperature measurement circuit and the antenna main body structure, the radio frequency tag chip is pre-stored with identification information of an article, when the antenna main body structure receives a radio frequency signal sent by an RFID reader, the antenna main body structure transmits the radio frequency signal to the radio frequency tag chip, the radio frequency tag chip converts radio frequency energy of the radio frequency signal into a power supply to supply power for the temperature measurement circuit, the temperature measurement circuit starts to perform temperature measurement work and transmits measured temperature data to the radio frequency tag chip, the radio frequency tag chip transmits the identification information of the article stored in the radio frequency tag chip and the received temperature data, the RFID reader receives the identification information and temperature data of the article transmitted by the radio frequency tag chip, decodes the identification information and temperature data of the article, then sends the identification information and temperature data to a computer for subsequent identification processing, thereby realizing article identification and temperature detection, the antenna main body structure comprises a radiation structure, a feed structure, a bonding pad structure, a connecting structure, a dielectric substrate, a first layer FR4 board and a second layer FR4 board, the dielectric substrate is a cuboid structure, 4 corners of the dielectric substrate are respectively cut into round corners with the radius of 2mm, the length of the dielectric substrate is 25mm, the thickness of the dielectric substrate is 3mm, the dielectric substrate is realized by adopting ceramics with the dielectric constant of 39 and the loss of 0.0001, the length of the first layer FR4 board is 25mm, the thickness of the second layer FR4 board is 25mm, the first layer of FR4 board and the second layer of FR4 board are both realized by adopting FR4 boards with dielectric constants of 4.4 and losses of 0.02, the temperature measuring circuit is embedded in the second layer of FR4 board, the dielectric substrate, the first layer of FR4 board and the second layer of FR4 board are laminated together in sequence from top to bottom, the centers of the dielectric substrate, the first layer of FR4 board and the second layer of FR4 board are positioned on the same straight line, the straight line is called a central axis, the thickness directions of the dielectric substrate, the first layer of FR4 board and the second layer of FR4 board are all along the up-down direction, the length directions of the dielectric substrate, the first layer of FR4 board and the second layer of FR4 board are all along the left-right direction, the width directions of the dielectric substrate, the center of the first layer of FR4 board is provided with a cuboid groove with the length of 1mm and the thickness dimension of 20mm, the center of the cuboid groove is positioned on the same straight line, and the thickness directions of the cuboid groove is along the left-right direction; the radiation structure comprises a first rectangular metal block, a second rectangular metal block, a third rectangular metal block, a fourth rectangular metal block, a fifth rectangular metal block, a sixth rectangular metal block, a seventh rectangular metal block, an eighth rectangular metal block, a ninth rectangular metal block, a tenth rectangular metal block and an eleventh rectangular metal block, wherein the first rectangular metal block, the second rectangular metal block, the third rectangular metal block and the fourth rectangular metal block are attached to the upper surface of the dielectric substrate, the length direction of the first rectangular metal block is along the left-right direction, the width is reversely along the front-back direction, the center of the first rectangular metal block is positioned on the central axis, the length of the first rectangular metal block is 24mm, the width is 22.5mm, the first rectangular metal block is provided with a first rectangular groove, a second rectangular groove, a third rectangular groove, a fourth rectangular groove, a fifth rectangular groove, a sixth rectangular groove, a seventh rectangular groove, an eighth rectangular groove, a ninth rectangular groove, a tenth rectangular groove, an eleventh rectangular groove, a twelfth rectangular groove, a thirteenth rectangular groove, a fourteenth rectangular groove, a fifteenth rectangular groove, a sixteenth rectangular groove and a seventeenth rectangular groove, the upper surface of the dielectric substrate is provided with the first rectangular groove, the second rectangular groove, the third rectangular groove, the fourth rectangular groove, the fifth rectangular groove, the sixth rectangular groove, the seventh rectangular groove, the eighth rectangular groove, the ninth rectangular groove, the tenth rectangular groove, the eleventh rectangular groove, the twelfth rectangular groove, the thirteenth rectangular groove, the fourteenth rectangular groove, the fifteenth rectangular groove, the sixteenth rectangular groove and the seventeenth rectangular groove are exposed, the right end face of the first rectangular groove is flush with the right end face of the first rectangular metal block, the rear end face of the first rectangular groove is flush with the rear end face of the first rectangular metal block, the length of the first rectangular groove along the left-right direction is 2mm, the width along the front-back direction is 2.5mm, the second rectangular groove is positioned at the front side of the first rectangular groove, the right end face of the second rectangular groove is flush with the right end face of the first rectangular metal block, the rear end face of the second rectangular groove is connected with the front end face of the first rectangular groove and is attached to the front end face of the first rectangular metal block, the length of the second rectangular groove along the left-right direction is 3.5mm, the width along the front-back direction is 1.5mm, the right end face of the third rectangular groove is flush with the right end face of the first rectangular metal block, the front end face of the third rectangular groove is flush with the front end face of the first rectangular metal block, the length of the third rectangular groove along the left-right direction is 1.5mm, the width of the fifth rectangular groove along the front-back direction is 3.8mm, the fourth rectangular groove is positioned at the rear side of the third rectangular groove, the right end face of the fourth rectangular groove is flush with the right end face of the first rectangular metal block, the front end face of the fourth rectangular groove is connected with the rear end face of the third rectangular groove and is attached to the rear end face of the third rectangular groove, the length of the fourth rectangular groove along the left-right direction is 4.5mm, the width along the front-back direction is 1.2mm, the front end face of the fifth rectangular groove is flush with the front end face of the first rectangular metal block, the length along the left-right direction is 4.8mm, the width along the front-back direction is 2mm, the distance between the right end face of the fifth rectangular groove and the left end face of the third rectangular groove is 7mm, the sixth rectangular groove is positioned at the left side of the fifth rectangular groove, the front end face of the sixth rectangular groove is flush with the front end face of the first rectangular metal block, the right end face of the sixth rectangular groove is connected with the left end face of the fifth rectangular groove and is attached to the left end face of the fifth rectangular groove, the length of the sixth rectangular groove along the left-right direction is 1.2mm, the width along the front-back direction is 3.5mm, the front end face of the seventh rectangular groove is flush with the front end face of the first rectangular metal block, the left end face of the seventh rectangular groove is flush with the left end face of the first rectangular metal block, the length of the seventh rectangular groove along the left-right direction is 2mm, the distance between the right end face of the seventh rectangular groove and the left end face of the sixth rectangular groove is 7.5mm, the eighth rectangular groove is positioned at the rear side of the seventh rectangular groove, the left end face of the eighth rectangular groove is flush with the left end face of the first rectangular metal block, the front end face of the eighth rectangular groove is connected with the rear end face of the seventh rectangular groove and is attached to the rear end face of the seventh rectangular groove, the length of the eighth rectangular groove along the left-right direction is 4.2mm, the width along the front-rear direction is 1.5mm, the ninth rectangular groove is positioned at the rear side of the eighth rectangular groove, the left end face of the ninth rectangular groove is flush with the left end face of the first rectangular metal block, the length of the ninth rectangular groove along the left-right direction is 1mm, the width along the front-rear direction is 2mm, the distance between the front end face of the ninth rectangular groove and the rear end face of the eighth rectangular groove is 9.5mm, the tenth rectangular groove is positioned at the rear side of the ninth rectangular groove, the left end face of the tenth rectangular groove is flush with the left end face of the first rectangular metal block, the front end face of the tenth rectangular groove is connected with the rear end face of the ninth rectangular groove and is attached to the rear end face of the tenth rectangular groove, the length of the tenth rectangular groove along the left-right direction is 7mm, the width of the tenth rectangular groove along the front-back direction is 1mm, the eleventh rectangular groove is positioned at the rear side of the tenth rectangular groove, the left end face of the eleventh rectangular groove is flush with the left end face of the first rectangular metal block, the length of the eleventh rectangular groove along the left-right direction is 8.5mm, the width of the eleventh rectangular groove along the front-back direction is 2mm, the distance between the front end face of the eleventh rectangular groove and the rear end face of the tenth rectangular groove is 2mm, the twelfth rectangular groove is positioned at the rear side of the eleventh rectangular groove, the right end face of the twelfth rectangular groove is flush with the right end face of the eleventh rectangular groove, the rear end face of the twelfth rectangular groove is flush with the rear end face of the first rectangular metal block, the length of the twelfth rectangular groove along the left-right direction is 1mm, the width of the thirteenth rectangular groove along the front-back direction is 2mm, the thirteenth rectangular groove is positioned on the right side of the twelfth rectangular groove, the rear end face of the thirteenth rectangular groove is flush with the rear end face of the first rectangular metal block, the length of the thirteenth rectangular groove along the left-right direction is 5mm, the width of the thirteenth rectangular groove along the front-back direction is 2mm, the distance between the left end face of the thirteenth rectangular groove and the right end face of the twelfth rectangular groove is 1mm, the fourteenth rectangular groove is positioned on the right side of the thirteenth rectangular groove, the rear end face of the fourteenth rectangular groove is flush with the rear end face of the first rectangular metal block, the left end face of the fourteenth rectangular groove is connected with the right end face of the thirteenth rectangular groove and is attached to the right end face of the thirteenth rectangular groove, the length of the fourteenth rectangular groove along the left-right direction is 1mm, the width of the fifteenth rectangular groove along the front-back direction is 3mm, the fifteenth rectangular groove is positioned on the front side of the thirteenth rectangular groove, the length of the fifteenth rectangular groove along the left-right direction is 1mm, the width of the fifteenth rectangular groove along the front-back direction is 13.2mm, the distance between the left end face of the fifteenth rectangular groove and the left end face of the first rectangular metal block is 10mm, the distance between the rear end face of the fifteenth rectangular groove and the front end face of the thirteenth rectangular groove is 3.05mm, the sixteenth rectangular groove is positioned on the right side of the fifteenth rectangular groove, the front end face of the sixteenth rectangular groove is flush with the front end face of the fifteenth rectangular groove, the left end face of the sixteenth rectangular groove is connected with and is attached to the right end face of the fifteenth rectangular groove, the length of the sixteenth rectangular groove along the left-right direction is 2mm, the width along the front-back direction is 1mm, the seventeenth rectangular groove is positioned on the right side of the sixteenth rectangular groove, the front end face of the seventeenth rectangular groove is flush with the front end face of the sixteenth rectangular groove, the left end face of the seventeenth rectangular groove is connected with the right end face of the sixteenth rectangular groove and is attached to the right end face of the sixteenth rectangular groove, the length of the seventeenth rectangular groove along the left-right direction is 1mm, the width along the front-back direction is 13.2mm, the second rectangular metal block is positioned on the left side of the first rectangular metal block, the left end face of the second rectangular metal block is flush with the left end face of the dielectric substrate, the rear end face of the second rectangular metal block is flush with the rear end face of the first rectangular metal block, the right end face of the second rectangular metal block is connected with the left end face of the first rectangular metal block and is attached to the left end face of the first rectangular metal block, the width of the second rectangular metal block along the front-back direction is 2mm, the third rectangular metal block and the fourth rectangular metal block are positioned at the rear side of the first rectangular metal block, the third rectangular metal block is positioned at the left side of the fourth rectangular metal block, the front end face of the third rectangular metal block is connected with the rear end face of the first rectangular metal block and is attached to the rear end face of the first rectangular metal block, the rear end face of the third rectangular metal block is level with the rear end face of the medium substrate, the length of the third rectangular metal block along the left-right direction is 1mm, the right end face of the third rectangular metal block is level with the left end face of the twelfth rectangular groove, the front end face of the fourth rectangular metal block is connected with the rear end face of the first rectangular metal block and is attached to the rear end face of the fourth rectangular metal block, the length of the fourth rectangular metal block along the left-right direction is 1mm, and the left end face of the fourth rectangular metal block is level with the twelfth rectangular groove; the fifth rectangular metal block, the sixth rectangular metal block, the seventh rectangular metal block and the eighth rectangular metal block are all attached to the lower surface of the dielectric substrate, the length direction of the fifth rectangular metal block is along the left-right direction, the width is reversely along the front-back direction, the center of the fifth rectangular metal block is positioned on the central axis, the length of the fifth rectangular metal block is 24mm, the width is 23mm, the fifth rectangular metal block is provided with an eighteenth rectangular groove, the rear end surface of the eighteenth rectangular groove is flush with the rear end surface of the fifth rectangular metal block, the length of the eighteenth rectangular groove along the left-right direction is 5mm, the width along the front-back direction is 2mm, the distance from the left end surface of the eighteenth rectangular groove to the left end surface of the fifth rectangular metal block is 5.5mm, the front parts of the sixth rectangular metal block and the seventh rectangular metal block are positioned in the eighteenth rectangular groove, the sixth rectangular metal block is positioned at the left side of the seventh rectangular metal block, the rear end face of the sixth rectangular metal block is flush with the rear end face of the medium substrate, the length of the sixth rectangular metal block along the left-right direction is 1mm, the width along the front-back direction is 2.5mm, the distance from the left end face of the sixth rectangular metal block to the left end face of the eighteenth rectangular groove is 1mm, the rear end face of the seventh rectangular metal block is flush with the rear end face of the medium substrate, the length of the seventh rectangular metal block along the left-right direction is 1mm, the width along the front-back direction is 2.5mm, the distance from the left end face of the seventh rectangular metal block to the right end face of the sixth rectangular metal block is 1mm, the eighth rectangular metal block is positioned at the left side of the fifth rectangular metal block, the right end face of the eighth rectangular metal block is connected and attached with the left end face of the fifth rectangular metal block, the left end face of the eighth rectangular metal block is flush with the left end face of the dielectric substrate, the distance between the rear end face of the eighth rectangular metal block and the plane where the rear end face of the fifth rectangular metal block is positioned is 1mm, the width of the eighth rectangular metal block along the front-rear direction is 1.5mm, the ninth rectangular metal block and the tenth rectangular metal block are both attached on the rear end face of the dielectric substrate, the ninth rectangular metal block is positioned at the left side of the tenth rectangular metal block, the upper end face of the ninth rectangular metal block is connected with the rear end face of the third rectangular metal block and attached with the rear end face of the third rectangular metal block, the lower end face of the ninth rectangular metal block is connected with the rear end face of the sixth rectangular metal block and is attached to the rear end face of the sixth rectangular metal block, the width of the ninth rectangular metal block along the left-right direction is 1mm, the upper end face of the tenth rectangular metal block is connected with the rear end face of the fourth rectangular metal block and is attached to the rear end face of the tenth rectangular metal block, the lower end face of the tenth rectangular metal block is connected with the rear end face of the seventh rectangular metal block and is attached to the rear end face of the seventh rectangular metal block, the width of the tenth rectangular metal block along the left-right direction is 1mm, the left end face of the third rectangular metal block, the left end face of the ninth rectangular metal block and the left end face of the sixth rectangular metal block are located on the same plane, the right end face of the third rectangular metal block, the right end face of the ninth rectangular metal block and the right end face of the sixth rectangular metal block are located on the same plane, the left end face of the fourth rectangular metal block and the fourth rectangular metal block are located on the same plane, the left end face of the tenth rectangular metal block and the left end face of the seventh rectangular metal block are positioned on the same plane, the right end face of the fourth rectangular metal block, the right end face of the tenth rectangular metal block and the right end face of the seventh rectangular metal block are positioned on the same plane, the eleventh rectangular metal block is attached to the left end face of the dielectric substrate, the upper end face of the eleventh rectangular metal block is connected with the left end face of the second rectangular metal block and is attached to the left end face of the second rectangular metal block, the lower end face of the eleventh rectangular metal block is connected with the left end face of the eighth rectangular metal block and is attached to the left end face of the eighth rectangular metal block, the width of the eleventh rectangular metal block along the front-back direction is 1.5mm, the front end face of the eleventh rectangular metal block, the front end face of the second rectangular metal block and the front end face of the eighth rectangular metal block are positioned on the same plane, and the rear end face of the eleventh rectangular metal block and the eighth rectangular metal block are positioned on the same plane; the feeding structure comprises a twelfth rectangular metal block, the bonding pad structure comprises a thirteenth rectangular metal block and a fourteenth rectangular metal block, the connecting structure comprises a first metal aluminum column and a second metal aluminum column, the twelfth rectangular metal block, the thirteenth rectangular metal block and the fourteenth rectangular metal block are all attached to the upper surface of the second FR4 board, the distance from the left end face of the twelfth rectangular metal block to the plane of the left end face of the second layer FR4 board is 8mm, the distance from the rear end face of the twelfth rectangular metal block to the plane of the rear end face of the second layer FR4 board is 3mm, the length of the twelfth rectangular metal block along the left-right direction is 1mm, the width along the front-rear direction is 0.5mm, the thirteenth rectangular metal block is positioned on the left side of the twelfth rectangular metal block, the front end face of the thirteenth rectangular metal block is aligned with the front end face of the twelfth rectangular metal block, the right end face of the thirteenth rectangular metal block is connected with the left end face of the twelfth rectangular metal block and is attached to the left end face of the twelfth rectangular metal block, the length of the thirteenth rectangular metal block along the left-right direction is 1mm, the width along the front-back direction is 2mm, the fourteenth rectangular metal block is positioned on the right side of the twelfth rectangular metal block, the front end face of the fourteenth rectangular metal block is aligned with the front end face of the twelfth rectangular metal block, the left end face of the fourteenth rectangular metal block is connected with the right end face of the twelfth rectangular metal block and is attached to the right end face of the twelfth rectangular metal block, the length of the fourteenth rectangular metal block along the left-right direction is 1mm, the width along the front-back direction is 2mm, the first metal aluminum column and the second metal aluminum column penetrate through the first layer FR4 board from top to bottom, the first metal aluminum column and the second metal aluminum column are positioned at the rear side of the cuboid groove, the upper end face of the first metal aluminum column is completely contacted and attached with the sixth rectangular metal block, the lower end face of the first metal aluminum column is completely contacted and attached with the thirteenth rectangular metal block, the upper end face of the second metal aluminum column is completely contacted and attached with the seventh rectangular metal block, and the lower end face of the second metal aluminum column is completely contacted and attached with the fourteenth rectangular metal block; the radio frequency tag chip is arranged on the twelfth rectangular metal block and is respectively connected with the thirteenth rectangular metal block and the fourteenth rectangular metal block.

The temperature measuring circuit comprises a singlechip with the model of MSP430FR2433IRGET and a digital temperature sensor with the model of TMP112, wherein the P1.2 pin of the singlechip is connected with the SDA pin of the digital temperature sensor, the P1.3 pin of the singlechip is connected with the SCL pin of the digital temperature sensor, the P2.2 pin of the singlechip is connected with the ALERT pin of the digital temperature sensor, the radio frequency tag chip adopts an ultrahigh frequency RFID tag chip ROCKY100 produced by Huabiao weft company, the RF+ pin of the radio frequency tag chip is welded on the thirteenth rectangular metal block, the RF-pin of the radio frequency tag chip is welded on the fourteenth rectangular metal block, the MOSI pin of the radio frequency tag chip is connected with the P2.6 pin of the singlechip, the SCK pin of the radio frequency tag chip is connected with the P2.6 pin of the singlechip, the radio frequency tag chip is connected with the temperature sensor chip, the temperature sensor chip is connected with the P2.4 of the SCM, and the temperature sensor is in the form of the temperature sensor chip, and the temperature sensor chip is capable of detecting the temperature signal of being read by the RFID tag chip, and the temperature signal is detected by the digital tag chip, and the temperature sensor is in the form of the temperature sensor is detected by the RFID chip, and the temperature signal is detected by the RFID chip, and the temperature sensor is in the form of the temperature sensor is detected by the RFID chip.

Compared with the prior art, the dual-frequency point temperature measurement RFID tag antenna has the advantages that the antenna main body structure, the radio frequency tag chip and the temperature measurement circuit for measuring temperature form the dual-frequency point temperature measurement RFID tag antenna, the antenna main body structure comprises a radiation structure, a feed structure, a bonding pad structure, a connecting structure, a dielectric substrate, a first layer of FR4 board and a second layer of FR4 board, the dielectric substrate, the first layer of FR4 board and the second layer of FR4 board are laminated together in sequence from top to bottom, the overall size of the tag antenna is reduced, the temperature measurement circuit is embedded at the second layer of FR4 board, a rectangular groove is formed in the center of the first layer of FR4 board, the placement of each element of the temperature measurement circuit is facilitated, the antenna radiation structure comprises a first rectangular metal block, a second rectangular metal block, a third rectangular metal block, a fourth rectangular metal block, a fifth rectangular metal block, a sixth rectangular metal block, a seventh rectangular metal block, an eighth rectangular metal block, a ninth rectangular metal block, a tenth rectangular metal block and an eleventh rectangular metal block, wherein the first rectangular metal block is provided with an eleventh rectangular groove and a twelfth rectangular groove, the fifth metal block is provided with an eighteenth rectangular groove, a first resonance frequency point of the tag antenna is generated, the fifteenth rectangular groove, the sixteenth rectangular groove and the seventeenth rectangular groove are arranged in the middle of the first metal block, the first rectangular groove, the second rectangular groove, the third rectangular groove, the fourth rectangular groove, the fifth rectangular groove, the sixth rectangular groove, the seventh rectangular groove, the eighth rectangular groove, the ninth rectangular groove, the tenth rectangular groove, the thirteenth rectangular groove and the fourteenth rectangular groove are arranged on four sides of the first metal block, the tag antenna generates a second resonance frequency point, return loss values of the two resonance frequency points are below-10 dB, and the impedance value of the tag antenna and the impedance value of the tag chip realize conjugate matching, simulation verifies that when the return loss value of the tag antenna is smaller than-10 dB, the bandwidths of the two resonance frequency points can meet the working bandwidth of the RFID tag antenna, the two resonance frequency points can work independently and do not interfere with each other, resonance and impedance matching of the tag antenna are realized by a simple rectangular groove structure, the cost is low, and subsequent processing is convenient, so that the tag antenna can be independently used for working environments needing to cover two frequency bands, the overall size is low, the cost is low, interference phenomenon does not occur, and the tag identification accuracy and the temperature detection accuracy are high.

Drawings

FIG. 1 is an exploded view of a dual-frequency point temperature sensing RFID tag antenna of the present invention;

FIG. 2 is a top view of the radiating structure and dielectric substrate of the dual-frequency point temperature sensing RFID tag antenna of the present invention;

FIG. 3 is a rear view of the radiating structure and dielectric substrate of the dual-frequency point temperature sensing RFID tag antenna of the present invention;

FIG. 4 is a left side view of the radiating structure and dielectric substrate of the dual-frequency point temperature sensing RFID tag antenna of the present invention;

FIG. 5 is a bottom view of the radiating structure and dielectric substrate of the dual-frequency point temperature sensing RFID tag antenna of the present invention;

fig. 6 is a schematic structural diagram of a radiation structure of the dual-frequency point temperature measurement RFID tag antenna and a first layer FR4 board of the invention;

fig. 7 is a schematic structural diagram of a radiation structure of the dual-frequency point temperature measurement RFID tag antenna and a second layer FR4 board of the invention;

FIG. 8 is a simulation S11 diagram of a dual-frequency point temperature measurement RFID tag antenna of the present invention;

FIG. 9 is an impedance matching diagram of a dual-frequency point temperature measurement RFID tag antenna of the present invention at two resonance points of 842MHz and 924 MHz;

FIG. 10 is a two-dimensional gain pattern of the dual-frequency point temperature measurement RFID tag antenna of the present invention at a 842MHz resonance point;

fig. 11 is a two-dimensional gain pattern of the dual-frequency point temperature-measuring RFID tag antenna of the present invention at a 924MHz resonance point.

Detailed Description

The invention is described in further detail below with reference to the embodiments of the drawings.

Examples: as shown in fig. 1-7, a dual-frequency point temperature measurement RFID tag antenna includes an antenna main structure, a radio frequency tag chip and a temperature measurement circuit for measuring temperature, wherein the radio frequency tag chip is respectively connected with the temperature measurement circuit and the antenna main structure, the radio frequency tag chip stores identification information of an article in advance, when the antenna main structure receives a radio frequency signal sent by an RFID reader, the antenna main structure transmits the radio frequency signal to the radio frequency tag chip, the radio frequency tag chip converts radio frequency energy of the radio frequency signal into a power supply to supply power to the temperature measurement circuit, the temperature measurement circuit starts to perform temperature measurement work, and transmits measured temperature data to the radio frequency tag chip, the radio frequency tag chip transmits the identification information of the article stored therein and the received temperature data, and after receiving the identification information of the article and the temperature data transmitted by the radio frequency tag chip, decoding identification information and temperature data of an article, then sending the identification information and the temperature data to a computer for subsequent identification processing, thereby realizing article identification and temperature detection, wherein the antenna main structure comprises a radiation structure, a feed structure, a bonding pad structure, a connecting structure, a dielectric substrate 1, a first layer of FR4 board 2 and a second layer of FR4 board 3, the dielectric substrate 1 is of a cuboid structure, 4 corners of the dielectric substrate 1 are respectively cut into round corners with the radius of 2mm, the length of the dielectric substrate 1 is equal to the width of the dielectric substrate 25mm, the thickness of the dielectric substrate 1 is equal to the thickness of the dielectric substrate 3mm, the dielectric substrate 1 is realized by adopting ceramics with the dielectric constant of 39 and the loss of 0.0001, the length of the first layer of FR4 board 2 is equal to the width of the dielectric substrate 25mm, the thickness of the second layer of FR4 board 3 is equal to the thickness of the dielectric substrate 25mm, the first layer of FR4 board 2 and the second layer of FR4 board 3 are respectively realized by adopting the rounded corners with the dielectric constant of 4.4 and the loss of 0.02, the temperature measurement is embedded in the second layer of FR4 board 3, the medium substrate 1, the first layer FR4 board 2 and the second layer FR4 board 3 are laminated together in sequence from top to bottom, the centers of the medium substrate 1, the first layer FR4 board 2 and the second layer FR4 board 3 are positioned on the same straight line, the straight line is called a central axis, the thickness directions of the medium substrate 1, the first layer FR4 board 2 and the second layer FR4 board 3 are all along the up-down direction, the length direction is all along the left-right direction, the width direction is all along the front-back direction, a cuboid groove 4 with the length of 20mm and the thickness of 20mm is formed in the center of the first layer FR4 board 2, the center of the cuboid groove 4 is positioned on the central axis, the thickness direction of the cuboid groove 4 is along the up-down direction, the length direction is along the left-right direction, and the width direction is along the front-back direction;

The radiation structure comprises a first rectangular metal block 5, a second rectangular metal block 6, a third rectangular metal block 7, a fourth rectangular metal block 8, a fifth rectangular metal block 9, a sixth rectangular metal block 10, a seventh rectangular metal block 11, an eighth rectangular metal block 12, a ninth rectangular metal block 13, a tenth rectangular metal block 14 and an eleventh rectangular metal block 15, wherein the first rectangular metal block 5, the second rectangular metal block 6, the third rectangular metal block 7 and the fourth rectangular metal block 8 are attached to the upper surface of the medium substrate 1, the length direction of the first rectangular metal block 5 is along the left-right direction, the width is reversely along the front-back direction, the center of the first rectangular metal block 5 is positioned on the central axis, the length of the first rectangular metal block 5 is 24mm, the width is 22.5mm, the first rectangular metal block 5 is provided with a first rectangular groove 16, a second rectangular groove 17, a third rectangular groove 18, a fourth rectangular groove 19, a fifth rectangular groove 20, a sixth rectangular groove 21, a seventh rectangular groove 22, an eighth rectangular groove 23, a ninth rectangular groove 24, a tenth rectangular groove 25, an eleventh rectangular groove 26, a twelfth rectangular groove 27, a thirteenth rectangular groove 28, a fourteenth rectangular groove 29, a fifteenth rectangular groove 30, a sixteenth rectangular groove 31 and a seventeenth rectangular groove 32, the upper surface of the medium substrate 1 is exposed at the first rectangular groove 16, the second rectangular groove 17, the third rectangular groove 18, the fourth rectangular groove 19, the fifth rectangular groove 20, the sixth rectangular groove 21, the seventh rectangular groove 22, the eighth rectangular groove 23, the ninth rectangular groove 24, the tenth rectangular groove 25, the eleventh rectangular groove 26, the twelfth rectangular groove 27, the thirteenth rectangular groove 28, the fourteenth rectangular groove 29, the fifteenth rectangular groove 30, the sixteenth rectangular groove 31 and the seventeenth rectangular groove 32, the right end surface of the first rectangular substrate 16 is flush with the right end surface of the first rectangular metal block 5, the rear end face of the first rectangular groove 16 is flush with the rear end face of the first rectangular metal block 5, the length of the first rectangular groove 16 in the left-right direction is 2mm, the width in the front-rear direction is 2.5mm, the second rectangular groove 17 is positioned at the front side of the first rectangular groove 16, the right end face of the second rectangular groove 17 is flush with the right end face of the first rectangular metal block 5, the rear end face of the second rectangular groove 17 is connected with the front end face of the first rectangular groove 16 and is attached to the front end face of the first rectangular groove 16, the length of the second rectangular groove 17 in the left-right direction is 3.5mm, the width in the front-rear direction is 1.5mm, the right end face of the third rectangular groove 18 is flush with the right end face of the first rectangular metal block 5, the length in the left-right direction of the third rectangular groove 18 is 1.5mm, the width in the front-rear direction is 3.8mm, the fourth rectangular groove 19 is positioned at the rear side of the third rectangular groove 18, the right end face of the fourth rectangular groove 19 is flush with the right end face of the first rectangular metal block 5, the front end face of the fourth rectangular groove 19 is connected with the rear end face of the third rectangular groove 18 and is bonded to the rear end face, the length of the fourth rectangular groove 19 in the left-right direction is 4.5mm, the width in the front-rear direction is 1.2mm, the front end face of the fifth rectangular groove 20 is flush with the front end face of the first rectangular metal block 5, the length of the fifth rectangular groove 20 in the left-right direction is 4.8mm, the width in the front-rear direction is 2mm, the distance between the right end face of the fifth rectangular groove 20 and the left end face of the third rectangular groove 18 is 7mm, the sixth rectangular groove 21 is positioned on the left side of the fifth rectangular groove 20, the front end face of the sixth rectangular groove 21 is connected with the left end face of the first rectangular metal block 5 and is bonded to the front end face of the fifth rectangular groove 20, the length in the left-right direction of the sixth rectangular groove 21 in the left-right direction is 1.2mm, the width in the front-rear direction is 3.5mm, the front end face of the seventh rectangular groove 22 is flush with the front end face of the first rectangular metal block 5, the left end face of the seventh rectangular groove 22 is flush with the left end face of the first rectangular metal block 5, the length of the seventh rectangular groove 22 in the left-right direction is 2mm, the width in the front-rear direction is 2.5mm, the distance between the right end face of the seventh rectangular groove 22 and the left end face of the sixth rectangular groove 21 is 7.5mm, the eighth rectangular groove 23 is located at the rear side of the seventh rectangular groove 22, the left end face of the eighth rectangular groove 23 is flush with the left end face of the first rectangular metal block 5, the front end face of the eighth rectangular groove 23 is connected with the rear end face of the seventh rectangular groove 22 and is in contact with the rear end face of the eighth rectangular groove 23, the length of the eighth rectangular groove 23 in the left-right direction is 4.2mm, the width in the front-rear direction is 1.5mm, the ninth rectangular groove 24 is located at the rear side of the eighth rectangular groove 23, the left end face of the ninth rectangular groove 24 is flush with the left end face of the first rectangular metal block 5, the length of the ninth rectangular groove 24 in the left-right direction is 1mm, the width in the front-rear direction is 2mm, the distance between the front end face of the ninth rectangular groove 24 and the rear end face of the eighth rectangular groove 23 is 9.5mm, the tenth rectangular groove 25 is located at the rear side of the ninth rectangular groove 24, the left end face of the tenth rectangular groove 25 is flush with the left end face of the first rectangular metal block 5, the front end face of the tenth rectangular groove 25 is connected with the rear end face of the ninth rectangular groove 24 and bonded with the rear end face of the ninth rectangular groove 24, the length of the tenth rectangular groove 25 in the left-right direction is 7mm, the width in the front-rear direction is 1mm, the eleventh rectangular groove 26 is located at the rear side of the tenth rectangular groove 25, the left end face of the eleventh rectangular groove 26 is flush with the left end face of the first rectangular metal block 5, the length in the left-right direction is 8.5mm, the width in the front-rear direction is 2mm, the distance between the front end face of the eleventh rectangular groove 26 and the rear end face of the tenth rectangular groove 25 is 2mm, the twelfth rectangular groove 27 is located at the rear side of the eleventh rectangular groove 26, the right end face of the twelfth rectangular groove 27 is flush with the right end face of the eleventh rectangular groove 26, the rear end face of the twelfth rectangular groove 27 is flush with the rear end face of the first rectangular metal block 5, the length of the twelfth rectangular groove 27 in the left-right direction is 1mm, the width in the front-rear direction is 2mm, the thirteenth rectangular groove 28 is located at the right side of the twelfth rectangular groove 27, the rear end face of the thirteenth rectangular groove 28 is flush with the rear end face of the first rectangular metal block 5, the length of the thirteenth rectangular groove 28 in the left-right direction is 5mm, the width in the front-rear direction is 2mm, the distance between the left end face of the thirteenth rectangular groove 28 and the right end face of the twelfth rectangular groove 27 is 1mm, the fourteenth rectangular groove 29 is located at the right side of the thirteenth rectangular groove 28, the rear end face of the thirteenth rectangular groove 29 is flush with the rear end face of the first rectangular metal block 5, the fourteenth rectangular groove 29 has a left end face connected to and bonded to the right end face of the thirteenth rectangular groove 28, the fourteenth rectangular groove 29 has a length of 1mm in the left-right direction, a width of 3mm in the front-rear direction, the fifteenth rectangular groove 30 is located on the front side of the thirteenth rectangular groove 28, the fifteenth rectangular groove 30 has a length of 1mm in the left-right direction, a width of 13.2mm in the front-rear direction, a distance between the left end face of the fifteenth rectangular groove 30 and the left end face of the first rectangular metal block 5 is 10mm, a distance between the rear end face of the fifteenth rectangular groove 30 and the front end face of the thirteenth rectangular groove 28 is 3.05mm, the sixteenth rectangular groove 31 is located on the right side of the fifteenth rectangular groove 30, the front end face of the sixteenth rectangular groove 31 is flush with the front end face of the fifteenth rectangular groove 30, the left end face of the sixteenth rectangular groove 31 is connected to and bonded to the right end face of the fifteenth rectangular groove 30, the length of the sixteenth rectangular groove 31 in the left-right direction is 2mm, the width in the front-rear direction is 1mm, the seventeenth rectangular groove 32 is positioned on the right side of the sixteenth rectangular groove 31, the front end face of the seventeenth rectangular groove 32 is flush with the front end face of the sixteenth rectangular groove 31, the left end face of the seventeenth rectangular groove 32 is connected with the right end face of the sixteenth rectangular groove 31 and is attached to the sixteenth rectangular groove, the length of the seventeenth rectangular groove 32 in the left-right direction is 1mm, the width in the front-rear direction is 13.2mm, the second rectangular metal block 6 is positioned on the left side of the first rectangular metal block 5, the left end face of the second rectangular metal block 6 is flush with the left end face of the dielectric substrate 1, the rear end face of the second rectangular metal block 6 is flush with the rear end face of the first rectangular metal block 5, the right end face of the second rectangular metal block 6 is connected with the left end face of the first rectangular metal block 5 and is attached to the sixteenth rectangular metal block 5, the width of the second rectangular metal block 6 in the front-rear direction is 2mm, the third rectangular metal block 7 and the fourth rectangular metal block 8 are positioned at the rear side of the first rectangular metal block 5, the third rectangular metal block 7 is positioned at the left side of the fourth rectangular metal block 8, the front end face of the third rectangular metal block 7 is connected with the rear end face of the first rectangular metal block 5 and is attached to the rear end face of the first rectangular metal block 5, the rear end face of the third rectangular metal block 7 is flush with the rear end face of the medium substrate 1, the length of the third rectangular metal block 7 in the left-right direction is 1mm, the right end face of the third rectangular metal block 7 is flush with the left end face of the twelfth rectangular groove 27, the front end face of the fourth rectangular metal block 8 is connected with the rear end face of the first rectangular metal block 5 and is attached to the rear end face of the fourth rectangular metal block 8, the length of the fourth rectangular metal block 8 in the left-right direction is 1mm, and the left end face of the fourth rectangular metal block 8 is flush with the twelfth rectangular groove 27; the fifth rectangular metal block 9, the sixth rectangular metal block 10, the seventh rectangular metal block 11 and the eighth rectangular metal block 12 are all adhered to the lower surface of the medium substrate 1, the length direction of the fifth rectangular metal block 9 is along the left-right direction, the width is reversely along the front-back direction, the center of the fifth rectangular metal block 9 is positioned on the central axis, the length of the fifth rectangular metal block 9 is 24mm, the width is 23mm, the fifth rectangular metal block 9 is provided with an eighteenth rectangular groove 33, the rear end surface of the eighteenth rectangular groove 33 is flush with the rear end surface of the fifth rectangular metal block 9, the length of the eighteenth rectangular groove 33 along the left-right direction is 5mm, the width along the front-back direction is 2mm, the distance from the left end surface of the eighteenth rectangular groove 33 to the left end surface of the fifth rectangular metal block 9 is 5.5mm, the front parts of the sixth rectangular metal block 10 and the seventh rectangular metal block 11 are positioned in the eighteenth rectangular groove 33, the sixth rectangular metal block 10 is located on the left side of the seventh rectangular metal block 11, the rear end face of the sixth rectangular metal block 10 is flush with the rear end face of the dielectric substrate 1, the length of the sixth rectangular metal block 10 in the left-right direction is 1mm, the width in the front-rear direction is 2.5mm, the distance from the left end face of the sixth rectangular metal block 10 to the left end face of the eighteenth rectangular groove 33 is 1mm, the rear end face of the seventh rectangular metal block 11 is flush with the rear end face of the dielectric substrate 1, the length of the seventh rectangular metal block 11 in the left-right direction is 1mm, the width in the front-rear direction is 2.5mm, the distance from the left end face of the seventh rectangular metal block 11 to the right end face of the sixth rectangular metal block 10 is 1mm, the eighth rectangular metal block 12 is located on the left side of the fifth rectangular metal block 9, the right end face of the eighth rectangular metal block 12 is connected and bonded to the left end face of the fifth rectangular metal block 9, the left end face of the eighth rectangular metal block 12 is flush with the left end face of the dielectric substrate 1, the distance between the rear end face of the eighth rectangular metal block 12 and the plane of the rear end face of the fifth rectangular metal block 9 is 1mm, the width of the eighth rectangular metal block 12 in the front-rear direction is 1.5mm, the ninth rectangular metal block 13 and the tenth rectangular metal block 14 are both attached to the rear end face of the dielectric substrate 1, the ninth rectangular metal block 13 is positioned at the left side of the tenth rectangular metal block 14, the upper end face of the ninth rectangular metal block 13 is connected with the rear end face of the third rectangular metal block 7 and is attached to the rear end face of the third rectangular metal block 7, the lower end face of the ninth rectangular metal block 13 is connected with the rear end face of the sixth rectangular metal block 10 and is attached to the rear end face of the sixth rectangular metal block 10, the width of the ninth rectangular metal block 13 in the left-right direction is 1mm, the upper end face of the tenth rectangular metal block 14 is connected with the rear end face of the fourth rectangular metal block 8 and is attached to the rear end face of the tenth rectangular metal block 14 and is attached to the rear end face of the seventh rectangular metal block 11, the width of the tenth rectangular metal block 14 in the left-right direction is 1mm, the left end face of the third rectangular metal block 7, the left end face of the ninth rectangular metal block 13 and the left end face of the sixth rectangular metal block 10 are located on the same plane, the right end face of the third rectangular metal block 7, the right end face of the ninth rectangular metal block 13 and the right end face of the sixth rectangular metal block 10 are located on the same plane, the left end face of the fourth rectangular metal block 8, the left end face of the tenth rectangular metal block 14 and the left end face of the seventh rectangular metal block 11 are located on the same plane, the right end face of the fourth rectangular metal block 8, the right end face of the tenth rectangular metal block 14 and the right end face of the seventh rectangular metal block 11 are located on the same plane, the eleventh rectangular metal block 15 is attached on the left end face of the dielectric substrate 1, the upper end face of the eleventh rectangular metal block 15 is connected with the left end face of the second rectangular metal block 6 and attached to both, the lower end face of the eleventh rectangular metal block 15 is connected with the left end face of the eighth rectangular metal block 12, and the lower end face of the eleventh rectangular metal block 15 and the left end face of the eighth rectangular metal block 12 are attached, the width of the eleventh rectangular metal block 15 along the front-back direction is 1.5mm, the front end face of the eleventh rectangular metal block 15, the front end face of the second rectangular metal block 6 and the front end face of the eighth rectangular metal block 12 are positioned on the same plane, and the rear end face of the eleventh rectangular metal block 15, the rear end face of the second rectangular metal block 6 and the rear end face of the eighth rectangular metal block 12 are positioned on the same plane;

The feeding structure includes a twelfth rectangular metal block 34, the pad structure includes a thirteenth rectangular metal block 35 and a fourteenth rectangular metal block 36, the connection structure includes a first metal aluminum pillar 37 and a second metal aluminum pillar 38, the twelfth rectangular metal block 34, the thirteenth rectangular metal block 35 and the fourteenth rectangular metal block 36 are attached to the upper surface of the second FR4 board, the distance from the left end face of the twelfth rectangular metal block 34 to the plane of the left end face of the second layer FR4 board 3 is 8mm, the distance from the rear end face of the twelfth rectangular metal block 34 to the plane of the rear end face of the second layer FR4 board 3 is 3mm, the length of the twelfth rectangular metal block 34 in the left-right direction is 1mm, the width in the front-rear direction is 0.5mm, the thirteenth rectangular metal block 35 is located on the left side of the twelfth rectangular metal block 34, the front end face of the thirteenth rectangular metal block 35 is aligned with the front end face of the twelfth rectangular metal block 34, the thirteenth rectangular metal block 35 has a right end face connected to and bonded to the left end face of the twelfth rectangular metal block 34, the thirteenth rectangular metal block 35 has a length of 1mm in the left-right direction and a width of 2mm in the front-rear direction, the fourteenth rectangular metal block 36 is located on the right side of the twelfth rectangular metal block 34, the front end face of the fourteenth rectangular metal block 36 is aligned with the front end face of the twelfth rectangular metal block 34, the left end face of the fourteenth rectangular metal block 36 is connected to and bonded to the right end face of the twelfth rectangular metal block 34, the fourteenth rectangular metal block 36 has a length of 1mm in the left-right direction and a width of 2mm in the front-rear direction, the first and

second aluminum columns

37 and 38 penetrate the first layer FR4 board 2 from top to bottom, the first and

second aluminum columns

37 and 38 are located on the rear side of the rectangular groove 4, the upper end face of the first aluminum column 37 is in full contact with and bonded to the sixth rectangular metal block 10, the lower end surface of the first metal aluminum column 37 is completely contacted and attached with the thirteenth rectangular metal block 35, the upper end surface of the second metal aluminum column 38 is completely contacted and attached with the seventh rectangular metal block 11, and the lower end surface of the second metal aluminum column 38 is completely contacted and attached with the fourteenth rectangular metal block 36; the radio frequency tag chip is disposed on the twelfth rectangular metal block 34, and the radio frequency tag chip is connected to the thirteenth rectangular metal block 35 and the fourteenth rectangular metal block 36, respectively.

In the embodiment, the temperature measuring circuit comprises a singlechip with the model of MSP430FR2433IRGET and a digital temperature sensor with the model of TMP112, wherein the P1.2 pin of the singlechip is connected with the SDA pin of the digital temperature sensor, the P1.3 pin of the singlechip is connected with the SCL pin of the digital temperature sensor, the P2.2 pin of the singlechip is connected with the ALERT pin of the digital temperature sensor, the radio frequency tag chip adopts an ultrahigh frequency RFID tag chip ROCKY100 produced by Huabiao weft company, the RF+ pin of the radio frequency tag chip is welded on the thirteenth rectangular metal block 35, the RF-pin of the radio frequency tag chip is welded on the fourteenth rectangular metal block 36, the MISO pin of the radio frequency tag chip is connected with the P2.5 pin of the singlechip, the MOSI pin of the radio frequency tag chip is connected with the P2.6 pin of the singlechip, the SCK pin of the radio frequency tag chip is connected with the P2.4 pin of the singlechip, the CS pin of the radio frequency tag chip is connected with the P2.3 pin of the singlechip, when temperature detection is carried out, the radio frequency tag chip supplies power for a temperature measuring circuit, a digital temperature sensor senses an environmental temperature signal, the sensed temperature signal is converted from an analog voltage form into a digital form and then is output to the singlechip, and the singlechip converts the received digital temperature signal into a signal which can be identified by an RFID reader according to a preset numbering rule in the signal and then sends the signal to the radio frequency tag chip.

In this embodiment, when the RFID reader transmits a radio frequency signal, the radiation structure receives the radio frequency signal through electromagnetic induction, and the radio frequency signal is transmitted to the radio frequency tag chip through the connection structure and the pad structure.

The simulation S11 diagram of the dual-frequency point temperature measurement RFID tag antenna is shown in FIG. 8; as can be seen from analysis of FIG. 8, two center working frequency points of the dual-frequency point temperature measurement RFID tag antenna of the invention are 842MHz and 924MHz respectively, and return loss S of the tag antenna is obtained through simulation ₁₁ At 842MHz reaches-15 dB, at 924MHz reaches-18 dB, as the smaller the value of return loss S11 in the antenna performance parameter, the less electromagnetic waves emitted by the antenna are reflected, so that the electromagnetic waves emitted by the dual-frequency point temperature-measuring RFID tag antenna are almost completely radiated, and the reflected electromagnetic waves are few.

The impedance matching diagrams of the dual-frequency point temperature measurement RFID tag antenna at the 842MHz and the 924MHz resonance points are shown in figure 9; as can be seen from an analysis of fig. 9, when the resonance point is 842MHz, the input impedance value of the antenna is 74.38+j470.80 Ω; when the resonance point is 924MHz, the input impedance value of the antenna is 64.62+j472.69 omega, and the input impedance value is close to the conjugate value of the impedance value 52-j479Ω of the radio frequency tag chip. These show that the dual-frequency point temperature measurement RFID tag antenna and the tag chip achieve better matching effect.

The two-dimensional gain pattern of the dual-frequency point temperature measurement RFID tag antenna of the present invention at the 842MHz resonance point is shown in fig. 10, in which theta=0°, phi=0° and 90 °. As is clear from fig. 10, the maximum gain values of the dual-frequency point temperature measurement RFID tag antenna of the present invention at the 842MHz resonance point are 2.2dBi, respectively.

The two-dimensional gain pattern of the dual-frequency point temperature-measuring RFID tag antenna of the present invention at 924MHz resonance point is shown in fig. 11, in which theta=0°, phi=0° and 90 °. As is clear from the graph, the maximum gain values of the dual-frequency point temperature measurement RFID tag antenna are respectively 1.5dBi at 924MHz resonance points.

Claims

1. The dual-frequency point temperature measurement RFID tag antenna comprises an antenna main body structure, a radio frequency tag chip and a temperature measurement circuit for measuring temperature, wherein the radio frequency tag chip is respectively connected with the temperature measurement circuit and the antenna main body structure, the radio frequency tag chip is pre-stored with identification information of an article, when the antenna main body structure receives a radio frequency signal sent by an RFID reader, the antenna main body structure transmits the radio frequency signal to the radio frequency tag chip, the radio frequency tag chip converts radio frequency energy of the radio frequency signal into a power supply to supply power for the temperature measurement circuit, the temperature measurement circuit starts to perform temperature measurement work and transmits measured temperature data to the radio frequency tag chip, the radio frequency tag chip transmits the identification information of the article stored in the radio frequency tag chip and the received temperature data, the RFID reader receives the identification information and temperature data of the article transmitted by the radio frequency tag chip, decodes the identification information and temperature data of the article, and then sends the decoded identification information and temperature data to a computer for subsequent identification processing, thereby realizing article identification and temperature detection, and is characterized in that the antenna main body structure comprises a radiation structure, a feed structure, a pad structure, a connecting structure, a dielectric substrate, a first layer FR4 board and a second layer FR4 board, the dielectric substrate is a cuboid structure, 4 corners of the dielectric substrate are respectively cut into round corners with the radius of 2mm, the length of the dielectric substrate is 25mm, the thickness of the dielectric substrate is 3mm, the dielectric substrate is realized by adopting ceramic with the dielectric constant of 39 and the loss of 0.0001, the length of the first layer FR4 board is 25mm, the thickness of the second layer FR4 board is 25mm, the first layer of FR4 board and the second layer of FR4 board are both realized by adopting FR4 boards with dielectric constants of 4.4 and losses of 0.02, the temperature measuring circuit is embedded in the second layer of FR4 board, the dielectric substrate, the first layer of FR4 board and the second layer of FR4 board are laminated together in sequence from top to bottom, the centers of the dielectric substrate, the first layer of FR4 board and the second layer of FR4 board are positioned on the same straight line, the straight line is called a central axis, the thickness directions of the dielectric substrate, the first layer of FR4 board and the second layer of FR4 board are all along the up-down direction, the length directions of the dielectric substrate, the first layer of FR4 board and the second layer of FR4 board are all along the left-right direction, the width directions of the dielectric substrate, the center of the first layer of FR4 board is provided with a cuboid groove with the length of 1mm and the thickness dimension of 20mm, the center of the cuboid groove is positioned on the same straight line, and the thickness directions of the cuboid groove is along the left-right direction;

The radiation structure comprises a first rectangular metal block, a second rectangular metal block, a third rectangular metal block, a fourth rectangular metal block, a fifth rectangular metal block, a sixth rectangular metal block, a seventh rectangular metal block, an eighth rectangular metal block, a ninth rectangular metal block, a tenth rectangular metal block and an eleventh rectangular metal block, wherein the first rectangular metal block, the second rectangular metal block, the third rectangular metal block and the fourth rectangular metal block are attached to the upper surface of the dielectric substrate; the length direction of the first rectangular metal block is along the left-right direction, the width is reversely along the front-back direction, the center of the first rectangular metal block is positioned on the central axis, the length of the first rectangular metal block is 24mm, the width of the first rectangular metal block is 22.5mm, the first rectangular metal block is provided with a first rectangular groove, a second rectangular groove, a third rectangular groove, a fourth rectangular groove, a fifth rectangular groove, a sixth rectangular groove, a seventh rectangular groove, an eighth rectangular groove, a ninth rectangular groove, a tenth rectangular groove, an eleventh rectangular groove, a twelfth rectangular groove, a thirteenth rectangular groove, a fourteenth rectangular groove, a fifteenth rectangular groove, a sixteenth rectangular groove and a seventeenth rectangular groove, the upper surface of the medium substrate is exposed at the first rectangular groove, the second rectangular groove, the third rectangular groove, the fourth rectangular groove, the fifth rectangular groove, the sixth rectangular groove, the seventh rectangular groove, the eighth rectangular groove, the ninth rectangular groove, the tenth rectangular groove, the eleventh rectangular groove, the twelfth rectangular groove, the thirteenth rectangular groove, the fourteenth rectangular groove, the fifteenth rectangular groove, the sixteenth rectangular groove and the seventeenth rectangular groove, the right end surface of the first rectangular groove is flush with the right end surface of the first rectangular metal block, the rear end surface of the first rectangular groove is flush with the rear end surface of the first rectangular metal block, the length of the first rectangular groove in the left-right direction is 2mm, the width in the front-rear direction is 2.5mm, the second rectangular groove is positioned on the right end surface of the first rectangular groove and the right end surface of the first rectangular metal block is flush with the right end surface of the first rectangular groove, the rear end face of the second rectangular groove is connected with the front end face of the first rectangular groove and is attached to the front end face of the first rectangular groove, the length of the second rectangular groove in the left-right direction is 3.5mm, the width of the fourth rectangular groove in the front-back direction is 1.5mm, the right end face of the third rectangular groove is flush with the right end face of the first rectangular metal block, the front end face of the third rectangular groove is flush with the front end face of the first rectangular metal block, the length of the third rectangular groove in the left-right direction is 1.5mm, the width of the third rectangular groove in the front-back direction is 3.8mm, the fourth rectangular groove is positioned at the rear side of the third rectangular groove, the right end face of the fourth rectangular groove is flush with the right end face of the first rectangular metal block, the front end face of the fourth rectangular groove is connected with the rear end face of the third rectangular groove and is attached to the rear end face of the third rectangular groove, the length of the fourth rectangular groove in the left-right direction is 4.5mm, the width along the front-back direction is 1.2mm, the front end face of the fifth rectangular groove is flush with the front end face of the first rectangular metal block, the length of the fifth rectangular groove along the left-right direction is 4.8mm, the width along the front-back direction is 2mm, the distance between the right end face of the fifth rectangular groove and the left end face of the third rectangular groove is 7mm, the sixth rectangular groove is positioned at the left side of the fifth rectangular groove, the front end face of the sixth rectangular groove is flush with the front end face of the first rectangular metal block, the right end face of the sixth rectangular groove is connected with the left end face of the fifth rectangular groove and is attached to the left end face of the fifth rectangular groove, the length of the sixth rectangular groove along the left-right direction is 1.2mm, the width along the front-back direction is 3.5mm, the front end face of the seventh rectangular groove is flush with the front end face of the first rectangular metal block, the left end face of the seventh rectangular groove is flush with the left end face of the first rectangular metal block, the length of the seventh rectangular groove along the left-right direction is 2mm, the width of the eighth rectangular groove along the left-right direction is 2.5mm, the distance between the right end face of the seventh rectangular groove and the left end face of the sixth rectangular groove is 7.5mm, the eighth rectangular groove is positioned at the rear side of the seventh rectangular groove, the left end face of the eighth rectangular groove is flush with the left end face of the first rectangular metal block, the front end face of the eighth rectangular groove is connected with the rear end face of the seventh rectangular groove and is attached to the rear end face of the seventh rectangular groove, the length of the eighth rectangular groove along the left-right direction is 4.2mm, the width along the front-rear direction is 1.5mm, the ninth rectangular groove is positioned at the rear side of the eighth rectangular groove, the left end face of the ninth rectangular groove is flush with the left end face of the first rectangular metal block, the length of the ninth rectangular groove along the left-right direction is 1mm, the width of the tenth rectangular groove along the left-right direction is 2mm, the distance between the front end face of the ninth rectangular groove and the rear end face of the eighth rectangular groove is 9.5mm, the tenth rectangular groove is positioned at the rear side of the ninth rectangular groove, the left end face of the tenth rectangular groove is flush with the left end face of the first rectangular metal block, the front end face of the tenth rectangular groove is connected with the rear end face of the ninth rectangular groove and is attached to the rear end face of the ninth rectangular groove, the length of the tenth rectangular groove along the left-right direction is 7mm, the width along the front-rear direction is 1mm, the eleventh rectangular groove is positioned at the rear side of the tenth rectangular groove, the left end face of the eleventh rectangular groove is flush with the left end face of the first rectangular metal block, the length along the left-right direction is 8.5mm, the width along the front-rear direction is 2mm, the distance between the front end face of the eleventh rectangular groove and the rear end face of the tenth rectangular groove is 2mm, the twelfth rectangular groove is positioned at the rear side of the eleventh rectangular groove, the right end face of the twelfth rectangular groove is flush with the right end face of the eleventh rectangular groove, the rear end face of the twelfth rectangular groove is flush with the rear end face of the first rectangular metal block, the length of the twelfth rectangular groove in the left-right direction is 1mm, the width of the twelfth rectangular groove in the front-rear direction is 2mm, the thirteenth rectangular groove is positioned at the right side of the twelfth rectangular groove, the rear end face of the thirteenth rectangular groove is flush with the rear end face of the first rectangular metal block, the length of the thirteenth rectangular groove in the left-right direction is 5mm, the width of the thirteenth rectangular groove in the front-rear direction is 2mm, the distance between the left end face of the thirteenth rectangular groove and the right end face of the twelfth rectangular groove is 1mm, the fourteenth rectangular groove is positioned on the right side of the thirteenth rectangular groove, the rear end face of the fourteenth rectangular groove is flush with the rear end face of the first rectangular metal block, the left end face of the fourteenth rectangular groove is connected with the right end face of the thirteenth rectangular groove and is attached to the right end face of the thirteenth rectangular groove, the length of the fourteenth rectangular groove along the left-right direction is 1mm, the width along the front-back direction is 3mm, the fifteenth rectangular groove is positioned on the front side of the thirteenth rectangular groove, the length of the fifteenth rectangular groove along the left-right direction is 1mm, the width along the front-back direction is 13.2mm, the distance between the left end face of the fifteenth rectangular groove and the left end face of the first rectangular metal block is 10mm, the distance between the rear end face of the fifteenth rectangular groove and the front end face of the thirteenth rectangular groove is 3.05mm, the sixteenth rectangular groove is positioned on the right side of the fifteenth rectangular groove, the front end face of the sixteenth rectangular groove is flush with the front end face of the fifteenth rectangular groove, the left end face of the sixteenth rectangular groove is connected with the right end face of the fifteenth rectangular groove and is attached to the right end face of the fifteenth rectangular groove, the length of the sixteenth rectangular groove along the left-right direction is 2mm, the width along the front-back direction is 1mm, the seventeenth rectangular groove is positioned on the right side of the sixteenth rectangular groove, the front end face of the seventeenth rectangular groove is flush with the front end face of the sixteenth rectangular groove, the left end face of the seventeenth rectangular groove is connected with the right end face of the sixteenth rectangular groove and is attached to the right end face of the sixteenth rectangular groove, the length of the seventeenth rectangular groove along the left-right direction is 1mm, the width along the front-back direction is 13.2mm, the second rectangular metal block is positioned on the left side of the first rectangular metal block, the left end face of the second rectangular metal block is flush with the left end face of the medium substrate, the rear end face of the second rectangular metal block is flush with the rear end face of the first rectangular metal block, the right end face of the second rectangular metal block is connected with the left end face of the first rectangular metal block and is attached to the left end face of the first rectangular metal block, the width of the second rectangular metal block along the front-back direction is 2mm, the third rectangular metal block and the fourth rectangular metal block are positioned at the rear side of the first rectangular metal block, the third rectangular metal block is positioned at the left side of the fourth rectangular metal block, the front end face of the third rectangular metal block is connected with the rear end face of the first rectangular metal block and is attached to the rear end face of the medium substrate, the length of the third rectangular metal block along the left-right direction is 1mm, the right end face of the third rectangular metal block is flush with the left end face of the twelfth rectangular groove, the front end face of the fourth rectangular metal block is connected with the rear end face of the first rectangular metal block and is attached to the rear end face of the first rectangular metal block, the rear end face of the fourth rectangular metal block is flush with the rear end face of the dielectric substrate, the length of the fourth rectangular metal block along the left-right direction is 1mm, and the left end face of the fourth rectangular metal block is flush with the right end face of the twelfth rectangular groove; the fifth rectangular metal block, the sixth rectangular metal block, the seventh rectangular metal block and the eighth rectangular metal block are all attached to the lower surface of the dielectric substrate, the length direction of the fifth rectangular metal block is along the left-right direction, the width is reversely along the front-back direction, the center of the fifth rectangular metal block is positioned on the central axis, the length of the fifth rectangular metal block is 24mm, the width is 23mm, the fifth rectangular metal block is provided with an eighteenth rectangular groove, the rear end surface of the eighteenth rectangular groove is flush with the rear end surface of the fifth rectangular metal block, the length of the eighteenth rectangular groove along the left-right direction is 5mm, the width along the front-back direction is 2mm, the distance from the left end surface of the eighteenth rectangular groove to the left end surface of the fifth rectangular metal block is 5.5mm, the front parts of the sixth rectangular metal block and the seventh rectangular metal block are positioned in the eighteenth rectangular groove, the sixth rectangular metal block is positioned at the left side of the seventh rectangular metal block, the rear end face of the sixth rectangular metal block is flush with the rear end face of the medium substrate, the length of the sixth rectangular metal block along the left-right direction is 1mm, the width along the front-back direction is 2.5mm, the distance from the left end face of the sixth rectangular metal block to the left end face of the eighteenth rectangular groove is 1mm, the rear end face of the seventh rectangular metal block is flush with the rear end face of the medium substrate, the length of the seventh rectangular metal block along the left-right direction is 1mm, the width along the front-back direction is 2.5mm, the distance from the left end face of the seventh rectangular metal block to the right end face of the sixth rectangular metal block is 1mm, the eighth rectangular metal block is positioned at the left side of the fifth rectangular metal block, the right end face of the eighth rectangular metal block is connected and attached with the left end face of the fifth rectangular metal block, the left end face of the eighth rectangular metal block is flush with the left end face of the dielectric substrate, the distance between the rear end face of the eighth rectangular metal block and the plane where the rear end face of the fifth rectangular metal block is positioned is 1mm, the width of the eighth rectangular metal block along the front-rear direction is 1.5mm, the ninth rectangular metal block and the tenth rectangular metal block are both attached on the rear end face of the dielectric substrate, the ninth rectangular metal block is positioned at the left side of the tenth rectangular metal block, the upper end face of the ninth rectangular metal block is connected with the rear end face of the third rectangular metal block and attached with the rear end face of the third rectangular metal block, the lower end face of the ninth rectangular metal block is connected with the rear end face of the sixth rectangular metal block and is attached to the rear end face of the sixth rectangular metal block, the width of the ninth rectangular metal block along the left-right direction is 1mm, the upper end face of the tenth rectangular metal block is connected with the rear end face of the fourth rectangular metal block and is attached to the rear end face of the tenth rectangular metal block, the lower end face of the tenth rectangular metal block is connected with the rear end face of the seventh rectangular metal block and is attached to the rear end face of the seventh rectangular metal block, the width of the tenth rectangular metal block along the left-right direction is 1mm, the left end face of the third rectangular metal block, the left end face of the ninth rectangular metal block and the left end face of the sixth rectangular metal block are located on the same plane, the right end face of the third rectangular metal block, the right end face of the ninth rectangular metal block and the right end face of the sixth rectangular metal block are located on the same plane, the left end face of the fourth rectangular metal block and the fourth rectangular metal block are located on the same plane, the left end face of the tenth rectangular metal block and the left end face of the seventh rectangular metal block are positioned on the same plane, the right end face of the fourth rectangular metal block, the right end face of the tenth rectangular metal block and the right end face of the seventh rectangular metal block are positioned on the same plane, the eleventh rectangular metal block is attached to the left end face of the dielectric substrate, the upper end face of the eleventh rectangular metal block is connected with the left end face of the second rectangular metal block and is attached to the left end face of the second rectangular metal block, the lower end face of the eleventh rectangular metal block is connected with the left end face of the eighth rectangular metal block and is attached to the left end face of the eighth rectangular metal block, the width of the eleventh rectangular metal block along the front-back direction is 1.5mm, the front end face of the eleventh rectangular metal block, the front end face of the second rectangular metal block and the front end face of the eighth rectangular metal block are positioned on the same plane, and the rear end face of the eleventh rectangular metal block and the eighth rectangular metal block are positioned on the same plane;

The feeding structure comprises a twelfth rectangular metal block, the bonding pad structure comprises a thirteenth rectangular metal block and a fourteenth rectangular metal block, the connecting structure comprises a first metal aluminum column and a second metal aluminum column, the twelfth rectangular metal block, the thirteenth rectangular metal block and the fourteenth rectangular metal block are all attached to the upper surface of the second layer FR4 board, the distance from the left end face of the twelfth rectangular metal block to the plane of the left end face of the second layer FR4 board is 8mm, the distance from the rear end face of the twelfth rectangular metal block to the plane of the rear end face of the second layer FR4 board is 3mm, the length of the twelfth rectangular metal block along the left-right direction is 1mm, the width along the front-rear direction is 0.5mm, the thirteenth rectangular metal block is positioned on the left side of the twelfth rectangular metal block, the front end face of the thirteenth rectangular metal block is aligned with the front end face of the twelfth rectangular metal block, the right end face of the thirteenth rectangular metal block is connected with the left end face of the twelfth rectangular metal block and is attached to the left end face of the twelfth rectangular metal block, the length of the thirteenth rectangular metal block along the left-right direction is 1mm, the width along the front-back direction is 2mm, the fourteenth rectangular metal block is positioned on the right side of the twelfth rectangular metal block, the front end face of the fourteenth rectangular metal block is aligned with the front end face of the twelfth rectangular metal block, the left end face of the fourteenth rectangular metal block is connected with the right end face of the twelfth rectangular metal block and is attached to the right end face of the twelfth rectangular metal block, the length of the fourteenth rectangular metal block along the left-right direction is 1mm, the width along the front-back direction is 2mm, the first metal aluminum column and the second metal aluminum column penetrate through the first layer FR4 board from top to bottom, the first metal aluminum column and the second metal aluminum column are positioned at the rear side of the cuboid groove, the upper end face of the first metal aluminum column is completely contacted and attached with the sixth rectangular metal block, the lower end face of the first metal aluminum column is completely contacted and attached with the thirteenth rectangular metal block, the upper end face of the second metal aluminum column is completely contacted and attached with the seventh rectangular metal block, and the lower end face of the second metal aluminum column is completely contacted and attached with the fourteenth rectangular metal block; the radio frequency tag chip is arranged on the twelfth rectangular metal block and is respectively connected with the thirteenth rectangular metal block and the fourteenth rectangular metal block.

2. The dual-frequency point temperature-measuring RFID tag antenna according to claim 1, wherein the temperature measuring circuit comprises a singlechip with a model MSP430FR2433IRGET and a digital temperature sensor with a model TMP112, a P1.2 pin of the singlechip is connected with an SDA pin of the digital temperature sensor, a P1.3 pin of the singlechip is connected with an SCL pin of the digital temperature sensor, a P2.2 pin of the singlechip is connected with an ALERT pin of the digital temperature sensor, an ultra-high frequency RFID tag chip ROCKY100 produced by Huabiao weft company is adopted by a radio frequency tag chip, an RF-pin of the radio frequency tag chip is welded on a thirteenth rectangular metal block, a MISO pin of the radio frequency tag chip is connected with a P2.5 pin of the singlechip, a P2 pin of the radio frequency tag chip is connected with a SCL pin of the digital temperature sensor, a temperature sensor is connected with a P2.5 pin of the SCL pin of the singlechip, a radio frequency tag chip is connected with a digital temperature sensor, a temperature sensor is connected with a digital temperature sensor is arranged in a preset form of the SCL 2, and a temperature sensor is connected with a digital temperature sensor chip of the SCL, and a temperature sensor is read by a digital RFID tag chip, and a digital tag chip is read by a radio frequency tag chip, and a RFID tag chip is in a radio frequency tag is welded on a thirteenth rectangular metal block, and a RFID tag chip is connected with a P.