Vegetable and fruit freshness detection device
By combining the RFID chip antenna and the airbag metal sheet, the freshness of fruits and vegetables is determined by different response frequencies, which solves the problem of low detection efficiency and realizes non-contact real-time detection and efficient monitoring of fruit and vegetable freshness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGSU COMM PROPERTY MANAGEMENT CO LTD
- Filing Date
- 2026-01-13
- Publication Date
- 2026-04-10
AI Technical Summary
In existing technologies, the detection of spoilage in fruits and vegetables is inefficient, relying on manual sampling and unable to be monitored in real time, resulting in high loss rates and increased product costs.
Using a radio frequency identification (RFID) chip antenna, it emits radio frequency signals with different response frequencies under different conditions to achieve non-contact real-time detection of the freshness of fruits and vegetables. The condition of fruits and vegetables is judged by the combined changes of air bladders and metal plates.
It enables efficient, non-contact detection of fruit and vegetable freshness, avoids damaging packaging, reduces the risk of contamination, promptly detects spoilage issues, and improves detection efficiency.
Smart Images
Figure CN121830729A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of fruit and vegetable testing, and more particularly to a device for testing the freshness of fruits and vegetables. Background Technology
[0002] In the fresh produce supply chain, spoilage of fruits and vegetables has consistently been a major factor contributing to high loss rates and increased product costs, with loss rates reaching 20%-30%. Traditional testing methods mainly rely on manual sampling or opening bags for inspection, which is not only inefficient but also prone to damaging packaging and lacking real-time monitoring capabilities. Therefore, there is an urgent need to develop an efficient, non-contact device capable of real-time monitoring of the freshness of fruits and vegetables. Summary of the Invention
[0003] This application aims to provide a fruit and vegetable freshness detection device, which uses a radio frequency identification (RFID) chip antenna to emit radio frequency signals with different response frequencies under different states to achieve efficient, non-contact and real-time detection of fruit and vegetable freshness. Unlike other RFID chip methods that use a single signal, this device can achieve multi-state detection through a single RFID chip and antenna, resulting in higher detection accuracy and reliability.
[0004] To achieve the above objectives, the technical solution of this application is as follows: A fruit and vegetable freshness detection device includes a radio frequency identification (RFID) chip antenna, a device housing, and an airbag. One side of the device housing serves as a baffle for the RFID chip antenna. The baffle fixes the airbag inside the device housing and below the RFID chip antenna. A metal plate is fixed to the top of the airbag. The RFID chip antenna includes a notch, and the metal plate fixed to the top of the airbag is located vertically below the notch. The RFID chip antenna uses radio frequency signals with two response frequencies based on the antenna length to determine the freshness of the vegetables.
[0005] Optionally, the RFID chip antenna includes: an RFID chip and a chip peripheral antenna, one end of which is connected to the RFID chip; the chip peripheral antenna includes a notch, and a metal plate fixed to the top of the airbag is located vertically below the notch.
[0006] Optionally, the chip peripheral antenna is a planar spiral structure, with one end of the planar spiral structure connected to the RFID chip.
[0007] Optionally, the fruit and vegetable freshness detection device also includes: an antenna fixing structure, which fixes the part of the radio frequency identification chip antenna that is not connected to the outer shell of the device housing to the side of the outer shell of the device housing where the radio frequency identification chip antenna is installed.
[0008] Optionally, the portion of the RFID chip antenna not connected to the device housing and the portion of the RFID chip antenna connected to the device housing constitute a planar spiral structure.
[0009] Optionally, the outer casing of the device can be made of insulating material.
[0010] Optionally, the airbag can be made of an elastic material.
[0011] Optionally, the width of the metal sheet is less than the width of a single antenna in the chip's peripheral antenna plus twice the antenna spacing in the chip's peripheral antenna.
[0012] Optionally, the antenna mounting structure may be made of insulating material.
[0013] Optionally, the radio frequency identification (RFID) chip in the fruit and vegetable freshness detection device is a high-frequency or ultra-high-frequency RFID chip.
[0014] The fruit and vegetable freshness detection device proposed in this application requires only one RFID chip antenna. By changing the antenna's connection state according to external conditions, a single RFID chip can switch its transmission response frequency according to different antenna connection states under different external conditions. This enables non-contact, real-time intelligent detection, eliminating the need to open the bag for detection, avoiding damage to the packaging, reducing the risk of contamination, and promptly detecting spoilage issues, while offering good real-time performance. Simultaneously, the RFID technology enables rapid scanning and data reading, improving detection efficiency. It is widely applicable to various scenarios such as cold chain logistics, supermarket retail, and household consumption.
[0015] To make the above-mentioned features and advantages of the application more apparent and understandable, specific embodiments are provided below, and detailed descriptions are given in conjunction with the accompanying drawings. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of the fruit and vegetable freshness detection device 1 under normal air pressure conditions.
[0017] Figure 2 This is a schematic diagram of the structure of the RFID chip antenna 11.
[0018] Figure 3 This is a side view of the fruit and vegetable freshness detection device 1 under normal air pressure conditions.
[0019] Figure 4 This is a schematic diagram of the structure of the fruit and vegetable freshness detection device 1 under increased air pressure.
[0020] Figure 5 This is a side view of the fruit and vegetable freshness detection device 1 under conditions of increased air pressure.
[0021] Figure 6 This is a circuit diagram of the radio frequency identification signal detection device 2.
[0022] In the accompanying drawings, similar reference numerals refer to the same elements. Detailed Implementation
[0023] To make the objectives and technical solutions of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the described embodiments of this application without creative effort are within the scope of protection of this application.
[0024] In this application, for the sake of clarity, the following explanation is provided: the up and down and left and right directions in the specification correspond to the up and down and left and right directions when an observer is looking at the accompanying drawings. The above explanation is only for the purpose of clearly describing this application and does not indicate or imply that the structure or component referred to must have a specific orientation or be constructed in a specific orientation, and therefore should not be construed as a limitation of this application.
[0025] In one embodiment of this application, taking normal air pressure as an example, please refer to... Figure 1 , Figure 1 This is a schematic diagram of the structure of the fruit and vegetable freshness detection device 1 under normal air pressure conditions. The fruit and vegetable freshness detection device 1 proposed in this application includes: radio frequency identification chip antenna 11, device housing shell 12 and airbag 13. One side of the device housing shell 12 is a baffle for the radio frequency identification chip antenna 11. The baffle fixes the airbag 13 inside the device housing shell 12. The baffle fixes the airbag 13 below the radio frequency identification chip antenna 11. A metal piece 14 is fixed to the top of the airbag 13.
[0026] For example, please refer to Figure 2 , Figure 2 The diagram shows the structure of the RFID chip antenna 11. The RFID chip antenna 11 includes an RFID chip 111 and a chip peripheral antenna 112. The chip peripheral antenna 112 has a planar spiral structure. One end of the chip peripheral antenna 112 located at the center of the planar spiral structure is connected to the RFID chip 111. The chip peripheral antenna 112 includes a notch. The metal plate 14 fixed to the top of the airbag 13 is located vertically below the notch.
[0027] The fruit and vegetable freshness detection device 1 proposed in this application requires only one antenna. By changing the antenna's connection state according to external conditions, a radio frequency identification (RFID) chip can switch its transmission response frequency according to the antenna connection state corresponding to different external conditions. This enables non-contact, real-time intelligent detection, eliminating the need to open the bag for detection, avoiding damage to the packaging, reducing the risk of contamination, and promptly detecting spoilage issues, while offering good real-time performance. Simultaneously, the RFID technology enables rapid scanning and data reading, improving detection efficiency. It is widely applicable to various scenarios such as cold chain logistics, supermarket retail, and household consumption.
[0028] As an example, the fruit and vegetable freshness detection device 1 also includes: an antenna fixing structure ( Figure 1 , Figures 3 to 5 (Not shown in the image) The antenna fixing structure fixes the part of the RFID chip antenna 11 that is not connected to the device housing 12 to the side of the device housing 12 where the RFID chip antenna 11 is installed. The part of the RFID chip antenna 11 that is not connected to the device housing 12 and the part of the RFID chip antenna 11 that is connected to the device housing 12 form a planar spiral structure.
[0029] As an example, the RFID chip 111 is a high-frequency or ultra-high-frequency RFID chip to ensure stable signal transmission.
[0030] In one specific embodiment of this application, the radio frequency identification chip 111 includes the model number Monza M730.
[0031] As an example, the outer casing 12 of the device is made of insulating material.
[0032] As an example, the airbag 13 is made of a material with good elasticity.
[0033] As an example, the width of the metal sheet 14 is less than the width of a single antenna in the chip peripheral antenna 112 plus twice the antenna spacing in the chip peripheral antenna 112. When the metal sheet 14 is pressed against the notch of the RFID chip antenna 11, it does not contact the adjacent antenna.
[0034] As an example, the antenna fixing structure is made of insulating material.
[0035] As an example, the freshness detection device 1 for fruits and vegetables is placed in a closed environment along with the fruits and vegetables.
[0036] The following is combined with Figures 1 to 5 This application explains the working principle of the fruit and vegetable freshness detection device 1.
[0037] The RFID chip antenna 11 of the fruit and vegetable freshness detection device 1 proposed in this application determines the freshness of vegetables using radio frequency signals with two response frequencies based on the antenna length. Please refer to [link / reference]. Figure 3 , Figure 3 This is a side view of the fruit and vegetable freshness detection device 1 under normal air pressure conditions. When the fruits and vegetables have not spoiled, the air pressure inside and outside the airbag 13 is normal, and the airbag 13 inflates. The air pressure inside the airbag 13 presses the metal plate 14 tightly against the notch of the RFID chip antenna 11, connecting the two disconnected antenna segments in the RFID chip antenna 11. That is, the notch of the chip's peripheral antenna 112 is connected by the metal plate 14. At this time, the antenna length coupled from the chip's peripheral antenna 112 to the RFID chip 111 is the longer length. The response frequency of the RFID chip 111 is... The first radio frequency signal.
[0038] Please continue reading. Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of the fruit and vegetable freshness detection device 1 under increased air pressure. Figure 5 This is a side view of the fruit and vegetable freshness detection device 1 under increased air pressure. When fruits and vegetables spoil, they produce metabolic gases such as carbon dioxide and methane, leading to an increase in air pressure within the sealed environment. This increases the external pressure of the air bladder 13, causing it to compress, and the metal plate 14 ( Figure 4 (Not shown) At the notch where the RFID chip antenna 11 is disconnected, the RFID chip antenna 11 is broken into two antenna segments. That is, the notch of the chip peripheral antenna 112 is disconnected because there is no metal piece 14 connecting it. At this time, the antenna length of the chip peripheral antenna 112 coupled to the RFID chip 111 is the shorter length. The response frequency of the RFID chip 111 is... The second radio frequency signal.
[0039] Furthermore, this application also proposes a radio frequency identification (RFID) signal detection device 2, which uses different scanning frequencies to read RFID information and distinguish between different signals. and Two response frequencies are used to determine whether vegetables have spoiled by detecting changes in the frequency of the signal emitted by the radio frequency identification signal detection device 2, thereby determining the freshness of fruits and vegetables.
[0040] Please see Figure 6 , Figure 6 This is a circuit diagram of the RFID signal detection device 2. The RFID signal detection device 2 includes a receiving circuit 21, a main control circuit 22, and a transmitting circuit 23, which are connected in sequence.
[0041] As an example, the receiving circuit 21 includes a first receiving unit 211 and a second receiving unit 212, the first ends of the first receiving unit 211 and the second receiving unit 212 being connected to the first end of the main control circuit 22, respectively.
[0042] As an example, the first receiving unit 211 includes: a first inductor L1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a first amplifier A1. The first terminal of the first inductor L1 is connected to the first terminal of the first capacitor C1, the first terminal of the second capacitor C2, and the first terminal of the first resistor R1. The second terminal of the first inductor L1 is connected to the second terminal of the first capacitor C1 and the first terminal of the first amplifier A1. The second terminal of the second capacitor C2 is connected to the second terminal of the first amplifier A1, the first terminal of the fourth capacitor C4, and the first terminal of the fourth resistor R4. The third terminal of the first amplifier A1 is connected to the first terminal of the third resistor R3, the first terminal of the third capacitor C3, and the second terminal of the fourth capacitor C4. The second terminal of the third capacitor C3 is connected to the second terminal of the fourth resistor R4. The second terminal of the first resistor R1 is connected to the second terminal of the third resistor R3 and the first terminal of the second resistor R2. The second terminal of the second capacitor C2 is grounded, the second terminal of the second resistor R2 is connected to the power supply VCC, and the second terminal of the third capacitor C3 is the first terminal of the first receiving unit 211.
[0043] As an example, the second receiving unit 212 includes: a second inductor L2, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a second amplifier A2. The first terminal of the second inductor L2 is connected to the first terminal of the fifth capacitor C5, the first terminal of the sixth capacitor C6, and the first terminal of the fifth resistor R5. The second terminal of the second inductor L2 is connected to the second terminal of the fifth capacitor C5 and the first terminal of the second amplifier A2. The second terminal of the sixth capacitor C6 is connected to the second terminal of the second amplifier A2, the first terminal of the eighth capacitor C8, and the first terminal of the eighth resistor R8. The third terminal of the second amplifier A2 is connected to the first terminal of the seventh resistor R7, the first terminal of the seventh capacitor C7, and the second terminal of the eighth capacitor C8. The second terminal of the seventh capacitor C7 is connected to the second terminal of the eighth resistor R8. The second terminal of the fifth resistor R5 is connected to the second terminal of the seventh resistor R7 and the first terminal of the sixth resistor R6. The second terminal of the sixth capacitor C6 is grounded, the second terminal of the sixth resistor R6 is connected to the power supply VCC, and the second terminal of the seventh capacitor C7 is the first terminal of the second receiving unit 212.
[0044] As an example, the number of turns of the first inductor L1 and the second inductor L2 are different, so as to receive radio frequency signals with different response frequencies.
[0045] In one embodiment of this application, the first inductor L1 has 60 turns, and the response frequency for receiving the signal transmitted by the RFID chip 111 is... The first radio frequency signal; the second inductor L2 has 40 turns and is used to receive the response frequency transmitted by the RFID chip 111. The second radio frequency signal.
[0046] As an example, the main control circuit 22 includes a microcontroller chip U1. Pins P10 and P11 of the microcontroller chip U1 constitute the first terminal of the main control circuit 22. Pins P12, P13, P14, and P15 of the microcontroller chip U1 constitute the second terminal of the main control circuit 22.
[0047] As an example, the second end of the third capacitor C3 is connected to the P10 pin of the microcontroller chip U1, and the second end of the seventh capacitor C7 is connected to the P11 pin of the microcontroller chip U1.
[0048] As an example, the transmitting circuit 23 includes a first transmitting unit 231 and a second transmitting unit 232, which are respectively connected to the second end of the main control circuit 22.
[0049] As an example, the first transmitting unit 231 includes: a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a fourteenth capacitor C14, a third inductor L3, a fourth inductor L4, a fifth inductor L5, a sixth inductor L6, a ninth resistor R9, a tenth resistor R10, a first transistor Q1, a first switch S1, and a first antenna RF1. The first terminal of the ninth capacitor C9 is connected to the first terminal of the first switch S1. The second terminal of the first switch S1 is connected to the first terminal of the tenth capacitor C10. The second terminal of the tenth capacitor C10 is connected to the first terminal of the third inductor L3 and the first terminal of the first transistor Q1. The second terminal of the third inductor L3 is connected to the first terminal of the fourth inductor L4 and the first terminal of the eleventh capacitor C11. The second terminal of the eleventh capacitor C11 is connected to the first terminal of the ninth resistor R9. The second terminal of the ninth resistor R9 is connected to the second terminal of the first transistor Q1. The third terminal of the first transistor Q1 is connected to the first terminal of the fifth inductor L5 and the first terminal of the twelfth capacitor C12. The second terminal of the twelfth capacitor C12 is connected to the first terminal of the thirteenth capacitor C10. The first terminal of C13 is connected to the first terminal of the sixth inductor L6. The second terminal of the thirteenth capacitor C13 is connected to the first terminal of the fourteenth capacitor C14 and the first terminal of the tenth resistor R10. The second terminal of the fourteenth capacitor C14 is connected to the second terminal of the sixth inductor L6, the second terminal of the tenth resistor R10, and the first antenna RF1. The first terminal of the ninth capacitor C9 and the control terminal of the first switch S1 constitute the first terminal of the first transmitting unit 231. The first antenna RF1 is the second terminal of the first transmitting unit 231. The second terminals of the ninth capacitor C9, the eleventh capacitor C11, the thirteenth capacitor C13, and the fourth inductor L4 are grounded. The second terminal of the fifth inductor L5 is connected to the power supply VCC.
[0050] As an example, the first terminal of the ninth capacitor C9 is connected to the P12 pin of the microcontroller chip U1, and the control terminal of the first switch S1 is connected to the P13 pin of the microcontroller chip U1.
[0051] As an example, the second transmitting unit 232 includes: a fifteenth capacitor C15, a sixteenth capacitor C16, a seventeenth capacitor C17, an eighteenth capacitor C18, a nineteenth capacitor C19, a twentieth capacitor C20, a seventh inductor L7, an eighth inductor L8, a ninth inductor L9, a tenth inductor L10, an eleventh resistor R11, a twelfth resistor R12, a second transistor Q2, a second switch S2, and a second antenna RF2. The first terminal of the fifteenth capacitor C15 is connected to the first terminal of the second switch S2. The second terminal of the second switch S2 is connected to the first terminal of the sixteenth capacitor C16. The second terminal of the sixteenth capacitor C16 is connected to the first terminal of the seventh inductor L7 and the first terminal of the second transistor Q2. The second terminal of the seventh inductor L7 is connected to the first terminal of the eighth inductor L8 and the first terminal of the seventeenth capacitor C17. The second terminal of the seventeenth capacitor C17 is connected to the first terminal of the eleventh resistor R11. The second terminal of the eleventh resistor R11 is connected to the second terminal of the second transistor Q2. The third terminal of the second transistor Q2 is connected to the first terminal of the ninth inductor L9 and the first terminal of the eighteenth capacitor C18. The second terminal of the eighteenth capacitor C18 is connected to the first terminal of the nineteenth capacitor C15. The first terminal of capacitor C19 is connected to the first terminal of the tenth inductor L10. The second terminal of the nineteenth capacitor C19 is connected to the first terminal of the twentieth capacitor C20 and the first terminal of the twelfth resistor R12. The second terminal of the twentieth capacitor C20 is connected to the second terminal of the tenth inductor L10, the second terminal of the twelfth resistor R12, and the second antenna RF2. The first terminal of the fifteenth capacitor C15 and the control terminal of the second switch S2 constitute the first terminal of the second transmitting unit 232. The second antenna RF2 is the second terminal of the second transmitting unit 232. The second terminals of the fifteenth capacitor C15, the seventeenth capacitor C17, the nineteenth capacitor C19, and the eighth inductor L8 are grounded. The second terminal of the ninth inductor L9 is connected to the power supply VCC.
[0052] As an example, the first terminal of the fifteenth capacitor C15 is connected to the P14 pin of the microcontroller chip U1, and the control terminal of the second switch S2 is connected to the P15 pin of the microcontroller chip U1.
[0053] In one embodiment of this application, the microcontroller chip U1 is model STC8W8R32H4. Pins P10 and P11 of the microcontroller chip U1 are configured in bidirectional input mode to receive two types of radio frequency (RF) signals from the receiving circuit and transmit them to the microcontroller for analysis and processing. Pins P12, P13, P14, and P15 of the microcontroller chip U1 are configured in push-pull output mode to output high and low level control signals based on the received RF signals, driving the switching of the transmitting unit to turn on and off, thereby achieving switching control of the first transmitting unit 231 and the second transmitting unit 232.
[0054] As an example, both the first transistor Q1 and the second transistor Q2 are NPN transistors. The first terminal of both transistor Q1 and the second transistor Q2 is the base, the second terminal of both transistor Q1 and the second transistor Q2 is the emitter, and the third terminal of both transistor Q1 and the second transistor Q2 is the collector.
[0055] The following will continue to combine Figure 4 This paper explains the working principle of the radio frequency identification signal detection device 2 of this application.
[0056] When the fruits and vegetables are not spoiled, the air pressure inside and outside the airbag 13 is normal, and the airbag 13 inflates. The air pressure inside the airbag 13 presses the metal plate 14 tightly against the notch of the RFID chip antenna 11, connecting the two disconnected antenna sections in the RFID chip antenna 11. The RFID chip 111 then transmits at a frequency of [frequency missing]. The first radio frequency signal is filtered and received by the first receiving unit 211 through the signal receiving tuning structure composed of the first inductor L1 and the first capacitor C1, and the response frequency is... The first radio frequency (RF) signal is impedance matched to reduce signal loss. The weak RF signal is then amplified by the first amplifier A1, filtered to optimize the quality of the RF signal, and finally transmitted to the input pin P10 of the microcontroller chip U1. The microcontroller chip U1 performs signal analysis, logic operations, and other data processing on the input RF signal. According to the preset program, it outputs the control signal corresponding to the RF signal to the first switch S1 and the second switch S2, controlling the first switch S1 to turn on and the second switch S2 to turn off. The first transistor Q1 converts the control signal into the first RF drive signal, which is finally transmitted by the first antenna RF1.
[0057] When fruits and vegetables spoil, they produce metabolic gases, causing an increase in air pressure within the enclosed environment. This increases the external pressure of the airbag 13, compressing it. The metal piece 14 then detaches from the notch in the RFID chip antenna 11, breaking the RFID chip antenna 11 into two segments. The RFID chip 111 then transmits at a frequency of... The second radio frequency signal, at this time the working principle of the radio frequency identification signal detection device 2 is the same as when the fruits and vegetables have not spoiled, and will not be described again here.
[0058] As an example, the fruit and vegetable freshness detection device 1 can be widely used in the following fields: In the cold chain logistics sector: real-time monitoring of the status of fruits and vegetables during transportation, timely warning of spoilage risks, and optimization of transportation routes and storage conditions.
[0059] Convenience store retail application: Intelligent shelf management, automatically identifies spoiled goods and triggers their removal from shelves, reducing manual inspection costs and improving the efficiency of product freshness management.
[0060] Household consumer applications: Consumers can quickly determine the freshness of fruits and vegetables by connecting their smartphones to RFID scanning devices, thus reducing food waste.
[0061] The fruit and vegetable freshness detection device proposed in this application requires only one antenna. By changing the antenna's connection state according to external conditions, a single radio frequency identification (RFID) chip can switch its transmission response frequency according to the antenna connection state corresponding to different external conditions. This enables non-contact, real-time intelligent detection, eliminating the need to open the bag for inspection, avoiding damage to the packaging, reducing the risk of contamination, and promptly detecting spoilage issues, while offering good real-time performance. Simultaneously, the RFID technology enables rapid scanning and data reading, improving detection efficiency. It is widely applicable to various scenarios such as cold chain logistics, supermarket retail, and household consumption.
[0062] Although this application has been disclosed above with reference to embodiments, it is not intended to limit this application. Anyone skilled in the art may make some modifications and refinements without departing from the spirit and scope of this application. Therefore, the scope of protection of this application shall be determined by the appended claims.
Claims
1. A device for detecting the freshness of fruits and vegetables, characterized in that, The device includes a radio frequency identification (RFID) chip antenna, a housing, and an airbag. One side of the housing serves as the RFID chip antenna, and the airbag is located inside the housing, below the RFID chip antenna. A metal plate is fixed to the top of the airbag. The RFID chip antenna includes a notch, and the metal plate fixed to the top of the airbag is located vertically below the notch. The RFID chip antenna uses radio frequency signals with two response frequencies based on its length to determine the freshness of the vegetables.
2. The fruit and vegetable freshness detection device as described in claim 1, characterized in that, The radio frequency identification (RFID) chip antenna includes: an RFID chip and a chip peripheral antenna, one end of which is connected to the RFID chip; the chip peripheral antenna includes a notch, and a metal plate fixed to the top of the airbag is located vertically below the notch.
3. The fruit and vegetable freshness detection device as described in claim 2, characterized in that, The chip's peripheral antenna is a planar spiral structure, with one end of the planar spiral structure connected to the RFID chip.
4. The fruit and vegetable freshness detection device as described in claim 1, characterized in that, Also includes: The antenna fixing structure fixes the part of the RFID chip antenna that is not connected to the device housing to the side of the device housing where the RFID chip antenna is installed.
5. The fruit and vegetable freshness detection device as described in claim 4, characterized in that, The portion of the RFID chip antenna not connected to the device housing and the portion of the RFID chip antenna connected to the device housing constitute a planar spiral structure.
6. The fruit and vegetable freshness detection device as described in claim 1, characterized in that, The outer shell of the device is made of insulating material.
7. The fruit and vegetable freshness detection device as described in claim 1, characterized in that, The airbag is made of elastic material.
8. The fruit and vegetable freshness detection device as described in claim 1, characterized in that, The width of the metal sheet is less than the width of a single antenna in the chip's peripheral antenna plus twice the antenna spacing in the chip's peripheral antenna.
9. The fruit and vegetable freshness detection device as described in claim 4, characterized in that, The antenna mounting structure is made of insulating material.
10. The fruit and vegetable freshness detection device as described in claim 1, characterized in that, The radio frequency identification chip is a high-frequency or ultra-high-frequency radio frequency identification chip.