Passive LIVE label based on plane sensing array

Abstract

A passive LIVE tag based on a plane sensing array is a four-port antenna sensor and comprises a dielectric substrate, a metal grounding plate arranged on the lower surface of the dielectric substrate and a radiation layer arranged on the upper surface of the dielectric substrate. The radiation layer comprises four sensing modules and a cross-shaped microstrip feeder line connected with the four sensing modules; four ports of the cross-shaped micro-strip feeder line are used as input / output ports of signals, namely RF (Radio Frequency) ports; the four sensing modules are respectively connected to four branch microstrip feeder lines of the cross microstrip feeder line; by selecting different RF port combinations and changing signal input / output ports, sensing mode conversion of the passive LIVE tag can be realized, and a multi-parameter and multi-mode sensing function is realized. A plurality of sensing channels can be integrated by combining different RF ports, the measurement parameter capacity is improved, the limitation of a single sensing mode is broken through, the multi-parameter and multi-mode sensing characteristic is achieved, and whether physical or chemical parameters in a target environment change or not can be monitored in real time.

Description

Technical Field

[0001] The present application belongs to the field of microwave sensing technology, and in particular relates to a passive LIVE tag based on a planar sensor array. Background Art

[0002] Antenna sensors are an emerging sensing technology used in the Internet of Things, such as monitoring pH, chemical gases, strain, temperature, and humidity in the environment. Currently, wireless sensing technology mainly uses active sensors to reliably transmit data without interference over a distance of several meters. However, active antenna sensors are more expensive than passive sensors, and sensors that rely on battery power are limited in large-scale deployment of sensor networks. Active sensors also have limited battery life, which poses considerable challenges in terms of battery replacement and electronic waste.

[0003] Wireless sensors can be designed with or without chips. Most IoT sensors on the market are based on integrated circuit (IC) chips. Although they have advantages such as large reading range and high accuracy, they are relatively expensive. In contrast, chipless antenna sensors are completely passive, low-cost, long-life, and dynamic sensing. Chipless and passive LIVE antenna sensors do not require electricity, have simple system design, low manufacturing cost, and can withstand extreme weather. They can be directly printed on any surface through additive manufacturing technology, becoming an important development direction for future sensors.

[0004] Existing passive antenna sensors are often used as competitors for optical barcodes. Passive antenna tags based on spectrum coding encode through resonant frequency. However, the sensing parameters and functions of existing passive antenna sensors are usually fixed and single, cannot be reconfigured, and do not have multimodal functions. Summary of the invention

[0005] In order to solve the above problems, the present application discloses a passive LIVE tag based on a planar sensor array.

[0006] Technical solution of the present invention: A passive LIVE tag based on a planar sensor array is a four-port antenna sensor, comprising a dielectric substrate, a metal grounding plate arranged on the lower surface of the dielectric substrate, and a radiation layer arranged on the upper surface of the dielectric substrate; The radiation layer includes four sensor modules and a cross microstrip feeder connecting the four sensor modules; the cross microstrip feeder is used for signal transmission, and its four ports serve as signal input / output ports, i.e., RF (Radio Frequency) ports; the four sensor modules are respectively connected to four branch microstrip feeders of the cross microstrip feeder; By selecting different RF port combinations and changing the signal input / output ports, the sensing mode conversion of the passive LIVE tag can be achieved, realizing multi-parameter and multi-modal sensing functions.

[0007] Beneficial effects of the present invention: The passive LIVE tag of the present invention has multi-parameter and multi-modal sensing characteristics by designing multiple sensor unit arrays and integrating thin film materials sensitive to different environmental physical or chemical parameters on the surfaces of different units. The passive LIVE tag can respond to and monitor different physical and chemical stimulus signals in the environment, and the introduction of its multi-sensing mechanism has changed the service paradigm of passive tag sensors. In addition, the passive LIVE tag of the present invention has a simple structure, low cost, and is easy to print and mass-produce. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is an overall schematic diagram of a passive LIVE tag based on a planar sensor array of the present invention; Figure 2 for Figure 1 Schematic side view of Figure 3 It is a schematic diagram of the structural integration process of each part of the resonance unit; Figure 4 It is a schematic diagram of the integration process of various components of the sensor module; Figure 5 This is a diagram showing the S-parameter simulation results of a passive LIVE tag without integrated sensitive polymer film in the embodiment; Figure 6 The present invention is a passive LIVE tag based on a planar sensor array. 12 Parameter simulation result diagram; Figure 7 The present invention is a passive LIVE tag based on a planar sensor array. 13 Parameter simulation result diagram; Figure 8 The present invention is a passive LIVE tag based on a planar sensor array. 14 Parameter simulation result diagram; Fig. 9 The present invention is a passive LIVE tag based on a planar sensor array. 23 Parameter simulation result diagram; Fig.10 The present invention is a passive LIVE tag based on a planar sensor array. 24 Parameter simulation result diagram; Fig.11 The present invention is a passive LIVE tag based on a planar sensor array. 34 Parameter simulation result diagram; Fig.12 This is a schematic diagram of an application of a passive LIVE tag based on a planar sensor array according to the present invention.

[0009] Reference numerals: 1 metal ground plane, 2 dielectric substrate, 3 radiation layer; 4 cross microstrip feed lines; 5 sensing modules, 5-1 a first sensing module, 5-2 a second sensing module, 5-3 a third sensing module, 5-4 a fourth sensing module; 6 sensing resonant units, 6-1 interdigital capacitor structure, 6-2 open split ring structure; 7 sensitive polymer film, 7-1 first sensitive polymer film, 7-2 second sensitive polymer film, 7-3 third sensitive polymer film, 7-4 fourth sensitive polymer film. DETAILED DESCRIPTION

[0010] The technical solution provided by the present application will be further described below in conjunction with specific embodiments and accompanying drawings. The advantages and features of the present application will become more apparent with the following description.

[0011] A passive LIVE tag based on a planar sensor array is a four-port antenna sensor, comprising a dielectric substrate 2, a metal grounding plate 1 arranged on the lower surface of the dielectric substrate, and a radiation layer 3 arranged on the upper surface of the dielectric substrate; The radiation layer 3 includes four sensor modules 5 and a cross microstrip feeder 4 connecting the four sensor modules; the cross microstrip feeder is used for signal transmission, and its four ports serve as signal input / output ports, i.e., RF (Radio Frequency) ports; the four sensor modules 5 are respectively connected to four branch microstrip feeders of the cross microstrip feeder 4; By selecting different RF port combinations and changing the signal input / output ports, the sensing mode conversion of the passive LIVE tag can be achieved, realizing multi-parameter and multi-modal sensing functions.

[0012] Specifically, the four sensor modules are respectively a first sensor module 5-1, a second sensor module 5-2, a third sensor module 5-3, and a fourth sensor module 5-4, and the four ports of the cross microstrip feeder connected to the four sensor modules are respectively RF port A, RF port B, RF port C, and RF port D.

[0013] like Figure 3 , 4 As shown, each sensing module 5 includes a sensing resonance unit 6 and a sensitive polymer film 7, wherein: The sensing resonance unit 6 includes an interdigital capacitor structure 6-1 and an open split ring structure 6-2, wherein the interdigital capacitor structure 6-1 is integrated in the gap of the open split ring structure 6-2; The sensitive polymer film 7 is arranged on the surface of the interdigital capacitor structure 6 - 1 of the sensor resonance unit 6 .

[0014] By integrating the interdigital capacitor structure into the gap of the open split ring structure, the resonant unit gathers high electric field energy density inside the interdigital capacitor structure.

[0015] The sensor resonance unit is a trap circuit, and resonates when a signal of a specific frequency passes through it, resulting in significant attenuation, and the signal of the specific frequency will have a significant trap in the frequency domain.

[0016] The sensing resonance unit can also be used to generate dual-frequency resonance characteristics of odd mode and even mode, and the lower frequency corresponds to the odd mode, and the higher operating frequency is generated by the even mode. The two resonance modes have opposite offset directions and do not interfere with each other, so they can be calibrated with each other when characterizing a function to reduce the error of sensing.

[0017] The sensitive polymer film 7 is a sensitive material, specifically a polymer material that is sensitive to physical or chemical parameters in a specific environment. The polymer material has the characteristics of a film and can be easily integrated on the surface of the sensor resonance unit. There are many types of sensitive polymer films to choose from, for example, polyimide films, polyvinyl alcohol hydrogel films, etc. for relative humidity sensing, reduced graphene oxide films, etc. for temperature sensing, chitosan hydrogel films, etc. for pH sensing, and carbon nanotube films, etc. for toxic gas ammonia sensing.

[0018] Sensing of specific parameter functions can be achieved by loading a sensitive polymer film 7 on the surface of the sensing resonance unit 6. The effective dielectric constant of the sensitive polymer film is easily changed by the change of the target environmental parameter, thereby causing the resonance frequency shift of the sensing module.

[0019] Furthermore, the multi-parameter sensing characteristics can be realized by integrating polymer materials that are sensitive to different physical or chemical parameters of the environment, i.e., sensitive polymer films 7, on the surfaces of the sensing resonance units 6 of different sensing modules 5. Specifically, the sensitive polymer films on the first sensing module 5-1, the second sensing module 5-2, the third sensing module 5-3, and the fourth sensing module 5-4 are the first sensitive polymer film 7-1, the second sensitive polymer film 7-2, the third sensitive polymer film 7-3, and the fourth sensitive polymer film 7-4, respectively.

[0020] The passive LIVE tag based on a planar sensor array described in the present invention can be reconstructed by selecting different RF port combinations as signal input / output to achieve multi-modal sensing characteristics. The reconstruction method is to select any two ports from the four ports to achieve sensing measurement, so there are six port combinations, namely: RF port A combined with RF port B, RF port A combined with RF port C, RF port A combined with RF port D, RF port B combined with RF port C, RF port B combined with RF port D, RF port C combined with RF port D, and the transmission channel S parameters corresponding to the above six port combinations are respectively recorded as S 12 Parameters, S 13 Parameters, S 14 Parameters, S 23 Parameters, S 24 Parameters, S 34 parameter.

[0021] Furthermore, in the passive LIVE tag based on a planar sensor array described in the present invention, the resonant frequency generated by each port combination is in the same preset operating frequency band, thereby realizing the frequency band sharing function of multimodal sensing and significantly improving the spectrum utilization efficiency. The resonant frequency generated by each sensor module is limited to a predetermined operating frequency band, and the sensor module and the port to which it is connected are related to each other through physical coupling. This coupling mechanism ensures that when measuring under any port combination, the observed resonant frequency is in the same operating frequency band. Through the above design, the operating frequency band sharing between the port combinations is achieved, thereby optimizing the spectrum utilization efficiency.

[0022] In order to further describe the resonant working characteristics of a passive LIVE tag based on a planar sensor array described in the present invention, the embodiment performs simulation experiments on six different port combinations and uses a vector network analyzer to measure S parameters.

[0023] First, as a reference, a simulation experiment is conducted on a passive LIVE tag without integrated sensitive polymer film. Figure 5 A passive LIVE tag without integrated sensitive polymer film S Parameter simulation result diagram. Since the sensitive polymer film is not integrated on the surface of the sensor resonance unit, the four sensing modules of the passive LIVE tag are the same. These four identical sensing modules produce the same dual-frequency resonance in odd mode and even mode, with the corresponding frequency in odd mode being 2.87 GHz and the corresponding frequency in even mode being 4.43 GHz.

[0024] When a passive LIVE tag integrates a sensitive polymer film on the surface of its sensor resonance unit, both the odd-mode frequency and the even-mode frequency will shift in opposite directions.

[0025] After the sensitive polymer film is integrated on the surface of the sensor resonance unit, the correlation between the effective dielectric constant of the sensor module and its corresponding resonant frequency can be explained by the following formula: in: f r is the resonant frequency corresponding to the sensor module; a is the effective length of the open split ring structure of the sensor module; The effective dielectric constant of the sensor module after the sensitive polymer film is integrated on the surface of the sensor resonance unit, and its value will change with the specific environment; is the effective dielectric constant of the sensitive polymer film, It is the effective dielectric constant of the sensing module without integrating the sensitive polymer film on the surface of the sensing resonance unit.

[0026] Next, in order to further describe the resonant working characteristics of a passive LIVE tag based on a planar sensor array described in the present invention, a simulation experiment is conducted on a passive LIVE tag with an integrated sensitive polymer film.

[0027] In the experiment, polymer materials that are sensitive to different physical or chemical parameters of the environment, i.e., sensitive polymer films, are integrated on the surfaces of the sensor resonant units of different sensor modules to achieve multi-parameter sensing characteristics. The effective dielectric constant ε of the sensitive polymer film 7 is film Used to distinguish different sensitive materials. Specifically, the effective dielectric constant of the sensitive polymer film on the first sensing module 5-1 is 10, the effective dielectric constant of the sensitive polymer film on the second sensing module 5-2 is 20, the effective dielectric constant of the sensitive polymer film on the third sensing module 5-3 is 30, and the effective dielectric constant of the sensitive polymer film on the fourth sensing module 5-4 is 40.

[0028] When RF port A is combined with RF port B, and the first sensitive polymer film 7-1 (with an effective dielectric constant of 10) is integrated on the sensing resonance unit of the first sensing module 5-1, and the second sensitive polymer film 7-2 (with an effective dielectric constant of 20) is integrated on the sensing resonance unit of the second sensing module 5-2, the S of the passive LIVE tag is obtained. 12 The parameter simulation results are as follows Figure 6 shown.

[0029] When RF port A is combined with RF port C, and the first sensitive polymer film 7-1 (with an effective dielectric constant of 10) is integrated on the sensing resonance unit of the first sensing module 5-1, and the third sensitive polymer film 7-3 (with an effective dielectric constant of 30) is integrated on the sensing resonance unit of the third sensing module 5-3, the S of the passive LIVE tag is obtained. 13 The parameter simulation results are as follows Figure 7 shown.

[0030] When RF port A is combined with RF port D, and the first sensitive polymer film 7-1 (with an effective dielectric constant of 10) is integrated on the sensing resonance unit of the first sensing module 5-1, and the fourth sensitive polymer film 7-4 (with an effective dielectric constant of 40) is integrated on the sensing resonance unit of the fourth sensing module 5-4, the S of the passive LIVE tag is obtained. 14 The parameter simulation results are as follows Figure 8 shown.

[0031] When RF port B is combined with RF port C, and the second sensing module 5-2 is integrated with the second sensitive polymer film 7-2 (with an effective dielectric constant of 20), and the third sensing module 5-3 is integrated with the third sensitive polymer film 7-3 (with an effective dielectric constant of 30), the passive LIVE tag S is obtained. 23 The parameter simulation results are as follows Fig. 9 shown.

[0032] When RF port B is combined with RF port D, and the second sensing module 5-2 is integrated with the second sensitive polymer film 7-2 (with an effective dielectric constant of 20), and the fourth sensing module 5-4 is integrated with the fourth sensitive polymer film 7-4 (with an effective dielectric constant of 40), the S of the passive LIVE tag is obtained. 24 The parameter simulation results are as follows Fig.10 shown.

[0033] When RF port C is combined with RF port D, and the third sensitive polymer film 7-3 (with an effective dielectric constant of 30) is integrated on the sensing resonance unit of the third sensing module 5-3, and the fourth sensitive polymer film 7-4 (with an effective dielectric constant of 40) is integrated on the sensing resonance unit of the fourth sensing module 5-4, the S of the passive LIVE tag is obtained. 34 The parameter simulation results are as follows Fig.11 shown.

[0034] The passive LIVE tag proposed in the present invention can integrate multiple sensing channels by combining different RF ports, improve the measurement parameter capacity, and break the limitation of a single sensing mode. The present invention has multi-parameter and multi-modal sensing characteristics, and can monitor in real time whether the physical or chemical parameters in the target environment have changed. Each sensing module can correspond to a specific physical or chemical parameter in the target environment. By integrating different sensitive polymer films on different sensing modules, multi-parameter sensing is realized; by selectively measuring the data of any two RF ports, the input and output ports of the signal are changed to realize multi-modal functions.

[0035] Application Examples like Fig.12 As shown in the figure, in the application scenario, a passive LIVE tag based on a planar sensor array has one RF port as an input port, connected to a receiving antenna, to receive signals from a reader; and another port as an output port, connected to a transmitting antenna, to transmit signals to a reader. A computer processing module is connected to the reader to control and read the data of the reader through the USB HOST protocol.

[0036] The passive LIVE tag monitors whether the physical or chemical parameters in the target environment have changed by integrating multiple sensor modules in the tag plane. The reader sends an excitation signal and transmits it to the passive LIVE tag through the receiving antenna; the passive LIVE tag converts the sensor information of the detected physical or chemical parameter changes into a transmission signal and transmits it to the reader through the transmitting antenna; the computer processing module obtains information indicating the change of the target environment parameters from the reader, and performs real-time data monitoring and early warning. The layout of the passive LIVE tag can greatly improve the convenience of the monitoring system and reduce the traditional monitoring cost.

[0037] The above description is only a description of the preferred embodiments of the present application, and is not intended to limit the scope of the present application. Any changes or modifications made by any person skilled in the art based on the above disclosed technical contents shall be deemed as equivalent effective embodiments and shall fall within the scope of protection of the technical solution of the present application.

Claims

1. A passive LIVE tag based on a planar sensor array, characterized in that: The passive LIVE tag is a four-port antenna sensor, comprising a dielectric substrate (2), a metal grounding plate (1) arranged on the lower surface of the dielectric substrate, and a radiation layer (3) arranged on the upper surface of the dielectric substrate; The radiation layer (3) comprises four sensor modules (5) and a cross microstrip feeder (4) connecting the four sensor modules; the cross microstrip feeder is used for signal transmission, and its four ports serve as signal input / output ports, i.e., RF ports; the four sensor modules are respectively connected to four branch microstrip feeders of the cross microstrip feeder; By selecting different RF port combinations and changing the signal input / output ports, the sensing mode conversion of the passive LIVE tag can be achieved, realizing multi-parameter and multi-modal sensing functions.

2. A passive LIVE tag based on a planar sensor array as claimed in claim 1, characterized in that: Each sensing module (5) comprises a sensing resonance unit (6) and a sensitive polymer film (7), wherein: The sensing resonance unit (6) comprises an interdigital capacitor structure (6-1) and an open split ring structure (6-2), wherein the interdigital capacitor structure (6-1) is integrated in the gap of the open split ring structure (6-2); The sensitive polymer film (7) is arranged on the surface of the interdigital capacitor structure (6-1) of the sensing resonance unit (6).

3. A passive LIVE tag based on a planar sensor array as claimed in claim 2, characterized in that: The multi-parameter sensing characteristic is achieved by integrating polymer materials that are sensitive to different environmental physical or chemical parameters, namely, sensitive polymer films, on the surfaces of the sensing resonance units of different sensing modules.

4. A passive LIVE tag based on a planar sensor array as claimed in claim 1, characterized in that: By selecting different RF port combinations as signal input / output, reconstruction is performed to achieve multi-modal sensing characteristics; the reconstruction method is to select any two ports from the four ports to achieve sensing measurement, with six port combinations; The four sensor modules are respectively a first sensor module (5-1), a second sensor module (5-2), a third sensor module (5-3), and a fourth sensor module (5-4); and the four ports of the cross microstrip feeder connected to the four sensor modules are respectively an RF port A, an RF port B, an RF port C, and an RF port D; The six port combinations are: RF port A combined with RF port B, RF port A combined with RF port C, RF port A combined with RF port D, RF port B combined with RF port C, RF port B combined with RF port D, and RF port C combined with RF port D.

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