Cable temperature measurement system integrating wireless RFID and micro-power-consumption MEMS sensor

Abstract

The invention belongs to the technical field of temperature monitoring, and particularly relates to a cable temperature measurement system integrating a wireless RFID (Radio Frequency Identification Device) and a micro-power-consumption MEMS (Micro-Electro-Mechanical System) sensor, which not only can realize long-term stable work in a complex and severe environment, but also can realize long-distance wireless communication and low-power-consumption operation through an optimized circuit design. Specifically, by adopting an efficient rectifier technology and a gated clock technology, the low-power-consumption operation of the system is realized, and the effective working distance of the passive tag is ensured; by adopting an ultra-low power consumption (nanowatt level) high-precision analog-to-digital conversion circuit (ADC) technology, the temperature detection precision of the system is improved; through the optimized sensor interface circuit design, accurate conversion and transmission of temperature signals are realized. In conclusion, the reliability and accuracy of the cable temperature measurement system can be remarkably improved, meanwhile, power consumption is reduced, the working distance is prolonged, and the actual application requirement is met.

Description

Technical Field

[0001] The invention belongs to the technical field of temperature monitoring, and in particular relates to a cable temperature measurement system integrating a wireless RFID and a micro-power consumption MEMS sensor. Background Art

[0002] With the development of power systems, the safe operation of cables has become particularly important. Cables may fail or even catch fire due to overheating during long-term operation, so real-time monitoring of cable temperature has become an important part of ensuring the stability and safety of power systems. Traditional cable temperature monitoring methods rely on manual inspections or wired sensors, which are not only costly but also difficult to achieve real-time monitoring.

[0003] In recent years, with the development of radio frequency identification (RFID) technology and micro-electromechanical system (MEMS) technology, a new type of cable temperature measurement system has been developed, which can realize remote contactless monitoring of cable temperature and has the advantages of no external power supply, easy installation and low cost. However, there are still some technical challenges in the existing cable temperature measurement system, especially the ability to work stably for a long time in complex and harsh environments.

[0004] The biggest technical problem that the current cable temperature measurement system faces in practical applications is how to achieve long-distance wireless communication and low-power operation while ensuring system reliability and accuracy. Summary of the invention

[0005] The purpose of the present invention is to provide a cable temperature measurement system that integrates wireless RFID and micro-power MEMS sensors, which can not only achieve long-term stable operation in complex and harsh environments, but also achieve long-distance wireless communication and low-power operation through optimized circuit design to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor, the system comprising: a temperature sensor for detecting the temperature of the cable and converting the temperature into an electrical signal; a radio frequency front end for receiving and sending radio frequency signals, wherein the radio frequency signals are converted into a DC voltage for system operation; a digital baseband processor for processing received signals; a memory module and a transmission module for storing temperature data and other user information and for wireless data interaction with an RFID reader; a rectifier and voltage regulator circuit for rectifying the carrier coupled to the inductor and stabilizing it to a DC voltage of 5V; a load modulation circuit for controlling the on and off of the MOS tube according to the frequency signal of the sensor, thereby modulating the amplitude of the carrier reflected back to the main system; a relaxation oscillator configured with a Schmitt trigger for converting the capacitance value of the sensor into a frequency signal; and an analog front-end module.

[0007] Preferably, the temperature sensor module includes: a sample-and-hold circuit for stabilizing the temperature detection signal; a comparator for comparing the sampled signal with a reference signal; a SARADC logic for converting an analog signal into a digital signal; and a DAC for charge redistribution during the digital-to-analog conversion process.

[0008] Preferably, the temperature sensor module further includes: a MOSFET-based temperature sensitive unit for detecting changes in drain current caused by temperature changes; a finger capacitor for converting temperature changes into capacitance changes; and a silicone oil layer for improving the sensitivity of temperature detection.

[0009] Preferably, the RF front-end module includes: a rectifier circuit for converting RF signal energy into a DC voltage; a modulator for modulating the signal; and a demodulator for demodulating the received signal.

[0010] Preferably, the RF front-end module also includes: a high-efficiency rectifier for improving rectification efficiency and increasing working distance; a gated clock circuit for reducing dynamic power consumption; and an ultra-low power ADC for improving the accuracy of analog-to-digital conversion.

[0011] Preferably, the analog front-end module includes: a voltage regulator circuit for providing a stable DC voltage; a clock generator for providing a clock signal; and a reset circuit for resetting the system.

[0012] Preferably, the analog front-end module further includes: a load modulation circuit for realizing signal modulation by turning on and off the MOS tube; and a linear regulator for providing a stable power supply.

[0013] Preferably, the system further comprises: a Cf conversion circuit for converting capacitance changes into a frequency signal; and an envelope detection circuit for recovering the modulation signal.

[0014] Preferably, the digital baseband processor further includes a frequency discrimination function module for extracting temperature data from the recovered modulation signal.

[0015] Preferably, the system further comprises a class E amplifier for improving the driving capability of the signal.

[0016] Technical effects and advantages of the present invention: Compared with the prior art, the cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor proposed in the present invention has the following advantages:

[0017] The present invention can not only achieve long-term stable operation in complex and harsh environments, but also achieve long-distance wireless communication and low-power operation through optimized circuit design. Specifically, by adopting efficient rectifier technology and gated clock technology, low-power operation of the system is achieved, ensuring the effective working distance of the passive tag; by adopting ultra-low power consumption (nanowatt level) high-precision analog-to-digital conversion circuit (ADC) technology, the temperature detection accuracy of the system is improved; through the optimized sensor interface circuit design, accurate conversion and transmission of temperature signals are achieved. In summary, the present invention can significantly improve the reliability and accuracy of the cable temperature measurement system, while reducing power consumption, extending the working distance, and meeting the needs of practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a block diagram of a cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor of the present invention;

[0019] Figure 2 This is a circuit diagram of the rectification, voltage stabilization and load modulation of the present invention;

[0020] Figure 3 is a block diagram of a MOSFET temperature sensor of the present invention;

[0021] Figure 4 Circuit diagram of a relaxation oscillator configured as a Schmitt trigger of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] The present invention provides a cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor, which can realize remote contactless monitoring of cable temperature and is particularly suitable for temperature monitoring of cables in power systems. The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0024] like Figure 1 As shown, it includes: a temperature sensor, a radio frequency front end, a digital baseband processor, a memory module and a transmission module, a rectifier and voltage regulator circuit, a load modulation circuit, a relaxation oscillator configured with a Schmitt trigger, and an analog front end module.

[0025] In this embodiment, the temperature sensor is used to detect the temperature of the cable and convert the temperature into an electrical signal; further, the temperature sensor module includes: a sample and hold circuit for stabilizing the temperature detection signal; a comparator for comparing the sampled signal with a reference signal; a SARADC logic for converting an analog signal into a digital signal; a DAC for charge redistribution during the digital-to-analog conversion process; a MOSFET-based temperature sensitive unit for detecting changes in drain current caused by temperature changes; a finger capacitor for converting temperature changes into capacitance changes; and a silicone oil layer for improving the sensitivity of temperature detection.

[0026] In this embodiment, the RF front end is used to receive and send RF signals, wherein the RF signals are converted into DC voltages for system operation.

[0027] Furthermore, the RF front-end module includes: a rectifier circuit for converting RF signal energy into a DC voltage; a modulator for modulating the signal; a demodulator for demodulating the received signal; a high-efficiency rectifier for improving the rectification efficiency and increasing the working distance; a gated clock circuit for reducing dynamic power consumption; and an ultra-low power ADC for improving the accuracy of analog-to-digital conversion.

[0028] In this embodiment, the digital baseband processor is used to process the received signal; the digital baseband processor also includes a frequency discrimination function module, which is used to extract temperature data from the restored modulated signal.

[0029] The digital baseband processor includes but is not limited to the following components:

[0030] Signal processing module: responsible for the preliminary processing of the received signal, including signal amplification, filtering and other operations to remove noise and improve the signal-to-noise ratio.

[0031] Frequency discrimination function module: This module is used to extract temperature data from the recovered modulated signal. The frequency discrimination function module usually includes:

[0032] Signal recovery submodule: responsible for demodulating the received modulated signal and restoring the original signal.

[0033] Frequency analysis submodule: Perform frequency analysis on the restored signal and extract the frequency components related to temperature.

[0034] Data extraction submodule: extract temperature data from frequency components.

[0035] Data processing module: further processes the received data, such as data calibration, data formatting, etc., to facilitate subsequent storage and transmission.

[0036] Control module: used to control the workflow of the entire digital baseband processor and ensure that each module works together.

[0037] Here’s how it works:

[0038] Signal processing: The received RF signal is first restored to a baseband signal by the demodulator in the RF front end, and then sent to the signal processing module in the digital baseband processor for preliminary processing.

[0039] Signal recovery: The signal recovery submodule in the frequency discrimination function module demodulates the baseband signal and recovers the original modulated signal.

[0040] Frequency analysis: The frequency analysis submodule performs frequency analysis on the recovered signal and extracts the frequency components related to temperature changes. Since the relaxation oscillator configured by the Schmitt trigger converts the capacitance value of the sensor into a frequency signal, the temperature change information can be indirectly obtained by analyzing the frequency change.

[0041] Data extraction: The data extraction submodule extracts specific temperature data based on frequency changes.

[0042] Data processing: The data processing module performs necessary processing on the received temperature data, such as data calibration and formatting.

[0043] Data output: The processed data is transmitted to the memory module for storage, or wirelessly interacts with the RFID reader through the transmission module.

[0044] As the core component of the cable temperature measurement system of the present invention, the digital baseband processor realizes accurate monitoring of the cable temperature by processing the received signal and extracting temperature data from it. Through the above design, not only the measurement accuracy and reliability of the system are improved, but also the structure of the system is simplified and the cost is reduced, making the cable temperature measurement system more practical and efficient in practical applications.

[0045] In this embodiment, the memory module is used to store temperature data and other user information, and the transmission module is used to perform wireless data interaction with the RFID reader.

[0046] In this embodiment, the rectifying and voltage-stabilizing circuit is used to rectify the carrier coupled by the inductor and stabilize the voltage to a 5V DC voltage.

[0047] In this embodiment, the load modulation circuit is used to control the on-off of the MOS tube according to the frequency signal of the sensor, thereby modulating the amplitude of the carrier reflected back to the main system.

[0048] Furthermore, the load modulation circuit mainly includes the following key components:

[0049] MOS tube: used to perform switching operations according to the frequency signal of the sensor, thereby changing the impedance at both ends of the inductor to achieve signal modulation.

[0050] Inductor: connected in series with the MOS tube. When the state of the MOS tube changes, the impedance at both ends of the inductor will also change, causing the amplitude of the carrier reflected back to the main system to change.

[0051] Sensor frequency signal input: The frequency signal generated by the sensor is used as the basis for controlling the on and off of the MOS tube.

[0052] Here’s how it works:

[0053] MOS tube selection: The load modulation circuit uses the IRF540 switch tube with a faster switching speed. Its on-resistance is extremely small (about 0.07 ohms) and it can quickly respond to the frequency signal generated by the sensor.

[0054] Signal control: The frequency signal generated by the sensor is used to control the on and off of the MOS tube. When the MOS tube is turned on, the impedance at both ends of the inductor is low; when the MOS tube is turned off, the impedance at both ends of the inductor is high. This change in impedance will cause the amplitude of the carrier reflected back to the main system to change, thereby achieving signal modulation.

[0055] Signal modulation: The on / off state of the MOS tube is controlled by the sensor frequency signal. When the MOS tube is turned on, the impedance at both ends of the inductor decreases, resulting in an increase in the carrier amplitude reflected back to the main system; when the MOS tube is turned off, the impedance at both ends of the inductor increases, resulting in a decrease in the carrier amplitude reflected back to the main system. This change in amplitude carries the temperature information of the sensor, which can be received and demodulated by the main system.

[0056] The load modulation circuit changes the impedance at both ends of the inductor by controlling the on-off state of the MOS tube, thereby modulating the carrier amplitude reflected back to the main system to achieve signal modulation. This design not only simplifies the circuit structure, but also improves the response speed and modulation efficiency of the system, and is very suitable for application in the cable temperature measurement system of the present invention.

[0057] In this embodiment, a relaxation oscillator configured with a Schmitt trigger is used to convert the capacitance value of the sensor into a frequency signal.

[0058] Specifically, the relaxation oscillator configured with a Schmitt trigger mainly includes the following key components:

[0059] Schmitt trigger: used to detect changes in capacitance value and generate corresponding switching actions.

[0060] Capacitor: The capacitance value of the interdigital capacitor in the temperature sensor changes with temperature.

[0061] Resistor: Used to form a charge and discharge circuit together with the capacitor to control the frequency of the oscillator.

[0062] Power supply: Provides the voltage required for the Schmitt trigger to operate.

[0063] Here’s how it works:

[0064] Capacitance change: The interdigital capacitors in the temperature sensor are covered with a layer of silicone oil. The dielectric constant of the silicone oil changes with temperature, causing the capacitance value to change accordingly.

[0065] Charging process: When the capacitor starts to charge, the Schmitt trigger is in a high state and the capacitor starts to charge through the resistor.

[0066] Trigger point: When the capacitor is charged to the upper trigger level of the Schmitt trigger, the Schmitt trigger flips to the low state.

[0067] Discharge process: After the Schmitt trigger flips, the capacitor begins to discharge through the discharge path inside the Schmitt trigger.

[0068] Re-triggering: When the capacitor discharges to the lower trigger level of the Schmitt trigger, the Schmitt trigger flips to the high level state again and the capacitor starts charging again.

[0069] Frequency signal: The charge and discharge cycle of the capacitor forms a frequency signal, which reflects the change of the capacitance value of the temperature sensor.

[0070] The relaxation oscillator configured with the Schmitt trigger realizes accurate transmission of temperature information by converting the capacitance value of the sensor into a frequency signal. This design not only improves the robustness of the system, but also simplifies the circuit structure and reduces the cost, and is very suitable for application in the cable temperature measurement system of the present invention.

[0071] In this embodiment, the analog front-end module includes: a voltage regulator circuit for providing a stable DC voltage; a clock generator for providing a clock signal; a reset circuit for resetting the system; a load modulation circuit for realizing signal modulation by turning on and off the MOS tube; and a linear regulator for providing a stable power supply.

[0072] In a further embodiment, the system comprises: a Cf conversion circuit for converting a capacitance change into a frequency signal; an envelope detection circuit for recovering a modulated signal; and a class E amplifier for improving a driving capability of a signal.

[0073] Specifically, the Cf conversion circuit mainly includes the following key components:

[0074] Relaxation oscillator in Schmitt trigger configuration: used to convert the capacitance value of the sensor into a frequency signal. Capacitor sensor: a temperature-sensitive unit based on MOSFET, whose capacitance value changes with temperature. Resistor: used to form a charge and discharge loop with the capacitor sensor to control the frequency of the oscillator.

[0075] The interdigital capacitors in the temperature sensor are covered with a layer of silicone oil. The dielectric constant of the silicone oil changes with temperature, causing the capacitance value to change accordingly. When the capacitor starts to charge, the Schmitt trigger is in a high state, and the capacitor starts to charge through the resistor. When the capacitor is charged to the upper trigger level of the Schmitt trigger, the Schmitt trigger flips to a low state. After the Schmitt trigger flips, the capacitor begins to discharge through the discharge path inside the Schmitt trigger. When the capacitor discharges to the lower trigger level of the Schmitt trigger, the Schmitt trigger flips to a high state again, and the capacitor starts to charge again. The charge and discharge cycle of the capacitor forms a frequency signal, which reflects the change in the capacitance value of the temperature sensor.

[0076] The Cf conversion circuit converts the capacitance change of the sensor into a frequency signal to achieve accurate transmission of temperature information. This design not only improves the robustness of the system, but also simplifies the circuit structure and reduces the cost, and is very suitable for application in the cable temperature measurement system of the present invention.

[0077] Specifically, the envelope detection circuit is another important component of the cable temperature measurement system of the present invention, and its main function is to restore the original modulated signal from the modulated signal. This embodiment describes the design and implementation of the envelope detection circuit in detail.

[0078] The envelope detection circuit mainly includes the following key components: Diode: used to rectify the high-frequency components in the modulated signal. Low-pass filter: used to filter out the high-frequency components and extract the low-frequency envelope signal. Resistors and capacitors: used to form a detection circuit together with the diode.

[0079] The diode rectifies the high-frequency components in the modulated signal, causing the negative half cycle of the signal to be "folded" onto the positive half axis. The low-pass filter removes the high-frequency components and retains the low-frequency envelope signal. The low-frequency envelope signal represents the original modulated signal and can be further processed and analyzed.

[0080] The envelope detection circuit recovers the original modulated signal from the modulated signal, thereby realizing effective signal recovery. This design not only simplifies the circuit structure, but also improves the efficiency of signal recovery, and is very suitable for application in the cable temperature measurement system of the present invention.

[0081] Specifically, the class E amplifier is another important component of the cable temperature measurement system of the present invention, and its main function is to improve the driving capability of the signal. This embodiment describes the design and implementation of the class E amplifier in detail.

[0082] Class E amplifiers mainly include the following key components: Power MOS tube: used to amplify the signal. Load network: used to match the power MOS tube and the output port to improve the efficiency of the amplifier. Drive circuit: used to control the on and off of the power MOS tube to amplify the signal.

[0083] By controlling the on and off of the power MOS tube, the signal is amplified. The parameters of the load network are adjusted to match the output characteristics of the power MOS tube to improve the efficiency of the amplifier. When the power MOS tube is turned on, the signal is amplified through the load network; when the power MOS tube is turned off, the signal stops being amplified.

[0084] The class E amplifier enhances the overall performance of the system by improving the driving capability of the signal. This design not only improves the quality of the signal, but also reduces energy consumption, and is very suitable for application in the cable temperature measurement system of the present invention.

[0085] The following will be described in detail with reference to specific embodiments.

[0086] In this embodiment, the system is composed of a temperature sensor, a radio frequency front end, an analog front end, a digital baseband processor, and a memory. The temperature sensor functions to realize temperature detection and digital processing, including a sample-and-hold circuit, a comparator, a SAR logic, and a digital-to-analog converter (DAC), a temperature sensitive circuit (Sensor), a voltage reference circuit, and a bias circuit. The first four circuits constitute the SARADC.

[0087] The function of the RF front end is to collect, receive and send signal energy, which includes a rectifier circuit, modulator and demodulator; the analog front end function provides the system with stable DC voltage, clock and reset signal; the digital baseband processor is used to process the received signal and is the brain of the system; the memory is used to store user information and system initialization information.

[0088] Since passive electronic tags have no energy supply, they need to obtain energy from the radio frequency waves emitted by the reader to work. Therefore, in order to obtain a tag chip with a long working distance, the power consumption of the chip itself must be low enough. Excessive power consumption of the circuit will reduce the effective working distance of the tag, thereby weakening the application advantages of UHFRFID. In order to achieve a readable distance of more than 5 meters, the entire power consumption of the system must be within 20uW. Start from the following aspects to study low power consumption solutions and achieve low system power consumption.

[0089] Specifically, the entire system consists of a subsystem and a main system, as follows:

[0090] 1. Subsystem

[0091] The rectifier of the secondary system converts the RF signal energy sent by the reader into a DC voltage that can be used for circuit operation. Its efficiency directly determines the working distance of the system. The dynamic power consumption of the system can be effectively reduced by combining global gating with local gating, which can save about 20% to 60% of the power consumption.

[0092] The function of ADC is to convert analog signals into digital signals that can be sent by the RFID tag system. ADC is the main part of the power consumption in the entire temperature sensor. Its accuracy and power consumption will affect the accuracy and power consumption of the system. Based on low-power design considerations, this solution intends to use the SARADC structure suitable for low-speed and low-power applications in the temperature sensor part. In order to further reduce power consumption, the DAC in the SARADC adopts a charge redistribution type; in terms of accuracy, this project will focus on the impact of DAC capacitor mismatch and parasitics, and comparator kickback noise on the accuracy of the analog-to-digital converter.

[0093] In order to make the chip meet the accuracy requirements, the temperature sensing circuit based on ultra-low power consumption (nanowatt level) temperature sensitive circuit linearization technology of CMOS process is adopted. The temperature sensing circuit is the core of the temperature sensor. Its function is to convert the temperature parameter into an electrical parameter (voltage, current or frequency) that can be detected by the circuit. In the CMOS process, the threshold voltage of the MOS tube and the turn-on voltage of the diode are usually used as temperature sensitive elements. Compared with the threshold voltage of the MOS device, the turn-on voltage of the diode has certain advantages in terms of process stability and linearity related to temperature, so diodes are widely used in most applications. The design will be based on the diode temperature sensitive unit and focus on its linearization technology. Starting from the analysis of the principle of nonlinear generation, the differential and self-compensation methods are used to reduce the influence of these parameters on temperature linearization and improve the accuracy of the temperature sensor.

[0094] Rectification voltage regulation and load modulation circuits such as Figure 2As shown in the figure: a full-wave bridge rectifier circuit with high rectification efficiency is used to rectify the carrier coupled to the inductor, and then a linear regulator TPS71550 with fast response speed, small output ripple, simple circuit and continuously adjustable output is used to output a 5V DC voltage to power the secondary system circuit. In the load modulation circuit, the MOS tube uses the switch tube IRF540 with a faster switching speed to control its on and off using the frequency signal of the sensor. The on-resistance of IRF540 is extremely small, only about 0.07 ohms. When the on-off conversion is performed, the impedance at both ends of the inductor also changes, so that the amplitude of the carrier reflected back to the main system changes, that is, the load modulation is completed.

[0095] Capacitive sensors are mainly used for the following reasons: 1. Low power consumption; 2. High reliability; 3. Convenient implementation. Capacitive sensors include temperature sensors, gas sensors, etc. The temperature measurement MEMS sensors of wireless sensing systems are mainly MOSFET-based temperature sensors, which use the characteristics of MOSFET drain current changing with temperature for measurement. The design principle is as follows Figure 3 .

[0096] The temperature sensor is made of a high aspect ratio, interdigital capacitor based on a glass substrate. A layer of silicone oil is evenly coated on the surface of the capacitor. Since silicone oil is sensitive to temperature, when the temperature changes, the dielectric constant of the silicone oil changes, causing the capacitance to change.

[0097] Cf conversion: Convert the capacitance value of the sensor into a frequency signal. On the one hand, the frequency signal is less affected by external interference and has good robustness; on the other hand, it is more convenient to implement using a relaxation oscillator. In this project, a simple Schmitt trigger is configured as a relaxation oscillator to complete the Cf conversion. The circuit diagram is as follows Figure 4 In actual circuit design, for capacitive sensors with different characteristic values, the converted frequency f can be made to fall within a consistent range by selecting a resistor of appropriate size to meet the bandwidth requirements of the circuit. However, due to different parameter settings of the three-way Cf conversion circuit, the Cf conversion accuracy is also different.

[0098] 2. Main System

[0099] The main system transmits a carrier to power the secondary system, and receives the modulated signal reflected by the secondary system, and restores the modulated signal through the envelope detection circuit. The restored modulated signal is shaped and input into the microcontroller, which uses the microcontroller for frequency discrimination.

[0100] During the design, we firstly use LTC6900 to generate a rectangular wave with a frequency of 3MHz, and input the MOS driver chip UCC27321 to increase the driving capability. Then use the RF signal to control the on and off of the MOS switch in the Class E amplifier. For the selection of MOS switches in the Class E amplifier, we must select power tubes that can withstand large currents and can also keep up with the RF signal to achieve high-speed on and off. We plan to compare the performance of several power MOS and finally select the best MOS chip. When selecting the load network parameters of the Class E amplifier, with the help of an antenna analyzer and an oscilloscope, adjust the C and R values ​​in the load network until the output waveform of the Class E amplifier tested by the oscilloscope is a standard sine wave, indicating that the Class E amplifier is working in a good state.

[0101] This system is planned to be built on PCB, and the primary and secondary system inductors are all printed inductors. After the circuit design simulation is completed, the PCB layout of the system is drawn and processed. In order to ensure that the Q value of the printed inductor is moderate, a process with a line width of 30mil and a thickness of 2 ounces (OZ) is planned to be used.

[0102] In summary, the present invention can not only achieve long-term stable operation in complex and harsh environments, but also achieve long-distance wireless communication and low-power operation through optimized circuit design. Specifically, by adopting efficient rectifier technology and gated clock technology, low-power operation of the system is achieved, ensuring the effective working distance of the passive tag; by adopting ultra-low power consumption (nanowatt level) high-precision analog-to-digital conversion circuit (ADC) technology, the temperature detection accuracy of the system is improved; through the optimized sensor interface circuit design, accurate conversion and transmission of temperature signals are achieved. In summary, the present invention can significantly improve the reliability and accuracy of the cable temperature measurement system, while reducing power consumption, extending the working distance, and meeting the needs of practical applications.

[0103] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor, characterized in that: The system comprises: a temperature sensor for detecting the temperature of the cable and converting the temperature into an electrical signal; an RF front end for receiving and transmitting RF signals, wherein the RF signals are converted into DC voltage for system operation; a digital baseband processor for processing received signals; A memory module and a transmission module, the memory module is used to store temperature data and other user information, and the transmission module is used to wirelessly interact with the RFID reader; A rectifying and voltage stabilizing circuit, used for rectifying the carrier coupled by the inductor and stabilizing the voltage to a 5V DC voltage; A load modulation circuit, used to control the on and off of the MOS tube according to the frequency signal of the sensor, thereby modulating the amplitude of the carrier reflected back to the main system; a relaxation oscillator in a Schmitt trigger configuration to convert the capacitance of the sensor into a frequency signal; and An analog front end module.

2. According to claim 1, a cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor is characterized in that: The temperature sensor module comprises: Sample and hold circuit, used to stabilize the temperature detection signal; a comparator for comparing the sampled signal with a reference signal; SARADC logic, used to convert analog signals into digital signals; DAC, used for charge redistribution during the digital-to-analog conversion process.

3. According to claim 2, a cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor is characterized in that: The temperature sensor module also includes: MOSFET base temperature sensitive unit, used to detect the change of drain current caused by temperature change; Interdigital capacitors, used to convert temperature changes into capacitance changes; Silicone oil layer, used to improve the sensitivity of temperature detection.

4. According to claim 1, the cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor is characterized in that: The radio frequency front-end module comprises: a rectifier circuit for converting RF signal energy into a DC voltage; A modulator, used to modulate the signal; The demodulator is used to demodulate the received signal.

5. The cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor according to claim 4 is characterized in that: The radio frequency front-end module also includes: High-efficiency rectifier, used to improve rectification efficiency and increase working distance; Gated clock circuit to reduce dynamic power consumption; Ultra-low power ADC, used to improve the accuracy of analog-to-digital conversion.

6. The cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor according to claim 1 is characterized in that: The analog front end module comprises: A voltage regulator circuit for providing a stable DC voltage; A clock generator, used for providing a clock signal; Reset circuit, used for system reset.

7. The cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor according to claim 6 is characterized in that: The analog front end module also includes: Load modulation circuit, used to realize signal modulation by turning on and off the MOS tube; Linear regulator, used to provide stable power supply.

8. The cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor according to claim 1 is characterized in that: The system further comprises: Cf conversion circuit, used for converting capacitance change into frequency signal; Envelope detection circuit, used to recover the modulated signal.

9. The cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor according to claim 1 is characterized in that: The digital baseband processor also includes a frequency discrimination function module for extracting temperature data from the restored modulation signal.

10. The cable temperature measurement system integrating wireless RFID and micro-power MEMS sensor according to claim 1 is characterized in that: The system further includes a class E amplifier for improving the driving capability of the signal.

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