Passive Wireless Temperature Sensor Research Articles

Evolution of dielectric properties of SiBCN ceramics and its derived wireless passive temperature sensor application

SiBCN ceramics derived from preceramic polymers are suitable candidates for high-temperature sensors due to their remarkable high-temperature stability and semiconducting properties. However, research into their dielectric performance together with relevant sensors is meaningful but inadequate. In this work, the correlation between dielectric properties and the structure of SiBCN ceramic is identified by studying the evolution trend of the chemical composition, microstructure, and dielectric properties with pyrolysis and environment temperature. SiBCN ceramic was prepared by powder pressing process and pyrolyzed at 1000–1400 °C. As the pyrolysis temperature increased, the dielectric constant and dielectric loss tangent of SiBCN ceramic gradually increased. Within the test temperature range of 500 °C, the dielectric loss was mainly polarization loss. In addition, SiBCN ceramic wireless passive temperature sensors were prepared to test their performance from room temperature to 500 °C. The results showed that the sensitivity increased with the test temperature, and the transmission efficiency of the sensor was closely related to the dielectric properties, indicating that SiBCN ceramic has promising application prospects in the field of high-temperature sensing with good repeatability and stability.

A wireless multiparameter cryogenic monitoring method using passive backscatter sensors

In this paper, we proposed the first wireless multiparameter monitoring method for cryogenic environments (−196 ℃). Present-day cryogenic industries implement a large array of wired sensors to monitor key parameters in fabrication processes. The wirings for a large sensor array greatly complicate the monitoring system. We presented the first wireless multiparameter monitoring method for cryogenic environments by making two efforts. First, a novel wireless passive vibration and pressure sensor is developed. We transfer vibrations and pressures to a relative displacement between a magnet and a tunnel magnetoresistor (TMR). This affects the magnetic field at the TMR and changes the TMR’s resistance. By integrating the TMR on a backscattering antenna, the antenna’s wireless return loss is modulated by both vibrations and pressures. We proposed a decoupling method for simultaneously monitoring vibration and pressure by a single sensor. Second, we demonstrated and evaluated the first wireless multiparameter cryogenic monitoring system. A wireless passive temperature sensor is developed by integrating a resistance temperature detector (RTD) on a backscattering antenna. The developed vibration and pressure sensor and temperature sensor are tuned to separate frequency bands, embedded in cryogenic environments, and calibrated in situ. Vibrations, pressures, and temperatures in cryogenic environments are synchronously obtained by our wireless cryogenic monitoring system, with an accuracy of 80∼90 %. This research provides a wireless option in large-scale automated cryogenic monitoring, thus it is desirable in implementing the Internet of Things in cryogenic industries.

CSRR-SIW wireless passive high quality factor temperature sensor

CSRR-SIW wireless passive high quality factor temperature sensor

A miniaturized and high Q-factor wireless passive frequency selective surface temperature sensor based on stacking coupling structure

A miniaturized and high Q-factor wireless passive frequency selective surface temperature sensor based on stacking coupling structure

An alumina ceramic inspired high temperature wireless chipless sensor for harsh environment

This paper proposes a wireless passive temperature sensor. The sensitive material as the substrate of the sensor employs an alumina ceramic. The resonator of the sensor is a split ring, which is printed with copper on the substrate. The dimensions of the split ring resonator are optimized to improve the temperature sensitivity of the sensor. A change in environment temperature will lead to a change in the dielectric constant of the sensitive material, thus resulting in the shift of the resonant frequency of the sensor. The variation range of the dielectric constant of the sensitive material is 10.17–11.2 corresponding to 500–1000 °C. The resonant frequency of the signal backscattered from the sensor is obtained through the simulation software with HFSS. The simulation results show that the resonant frequency of the sensor decreases from 5.84 to 5.56 GHz with temperature increasing from 500 to 1000 °C and the temperature sensitivity is 0.56 MHz/°C. The high temperature sensor has the characteristics of wireless and passive operation, low profile, and high sensitivity. It can be widely adapted to a variety of high temperature and harsh environments.

High-Linearity Wireless Passive Temperature Sensor Based on Metamaterial Structure with Rotation-Insensitive Distance-Based Warning Ability.

A wireless passive temperature sensor based on a metamaterial structure is proposed that is capable of measuring the temperature of moving parts. The sensor structure consists of an alumina ceramic substrate with a square metal double split-ring resonator fixed centrally on the ceramic substrate. Since the dielectric constant of the alumina ceramic substrate is temperature sensitive, the resonant frequency of the sensor is altered due to changes in temperature. A wireless antenna is used to detect the change in the resonant frequency of the sensor using a wireless antenna, thereby realizing temperature sensing operation of the sensor. The temperature sensitivity of the sensor is determined to be 205.22 kHz/°C with a strong linear response when tested over the temperature range of 25-135 °C, which is evident from the R2 being 0.995. Additionally, the frequency variation in this sensor is insensitive to the angle of rotation and can be used for temperature measurement of rotating parts. The sensor also has a distance warning functionality, which offers additional safety for the user by providing early warning signals when the heating equipment overheats after operating for extended durations.

Introduction of Passive Wireless SAW Temperature Sensors and Application

Introduction of Passive Wireless SAW Temperature Sensors and Application

Contactless Air-Filled Substrate-Integrated Waveguide (CLAF-SIW) Resonator for Wireless Passive Temperature Sensing

In this article a wireless passive temperature sensor is designed, fabricated, and tested. The sensor uses a contactless air-filled substrate-integrated waveguide (CLAF-SIW) resonator that consists of an air cavity surrounded by a low-impedance electromagnetic band gap (EBG) structure. The contactless feature of the sensor mitigates the fabrication complexity issue of air-filled SIW (AF-SIW) while it benefits from the high-quality factor of an air-filled resonator. The resonant frequency of the CLAF-SIW resonator is dependent on the permittivity of the substrate and the dimensions of the structure which are both temperature-dependent. Change in temperature results in a variation in the resonant frequency of the sensor. As such, we measure temperature by measuring the resonant frequency of the sensor. The developed CLAF-SIW sensor has a measured unloaded quality factor of 1340 that allows for long-range wireless measurements. The resonant frequency of the sensor is measured using a ringback-based wireless interrogation system. The interrogation system energizes the sensor using radio frequency (RF) pulses and determines the frequency of the ringback signals radiated by the sensor using frequency domain analysis. The sensor has a sensitivity of 300 kHz/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^\circ \text{C}$ </tex-math></inline-formula> and an interrogation-to-sensor distance of 80cm.

Design and Research of Wireless Passive High-Temperature Sensor Based on SIW Resonance

The temperature of advanced components in aviation and aerospace fields is difficult to obtain timely. In this study, we aimed to investigate microwave backscattering technology combined with the theory of substrate integrated waveguide and resonant cavity to design a wireless passive temperature sensor and explore its potential in this field. We employed silicon carbide and aluminum ceramic as the substrate to make sensors. The interrogation antenna was designed to test the sensor, which could completely cover the working frequency of the sensor and had good radiation characteristics. Based on the test results, the silicon carbide sensor was capable of bearing a temperature limit of about 1000 °C compared to the alumina sensor. From 25 °C to 500 °C, its sensitivity was 73.68 kHz/°C. Furthermore, the sensitivity was 440 kHz/°C in the range of 501 °C to 1000 °C. Moreover, we observed the surface of this sensor by using the scanning electron microscope, and the results showed that the damage to the sensor surface film structure caused by long-term high temperature is the major reason for the failure of the sensor. In conclusion, the performance of the silicon carbide sensor is superior to the alumina sensor.

A dual LC resonant circuit integrated wireless passive force and temperature sensor for harsh-environment applications

This paper proposes a dual inductor-capacitor (LC) circuit integrated wireless and passive force and temperature sensor for the simultaneous measurement of force and temperature in high-temperature environments. The sensor is fabricated by a two-step process: the preparation of the Al2O3 substrate and the fabrication of the dual LC sensor with Ag paste using screen-printing technology and metallization. The variation in ambient force and temperature can be detected wirelessly by extracting the resonant frequencies of the antenna. The sensor can work in the force range of 0–10 N and temperature range of 25–500 °C with a maximum force sensitivity of 107 kHz/N at 500 °C and temperature sensitivity of 21.7 kHz/°C. To precisely measure the force, the temperature compensation method is proposed. The sensor has the advantages of low cost, simple fabrication and test, and high stability and repeatability, which are promising for the force and temperature application on the engine turbine blade in high-temperature environments.

All-Ceramic Passive Wireless Temperature Sensor Realized by Tin-Doped Indium Oxide (ITO) Electrodes for Harsh Environment Applications.

In this work, an all-ceramic passive wireless inductor–capacitor (LC) resonator was presented for stable temperature sensing up to 1200 °C in air. Instead of using conventional metallic electrodes, the LC resonators are modeled and fabricated with thermally stable and highly electroconductive ceramic oxide. The LC resonator was modeled in ANSYS HFSS to operate in a low-frequency region (50 MHz) within 50 × 50 mm geometry using the actual material properties of the circuit elements. The LC resonator was composed of a parallel plate capacitor coupled with a planar inductor deposited on an Al2O3 substrate using screen-printing, and the ceramic pattern was sintered at 1250 °C for 4 h in an ambient atmosphere. The sensitivity (average change in resonant frequency with respect to temperature) from 200–1200 °C was ~170 kHz/°C. The temperature-dependent electrical conductivity of the tin-doped indium oxide (ITO, 10% SnO2 doping) on the quality factor showed an increase of Qf from 36 to 43 between 200 °C and 1200 °C. The proposed ITO electrodes displayed improved sensitivity and quality factor at elevated temperatures, proving them to be an excellent candidate for temperature sensing in harsh environments. The microstructural analysis of the co-sintered LC resonator was performed using a scanning electron microscope (SEM) which showed that there are no cross-sectional and topographical defects after several thermal treatments.

A review on advanced wireless passive temperature sensors

Now-a-days inductor-capacitor (LC) resonator based sensors are widely used in the field of measurement for the measurement of different parameters like pressure, humidity, strain, temperature, pH etc. The basic principle of the sensor is inductive coupling between two loosely coupled inductors in sensing side and reading side. It has the facility of the passive, non-contact and wireless sensing which makes it very advantageous in various field where direct contact with the measurand body is difficult like furnaces, automobile engines, rotating objects, human body etc. In the case of temperature measurement, the LC sensor really plays a crucial role as it helps to measure temperature in inaccessible areas like any harsh and sealed temperature system. A lot of research works are carried out by different researchers for many practical applications. In this paper, a review has been done for a number of recent works on the temperature measurement techniques using LC sensors, which explores the key technologies, different design considerations and methods for assisting the development of LC sensors and configurations and modifications adopted for the respective researches for different future applications.

Research on Monitoring System of Cable Joints of Ring Network Cabinet Based on Wireless Temperature Sensor

In this paper, a state monitoring system for the cable joints of the ring main unit is constructed based on the passive wireless temperature sensor. Considering the sensor packaging structure and housing material, a temperature sensor that can meet the monitoring requirements of the T-shaped insulating sheath of the cable joint is designed. Based on the thermal circuit method, the real temperature value of the internal cable joint is calculated by using the outer surface temperature of the T-shaped insulating sheath to provide more accurate data for monitoring and early warning. The background monitoring software of the monitoring system is designed to realize the temperature of the T-shaped cable joint in the ring network cabinet. Online monitoring and abnormal early warning facilitate the operation and maintenance personnel to take timely measures, which can effectively improve the operation and maintenance efficiency of the ring cabinet of the distribution network and ensure the reliability of power supply.

Eight Channels of Passive Wireless SAW Temperature Sensors for Specific Low Power Wireless Station

Eight Channels of Passive Wireless SAW Temperature Sensors for Specific Low Power Wireless Station

Conductivity of SiCNO-BN composite ceramics and their application in wireless passive temperature sensor

SiCNO-BN composite ceramics were synthesized by polyvinylsilazane and hexagonal boron nitride. It was found that the electrical conductivity of SiCNO-BN composites varied nonmonotonically with BN content. According to the scanning electron microscope and Raman spectroscopy analysis, we can conclude that the conductive behavior of SiCNO-BN composites was strongly related to the graphitization degree of free carbon in the SiCNO-BN composites. Compared with SiCNO ceramic, the conductivity of the SiCNO-BN composite decreased from 1.68 × 10−8 (Ω cm)−1 to 4.41 × 10−9 (Ω cm)−1 when the content of BN was 15 wt%, and the graphitization degree of free carbon also decreased dramatically. The dielectric loss of SiCNO-BN composites was also reduced as the conductivity of SiCNO ceramic decreased. In addition, one of the potential applications of polymer derived ceramics (SiCNO) is high-temperature sensors. However, its real application process is limited. In order to solve this problem, the wireless passive temperature sensors based on SiCNO-BN composite ceramics were fabricated. The results showed that the maximum measurement temperature of SiCNO-BN temperature sensor with 15 wt% BN can reach up to 1250 °C, which is higher than 900 °C of the SiCNO temperature sensor.

PDC-SiAlCN ceramic based wireless passive temperature sensors using integrated resonator/antenna up to 1100°C

PurposeThis paper aims to present wireless passive temperature sensors by using high-temperature stable polymer-derived silicoaluminum carbonitride (PDC-SiAlCN) ceramic materials.Design/methodology/approachIn this paper, a novel PDC-SiAlCN ceramic was synthesized by using polyvinylsilazne and aluminum-tri-sec-butoxide as precursors. Then, PDC-SiAlCN was used as the sensing material to fabricate sensors. The sensors are based on a cavity resonator and an integrated slot antenna. The resonant frequencies of the sensors are determined by the dielectric constants of PDC-SiAlCN ceramic, which monotonically increase versus temperature.FindingsThe effect of sensor dimension on the performance of the sensors was investigated using simulation and experimental methods. The using temperature, reliability and sensing distance of the sensors were studied experimentally. The sensors performed measurement up to 1100°C with excellent reliability and repeatability. The sensing distance varied from 38 to 14 mm when the temperature increasing from 20°C to 1100°C.Originality/valuePDC-SiAlCN ceramic based wireless passive temperature sensors have the advantage of seamless integration of slot antennas and resonators, which greatly reduces the size of the sensor, reduces the direction of antenna transmission and increases the transmission space. The sensors can be used for many harsh environment applications such as engine monitoring.

Wireless passive separated LC temperature sensor based on high-temperature co-fired ceramic operating up to 1500 °C

This paper presents a wireless passive resonant temperature sensor based on high-temperature co-fired ceramic (HTCC) and platinum conductive metal, which has a new structure that separates inductors and capacitors, allowing the sensor’s maximum operating temperature to reach 1500 °C. In the temperature range of 43 °C–1500 °C, the resonant frequency of the sensor is extracted and the fitting curve between the frequency and temperature is obtained to demarcate the sensor. The average sensitivity of the sensor can be calculated as 6.7562 kHz °C−1 over the entire test temperature range. In addition, it was found that the maximum relative error of the sensor was only 0.24% via a repeatability experiment, and the hysteresis of the sensor mentioned in this paper is significantly reduced. Moreover, the signal intensity of the sensor mentioned in this paper and the traditional LC sensor are compared in experiments. The experimental results show that the proposed sensor has strong signal readability and meets the requirements of high-temperature testing.

A Novel Surface &lt;inline-formula&gt; &lt;tex-math notation="LaTeX"&gt;$LC$ &lt;/tex-math&gt; &lt;/inline-formula&gt; Wireless Passive Temperature Sensor Applied in Ultra-High Temperature Measurement

In this paper, we demonstrate a passive wireless surface temperature sensor, based on a high-temperature co-fired ceramic process and a thick-film technology, which is functional up to 1400 °C. In addition, we propose a temperature measurement technique that makes use of the absolute amplitude of the S11 parameter. The sensor comprises an inductor (created from platinum) deposited on a ceramic substrate (99% alumina), making it cheap and easy to fabricate using a screen-printing technology, due to its simple structure. The use of temperature resistant materials, and a completely passive structure, means that this sensor is robust to harsh environments. The device operates using the principle of $LC$ resonance, illustrated in this paper with a lumped circuit model. The dielectric constant of the substrate increases with increasing temperature, leading to a monotonic variation in the resonant frequency of the sensor, which is retrieved wirelessly via a readout antenna. We set the test distance between the sensor and the antenna to 10 mm and observed a repeatable response between 26 °C and 1400 °C. S11 amplitude and resonant frequency are used to reflect the change temperature, respectively. And we found that it is more accurate to test the temperature by resonant frequency after comparing the experimental results. The average sensitivity of temperature test by resonance frequency is obtained, which is 14.3 kHz/°C.

Design of an Ultra-low Power Wireless Temperature Sensor Based on Backscattering Mechanism

In this paper, we propose a passive wireless temperature sensor for long-term and long-range application. A novel architecture of the wireless temperature sensor is proposed based on backscattering mechanism of RFID technology for ultra-low power application. The temperature sensor adopts phase-locked loop-based architecture and can achieve the temperature-digital conversion in frequency domain without any external clock signal. The rectifier employs a gate-boosting scheme to improve the power conversion efficiency. The measurement results show that the proposed wireless temperature sensor obtains a high linearity with a resolution of 0.3 °C/LSB. The measured minimum power dissipation is 2.7 µW, resulting in a maximum operating distance of 34 m under 4 W radiation power.

Dielectric and luminescent properties of Sm3+ doped Ba(Zn1/3Nb2/3)O3 ceramics with perovskite structure

Aiming to broaden its application as wireless temperature sensors, a temperature-sensibility-enhanced Ba1−xSm2x/3(Zn1/3Nb2/3)O3 (x = 0%–4.5%) ceramics with a large temperature coefficient of the resonant frequency have been prepared by conventional solid state reaction method. X-ray diffraction analysis shows that single-phase solid solutions are formed within x range of 0.37% to 3%. A minor substitution of Sm for Ba facilitates the enhancement of εr and τf, which is related to variations in polarizability and crystal structure. τf expands remarkably as x increases, indicating that Ba1−xSm2x/3(Zn1/3Nb2/3)O3 ceramics could serve as a potential candidate for wireless passive temperature sensor application. Moreover, Photoluminescence and excitation spectra illustrate that Ba1−xSm2x/3(Zn1/3Nb2/3)O3 exhibits luminescent properties. Although Raman spectra and scanning electron microscope studies reveal that excess Sm3+ dopant has destroyed the complex perovskite structure and generated secondary phase Ba3Nb2O8, which have caused the deterioration of Q × f value, Sm3+ doped Ba(Zn1/3Nb2/3)O3 ceramics paves the way to develop a promising multi-functional material utilized in temperature sensors and optical-electron integration devices in high frequency.