Journals >Piezoelectrics & Acoustooptics
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2023
Volume: 45 Issue 1
31 Article(s)
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Forward Design of Ladder Surface Acoustic Wave Filter Based on Hierarchical Cascading Technique
ZHAO Xuemei, ZHENG Zeyu, BAI Tao, HE Zhen... and MA Jinyi|Show fewer author(s)
In view of accurate and fast design of ladder surface acoustic wave(SAW) filter with arbitrary and complex topology, based on acoustic/electrical/magnetic multi-physical field coupling full-wave simulation platform and combined with genetic optimization algorithm and general graphics processor(GPGPU) acceleration technIn view of accurate and fast design of ladder surface acoustic wave(SAW) filter with arbitrary and complex topology, based on acoustic/electrical/magnetic multi-physical field coupling full-wave simulation platform and combined with genetic optimization algorithm and general graphics processor(GPGPU) acceleration technology, the hierarchical cascade exact model(HCT) is used to replace COM model for the design and optimization of SAW filter. The calculation and optimization speed are comparable with that of COM model. The optimized design and development of 42°Y-X LiTaO3 conventional SAW filter with insertion loss of 0.67 dB and 2 dB fractional bandwidth of 3.85% verifies the effectiveness and feasibility the proposed method..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 1 (2023)
Experimental Observation of Frequency-Mixing Harmonic of Surface Acoustic Waves
LU Lu, LAI Quanqing, and DENG Mingxi
Based on the needs of ultrasonic nondestructive testing technology, a method for exciting the frequency-mixing surface acoustic waves based on the theoretical analysis of the frequency-mixing effects of surface acoustics waves is proposed in this paper, and the corresponding experimental observation of frequency-mixingBased on the needs of ultrasonic nondestructive testing technology, a method for exciting the frequency-mixing surface acoustic waves based on the theoretical analysis of the frequency-mixing effects of surface acoustics waves is proposed in this paper, and the corresponding experimental observation of frequency-mixing harmonic of surface acoustic waves is carried out. A wedge transducer consisting of a transverse transducer and a longitudinal one is designed and fabricated to excite the mixing surface acoustic waves induced by the oblique incidence of a bulk transverse wave and a bulk longitudinal one. By choosing appropriate cycle number and time delay of the transverse and longitudinal wave excitation signals, the surface acoustic waves excited by the oblique incident bulk transverse and longitudinal waves can be completely mixed. By performing pulse inversion processing and Fourier transform on the received time-domain signals, the apparent surface acoustic wave mixing harmonic signals can be obtained. The results show that the mixed-frequency surface waves can be effectively generated with the help of the oblique incident transverse and longitudinal waves passing through the wedge, and the experimental observation is consistent with the theoretical expectation, which lays a foundation for the development of ultrasonic non-destructive testing technique based on the mixing surface acoustic waves..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 6 (2023)
Study on Characteristics of Rayleigh Wave Devices with Layered Layout Structure of IDTs Electrode
YUAN Yuxin, WU Qingpeng, SUN Li, SUN Kexue, and WANG Yan
The development of modern technology has increased the demands for high-frequency surface acoustic wave (SAW) devices, and has placed higher requirements on their operating frequencies. In order to increase the frequency of SAW devices, a device model with layered layout of IDTs electrodes is established, that is, IDTsThe development of modern technology has increased the demands for high-frequency surface acoustic wave (SAW) devices, and has placed higher requirements on their operating frequencies. In order to increase the frequency of SAW devices, a device model with layered layout of IDTs electrodes is established, that is, IDTs/AlN/IDTs/R-sapphire structure. The finite element method is used to analyze its acoustic performance, including the admittance, phase velocity, electro-mechanical coupling coefficient, etc.. The results show that the Rayleigh waves can be excited in the IDTs/AlN/IDTs/R-sapphire structure, and when hAlN=0.4λ, the horizontal center distance Pb=4 μm, the operating frequency of the device is 692 MHz, which is nearly one time higher than that of the traditional device with IDTs/AlN/R-sapphire structure (356 MHz), and the electro-mechanic coupling coefficient K2 is 0.3%, which is also improved compared with the traditional structure. In addition, the performances of Rayleigh wave device can be further improved and modulated by optimizing the electrode structure parameters of IDTs. When the thickness ratio (Δh) of upper copper electrode to lower aluminum electrode of IDTs is 1.2, and Pb=4 μm, hAlN/λ=0.5, the resonant frequency of 657.9 MHz and K2 of 1.27% are obtained for the Rayleigh wave device; and when Pb=6 μm, the operating frequency of the Rayleigh wave and the maximum electromechanical coupling coefficient K2max are 461 MHz and 1.34%, respectively, which are 30% and 300% higher than that of the traditional Rayleigh wave device with single layered layout structure of IDTs electrode, respectively. From the above-mentioned results, it can be seen that the layered layout structure of IDTs can not only effectively improve the operating frequency and electromechanical coupling coefficient of SAW devices, but also reduce the fabrication difficulty of high frequency SAW devices..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 11 (2023)
Simulation and Preparation of Thin Film Bulk Acoustic Resonator with High Quality Factor
ZHAO Lishuai, YI Xinyan, OUYANG Peidong, ZHANG Tielin... and LI Guoqiang|Show fewer author(s)
The effect of the double reflection layer on performance of thin film bulk acoustic resonator is studied in this paper. The finite element method is used to establish the model of the device with silicon nitride as the support layer, aluminum nitride as the piezoelectric layer and molybdenum as the electrode. Firstly, The effect of the double reflection layer on performance of thin film bulk acoustic resonator is studied in this paper. The finite element method is used to establish the model of the device with silicon nitride as the support layer, aluminum nitride as the piezoelectric layer and molybdenum as the electrode. Firstly, the influence of the width of the reflection layer on the input impedance is investigated. In order to further verify the simulation results, a cavity structure of thin film bulk acoustic resonator is prepared. The results show that when the width of the reflection layer is 0.5 μm, the quality factor of the device will be greatly enhanced..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 18 (2023)
Finite Element Simulation Analysis of Edge Load FBAR Resonators
LIU Hongbin, ZHANG Tielin, HU Han, YI Xinyan, and LI Guoqiang
When the external excitation is applied to the thin film bulk acoustic resonator(FBAR), the longitudinal and transverse shear vibration will be excited, resulting in energy loss. In order to reduce parasitic resonance, reduce the working loss of FBAR device and improve the quality factor of the device, it is necessary When the external excitation is applied to the thin film bulk acoustic resonator(FBAR), the longitudinal and transverse shear vibration will be excited, resulting in energy loss. In order to reduce parasitic resonance, reduce the working loss of FBAR device and improve the quality factor of the device, it is necessary to suppress the transverse shear vibration. In this paper, the influence of the top electrode edge load parameters on the transverse parasitics of FBAR device is investigated by using the finite element simulation and implemented by the COMSOL simulation software, and the resonator with complete structure is prepared. It is tested that the load structure can effectively improve the quality factor of the device by about 10%..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 21 (2023)
Study on Growth and Properties of 42° Rotated Y Cut Lithium Tantalate Single Crystals
YU Mingxiao, LONG Yong, SHI Zibing, CHEN Zheming... and DING Yuchong|Show fewer author(s)
The lithium tantalate (LiTaO3) single crystals have excellent piezoelectric properties and are widely used as substrate material for SAW filters. In this work, an 4 inch, 42° rotated Y cut, integral, crack-free LiTaO3 single crystal was successfully grown using the in-house developed Czochralski (CZ) furnace. The The lithium tantalate (LiTaO3) single crystals have excellent piezoelectric properties and are widely used as substrate material for SAW filters. In this work, an 4 inch, 42° rotated Y cut, integral, crack-free LiTaO3 single crystal was successfully grown using the in-house developed Czochralski (CZ) furnace. The transmittance is close to 80% by the visible and near infrared spectrophotometer test, its full width at half maximum (FWHM) is 28.4″ by X-ray rocking test, which show that the grown crystal has good single crystal property. The Curie temperature of the head and tail of the grown crystal is measured by the differential thermal analyzer, and the Curie temperature deviation is 4.4 ℃. The results of SAW performance test show that the SAW velocity, electromechanical coupling coefficient and frequency temperature coefficient of LiTaO3 single crystal meet the requirements of SAW filter..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 26 (2023)
Study on Sr-Substituted Hard PMS-PZT Piezoelectric Ceramics
LUO Yaxia, LIU Hong, and ZHU Jianguo
The Pb1-xSrx(Mn1/3Sb2/3)0.05Zr0.48Ti0.47O3 +0.25%CeO2+0.50%Yb2O3+0.15%Fe2O3(PMS-PZT, x=0, 0.02, 0.04, 0.06) ternary system hard piezoelectric ceramics were synthesized by the conventional solid-state reaction method. The effects of Sr-substitution on the phase structure and electrical properties of the PMS-PZT ceramicsThe Pb1-xSrx(Mn1/3Sb2/3)0.05Zr0.48Ti0.47O3 +0.25%CeO2+0.50%Yb2O3+0.15%Fe2O3(PMS-PZT, x=0, 0.02, 0.04, 0.06) ternary system hard piezoelectric ceramics were synthesized by the conventional solid-state reaction method. The effects of Sr-substitution on the phase structure and electrical properties of the PMS-PZT ceramics were systematically studied by X-ray diffractometer, quasi-static piezoelectric constant tester and ferroelectric tester. The experimental results show that both the PMS-PZT piezoelectric ceramics with and without Sr-substitution have a single tetragonal crystal structure. When x=0.02, PMS-PZT has the best performance: d33=415 pC/N, Qm=522, TC=291 ℃, kp=0.64, εr=1 304, Pr=11.32 μC/cm2, Ec=9.05 kV/cm..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 29 (2023)
Adjustment of Tightness of Striker and Nozzle of Piezoelectric Ceramic Injection Valve Based on PSO-LM-BP Neural Network
ZHU Yanfei, WANG Mingyue, LI Chuanjiang, and GU Ya
The piezoelectric ceramic injection valve is the core executive component of the dispensing robot, and the tightness of its striker and nozzle will affect the dispensing frequency, the volume of glue point, and the amount of glue in a single point and so on. In the prior art, the tightness of the top tightening of the The piezoelectric ceramic injection valve is the core executive component of the dispensing robot, and the tightness of its striker and nozzle will affect the dispensing frequency, the volume of glue point, and the amount of glue in a single point and so on. In the prior art, the tightness of the top tightening of the striker and nozzle is manually adjusted according to the operation experience. This method is time-consuming and cannot keep the same tightness every time. In order to overcome the shortcomings of the existing technology, this paper designs a method to adjust the tightness of the top tightening of the striker and nozzle of piezoelectric ceramic injection valve based on the current sensor. By collecting the load current of the controller in real time, the model between the current value and the corresponding screw sleeve rotation angle is established offline by using the improved BP neural network. The relative value of the tightness is obtained via the transformation of the angle value, so that the tightness of each adjustment is consistent to ensure the same displacement of piezoelectric ceramics. The experimental results show that the established model can basically ensure the consistency of tightness according to the relative value, and realize the visual adjustment..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 33 (2023)
Study on MnO2 Doped Pb(Sc,Nb)O3-Pb(Hf,Ti)O3 Ceramics for Ultrasonic Piezoelectric Transducers
LEI Lei, WAN Hao, LI Rui, WANG Jin... and XUE Jian|Show fewer author(s)
In this paper, high performance 0.07Pb(Sc1/2Nb1/2)O3-0.93Pb(Hf0.47Ti0.53)O3(PSN-PHT) ceramics were successfully synthesized by solid state reaction method, and the improvement of PSN-PHT ceramic properties by MnO2 doped was comprehensively analyzed from the aspects of microstructure, phase structure and electrical propIn this paper, high performance 0.07Pb(Sc1/2Nb1/2)O3-0.93Pb(Hf0.47Ti0.53)O3(PSN-PHT) ceramics were successfully synthesized by solid state reaction method, and the improvement of PSN-PHT ceramic properties by MnO2 doped was comprehensively analyzed from the aspects of microstructure, phase structure and electrical properties. The experimental results show that the addition of MnO2 changes the phase structure of PSN-PHT ceramics, reduces the content of ferroelectric tetragonal phase, and leads to the appearance of crystalline phase boundary (MPB). At the same time, the addition of MnO2 can increase the grain size and homogenize the grain. When the doping amount of MnO2 is 0.8 mol%, the sample achieves the best performance, and its d33、kp、TC、Qm and tanδ were 450 pC/N, 0.65, 348 ℃, 1 200 and 0.003 2 respectively. In particular, the temperature stability of PSN-PHT-0.8Mn samples is much higher than that of commercial PZT-5 and PZT-8 ceramics. It has a great application prospect in the field of piezoelectric ceramic transducers..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 39 (2023)
Study on Composite Control Method of Piezoelectric Ceramic Displacement Platform
HAN Zhen, LIU Yuetao, LI Zhihe, CAI Ruyan... and QU Dongming|Show fewer author(s)
A composite control method with feedforward compensation was adopted to address the problem that the system positioning accuracy of the piezoelectric ceramic (PZT) displacement platform was degraded due to the hysteresis characteristics.First, a segmented Prandtl-Ishlinskii (P-I) model was proposed for the establishmenA composite control method with feedforward compensation was adopted to address the problem that the system positioning accuracy of the piezoelectric ceramic (PZT) displacement platform was degraded due to the hysteresis characteristics.First, a segmented Prandtl-Ishlinskii (P-I) model was proposed for the establishment of the feedforward model, and the hysteresis model of the constructed platform was inverted. The error rate of the model was within 0.7%.Then, a series proportional integral (PI) analog circuit, a filter circuit and a detection circuit were designed for the closed-loop, which further improves the response speed and control accuracy of the control system. The experimental results show that the average absolute error of the composite control system based on feedforward compensation is 0.039 μm and the maximum error is 0.16 μm for the piezoelectric ceramic displacement platform at the frequency of 100 Hz and the stroke of 0-140 μm.Compared with feedforward control only, its control accuracy is improved by 73.76%..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 45 (2023)
Research on Fluid Kinetic Energy Harvesting Technology Based on Flow-Induced Oscillation
QIAN Cheng, XU Ya, XIE Dailiang, LIU Tiejun, and HUANG Zhengwei
In order to address the problem that it is difficult to maintain the power supply of low-power wireless sensor nodes in remote areas and special scenarios, this work investigates a fluid kinetic energy harvesting technology based on flow-induced oscillation phenomenon, which can realize the conversion process from fluiIn order to address the problem that it is difficult to maintain the power supply of low-power wireless sensor nodes in remote areas and special scenarios, this work investigates a fluid kinetic energy harvesting technology based on flow-induced oscillation phenomenon, which can realize the conversion process from fluid kinetic energy to electric energy by combining with piezoelectric technology. Through numerical simulation and experimental research on the phenomenon of flow-induced oscillation, the flow field and sound field distribution characteristics in the cavity structure are analyzed, and the influence of fluid velocity on the frequency and amplitude of acoustic oscillation is explored. The acoustic-electric conversion process is simulated by COMSOL software, and the complete conversion process of fluid kinetic energy to electric energy is realized. The research results show that there exists an acoustic oscillation range with stable frequency under certain speed conditions, which can drive the piezoelectric transducer to output a voltage with stable frequency. When the gas flow rate is 30.5 m/s (equivalent to the flow rate range of high-pressure gas transmission pipeline), the amplitude of the sound field pressure can reach 6.12 kPa, corresponding to an output open circuit voltage of 2.62 V. When an external 15 kΩ resistor is connected, the maximum output power is up to 0.29 mW..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 51 (2023)
A Novel Piezoelectric Hybrid Energy Harvesting Method Based on Shockproof Hammer
ZHANG Jiajia, YUAN Qiangjing, YAN Dong, LI Xuefeng... and MU Xiaojing|Show fewer author(s)
A piezoelectric vibration and magnetic field hybrid energy harvesting shockproof hammer was designed to solve the problem of harmful vibration and power supply and endurance of sensors in the smart grid environment. The main piezoelectric beam of the shockproof hammer harvests the vibration energy of the transmission lA piezoelectric vibration and magnetic field hybrid energy harvesting shockproof hammer was designed to solve the problem of harmful vibration and power supply and endurance of sensors in the smart grid environment. The main piezoelectric beam of the shockproof hammer harvests the vibration energy of the transmission line, and the secondary piezoelectric beam harvests the changing magnetic field energy generated by the current via the magnet installation, avoiding the need for the coil in standard magnetic field energy harvesting. The finite element simulation analysis and experiment test on the harvester are carried out. The results show that the harvester operates in a wider frequency band, which is 54% higher than that of the output of the traditional single beam. The maximum output power of the main piezoelectric cantilever beam can reach 874 μW, and the maximum power of the secondary piezoelectric beam can reach 683 μW..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 56 (2023)
Inertial Impact Rotating Piezoelectric Motor Based on Disk Symmetric Drive
DOU Haotian, SHAN Zengxiang, LI Kun, YUE Xukang... and HE Liangguo|Show fewer author(s)
An inertial impact rotating piezoelectric motor based on disk symmetric drive is proposed in this paper. The motor is mainly composed of stator, rotor, driving foot and pre-tightening device. The motor excitation signal is sawtooth wave signal, using the piezoelectric stack excitation to realize the high power output oAn inertial impact rotating piezoelectric motor based on disk symmetric drive is proposed in this paper. The motor is mainly composed of stator, rotor, driving foot and pre-tightening device. The motor excitation signal is sawtooth wave signal, using the piezoelectric stack excitation to realize the high power output of the motor. The stator and the pre-tightening device are integrated through the screw, realizing the compactness and miniaturization of the motor structure. A motor prototype is designed and fabricated, and the working principle of the motor is verified by experiments. The comprehensive performance of the motor is analyzed and tested. The test results show that when the preload applied by the motor pre-tightening device is 1 N, the input excitation voltage is 80 Vp-p, and the excitation signal frequency is 1 kHz, and each cycle of sawtooth excitation signal is output, the next one is output with a delay of 100 ms to study the static starting characteristics and step length of the motor. The measured maximum no-load speed of the motor is 3.05 r/min, and the average step length is 0.032 rad. When the excitation signal frequency is 3 kHz, the maximum no-load speed of the motor is up to 9.1 r/min, and the maximum load of the motor can reach 16.2 N·mm. The motor can rotate within the excitation signal frequency ranging from 0.5 kHz to 3 kHz..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 61 (2023)
Single-Crystal LiTaO3 Composite Film Material on Si Substrate and Its Applications
DING Yuchong, HE Jie, CHEN Zheming, LONG Yong... and MA Jinyi|Show fewer author(s)
The piezo-on-insulator (POI) substrate is an emerging piezoelectric single-crystal composite thin film structural material. The POI substrate is composed of a thin layer of piezoelectric single-crystal material (single-crystal lithiumtantalate/lithium niobate), a silicon dioxide layer and a high-resistance silicon subsThe piezo-on-insulator (POI) substrate is an emerging piezoelectric single-crystal composite thin film structural material. The POI substrate is composed of a thin layer of piezoelectric single-crystal material (single-crystal lithiumtantalate/lithium niobate), a silicon dioxide layer and a high-resistance silicon substrate. It is prepared by the Smart-Cut process, which can ensure the high uniformity and high-quality batch production of the layer. Through this substrate, the high performance integrated SAW resonators and filters that meet the 5G communication requirements can be designed. The SAW devices based on POI material have excellent characteristics such as high frequency, high Q, low temperature sensitivity and large bandwidth, and at the same time, multiple SAW filters can be integrated on the same chip, which has broad market application prospects. This paper introduces the preparation of POI substrate and the research status at home and abroad, the applications of POI substrate in high performance SAW filter, reviews the key techniques of preparing POI substrate and outlooks the future development trend..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 66 (2023)
Recent Progress of High-Temperature Lead-Free Piezoelectric Materials
WU Chaofeng, GONG Wen, GENG Jinfeng, CUI Jianye... and LI Jiajiu|Show fewer author(s)
With the rapid development of aerospace, petrochemical and other fields and the implementation of sustainable development strategies, the role of high-temperature lead-free piezoelectric materials is becoming more and more important. This article summarizes the research progress of lead-free piezoelectric materials witWith the rapid development of aerospace, petrochemical and other fields and the implementation of sustainable development strategies, the role of high-temperature lead-free piezoelectric materials is becoming more and more important. This article summarizes the research progress of lead-free piezoelectric materials with high Curie temperature points, mainly including perovskite BiFeO3-based and BiAlO3-based ceramics, bismuth layered ceramics, perovskite layered structured ceramics, LiNbO3, langasite (LGS) and rare earth calcium oxyborate (ReCOB) single crystals. Finally, the problems existing in the high-temperature lead-free piezoelectric materials are summarized, and the development direction is proposed..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 72 (2023)
Signal Processing Method of Wireless Temperature Sensor for Transformer Based on SAW Technology
WU Runfa, E Zhenwei, FU Dong, YU Zhengzhi... and LI Shuxiang|Show fewer author(s)
At present, the condition monitoring of distribution transformer urgently needs a wireless passive sensing monitoring method, and surface acoustic wave (SAW) sensor is an important technical means to meet this demand. Taking the SAW sensor used for temperature measurement at the outlet of transformer as the research obAt present, the condition monitoring of distribution transformer urgently needs a wireless passive sensing monitoring method, and surface acoustic wave (SAW) sensor is an important technical means to meet this demand. Taking the SAW sensor used for temperature measurement at the outlet of transformer as the research object, this paper proposes an echo signal processing procedure of SAW sensor, and designs other signal processing procedures such as the signal de-noising, spectrum analysis etc.. In order to solve the interference problem caused by the same frequency signal to the sensor measurement, the anti-interference effect of the single channel blind source separation algorithm based on singular spectrum analysis and independent component analysis on the SAW sensor is studied. The effectiveness of the proposed algorithm in signal separation and interference suppression is verified by the built signal acquisition platform..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 82 (2023)
Wearable Snore Monitoring System Based on PVDF
QIAN Chenghui, and WANG Fulong
The obstructive sleep apnea syndrome (OSAS) is a common sleep disorder. In order to meet the initial screening and diagnosis of OSAS at home, a snoring monitoring system based on PVDF piezoelectric film was designed in this paper. The wearable snore monitoring system consists of a high-sensitivity snore sensor, a low-nThe obstructive sleep apnea syndrome (OSAS) is a common sleep disorder. In order to meet the initial screening and diagnosis of OSAS at home, a snoring monitoring system based on PVDF piezoelectric film was designed in this paper. The wearable snore monitoring system consists of a high-sensitivity snore sensor, a low-noise signal conditioning circuit, an embedded system and a host computer system. According to the characteristics of the large energy difference between the snoring segment and the non-snoring segment, the snoring endpoint detection algorithm is designed based on the short-time energy method, and the algorithm is verified by the collected snoring sound signals. The testing results show that the signal-to-noise ratio of snoring signals collected by the monitoring system is high, the average error of endpoint detection is less than 0.032 s, and the accuracy rate is 92.6%, which meets the screening requirements of potential OSAS patients and the self-examination of rehabilitation training for OSAS patients, and can reduce the burden of patient screening and medical polysomnography (PSG) detection..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 89 (2023)
Measurement of Young’s Modulus of Linear Material Using Air-Coupled Ultrasonic Technology
WANG Xiaoyu, GUO Ziyi, HUANG Wenqian, WU Haodong, and CHEN Jie
This paper presents a method for evaluating Young’s modulus of materials based on air-coupled ultrasonic technology. Firstly, the air-coupled ultrasonic transducer is developed based on 1-3 piezoelectric composites and double-layer matching structure. In the mode of one-transmitter-one-receiver, the insertion loss and This paper presents a method for evaluating Young’s modulus of materials based on air-coupled ultrasonic technology. Firstly, the air-coupled ultrasonic transducer is developed based on 1-3 piezoelectric composites and double-layer matching structure. In the mode of one-transmitter-one-receiver, the insertion loss and -6 dB bandwidth of the designed air-coupled ultrasonic transducer are -23.9 dB and 26.9%, respectively. Then, an experimental platform is set up to evaluate the Young’s modulus of copper wire and silver wire by combining the static tensile method and air-coupled ultrasonic technology. The evaluated results are consistent with the corresponding recognized values..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 94 (2023)
Study on Sound Field Emitted by Close-Packed CMUT Element Based on Thin Plate Vibration Theory
SHEN Shujun, HE Changde, ZHANG Yanjun, GAO Pengfei... and ZHANG Wendong|Show fewer author(s)
The capacitive micromachined ultrasonic transducer (CMUT) made by MEMS technology has the advantages of wide frequency band, easy integration with electronic circuits, and broad application prospects in the field of medical imaging. In order to study the characteristics of acoustic field emitted by a close-packed CMUT,The capacitive micromachined ultrasonic transducer (CMUT) made by MEMS technology has the advantages of wide frequency band, easy integration with electronic circuits, and broad application prospects in the field of medical imaging. In order to study the characteristics of acoustic field emitted by a close-packed CMUT, a simple physical domain interaction analysis method is proposed in this paper. Based on the vibration theory of thin plate, the analytical solution of the radiation sound field of CMUT element is obtained by the calculation from the acoustic radiation principle and characteristics of CMUT cell. The correctness of the first-order vibration mode equation based on the thin plate vibration theory is verified by the vibration distribution experiment of diaphragm. Through simulation and experiment, the acoustic field distribution, axial sound pressure and directivity of CMUT transmitter units under different arrangement modes and conditions are studied, which provides theoretical basis for the design and performance analysis of CMUT..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 98 (2023)
Study on Sensing Mechanism of Single-Axis MEMS Thermal Accelerometer with Dynamic Heat Source Pendulum
PIAO Linhua, TONG Jiacheng, LI Bei, and ZHANG Yan
The sensing mechanism of a dynamic thermal source pendulum single-axis MEMS thermal accelerometer was revealed in this paper. Based on the principle of the sensitive structure, the temperature field inside the sensitive structure is calculated by establishing the two-dimensional physical research model, meshing the griThe sensing mechanism of a dynamic thermal source pendulum single-axis MEMS thermal accelerometer was revealed in this paper. Based on the principle of the sensitive structure, the temperature field inside the sensitive structure is calculated by establishing the two-dimensional physical research model, meshing the grid, loading the acceleration and other methods. The results show that a stable temperature field centered at the dynamic heat source is formed within the sensitive structure after 1.8 s of power-on. When inputting the acceleration a, the dynamic heat source shifts along the direction of acceleration, then the temperature field is shifted. The temperature difference ΔTX between the two hot lines symmetrically set in the direction of sensitive axis increases linearly with the increase of input acceleration a, and the temperature sensitivity is 7.1×10-2 mK/g. According to the input-output characteristic a-VXOUT curve, the mathematical model is given, and the sensitivity of accelerometer is 0.5 V/g, and the nonlinearity is 2.8%, which reveals the sensing mechanism..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 105 (2023)
Structure Design and Simulation of Biaxial Accelerometer with High Sensitivity
ZHANG Meimei, and HUANG Libin
A biaxial resonant micro accelerometer with high sensitivity and low cross coupling is designed in this paper. The I-beam is used as the decoupling beam, and the force is amplified by the micro lever mechanism. The structure is symmetrical in the center, and the differential output method is used to detect the signal. A biaxial resonant micro accelerometer with high sensitivity and low cross coupling is designed in this paper. The I-beam is used as the decoupling beam, and the force is amplified by the micro lever mechanism. The structure is symmetrical in the center, and the differential output method is used to detect the signal. The structure is optimized through simulation analysis and the overall structure design of the accelerometer is completed, so as to improve the sensitivity of the accelerometer and reduce the cross coupling. The modal analysis, sensitivity analysis, cross coupling analysis and harmonic response analysis of the accelerometer structure are carried out. The results show that within the range of ±20g, the x-direction scale factor is 423.6 Hz/g, the y-direction scale factor is 421.8 Hz/g, the x-direction cross sensitivity is 0.000 047%, and the y-direction cross sensitivity is 0.000 78%. The simulation results verify the feasibility of the designed structure..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 112 (2023)
Design of Piezoelectric Single Crystal Face Shear Mode Accelerometer for Vector Hydrophones
LI Zhenghui, LI Shiyang, and GE Qiqi
The face shear vibration mode is generated in the piezoelectric single crystal with the zxt-45°cut in the ［011］polarization direction. Due to its advantages of high piezoelectric coefficient, high mechanical quality factor, high compliance coefficient and low cross-talk effect, the face shear mode has become an idThe face shear vibration mode is generated in the piezoelectric single crystal with the zxt-45°cut in the ［011］polarization direction. Due to its advantages of high piezoelectric coefficient, high mechanical quality factor, high compliance coefficient and low cross-talk effect, the face shear mode has become an ideal choice for small size, high sensitivity piezoelectric sensors, and has a good application prospect in the vector hydrophones. In this paper, the voltage sensitivity expression of the face shear mode piezoelectric accelerometer is derived by analyzing the vibration principle of the face shear mode. The finite element analysis software was used to establish the face shear accelerometer model, study the influence of structural parameters on the voltage sensitivity and resonance frequency of the face shear piezoelectric accelerometer, and optimize the structure size. The final simulation results show that the open circuit voltage sensitivity of the face shear accelerometer is 389.72 mV/g, the working frequency band is 20 Hz-3 kHz, and the lateral sensitivity is less than 3.45%. The research results show that compared with the traditional shear accelerometer, the designed face shear accelerometer has 11.6% higher voltage sensitivity while the weight of the mass block is reduced by 50%, which provides a new idea for reducing the average density of hydrophones and improving the performance of underwater acoustic detection..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 117 (2023)
Integrated Navigation Method Based on Grey Markov Predictions
LI Jian, WANG Lixin, and BAI Liwei
Aiming at the problem of long-term precision navigation of traditional MEMS/GNSS integrated navigation in the case of bad satellite signal, a MEMS/GNSS integrated navigation method based on gray Markov prediction is proposed in this paper. The stability of the system is improved by improving the gray prediction, addingAiming at the problem of long-term precision navigation of traditional MEMS/GNSS integrated navigation in the case of bad satellite signal, a MEMS/GNSS integrated navigation method based on gray Markov prediction is proposed in this paper. The stability of the system is improved by improving the gray prediction, adding Markov correction links, predicting the GNSS measurement value when the satellite signal is poor, and then replacing the original measurement value, and the result is subject to robust extended Kalman filtering(EKF) to overcome the influence of noise interference. The simulation and sports car experiments verify that the integrated navigation method can still output high-precision navigation results when the satellite signal is poor, and can better overcome the influence of abnormal observations on the system..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 124 (2023)
Design of a Broadband Circularly Polarized Antenna with Parasitic Array
LU Chang, CHEN Qinwen, CHANG Rui, DUAN Junping, and ZHANG Binzhen
A broadband circularly polarized antenna with C-band single-fed parasitic array is designed in this paper. The antenna adopts the adjacent double-layer F4B dielectric substrate, and the circular polarization is realized by slotting on the square drive patch and adopting the design of parasitic array. The design steps oA broadband circularly polarized antenna with C-band single-fed parasitic array is designed in this paper. The antenna adopts the adjacent double-layer F4B dielectric substrate, and the circular polarization is realized by slotting on the square drive patch and adopting the design of parasitic array. The design steps of the antenna structure are described, and the effects of each structure on the antenna impedance bandwidth and axial ratio bandwidth are studied. The effects of the parasitic patch tangent length and the slot width in the drive patch on the axial ratio and bandwidth of the antenna are also investigated. The circular polarization pattern of the antenna is simulated. The simulated results show that the antenna has a right-hand circular polarization is achieved at 5.5 GHz with a maximum gain of 8.1 dBi. The broadband circularly polarized antenna was fabricated and tested, and the test results were basically consistent with the simulation results. The measured impedance bandwidth of the antenna was 1.3 GHz, and the axial ratio bandwidth was 1.26 GHz. The designed stacked antenna has the advantages of compact structure, simple assembly and large axial ratio bandwidth..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 130 (2023)
Research on High Precision North Seeking Angle Measurement Method for Individual Soldier Based on Single-Axis Fiber Optic Gyroscope
ZHANG Yan, XIE Changcheng, YANG Hong, and TANG Zhongjian
The fiber optic gyroscopes measure angular velocity based on the Sagnac effect, which is less disturbed by the external environment and has good autonomy. Therefore, the north seeking angle measurement system based on fiber optic gyroscopes has been used in a series of applications in the military field. In this articlThe fiber optic gyroscopes measure angular velocity based on the Sagnac effect, which is less disturbed by the external environment and has good autonomy. Therefore, the north seeking angle measurement system based on fiber optic gyroscopes has been used in a series of applications in the military field. In this article, the fiber optic gyroscope realizes high-precision north-seeking angle measurement by sensitive to the angular velocity components of the earth’s rotation at four positions. In order to meet the requirements of miniaturization, rapidity of individual soldier’s north seeking angle measurement, this paper studies the automatic and fast north seeking method of the individual soldier’s high precision north seeking angle measurement device based on single-axis fiber optic gyroscope under tilt placement. There may be interference in the measurement process of the device, which affects the accuracy of north seeking angle measurement. By studying the output characteristics of the sensor in the process of north seeking angle measurement of the device, and identifying and processing the interference, the high precision north seeking angle information is obtained. Finally, through experimental comparison and analysis, the effectiveness of the identification and process of interference under tilted conditions is verified to meet the needs of high precision north seeking angle measurement for individual soldier reconnaissance..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 134 (2023)
Study on Temperature and Strain Sensing Characteristics of Tapered Hollow Fiber
LU Zhiqi, LIU Changning, XU Xiumei, ZHOU Wenbiao... and JIANG Wanjun|Show fewer author(s)
In this paper, a simple sensor with high sensitivity based on tapered hollow fiber was designed and fabricated, and its temperature and strain characteristics were measured by experiments. Firstly, a section of hollow fiber was fused between two standard single-mode fibers by using the optical fiber fusion splicer, andIn this paper, a simple sensor with high sensitivity based on tapered hollow fiber was designed and fabricated, and its temperature and strain characteristics were measured by experiments. Firstly, a section of hollow fiber was fused between two standard single-mode fibers by using the optical fiber fusion splicer, and then a discharge was applied to the middle of the hollow fiber, while two stepper motors were used to apply a certain tension at both ends of the single-mode fiber, which led to the conversion of Fabry-Perot interferometer to Mach-Zehnder interferometer. The experimental results show that the temperature sensitivity of the fiber optic sensor is improved from the theoretical value of 0.85 pm/℃ to 69.1 pm/℃ by approximately 81.3 times and the axial strain sensitivity is up to 3.6 pm/με after the tapered process. The device has the characteristics of small size, simple structure and high sensitivity, and has a broad application prospect in aerospace, medical monitoring and other fields..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 139 (2023)
Simulation of Full Tensor Gravity Gradient for Rotational Accelerometer
CAI Tijing, TANG Ziwei, WU Liming, and LIU Ying
In order to lay a solid theoretical foundation for the physical manufacture of gravity gradiometers at, this paper mainly studies the signal simulation generation of the umbrella-type full-tensor rotational accelerometer gravity gradiometer, simulates the measurement process of the umbrella-type gravity gradiometer thrIn order to lay a solid theoretical foundation for the physical manufacture of gravity gradiometers at, this paper mainly studies the signal simulation generation of the umbrella-type full-tensor rotational accelerometer gravity gradiometer, simulates the measurement process of the umbrella-type gravity gradiometer through semi-physical simulation experiments, and tests the performance of the tensor gravity gradient simulation system The test data is the three-disk accelerometer data of the umbrella-type gravity gradiometer in the ideal state generated by MATLAB. The data is loaded into the full tensor gravity gradient simulation system and demodulated to obtain the cross and inline gravity gradient component, the full tensor gravity gradient value in the measurement coordinate system is obtained through the linear operation, and then the coordinate system is converted to obtain the gravity gradient value in the platform coordinate system. The results show that the measurement accuracy of the simulation system reaches 1E(1E=1×10-9 s-2)..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 144 (2023)
Criteria for Adjusting Bandwidth of AWLR Hybrid Filter by Immittance Inverters
LIU Zhaonian, LIU Tingting, HUANG Yi, and FENG Mingkun
In order to adjust the bandwidth of extremely narrow band filter, a novel hybrid acoustic-wave-lumped-element resonator(AWLR) filter is proposed in this paper. In this structure, the immittance inverter is introduced to adjust the bandwidth of the filter. The principle and criteria of its bandwidth adjustment are invesIn order to adjust the bandwidth of extremely narrow band filter, a novel hybrid acoustic-wave-lumped-element resonator(AWLR) filter is proposed in this paper. In this structure, the immittance inverter is introduced to adjust the bandwidth of the filter. The principle and criteria of its bandwidth adjustment are investigated. The parameter matrix of the two-port network is analyzed and the circuit network parameters before and after introducing into the immittance inverter are compared to obtain its criteria for adjusting the bandwidth. The simulation results after introducing different inverters are compared and verified. Taking the J-type inverter with J=1/123 as an example, the relative bandwidth of the filter is increased from 0.072% to 0.41% after introducing the inverter. The criteria for adjusting the bandwidth of hybrid AWLR filter are obtained and its correctness is verified..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 149 (2023)
Design of New LTCC 3 dB 90° Bridge with High Isolation and Low Insertion Loss
SHEN Junwei, CHEN Zhihua, YE Qiang, LUO Changwei, and TANG Song
Based on the wide-side coupled stripline structure, a 3 dB 90° bridge with high isolation and low insertion loss based on low-temperature co-fired ceramic (LTCC) technology is designed in this paper. The spiral coupling line is used to effectively reduce the size of the bridge, and the symmetrical structure modeliBased on the wide-side coupled stripline structure, a 3 dB 90° bridge with high isolation and low insertion loss based on low-temperature co-fired ceramic (LTCC) technology is designed in this paper. The spiral coupling line is used to effectively reduce the size of the bridge, and the symmetrical structure modeling is more convenient for later optimization and adjustment. By introducing an extended adjustable isolation capacitor in the vertical directions of the wide-side spiral coupling stripline, the isolation of the bridge is greatly improved, making it up to 27 dB, and the insertion loss is less than or equal to 0.2 dB. Compared with the traditional directional coupler structure, this can greatly reduce the device size while improving the performance. The electric field intensity at the right-angle corner of the coupling line is analyzed and optimized, and the electric field intensity at the corner is roughly equal to that at the straight line by adopting the 45° oblique cutting method. At the same time, the upper grounding metal plate is hollowed out annularly, which improves the amplitude balance in the band. The designed 3 dB 90° bridge has passband of 0.96-1.53 GHz, insertion loss of ≤0.2 dB, amplitude balance of ≤±0.7 dB, phase balance of 90°±1°, and isolation of ≥27 dB, which has a good prospect application in market field..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 153 (2023)
Optimal Design of Dual-Band Power Divider Using Convolutional Neural Network
SUN Siyue, ZHOU Wenying, and LU Mai
As a common RF device in the microwave circuits, the power divider is an important building block for building the multiple-input multiple-output (MIMO) feed network in 5G communication systems. In order to optimize and quickly redesign the existing fixed frequency power divider structure so as to apply to any actuallyAs a common RF device in the microwave circuits, the power divider is an important building block for building the multiple-input multiple-output (MIMO) feed network in 5G communication systems. In order to optimize and quickly redesign the existing fixed frequency power divider structure so as to apply to any actually desired operating band, including the 5G operating band, in this paper, we propose a deep learning scheme based on a modified one-dimensional convolutional neural network taking a pre-designed dual-band power divider as the optimized design target. The one-dimensional convolutional neural network could predict that the geometric structure parameter of the power divider has good performance at other arbitrary double resonant frequencies. The self-organizing mapping neural network is used to select samples to improve the training efficiency of convolutional neural network. The predicted power divider performance is verified in the electromagnetic(EM) simulation software. The simulation results show that the return loss of the power divider is higher than 20 dB at the resonant frequency, the isolation is higher than 25 dB, the insertion loss is lower than 3.4 dB, and the working bandwidth is about 450~600 MHz, which proves that the optimized design of multi-parameter objective power divider is a fast and effective method..
Piezoelectrics & Acoustooptics
- Publication Date: Apr. 07, 2023
- Vol. 45, Issue 1, 158 (2023)
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