Aiming at the problem that the domestic space-borne data transmitter cannot achieve flexible and variable carrier frequency, a scheme of carrier source with configurable output frequency was proposed. The highly accurate and variable reference frequency and flexible configuration of the phase detection frequency in the phase detector in the phase-locked loop (PLL) were realized to make the output frequency of the carrier source programmable configuration by combining the field programmable gate array(FPGA) and digital-to-analog converter(DAC).The measured results from the carrier source with programmed output frequency were shown that the function for arbitrarily configuring output center frequency points in the X-band frequency range of 8.025~8.4 GHz could be realized, and the phase noise were less than -66 dBc/Hz@100 Hz、-75 dBc/Hz@1 kHz、-80 dBc/Hz@10 kHz、-95 dBc/Hz@100 kHz、-120 dBc/Hz@1 MHz, the spurious suppression was below -74 dBc, the frequency resolution was less than 10 Hz. The related circuit can replace the function of the dedicated direct digital frequency synthesis (DDS) chip and can be adapted to the space applications environment.

In this paper,a magnetic acoustic surface wave(MSAW) resonator based on flexible polyimide (PI) substrate is studied and fabricated by solving the technique problem of preparing amorphous soft magnetic thin films on flexible substrates. By sputtering and depositing amorphous FeCoSiB magnetostrictive film and ScAlN piezoelectric film on flexible polyimide (PI) substrate, the interdigital electrode was fabricated by photolithography and the layered structure of IDT/ScAlN/FeCoSiB/PI was formed, the flexible MSAW resonator was fabricated successfully. The structure and surface morphology of the films were analyzed by X-ray diffraction(XRD) and atomic force microscopy (AFM). The static and high frequency magnetic properties of FeCoSiB films were measured by VSM and short-circuit microstrip method.Finally,the device is tested on the probe platform by vector network analyzer and compared with the simulation results of COMSOL.The experimental results showed that the MSAW device had two resonance peaks,of which the Rayleigh wave appears at 28.32 MHz and Lamb wave appears at 93.69 MHz.

In order to conveniently calculate the group delay ripple of the bulk acoustic wave (BAW) filter by the S parameters measured by the vector network analyzer, two methods of calculating the group delay ripple of BAW filter in ADS and MATLAB are put forward. In this paper, the calculation and the calculating process of group delay ripple by the MATLAB programming and ADS are introduced, and the two methods are compared. Then, the difference between using “delay (S12)” and “group~~delay” to calculate the group delay ripple in ADS is pointed out. The results show that the calculation in MATLAB is basically consistent with the group delay ripple calculated in ADS using “group~~delay” and both can accurately calculate the group delay ripple of the BAW filter.

The 43°Y-cut lithium niobate single crystal piezoelectric thin film was prepared by ion implantation transferring method, and the solid-state acoustic reflective thin film bulk acoustic device was prepared with SiO2/Mo as the acoustic reflection structure. The operating frequency of the resonator is at 3 GHz, and the equivalent electromechanical coupling coefficient of LN film is 14.15%. The frequency and temperature characteristic of the resonator is characterized. The results show that although the frequency temperature coefficient of LN single crystal is between (-70~-90)×10-6/℃, the frequency temperature coefficient of the resonator is reduced to -18×10-6/℃ because the acoustic reflection structure contains a SiO2 layer with positive temperature coefficient, which shows that the solid acoustic reflection structure can effectively suppress the temperature drift of LN single crystal thin film and obtain a resonator with low frequency temperature coefficient.

In this paper, a low loss and high suppression surface acoustic wave filter is developed by the methods of pitch-modulated IDT and two acoustic channel designs. The filter uses 64°Y-X LiNbO3 as the substrate material, its center frequency is about 475 MHz, the insertion loss is less than 2 dB, the stop band rejection is better than 60 dB and the relative bandwidth of 1 dB is about 5%. The developed filter has the characteristics of low insertion loss and high stop band rejection. The results show that the design method has good practicability.

QCM is a kind of high-sensitivity sensor that can be quantitatively analyzed and characterized by establishing the relationship between QCM parameters changes and the measured viscoelastic films. In this paper, based on the constitutive equation of quartz crystal, the QCM equivalent BVD model of the adsorption of viscoelastic film without considering the capacitance effect under gas-phase conditions is derived. An explicit expression of the QCM equivalent parameters and frequency changes regarding the physical properties of the viscoelastic film is given, revealing the physical phenomena of “extra mass effect” in the gas phase caused by the loss modulus and storage modulus of the viscoelastic film. The BVD model derived in this paper has higher accuracy than that of the EBVD model given by Arnau. The results show that the model can be applied to analyze the characteristics of gas phase viscoelastic films.

An improved LC voltage-controlled oscillator (LC-VCO) with low power consumption and low phase noise at 2.4 GHz oscillation frequency is proposed in this paper. As an optimization scheme, the active MOS transistor devices are employed to replace the passive resistors and capacitors in order to reduce the layout area and power consumption, as well as improve the comprehensive performance of VCO. Based on TSMC 65 nm/ 1.8 V CMOS process, a VCO circuit is designed and simulations are performed for performance analysis. By combining theoretical modeling with small signal equivalence circuit, appropriate parameter tuning is realized for the replacement of key passive devices. The simulation results show that the improved VCO has a tuning range from 2.365 GHz to 2.506 GHz and the tuning bandwidth of 141 MHz, phase noise of -127.272 dBc/Hz@1 MHz, and as low as 1.323 mW power consumption at 1.8 V power supply voltage. Furthermore, the value of figure of metrics(FoM) is up to -193.84 dBc·Hz-1, which is better than most of other same LC-VCOs at the same frequency range.Key words:

In this paper, a new SAW gas sensor with three-dimensional nanowire structure is presented. The preparation and modification of nanowire on SAW resonator, the design of sensor signal extraction circuit and the design of alarm detector are described in detail. In the end, a gas alarm detector sample is developed, and the performance index of the sensor is tested with GB simulator, the response threshold of the sensor is 2 mg/m3, and the corresponding time is only 20 s. The results show that the three-dimensional nanowire SAW gas sensor has a significant improvement both in response threshold and in corresponding time compared with the conventional two-dimensional SAW gas sensor.

In order to quickly and accurately predict the health status of the system, a temperature measurement method based on SAW technology in wireless sensor network is proposed. The detection method uses the unidirectional radar pulse triggered by the switch to provide the transmission and reception channels through the radio modem. According to the structure of the sensor, the cross-section characteristics of the cooperative target are characterized to restore the physical quantity that defines the material characteristics of the transducer. At the same time, the anti-interference processing methods in the communication from interrogator to interrogator and from sensor to interrogator are given. The effectiveness of the proposed method has been verified by the indoor and outdoor temperature measurement experiments lasting for one and a half years, which can support industrial system monitoring and health status assessment.

In this paper, a large aperture medium-wave (3~4.5 μm) acousto-optic tunable filter using tellurium oxide crystal as acousto-optic medium material is introduced in this paper. Through optimizing the design,its clear aperture has reached 20 mm×20 mm,and its luminous flux has increased by 3 times compared with the commonly used acousto-optic tunable filters (optical aperture 10 mm×10 mm).This acousto-optic tunable filter is designed for the incident o-light, which adopts a single-chip transducer structure. The results show that through design optimization, the filter achieves a filter range of 3.0~4.5 μm,a separation angle of 5.25°,a diffraction efficiency of greater than 60%,and a spectral resolution of less than 45 nm.

In order to solve the problem of dynamic measurement of mN-level thrust output by electric thruster, a micro force measurement device based on piezoelectric torque sensor is developed in this paper. By converting the “little force-large force arm” of the thruster into the “little force arm-large force” of the measuring end, the tiny force output from the thruster is converted into torque measurement, and the measurement of the mN-level tiny force is realized. The measuring device is statically calibrated by applying a standard tiny force with electromagnetic force; the nonlinear error and repeatability error are 1.26% and 1.43% respectively. The natural frequency of the measuring device in the thrust measurement direction is 35 Hz by the pulse excitation response experiment method. The test result shows that the proposed device is feasible to measure the micro output force of mN-level electric thrusters.

In order to realize ultra-high speed acousto-optic modulation, a method of designing and simulating the bonding membrane system of a fiber optic coupling acousto-optic modulator is presented in this paper. An optical fiber coupled acousto-optic modulator with a working frequency of 200 MHz and a rise time of 10 ns was designed and manufactured by this method。The device uses TeO2 as the acousto-optic medium, 36 ° Y-cut LiNbO3 as the piezoelectric transducer wafer, the substrate layer uses high-purity Cr, the bonding layer is high-purity Au, and the results show that the device performance test is good.

Using Mg(OH)2, NH4H2PO4, ZrCl2O·8H2O as raw materials, MgZr4(PO4)6 (MZP) powder was synthesized by solid phase reaction method at four different heat treatment temperatures of 800 ℃, 900 ℃,1 000 ℃,1 100 ℃. The TG/DSC atlas, phase composition, micro-morphology, high temperature electrical properties of the synthesized MZP powder were investigated. The results show that pure phase MZP powder can be synthesized at 900 ℃, and the powder can exist stably. With the increase of the heat treatment temperature, the second phase product of Zr2O (PO4)2 appeared in the synthesis product, and its amount increased with the increase of the heat treatment temperature. The synthetic MZP powder has two forms, one is a granular shape with a size ranging from 2 μm to 5 μm, the surface is rough, and smaller particles are aggregated; the other is an irregular cube shape, and a very small amount of shape is rod-shaped with a smooth surface and a size of 2 μm. As the temperature increases, the conductivity of the MZP sample increases by three orders of magnitude due to the increased diffusion capacity of the magnesium ion channel.

The Ca1-xBaxCu3Ti4O12 (x=0, 0.005, 0.010, 0.020, 0.030, 0.040, 0.050, 0.100) ceramics have been prepared by the traditional solid state reaction method. The effects of the changes of Ba2+ doping contents on the phase structure, surface morphology and electric properties of Ca1-xBaxCu3Ti4O12 have been investigated by the X-ray diffraction, scanning electron microscopy, and dielectric temperature relationship measurement system and impedance tester. The results show that the second phase CuO is produced in ceramic samples with the increase of Ba2+ doping content, and the Ba2+ doping increases the lattice constant of CaCu3Ti4O12 at the same time. The grain size of Ca1-xBaxCu3Ti4O12 decreases with the increase of the doping amount of Ba2+ and the porosity decreases accordingly. The dielectric loss of CaCu3Ti4O12 ceramics and the change rate of relative dielectric constant with temperature can be reduced effectively by doping appropriate Ba2+. A certain amount of Ba2+ doping can also increase the grain boundary resistance of CaCu3Ti4O12.

The numerical simulation and experimental study on the non-destructive and destructive timber beams with piezoelectric ceramic (PZT) sensors are carried out based on the piezoelectric impedance technology, and the damage index, that is the root mean square deviation (RMSD), is used to quantitatively evaluate the relationship between the impedance value of the timber beams as a function of the damage degree and the damage location. The results indicated that the piezoelectric impedance method could efficiently estimate the local damage. The RMSD value increased with the increase of the damage degree when the distance between the PZT transducer and damage location was fixed, while the RMSD decreased with the increase of the distance between the PZT transducer and damage location when the damage degree was fixed. The numerical results are consistent with the existing experimental results. Both of the numerical results and the experimental results indicate that the piezoelectric impedance method can efficiently detect the local damage of the timber beams, which can provide a reference for engineering practice.

In order to simulate human tactile sensation and realize intelligent tactile sensation, a multi-information tactile detection system based on polyvinylidene fluoride (PVDF) piezoelectric film was developed, which initially realized the detection and recognition of the five dimensional information of the surface softness, viscosity, texture roughness, texture regularity and heat of an object. The tactile signal detection system uses a bump-type piezoelectric thin film sensor to obtain object surface information, and the host computer performs digital filtering, feature extraction, and feature classification on the sampled signal, and finally obtains the surface characteristic information of the object, and draws a five-sensing map of the surface characteristics of the object. Among them, the texture roughness adopts the main frequency recognition method, and uses the Fourier transform (FFT) to perform feature extraction. The experimental results show that the system can effectively distinguish the surface information of the measured object.

In view of the problem that the large azimuth installation error angle of the horizontal sensor will lead to the extension of the leveling time, this paper briefly describes the four-point leveling strategy and the working principle of the dynamic horizontal sensor, and establishes the coordinate matrix and matrix conversion relationship, and discusses the influence of the azimuth installation error of the dynamic horizontal sensor on the leveling system. The test results show that the method of making the shafting of the dynamic level sensor parallel to the shafting of the mounting base can reduce the azimuth mounting error angle and improve the system performance.

In single-axis rotation inertial navigation system (SRINS), the z-axis gyro drift (εz) dramatically limits its navigation precision because it cannot be modulated by rotation. In addition, in the process of alignment, in order to alleviate the contradiction between the alignment accuracy and the alignment time, and guarantee the alignment accuracy to the greatest extent and identify the z-axis gyro drift within a limited alignment time, a fast alignment method based on the time forward and reverse algorithm in stationary base is proposed, which can identify the parameters by using the least square method by adding the azimuth angle into the measurement in this study. This algorithm can not only reduce the alignment time, but also quickly estimate the z-axis gyro drift and improve the navigation accuracy. The experiment on a SRINS with FOGs is carried out. The results show that after the error compensation, the positioning accuracy of the SRINS is improved by about 24% and the positioning error is less than 2 n mile/12 h.

The daily monitoring of the human heart rate and respiratory signals is helpful for the healthy human life management. A non-contact physiological signal monitoring system is designed in this paper. A new chair structure with polyvinylidene fluoride(PVDF) piezoelectric film sensor senses the tiny pressure generated by human vibration, and transmits the vibration signals to the host computer software; then the cardiac shock signal and the breathing signal from the vibration signal are extracted; and display the waveform change is displayed through LabVIEW, thus the real-time monitoring of heart rate and breathing can be carried out. The results show that the heart rate value monitored by the device has an average error of 2.013% and an average respiratory rate error of 4.88% compared with that of the pulse oximeter, which has better practicability.

The advantages, principle and structure of the IEPE circuit of piezoelectric shock wave overpressure sensor are analyzed and discussed, and the IEPE signal conditioning circuit based on discrete devices is designed. The circuit is simulated and verified by experiments, and the amplification factor, amplitude-frequency characteristic, linearity and temperature characteristic of the circuit are obtained. The test results show that the frequency response bandwidth of the circuit is greater than 600 kHz, the linearity is about 0.4%, and the fluctuation of frequency response at full-temperature is less than 4.3%, which can meet the requirements of the IEPE circuit of the shock wave overpressure sensor. The influence of electromagnetic interference and other factors on the shock wave pressure test system is avoided, the circuit miniaturization is realized, and the test system is simplified. It has practical significance for the realization of IEPE piezoelectric overpressure sensor.

An improved Maxwell-slip model with adaptive control is proposed to reduce the hysteresis nonlinearity of the piezoelectric ceramic actuator, so that it has good hysteresis compensation in a wide frequency band. In classic Maxwell-slip model, the relationship between output force and input displacement will exhibit hysteresis, appearing as a parallelogram, which is close to the hysteresis characteristics of piezoelectric actuators. Since the maximum friction force of each unit slider is proportional to the spring elastic coefficient, if the spring coefficient is a fixed value, then the maximum friction force of each unit is constant in the system real-time control, the output value can be updated by using the adaptive control algorithm, and the input voltage of the piezoelectric actuator can be compensated. To validate the proposed model, a piezoelectric experimental platform was built, and the hysteresis model was used for hysteresis compensation control. The experimental results show that, for the adaptive control of Maxwell-slip model, the root mean square error and mean absolute deviation error in the 0.1~20 Hz wide frequency band are reduced. The displacement error is 0.037 5 μm without control at 0.1 Hz, and the adaptive control method can reduce the positioning error of the piezoelectric micro-positioning platform within 0.012 4 μm. Compared with the classic methods, the proposed adaptive control has the advantages of precision positioning in wide frequency band.

Breathing, heart rate and snoring can reflect a lot of information of human body during sleep. In this paper, the polyvinylidene fluoride (PVDF) is used as a sensitive unit to monitor the signals of respiration, pulse and snoring. According to the characteristics of the sensor, the charge amplifier circuit, the notch circuit and the voltage amplifier circuit are designed. The hardware circuit is powered by the polymer lithium battery. According to the characteristics of polymer battery, charging circuit, protection circuit and discharge circuit are designed for the battery. The whole hardware circuit is integrated on a PCB. At the same time, the APP based on Android device is designed to display the physiological signal data in real time in the form of visualization, and to store the signal data for a long time, so as to facilitate the analysis and diagnosis of sleep breathing diseases by doctors in the later stage. The purpose of this study is to monitor sleep physiological parameters accurately and improve the comfort of subjects.

It introduces a vibrating-string gyro with electromagnetic driving frequency detection. In order to realize the amplitude stabilizing resonance of the vibrating-string gyro, the dynamic and electrical characteristics of the vibrating-string gyro driving mode are analyzed. The closed-loop drive system based on the phase negative feedback was designed according to the characteristics, and its Simulink system model was established, the frequency-locked amplitude stabilization performance of the drive system was analyzed when the natural frequency of the drive mode was deviated. The device-level circuit implementation and simulation of the closed-loop drive system were carried out. The results show that the gyro’s stable amplitude start-up time is about 1.5 s, and the frequency jitter after stabilization is less than 0.020 6 Hz. Finally, the closed-loop drive circuit was fabricated and the drive test was carried out, the test results were consistent with the simulation results, which verified that the closed-loop drive circuit was able to achieve the control requirements of gyro frequency tracking and stable amplitude.

In order to study the radiation shielding design of piezoelectric acceleration sensor for nuclear power, the Monte Carlo N-Particle Transport Code (MCNP) software is used in this paper, aiming at the fission neutron spectrum and gamma spectrum released during the operation of the reactor. Two shielding modes are proposed, which are lead polyethylene lead multilayer combination and Fe+W+B4C composite, while considering the service temperature, radiation resistance, cost, shielding effect and other factors. The results show that the combination of Pb (10 cm)+PE (15 cm)+Pb (5 cm) can be used when the service time is relatively short, the radiation dose of the shield is not strong, and the service temperature is less than the service temperature of PE. The combination of 60%Fe+30%W+10%B4C can be considered when both of the radiation dose to the shield and the service temperature are very high.

To improve the anti-overload capability of the ultrasonic motor used for the control of guided-ammunition steering gear, by selecting the stator support of the weakest part of the ultrasonic motor as the research object, and taking its thickness, position and width as the design variables, using the finite element method to simulate the high overload environment of 10 000 g(g=9.8 m/s2) produced when firing artilleries, studying the anti-overload capability supported by different stator parameters, so as to a reasonable structure of the ultrasonic motor stator was designed in this paper. The high overload impact deformation of the stator before and after the optimization was obtained through the Machete hammer test, and the output performance of the ultrasonic motor with two stators after the impact deformation was tested by the hysteresis dynamometer. The test results showed that the ultrasonic motor with optimized stator structure had better output performance after large overload impact.

This paper focuses on the dynamic shape control theory of the flexible cantilever structure driven by the macro fiber composite actuator (MFC). Based on the finite element method, homogenization theory and load analogy method, the mechanical-electrical coupling dynamic equation of the piezoelectric driven laminated structure is established, and the state space control model is obtained by combining the modal reduction method. At the same time, in view of the serious influence of the nonlinear characteristics of the hysteresis creep of the piezoelectric actuators on the control accuracy, the research on the hysteresis-creep modeling and the feedforward inverse compensation control method based on the experimental data was carried out. Furthermore, the composite control system of the hysteresis-creep feedforward compensation and the active disturbance rejection feedback control for the dynamic shape control of the piezoelectric driven flexible structure is constructed. The calculated example shows that the composite control method can effectively improve the accuracy of dynamic shape control of the system on the premise of ensuring the stability of the system.

A novel nonlinear robust controller is proposed in view of uncertain nonlinear factors that commonly exist in achieving the micro/nano motion of piezoelectric ceramics. The controller can achieve robustness by controlling non-singular terminal sliding mode, and achieve real-time compensation and model-free control of unknown terms by delay estimation technology, which is beneficial to achieving the estimation of the full status by robust exact differentiator in engineering applications. The closed-loop stability of the system is proved by Lyapunov criterion. The results of the semi-physical simulation experiment show that the proposed controller can control piezoelectric ceramics to achieve sub-micron precision motion control. Theoretical analysis and practice prove that the proposed control strategy can achieve model-free, energy-saving, highly precise and robust-controlling effects. It has strong engineering application and can be effectively applied to micro/nano operations driven by piezoelectric ceramics.

In this paper, the polydimethylsiloxane (PDMS), carbon black (C), and barium titanate (BTO) nanoparticles prepared by the hydrothermal method were composited and spin-coated to obtain a BTO/PDMS/C flexible piezoelectric composite film. The results show that the prepared BTO nanoparticles have a uniform size with diameter of about (58±10) nm. When the content of C is 12%, the BTO/PDMS/C flexible composite film has the best output performance, and the output voltage and current are 11.14 V and 6.23 μA, respectively, and the output power of 8.45 μW can be obtained at a load resistance of 5 MΩ. After 4 000 cycles of testing, the prepared BTO/PDMS/C flexible piezoelectric composite film has a stable piezoelectric output, which is a good choice for manufacturing wearable electronic devices and monitoring components.

It is difficult to obtain the navigation information in the case of GNSS rejection, while the methods based on infrared, ultrasonic, radio, Wi-Fi, ultra-wide-band need the assist of electronic label, and the traditional dead reckoning algorithm is to draw the trajectory of a pedestrian on the condition of walking forward. It may be opposite or perpendicular to the actual trajectory if the pedestrian takes backward and lateral walking. To solve the above-mentioned problems, the inertial measurement unit embedded in mobile terminal is used to realize the short-time multi-mode pedestrian tracking based on multi-sensor without relying on any electronic label. The results of repeated tests show that the detected accuracy of walking mode is higher than or equal to 92%. Taking the actual garage scene as the experimental background, this method can obtain autonomous path tracking in full walking mode, and the path tracking error is less than 3 m.

The piezoelectric actuators have the characteristics of nanometer/micrometer positioning and are widely used in precision control motion platforms. Therefore, the requirements for the speed and accuracy of piezoelectric actuators are becoming higher and higher. According to the driving principle of stepping piezoelectric motor and the dynamic model of quadruped piezoelectric actuator, a driving power supply for the quadruped piezoelectric actuator with new stacked structure is designed in this paper. The power supply is linear with a high voltage of ±250 V and a high frequency of 1.5 kHz. Two strategies of hardware impedance compensation and signal switching are adopted to further eliminate the influence of capacitive load on signal bandwidth, so that the quadruped piezoelectric actuator can output at high precision and constant speed. Meanwhile, the hardware in-loop simulation and testing methods are used to set up an experimental platform. The results show that in the laser interferometer acquisition equipment with a resolution of 1 nm, the motion test of the point-to-point 50.7 nm four-legged piezoelectric actuator was realized.

Using 41°Y-X LiNbO3 as substrate material, selecting the double T-type impedance element structure, and adopting the water level packaging technology, a miniaturized WLP packaged SAW filter with relative bandwidth of 5.8%, minimum insertion loss of -2.8 dB and volume of 1.1 mm×0.9 mm×0.5 mm is fabricated. A special probe card is developed to complete the test of the packaged wafer on-line. The test results show that the test results of the probe card are in good agreement with that of the wafer assembled into the actual circuit, which solves the test problem of WLP packaged SAW filter.