This paper introduced the principle and design method of a narrowband band-pass cavity filter. The parasitic passband was moved away from the passband by increasing the loading capacitance. The resonator with dumbbell-shaped cross-bar was designed to form the zero point of the voltage standing wave at the junction of the resonator in order to suppress the parasitic passband of the filter and to implement a band-pass filter with wide attenuation band. Finally, a band-pass filter with a center frequency of 2.45 GHz and bandwidth of 4.08% was designed using the simulation software CST. The simulation results showed that the designed filter had high out-of-band rejection, wide attenuation band and good performance of voltage standing wave ratio in the passband, which meet the design specifications.

A new and low cost method for fabricating the microfluidic device was presented in this paper. The microfluidic device patterns were made from a low-melting-point electric soldering wire with 138 ℃ of melting-point and 500 μm of diameter. The patterns were dipped into a small tank containing un-solidified polydimethylsiloxane (PDMS) and solidified in a constant temperature box at 80 ℃. Then, the electric soldering wire was melted at 200 ℃ and extruded using a syringe to form the micro-channels. The microfluidic device, together with a paper-based device, was mounted on 128°-YX LiNbO3 piezoelectric substrate. A biochemical reaction on the paper-based device, in which reaction solutions were transported by the microfluidic device, can be implemented with the assistance of surface acoustic wave energy radiation. The transport of red ink solution and the color development reaction of starch were implemented by the piezoelectric microfluidic device, which verified the function of microfluidic analysis device.

A spoof surface plasmon polaritions (SSPPs) microwave band pass filter with stepped slot structure is designed by using FDTD method. The filter is composed of four sections, in which the second section (i.e. the stepped impedance slot section) is the transition section. The novel periodically arranged stepped impedance slot design can enhance the confinement effect of microwave band sub-wavelength, improve the pass-band characteristics and the ability of resisting electromagnetic interference of the SSPPs band pass filter. The transmission and reflection properties of the SSPPs filter in the microwave frequency range are investigated by FDTD method. The results show that through adjusting the geometrical dimensions of the stepped impedance slot structure as well as the coupling gap parameters in the transmission line, the bandwidth and suppression characteristics of the filter can be flexibly controlled and the filter has strong resistance to the space electromagnetic interference.

In order to reduce the complexity of the structure of electrically tuned bandpass filters, an electrically tuned filter based on step impedance resonators is designed in this paper. The varactor diodes are used as tuning elements and the chip inductors are used as input-output coupling elements. The ADS and HFSS software were used to analyze the relationships between the coupling coefficient and the external quality factor with frequency. The simulation results show that the coupling coefficient and external quality factor keep constant from 0.45~1.0 GHz. The proposed filter was manufactured on a Rogers 5880 (tm) dielectric substrate with relative dielectric constant of 2.2 and measured by network analyzer. The measured results are basically consistent with the simulation results.

The generation of frequency modulated continuous wave, namely FMCW signal source, is an important part of the frequency domain sampling reader of the surface acoustic wave (SAW) radio frequency identification (RFID) system. To satisfy the requirements of frequency sweep speed, bandwidth and linearity, the ultra-high frequency (UHF) FMCW signal source is designed by the mixing of direct digital frequency synthesizer (DDS) and phase locked loop (PLL) and combining with IQ modulation. The signal source circuit is actually fabricated. The DDS chip outputs the dual-channel quadrature signals, I and Q, which are transmitted to IQ modulation chip in differential form for up-conversion respectively. The differential and orthogonal characteristics of the DDS output signals are tested; the single frequency signal and sweep frequency signal generated by signal source are tested respectively. Finally, a test system is built to measure the SAW tag, and the test results show the effectiveness of the design of the FMCW signal source.

The high-speed fiber acousto-optic modulator based on InP was introduced in this paper．The design principle of high-speed fiber acousto-optic modulator was analyzed．The design parameters of high-speed fiber acousto-optic modulator are obtained by simulation. A 300 MHz fiber acousto-optic modulator with optical wavelength of 1 550 nm was fabricated. The results showed that the insertion loss is 2.8 dB, extinction ratio is 49 dB and rise time of optical pulse is 6.34 ns.

Based on the distributed optical fiber sensing technology, the high density strain information was used to identify the de-bonding defects in the bonded structure, and the research on the identification method of the de-bonding defect was carried out with the insulation foam bonding aluminum alloy structure as the research object. The effect of de-bonding defect detection was studied by using the distributed optical fiber sensor network installed on the metal cantilever beam structure, considering the relative position of fiber and heat-insulating foam, strain level and de-bonding area of heat-insulating foam. The results were verified by bending test of aluminum alloy cantilever plate with heat insulation foam. The results indicated that the distributed optical fiber sensor buried in the adhesive layer was sensitive to the de-bonding defect. The high-density strain information collected before and after de-bonding presented obvious differences, and the strain difference curves in the de-bonding area boundary showed obvious oscillation phenomenon. Therefore, the distributed optical fiber sensor network buried in the bonding layer of the bonding structure can effectively identify the de-bonding defects on the layout path.

The working principle of the differential pressure fiber vector hydrophone and its elements are introduced,and the influence of the equivalent treatment of the fiber layer on the simulation results is analyzed in this paper.Based on the finite element method, the performance of differential pressure fiber vector hydrophone is simulated.Based on the parameters selected by the simulation model, a differential pressure fiber-optic vector hydrophone sample is developed and tested at a frequency of 20 Hz to 1 000 Hz.The test results show that the simulation results of the phase sensitivity of the acoustic pressure are basically consistent with the experimental results, and the average difference is about 1.0 dB.The results show that it is feasible to use the finite element method to simulate the acoustic pressure phase sensitivity of the differential pressure fiber-optic vector hydrophone.

The research on the analytical calculation and design method of bulk acoustic wave (BAW) magnetoelectric antenna is not mature. In view of the errors of existing analytical calculation methods, a set of relatively accurate analytical calculation method for BAW magnetoelectric antennas is proposed. The potential energy of piezoelectric layer and magnetostrictive layer in the magnetoelectric antenna is calculated by the analytical method, and the total potential energy of the magnetoelectric antenna is calculated. Since the radiation power of the magnetoelectric antenna is determined by the aperture electric field of the magnetostrictive layer surface, the constitutive equation is used in this paper to replace the aperture electric field with the sinusoidal stress field, and the average radiation power of the magnetoelectric antenna is calculated, and then the normalized antenna radiation quality factor is obtained. By comparing and analyzing the normalized potential energy, average radiation power and radiation quality factor of the magnetoelectric antenna with different layers, the optimized three-layer alternating stacking structure of ‘piezoelectric layer-magnetostrictive layer-piezoelectric layer’ is obtained, and the optimal multi-layer design of the radiation performance of the magnetoelectric antenna is realized.

Based on the Lamb wave damage detection for the plate structures by using the piezoelectric transducers, a non-reference damage detection method using the single mode Lamb wave is proposed and a damage detection experiment on an aluminum plate is carried out. According to the theoretical model of piezoelectric transducer, the damage reflection echo signals from the detection signal of the damaged plate is accurately identified by selecting the detection frequencies of single mode Lamb wave in the experiment. The distance between the damage and the transducer is calculated through the propagation time of the damage reflection wave and the corresponding group velocity. Aiming at the error in distance calculation caused by the difference between the theoretical group velocity and the experimental group velocity, an improved calculation method is proposed, which reduces the error to less than 3%. The results show that the damage scattering signals in the structure can be identified using the single mode Lamb wave, and the distance between the damage and the transducer can be calculated effectively.

The effect of the piezoelectric ceramics excited Lamb wave on the oil droplet movement on the steel plate is studied. By analyzing the motion equation of oil droplets on the surface of steel substrate, three variables affecting the displacement of oil droplets movement were obtained. The excitation voltage, oil droplet volume and plate inclination angle were treated as three different conditions to study the driving effect of Lamb wave on oil droplets. The experiments showed that when the excitation voltage and oil droplet volume were constant, the motion displacement of the Lamb wave driven oil droplets increased with the increase of the substrate inclination angle, and this feature was more obvious when the oil droplet volume was 10 μL; when the substrate inclination angle and oil droplet volume were constant, the displacement of the oil droplet increased with the increase of the excitation voltage, and the displacement of oil droplet was larger when the oil droplet on the inclined substrate than that on the horizontal substrate; when the substrate inclination angle and the excitation voltage were constant, the driving force of Lamb wave increased with the increase of the volume of the oil droplet, therefore the displacement of the oil droplet increased. The oil droplet with a volume of 30 μL was more affected by the driving and its motion displacement is significantly larger than those of 10 μL and 20 μL oil droplets.

To improve the reliability of MEMS accelerometers, reduce sensor failures caused by wire bonding breakage, a wireless bonding package based on low temperature co-fired ceramics (LTCC) is designed in this paper. The package uses an anodic bonding technique to connect the LTCC substrate to the chip,and simultaneously integrates the circuit transfer board synchronously.This package structure can reduce the package size of the sensor and effectively improve the reliability of the MEMS accelerometers.

On the basis of analyzing the anti-collision principle of the correlation inter-digital transducer (CIDT), by using correlation function and taking the autocorrelation and cross-correlation characteristics of the codes as indicators, two sets of phase codes which respectively containing eight sequences were obtained from the search through the pseudo-random code Gold sequences and Walsh sequences. The δ function model of the CIDT was established to simulate its transfer function and the surface acoustic wave response signals of the CIDTs encoded by the two sets of phase codes were analyzed. The research shows that the CIDTs encoded by Walsh sequences have better anti-collision performance, which indicates that the cross-correlation of codes plays a more critical role in anti-collision performance compared with the autocorrelation codes.

An intelligent cantilever beam model with uniform and variable thickness is designed with uniaxial glass fiber as matrix material and piezoelectric ceramic plate as the research object. The effects of piezoelectric ceramic plates on the modal frequency, the maximum displacement of the unconstrained end and strain distribution of cantilever beam are analyzed by using a method combining numerical simulation with experiment. The results show that increasing the number of PZT laying can effectively increase the natural frequency of the cantilever beam and reduce the maximum displacement of the free end, but it has no significant effect on the strain distribution. When the voltage is applied, the maximum displacement at the free end of the cantilever beam can be further reduced and the strain value at each monitoring point can also be reduced.

In this paper, taking the d33-mode piezoelectric transducer represented by PZT-5H as the research object, the relationship between the actual open circuit voltage of piezoelectric ceramics and the loading frequency is deduced and the necessity of considering the influence of dielectric loss is analyzed. By designing a verification test and using a finite element simulation method, the agreement between the predicted values and the tested values are verified under different transducer structures (single-plate and multi-plate stacking), different loading amplitudes, and different loading frequencies. Based on the experimental results of different structures of piezoelectric transducers, loading amplitudes and frequencies, the correctness of the formula was verified. The experimental results show that the actual open circuit voltage of the piezoelectric ceramics keeps non-linearly increasing with the increase of loading frequency at relatively low loading frequency, while increases slightly when the loading frequency gets higher. The predicted value of the theoretical formula is in good agreement with the test value. The theoretical formula deduced in this paper can be used for the prediction and analysis of the actual output voltage of PZTs.

A narrowband temperature compensated SAW (TC-SAW) filter with near zero temperature coefficient of frequency (TCF) is developed in this work. The blackened 42° Y-X LiTaO3 wafer was adopted as the substrate and SiO2 film was used as the temperature compensated layer. A flattened SiO2 thin film was obtained by CMP method. A TC-SAW filter prototype was fabricated and tested. The tested results showed that the TC-SAW filter had a center frequency of 1 360 MHz and only 390 kHz frequency drift with temperature in the range of -55 ℃ to 85 ℃, the temperature coefficient of frequency(TCF) was about -2×10-6/℃ and insertion loss was about 1.3 dB.

In order to meet the requirements of piezoelectric ceramics to output a larger range of micro-displacement and maintain higher precision in the vibration platform micro-displacement test system, a high-voltage and high-current piezoelectric ceramic driving power supply with DC-biased continuously frequency-amplitude-modulated sine wave output is designed. The design scheme of the drive power supply, key circuit design, control system software design and experimental test are mainly introduced in this paper. The driving power supply is implemented based on a full-bridge inverter circuit and an isolated DC-DC voltage-raising circuit. The fundamental wave of the voltage-current double-closed-loop proportional-integral-controlled sinusoidal pulse width modulation(SPWM) wave is used to adjust the output voltage. By setting up the experimental platform, it is verified that when the piezoelectric ceramic is 5 μF, the driving power supply can realize 100 times gain amplification in the frequency response of 5 Hz~1 kHz, output 0~1 000 V of dynamic sinusoidal voltage, and 7 kW of maximum output power can be achieved. The results show that the designed piezoelectric ceramic driving power supply has higher output voltage, greater output power, faster frequency response, and reduces the size and weight of the power supply.

A spherical ultrasonic motor with synchronous centering structure was proposed, and the mathematical model of driving moment of the motor is established. The emphasis was focused on the structural optimization design of the traveling wave type stator. The modal analysis and harmonic response analysis of the stator were carried out by ANSYS. The optimization variables of structural parameters were determined through the sensitivity analysis. The response surface model of design space was established by taking the maximum frequency difference between the working mode and the disturbing mode and the maximum stator surface amplitude of the stator surface as the optimization target. The multi-objective genetic algorithm(MOGA) was used to optimize the solution to obtain the Pareto frontier, and the final structural parameters were determined and the fabricated stator was tested through the fixed and swept frequency experiments. The test results showed that no disturbing mode was generated within the range of ±2 kHz of the working mode frequency of the optimized stator, and the points on the surface of stator under the two phase standing waves had high vibration amplitude, which met the operating requirements.

In order to solve the problem of the directivity design of transducer array under non-ideal conditions, the theoretical calculation model is established in this paper, and the influence of vibration velocity and phase of array elements with the Normal distribution and Poisson distribution on the three-dimensional directivity of transducer array are investigated. Through the simulation analysis, it is found that the influence of the inconsistency of the array element performance under non-ideal conditions on the directivity of transducer array is mainly reflected in the directional angle and the symmetric distribution of the three-dimensional directivity. The lower the frequency, the greater the influence is. The effects of the vibration velocity and phase of the array elements with different distribution laws on the directivity of transducer array are different, but in general, the greater the dispersion, the more significant the influence is. The method for evaluating and analyzing the directivity of the transducer array under non-ideal conditions presented in this paper can be applied to guide the directivity design of the transducer array and control the directivity parameters of the transducer array during the mass production, which has both theoretical guiding significance and practical engineering application value.

The in-plane mode piezoelectric vibrator is an important branch of piezoelectric actuators, and the miniature in-plane mode piezoelectric vibrator is rarely studied. In order to broaden the application of in-plane bending piezoelectric vibrator, a short-cylinder piezoelectric vibrator is proposed for flexible driving. The structure size, working mode and natural frequency of piezoelectric vibrator are determined by ANSYS. The outer diameter of vibrator is 30 mm, the height is 12 mm, and 36 teeth structures with height of 2 mm are evenly distributed on the outer ring, which is used to amplify the amplitude. The tested results show that the bending working modes of the same frequency orthogonal third-order plane. The experimental results show that the structure can well excite the third-order in-plane bending working modes with two same frequencies orthogonal. The vibrator has the same frequency orthogonality and the resonance frequency is 27 140 Hz in the working mode of B03, which is consistent with the simulation results. The feasibility of the piezoelectric vibrator for flexible driving is verified by experiments.

In order to meet the self-powered requirements of wireless sensor systems with vibration frequency varying in a certain range and limited space, a three degree-of-freedom vibration beam piezoelectric energy harvester with folded beam structure is designed. Based on the system structure and working principle, the theoretical analysis was carried out, and the finite element model of the folded beam structure was established. The finite element analysis and modal simulation are carried out. A prototype of the piezoelectric energy harvester with folded beam is fabricated, and the test platform was built and tested on the vibration table. The experimental results show that the theoretical analysis and finite element simulation results are basically consistent with the experimental results. Under the low frequency vibration of 3.5~8.5 Hz, the voltage greater than 5 V can be generated, and the maximum output voltage is about 17.5 V, which is 1.4 times that of the traditional single beam structure. Furthermore, it has three output voltage peaks and the working bandwidth is 4.5 times that of the traditional single beam structure. The effect of wide frequency is realized. The proposed piezoelectric energy harvester with folded beam structure can be effectively and adaptively used in low frequency and vibration frequency changing environments.

To meet the demands of high precision planar motion drive in the application fields, a novel planar motor driven by dual-H-shaped stator and its dynamic structure were presented. The out-of-plane symmetrical bending vibration, the in-plane bending vibration of the left and right bars, the in-plane bending vibration of the upper and lower bars of the stator were selected as the working modes. Through the resonance coupling with the out-of-plane bending vibration mode and the in-plane bending vibration modes of the upper and lower bars, two elliptical trajectories processing along xz and yz planes were compounded on the driving feet of the upper and lower bars and the left and right bars of the stator respectively to drive the slider along the x-and y-direction motion. A finite element model of the stator was established, so that the working modes of the stator were calculated, and the existence of expected working modes was verified. By calculating the frequency consistency of the stator, the main dimension of 30 mm×8.7 mm×7.4 mm was determined. Based on the harmonic response analysis, the stator’s disturbance mode characteristics were calculated so that the separation of the disturbance mode was implemented. The elliptical trajectories of the feet moving along xz and yz planes were simulated, and the feet vibration amplitudes along x (or y)-and z-direction under 250 V voltage excitation were 1.5 μm and 1.3 μm respectively. The operating principle of the motor was verified, and the vibration regulation characteristics of the feet under the voltage regulation, frequency regulation and the phase modulation were investigated. A fixed scheme for the stator was determined, and the assembly structure of motor is designed. The motor has good dynamic characteristics and application prospects.

As a voltage control device, the stability of piezoelectric ceramic drive power supply is seriously affected by the change of load capacitance. According to the dynamic characteristics of load equivalent capacitance under the change of driving voltage, a piezoelectric driving power supply based on capacitive load is proposed for the first time. The power supply combines RC pre-filtering and capacitive advanced feedback, which can improve the stability and the robustness of the power supply. The analysis results show that the optimized driving power supply with rated load of 1.5 μF has good dynamic performance within 0~3 μF, and the output voltage accuracy reaches 0.7 mV.

The monitoring of horizontal displacement field of deep soil is an important index for the safe excavation of foundation pit. The existing inclinometer method consumes a lot of manpower and has a low accuracy, but it is still the main method to obtain horizontal displacement at present. A distributed optical fiber measurement method based on the optical frequency domain reflectometry (OFDR) technology is proposed in this paper. The conversion relationship between the strain-deflection deformations is derived. The feasibility and accuracy of the distributed optical fiber inclination measurement are verified by indoor experiments. The measurement method based on OFDR has been applied to a foundation pit project in Suzhou, and the displacement information of deep soil during the excavation process is obtained accurately.

Micro-nano manipulation imaging system is an important tool to explore the micro world. The traditional PI controller has problems such as difficult parameter adjustment, low control accuracy and weak anti-interference ability. In this paper, based on adrc, a differential feed-forward link is added to solve the tracking error of adrc in high frequency periodic signals. Firstly, the mathematical model of micro-nano manipulation system structure is given, and an adrc is designed based on the model information. The differential feedforward is given by using the known information. Finally, the simulation is carried out in Matlab. The results show that, compared with the linear adrc and PI control, the adrc with differential feedforward has smaller tracking error, and the system’s anti-interference ability is improved significantly.

Based on the displacement amplification effect of lever, a capacitance detection micromachined gyroscope structure with a micro-lever structure was proposed. The designed lever amplification mechanism was set in the detection mode of the gyroscope, through which the detection displacement of Coriolis mass was amplified and transmitted to the detection frame to improve the detection displacement. The second-order vibration differential equation of lever-coupled micromachined gyroscope was established. The influence of lever on static stiffness and natural frequency of micro gyroscope was analyzed. The magnification effect of lever structure on the detection displacement under different structural conditions was investigated. The accuracy and feasibility of theoretical analysis was verified through simulation. The results showed that in the state of resonance, the displacement of detection frame can be effectively increased by more than 60%, the detection sensitivity is also improved effectively.

Based on the parameters such as the aspect ratio of the permanent magnet and the uniformity of the air gap magnetic field, the magnetic circuit of the quartz flexible accelerometer with Samarium-Cobalt permanent magnet (Sm2Co17) was designed using theoretical calculations and simulation analysis. The height ratio of the permanent magnet to the magnetic cap was adjusted, and the air-gap magnetic field of the two height ratios is measured. The one-month repeatability test was performed on the scale factor of the quartz flexible accelerometer with two different magnetic circuits. The results show that the optimized magnetic circuit can obtain the uniform air-gap magnetic field and maintain good long-term performance.

A high sensitive and low cost hydrophone based on resonant air cavity is proposed in this paper. The hydrophone is formed by a sealed hollow spherical shell/cavity with a microphone inside to sense the sound coupled from the water outside. The frequency response of the hydrophone is predicted by finite element simulation, and it is confirmed that the characteristic peak of the frequency response curve depends on the resonant mode of the air cavity and is independent of the shell resonance. Therefore, the resonant frequency of the hydrophone only depends on the size of the internal air cavity. The experimental results demonstrate that the frequency response of the hydrophone is consistent with the simulation results, and the sensitivity is improved compared with the conventional piezoelectric hydrophone. The receiving sensitivity at the resonant frequency is 10 times higher than that of the conventional piezoelectric hydrophone.

The guided wave field analysis method can effectively identify and characterize the structural damage, but due to the limitation of Nyquist sampling law, the acquisition of full-wave field signals is often time-consuming. In order to improve the acquisition efficiency of full-wave field signals, the existing methods rely on compressed sensing technology and laser Doppler vibration measurement technology to reconstruct the original wave field with a small number of spatial signals. However, these methods rely on a random jittered sampling strategy, which is difficult to achieve in commercial laser Doppler vibration measurement system. In order to solve this problem, a guided wave field reconstruction method based on uniform sparse sampling strategy is proposed in this paper, and a PZT-excitation/SLDV-sensing experimental platform is constructed to verify this method on an aluminum plate with artificial damage. The experimental results show that the proposed method can reduce the number of space measurement points to less than 10% of Nyquist sampling points, and achieve the same level of reconstruction accuracy and damage imaging accuracy as the existing jittered sampling strategy, which can greatly improve the practicability and efficiency of guided wave field analysis method.

Aiming at the problem of excessive state dimension of nonlinear filter in SINS filtering alignment process under large misalignment angles, the Kalman filtering/extended Kalman filtering (KF/EKF2) hybrid filtering method based on the model decomposition is proposed. The initial alignment model based on Euler platform error angle (EPEA) is decomposed into the linear part and nonlinear part, and is processed by the linear KF filter and nonlinear EKF2 filter respectively. The filtering process is designed to ensure the overall optimization of state variables. The experiment results show that the KF/EKF2 hybrid filtering algorithm is superior to the most commonly used unscented Kalman filtering (UKF) and EKF2 filtering in terms of computational complexity, real-time performance and accuracy.

In view of the demand of the early strength monitoring of sleeve grouting materials in practical engineering, based on the principle of piezoelectric wave analysis method, a method of monitoring early strength of sleeve grouting materials by using piezoelectric smart aggregate is proposed, and the experimental research on early strength monitoring of sleeve grouting materials is carried out. Through the experiment, it is found that the signal amplitude of smart aggregate decays rapidly in the first 5 days of age, while the strength of the grouting material increases rapidly. Then the change of the two gradually slows down and eventually stabilized with age, which shows the changing trend of signal amplitude of the smart aggregate can well reflect the strength development trend of grouting material. The amplitude of the monitoring signal and the measured strength of the grouting material are normalized, and the data are fitted and analyzed by using the univariate cubic polynomial function, the exponential function and the power function respectively. By comparing the parameters of the fitting goodness, the fitting effect of the univariate cubic polynomial function is the best. Finally, the standard of nondestructive monitoring method for the early strength of the sleeve grouting material based on piezoelectric smart aggregate is given. The condition and standard equation can provide reference for practical engineering application.