This paper proposes a dual-core D-type high-sensitivity SPR-PCF sensor, which uses the surface plasmon resonance (SPR) technology to measure the change of the resonance wavelength by the core loss spectrum to achieve the purpose of measuring different refractive indices of the substance to be measured. By changing the arrangement of the internal air holes, it achieves the effect of dual core transmission, and the D-type structure is beneficial to speed up the surface plasmon reaction. Its working wavelength range can be adjusted, and its structure is simple and easy to measure and operate. The experimental results show that the refractive index measurement interval is 1.35-1.40.The maximum spectral sensitivity is 15 000 nm/RIU, maximum amplitude sensitivity is 582.12 RIU-1, and the refractive index accuracy of the probe is 1.56×10-5 RIU.

The swept light source is a key component of the swept source optic coherence tomography (SSOCT).A high quality swept light source can improve the imaging speed, resolution and signal-to-noise ratio of the SSOCT. In this work, a ring-cavity swept source was built by using fiber acousto-optical tunable filter (FAOTF), polarization-maintaining booster optical amplifier (PMBOA), fiber isolator and fiber coupler. The experimental results show that an all-fiber swept light source with the sweep speed of 100 kHz, sweep range of 119 nm (from 1 550.146 2 nm to 1 619.470 0 nm), single spectrum 3 dB bandwidth of 0.096 6 nm and average optical output power of 12 mW has been realized. The swept source has the advantages of wide sweep frequency range, fast speed, and good coherence and so on. It has certain practical value as a light source in SSOCT system.

A Doppler frequency shift method based on acousto-optic modulation for microwave signals was introduced in this paper. This technology is based on microwave photonics signal processing and acousto-optic frequency shifting technology. The Doppler frequency shift of microwave signals in the optical domain has been realized and it can be used for generating radar interference signals. The operating frequency range of the system is 2-20 GHz. The test results show that the frequency shift range of the velocity deception interference signals is ±1 MHz and the minimum frequency shift is ± 10 Hz. The system realizes the Doppler frequency shift simulation test of radar pulse signal when the target velocity reduced from 1 200 m/s to 1 000 m/s.

Based on the metamaterial structure, a terahertz electro-optic modulator operating at the frequency of 0.34 THz is designed, manufactured and characterized in this paper. The modulator loads voltages through the metamaterial structure and obtains a strong electric field at the opening of the metamaterial structure to transport the photon-generated carrier generated by the silicon under constant laser irradiation. By modulating terahertz waves with the voltage modulation signals, the modulation depth is increased from 9% to 50%, and the modulation speed is up to 30 kHz.

The design and fabrication of a novel Bragg reflection-type thin film bulk acoustic wave (BAW) filter is investigated in this work. In BAW devices, Y43° lithium niobate single crystal thin film (Y43°-LN) with high electromechanical coupling coefficient was selected as the piezoelectric material and the Benzocyclobutene (BCB) was used as wafer bonding layer. The Y43°-LN monocrystalline thin film with submicron thickness was transferred to the substrate with Bragg reflection layer by the crystal-ion-slicing method. As both the bonding layer and the first low impedance layer of Bragg reflector, BCB is used to prepare the single crystal BAW filter. The third-order BAW filter wwith the central frequency of 2.93 GHz, absolute bandwidth and fractional bandwidth of 247 MHz and 8.4% respectively is designed and fabricated. The results indicate that the high electromechanical coupling coefficient LN single crystal thin film prepared by film transfer technology can realize the preparation of large-bandwidth BAW filter.

As a new type of acoustic circulator, the bulk acoustic wave(BAW) circulator has the advantages of small volume, low cost and compatibility with CMOS technology, and does not need ferromagnetic materials and external bias magnetic field compared to the traditional ferrite circulator. It has a broad market prospect in modern wireless communication system. This paper describes the basic principle and structure of BAW circulator, introduces the research progress of BAW circulator at home and abroad, compares the performance of BAW circulator with different structure and modulation circuits, analyzes the PCB layout and test, and summarizes the characteristics and development direction of BAW circulator.

In order to improve the static power consumption and dynamic performance of piezoelectric ceramic drive power supply, a high-voltage amplifier with variable static operating point and operating voltage is proposed. First, an amplifier with a constant current source structure is used to construct a typical high-voltage amplifier. Then, the working current of the amplifier is dynamically adjusted by a proportional differential circuit. Finally, the multiple sets of tap power are used to supply power to the high-voltage amplifier in sections to further reduce system power consumption. The experimental results show that the amplifier can dynamically output 400 mA at 10 mA quiescent current; the working voltage of the amplifier can be automatically switched among 50 V, 100 V, 150 V, and 210 V according to the output voltage. The amplifier can obtain excellent dynamic characteristics at a very low quiescent current, which can meet the design requirements.

In order to solve the contradiction between the large motion range and the large scanning range of the precision positioning platform and realize the cross-scale nano positioning of the large motion range, a precision positioning platform based on the driving principle of dual piezoelectric ceramics was proposed in this study. The device combines the advantages of large motion range of the stick slip drive positioning platform, large scanning range of the piezoelectric scanner and high resolution. The platform consists of a base, a driving module, a flexible hinge mechanism and a guide rail. The driving module includes large and small piezoelectric ceramics, which drive the positioning platform in scanning mode and stepping mode respectively The experiment shows that the precision positioning platform has a maximum motion range of 21 mm, a maximum scanning range of 4.9 μm, a minimum resolution of 16 nm, and a maximum horizontal stepping motion speed of 10 mm/s, which meets the compatible requirements of large stroke and large scanning range.

In this paper, a dual-mode piezoelectric stick-slip actuator is proposed. The combination of a non-resonant mode and a resonant mode is realized by an intermediately fixed piezoelectric unimorph and a flexible amplifying mechanism, so that the actuator can achieve high motion accuracy and fast response. The appropriate flexible amplification mechanism parameters are obtained by the finite element method, and the feasibility of the dual-mode operation of the driver is analyzed and verified. The dynamic model of the actuator is established, and the test system is set up. The experimental results show that the stick-slip actuator driven by an intermediately fixed piezoelectric unimorph can achieve dual-mode operation. In non-resonant mode, the prototype can achieve a minimum step of 0.056 μm and a maximum output load of 1.2 N. In resonant mode, the maximum output speed of the prototype is 12.56 mm/s and the maximum output load is 1.4 N.

In this paper, a flapping wing micro-aircraft with double-drive was designed, fabricated and investigated. This aircraft was mainly fabricated by smart composite microstructures(SCM). The total quality of the prototype was 244 mg, and the wingspan was 61 mm. The performance of the prototype piezoelectric driver was tested. The results showed that the no-load resonance frequency of the piezoelectric actuator was 1 100 Hz and the load resonance frequency was 28 Hz. The lift test of the prototype was carried out, and the lift of the prototype was 0.689 mN.

In order to achieve the purpose of suppressing the vibration of wind tunnel model under pulsating airflow excitation, an active vibration control method of the wind tunnel model based on neural network model of piezoelectric ceramic actuator is proposed, and the experiment study was carried out in this work. Firstly, the vibration characteristics of the wind tunnel model system were analyzed, and the active vibration control system of the embedded piezoelectric ceramic actuator was set up. Secondly, a neural network model of piezoelectric ceramic actuator’s expected output damping force and excitation voltage was established, and a real-time control method was designed based on the neural network model to calculate the acceleration as excitation voltage. Finally, the effectiveness of the control method was verified by ground test. The experimental results showed that the control method had good real-time performance and robustness. In the hammer test, the decay time of vibration acceleration is reduced by 54.46% compared with the piezoelectric equation linear control, the system damping ratio is increased by 1.58 times, and a good control effect is obtained.

In order to meet the requirements of high frequency, high power, and miniaturization of RF devices, a two-dimensional model of a solidly mounted resonator (SMR) with a resonance frequency of 3.455 GHz was designed using the finite element analysis software COMSOL Multiphysics. The effects of different electrode area (200 μm2, 150 μm2, 100 μm2, 50 μm2, 25 μm2) on the lateral parasitic resonance of the resonator are investigated, and the influences of changes in the top electrode and simultaneous changes in the top and bottom electrodes on the lateral parasitic resonance of the device are compared. The lateral parasitic resonance of the device near the resonance point (3.455 GHz) increases with the reduction of the electrode area. The lateral parasitic resonance of the device is most significant when the electrode area is 25 μm2. When the amount of change in the electrode area is constant, the lateral parasitic resonance caused by simultaneously changing the areas of the top and bottom electrodes is greater than that caused by only changing the top electrode area.

The BST thin films were prepared by RF magnetron sputtering with two different processes of high-temperature sputtering or low-temperature sputtering followed by high-temperature annealing processes. The effects of the two sputtering processes on the structure, micromorphology and dielectric properties were studied. The crystal structures of BST thin films were characterized by X-ray diffraction (XRD). The micromorphology and surface profileof samples were analyzed by scanning electron microscopy (SEM) and surface profilometer. The uniformity of component distribution was showed by energy dispersive spectroscopy (EDS) analysis. Finally, the dielectric constant bias characteristic of the BST film was obtained bymeasuring the capacitance-voltage (C-V) curve.The results show that, compared with the BST thin film prepared by the low temperature sputtering and high temperature annealing process, the BST thin film prepared by the high temperature sputtering has better crystallinity, higher density, smoother surface, and uniform film composition distribution. Therefore, the BST thin filmsprepared by thehigh-temperature sputtering process have better properties.At a frequency of 300 kHz, the dielectric constant of the BST film prepared by high-temperature sputtering is 127.5-82.0, and the tunability is 23.86%-27.9%.

In this study, the ErAlN films under different nitrogen-argon flow ratios were deposited on a sapphire (0001) substrate by RF reactive magnetron sputtering, and surface acoustic wave (SAW) filters were fabricated based on the ErAlN films. The results show that as the nitrogen-argon flow ratio increases, the crystalline quality and c-axis orientation of the film become better first and then worse, and the surface roughness decreases first and then increases. When the N2/Ar ratio is 12∶17, the ErAlN thin films own best crystal quality and minimal surface roughness. The SAW filter based on ErAlN film has a resonance effect between 273 MHz and 288 MHz, and when the N2/Ar ratio is 12∶17, the SAW filter has the smallest insertion loss and the largest transmission coefficient.

The ZnO seed layers with different Bi3+-doping concentrations were prepared by Sol-Gel method, and wurtzite structured ZnO nanorods were synthesized by hydrothermal method. The X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and photoluminescence (PL) spectrum were used to measure and characterize the structure, morphology and optical properties of the samples. The results show that the nano ZnO films grown on the Bi-doped ZnO seed layer with different concentrations has no change in the crystal structure of ZnO, which is hexagonal wurtzite structure, and the peak intensity of (002) crystal surface is significantly higher than that of other crystal surfaces. It was found by FESEM that the hydrothermal growth of nano ZnO films on the seed layer of Bi-doped ZnO with different doping concentration is in the shape of nanorods. The PL spectrum shows that the peak values of near ultraviolet (UV) emission and lattice defect increase obviously with increase of the amount of the Bi-doping, and the red shift phenomenon occurs. The band gap width decreases with the increase of the amount of Bi-doping, which indicates that Bi3+ can effectively adjust the band gap width of ZnO.

The ZnO varistor ceramics with rare earth oxide La2O3 doping were prepared by conventional solid state reaction method. The phase compositions, microstructure and electrical properties of the as-prepared samples were investigated by X-Ray diffraction (XRD), scanning electron microscope (SEM) and varistor DC parameter tester. The results show that with the increase of La2O3 doping content, the potential gradient of ZnO varistor ceramics increases monotonically, the nonlinear coefficient initially increases and then decreases, while the leakage current first decreases and then increases. According to the comprehensive evaluation of the specifications of ZnO varistor, when the doping content of Gd2O3 is 0.25% (mass fraction) at the sintering temperature of 1 000 ℃, the comprehensive performance of the ZnO varistor is the best, and the potential gradient, the nonlinear coefficient and the leakage current are 532.2 V/mm, 41.6 and 3.3 μA, respectively.

In the structure of bulk acoustic wave (BAW) magnetoelectric antenna, the induced current generated by the magnetic film in the magnetostrictive layer in the high frequency magnetic field will cause eddy current loss, which in turn affects the radiation performance of the antenna. To analyze and suppress the eddy current loss of magnetic thin films, the eddy current loss model of FeGaB magnetic thin film is established by using the finite element simulation method. According to the skin effect of eddy current, the surface eddy current and internal eddy current are discussed. And eddy current suppression is carried out by inserting Al2O3 thin film to isolate the current. Through the comparative analysis of three kinds of Al2O3 film separation methods, the optimal separation methods for the surface eddy current suppression and the internal eddy current suppression are obtained. Considering the influence of the total eddy current, a cross separation method is proposed as the optimal separation method to suppress the eddy current loss. The simulation results show that the total eddy current loss can be suppressed more than 65% by using the proposed method to insert 10 nm Al2O3 thin film into the FeGaB magnetic thin film.

The fabrication of composite single crystal film and the use of wafer-level packaging are needed with the development of surface acoustic wave devices toward miniaturization, integration and higher performance. In this paper, the key process of wafer bonding is studied, and the process requirements are proposed. The key process requirements and equipment characteristics are briefly described, and the metal bonding process is verified. The experiment shows that both the equipment and process can meet the product packaging requirements.

In order to provide technical support for the design and optimization of the fluid-induced vibration energy harvesting device based on the flexible piezoelectric materials, the piezoelectric properties of the MFC (Macro-Fiber Composite) under the action of bending and swinging was studied. Firstly, the piezoelectric output mechanism of MFC piezoelectric fiber sheet was analyzed theoretically, the piezoelectric model of MFC piezoelectric fiber sheet was established, and various factors affecting the magnitude of the open circuit voltage output of the MFC piezoelectric fiber sheet are obtained. Then a MFC piezoelectric fiber sheet reciprocating bending and swinging test bench based on stepper motor is designed and built, the piezoelectric properties of MFC piezoelectric fiber under different bending angles, bending and swinging speeds, substrates, surface areas and other factors were studied by using the test bench. The results show that the output open-circuit voltage amplitude of MFC piezoelectric fiber increases with the increase of bending angle. When the output voltage amplitude reaches the maximum and the bending angle continues to increase, the output open-circuit voltage amplitude will not change significantly. The output open-circuit voltage amplitude will increase as the surface area of the piezoelectric sheet increase, and the bending swing speed and substrate have no obvious influence on the output open-circuit voltage amplitude.

In the field of aerospace and high-end equipment manufacturing, it is often accompanied by the occurrence of a large value ratio load. In order to monitor its working status, it is necessary to accurately measure the size and direction of large ratio load. In this paper, a piezoelectric force test system is taken as the research object, and a method of rotating simulation loading for dynamometer calibration is proposed. First, based on the principle of force decomposition, combing the principle of deviation between the actual axis and the theoretical axis of the calibration device, the geometric distribution law of lateral combined force with loading azimuth was obtained during the simulated loading process. Aiming at the characteristics of the lateral force fluctuation, a new simulation loading method-rotation simulation loading method was proposed. Finally, a vector force simulation loading experiment was designed. The experiments of non-rotation simulation loading method and the rotation on the test system was carried out and compared. The results show that the rotation load calibration method reduced the lateral total force output error by 18.7%F.S., which verified the feasibility and rationality of the rotation simulation loading method.

In order to ensure the safety of constructors and construction machinery in the process of physical excavation and demolition of Dalian Huaneng concrete silo, a long-gauge fiber Bragg grating (FBG) strain sensor was designed to monitor the whole process in real time. Through the static and dynamic analysis of the strain data collected by sensors, the variation of the surface strain and natural frequency of the silo structure with the opening rate was obtained, and then the structural damage was identified. During the monitoring of the concrete silo, the sensor operated steadily, the structural strain response data during the whole demolition process was obtained, and an early warning of structural collapse was given. The concrete silo collapsed successfully according to the predetermined direction. The research results have solved the problems of blindness and passive delay of safety measures in traditional demolition work and provided an important technical reference for similar concrete demolition work.

In view of the development demand that the existing high-temperature acceleration sensor needs to quantify the temperature response gap with similar imported products, a synchronous high-temperature vibration comparative test method of high-temperature acceleration sensor is proposed, and a special test system is developed. The test and evaluation of the temperature response and high-temperature stability of a certain type of high-temperature piezoelectric acceleration sensor and the same kind of imported products are carried out by comparison. The sensitivity of the piezoelectric acceleration sensor increases with the increase of temperature in the temperature range of 23-400 ℃.The maximum sensitivity temperature drift of the piezoelectric accelerometer is 6.17%, which is about 2.53 times of the Kistler accelerometer. In terms of high-temperature stability, the average high-temperature sensitivity stability of the piezoelectric accelerometer is about twice that of the Kistler accelerometer.

An optical terahertz modulator based on graphene/boron nitride 2D heterostructure coated silicon was studied in this paper. The static and dynamic modulation of THz wave were tested respectively with a 808 nm laser by using the terahertz time-domain spectrum system and a terahertz wave dynamic test system independently built by the laboratory. When the laser power is increased from 0 to 500 mW, the average transmittance through the terahertz modulator decreased from 58% to 13% with maximum modulation depth of 76% (500 mW). The maximum modulation speed obtained by the dynamic modulation test is 15 kHz (100 mW). The experimental results show that the modulation depth and speed can be obviously enhanced by graphene/boron nitride 2D hetrostructure in contrast to the single-layer graphene coated silicon.

A sixth-order Chebyshev active analog bandpass filter is designed for the characteristics and extraction requirements of the quartz tuning fork resonance signal in the quartz enhanced photoacoustic detection system. The actual circuit design is completed according to the Chebyshev filter theory and the Sallen-Key topology structure model, and the performance of the filter is verified through a quartz tuning fork resonance characteristic test experiment. The experimental results show that this filter can filter and de-noise the quartz tuning fork photoacoustic signal without distortion amplification. The specifications of the filter are that the passband is 935 Hz, ripple is 0.8 dB, out-of-band attenuation is 51 dB, and Q value is 35.09, which can effectively suppress ambient noise and can be used for processing photoacoustic front-end signals in the field of quartz enhanced photoacoustic spectrum detection.

The attitude measurement under the conditions of high overload is a recognized problem, mainly because the angular velocity sensor is difficult to withstand the impact of high overload. The gyroscope based on micro electro mechanical system (MEMS) technology is the core device to solve the problem of attitude measurement of high overload. Its ability to resist high overload directly restricts the application of inertial navigation system in high overload environment. First, the characteristics of two typical high-overload environments for ammunition launch and penetration are introduced, and the response types of MEMS gyroscope in high-overload environments are summarized. Secondly, the failure modes of MEMS gyroscope under the conditions of high overload are summarized, including complete failure and functional failure. Then, the research progress of MEMS gyroscope with high overload resistance at home and abroad is introduced. Finally, from the perspective of device design and engineering applications, the design method and application ideas of MEMS gyroscope with high overload resistance are proposed.

The hemispherical resonant gyro in the whole angle mode is a rate integrating gyro, which has the characteristics of wide measurement range, high bandwidth and high accuracy. In this paper, the whole angle mode of a two-piece hemispherical resonator gyro composed of resonators and surface electrodes is studied. The pattern control and the single solution method are introduced and implemented through the FPGA and DSP architecture and the standing wave azimuth is resolved. The experimental data show that the developed two-piece hemispherical resonance gyro prototype can realize the function of rate integrating gyro, with the measurement range of ± 400 (°)/s and the maximum system drift of 20 (°)/h. Compared with the hemispherical resonant gyro in the force balance mode, it broadens the measuring range of the hemispherical resonant gyro, and lays a foundation for further improving the accuracy of the full-angle hemispherical resonant gyro

The micro electro mechanical system (MEMS) gyroscope has the advantages of small size, high accuracy and broad application prospect. Due to the different thermal stress and thermal resistance of inertial components, the output of the corresponding sensor will produce temperature hysteresis effect, which seriously affects the zero bias stability of gyroscope. In view of the poor adaptability of the traditional gyroscope temperature error compensation method, this paper proposes a temperature hysteresis zero bias compensation model by using the moving average algorithm (MAA) to compensate the zero deviation of MEMS gyroscope in the full temperature range. The experimental results show that when the working temperature of the gyroscope changes in the range of -30 ℃ to +90 ℃ after compensation, the absolute error of the corresponding zero bias decreases from 0.21 (°)/s to 0.02 (°)/s, and the stability of the zero deviation increases by nearly one order of magnitude.

In this paper, an ultrasonic fixed-point liquid level monitoring sensor for airborne wastewater storage tanks is designed. The sensor adopts a fully enclosed structure, which effectively eliminates the adverse effect of the environment on the monitoring process. At the same time, a dual decision algorithm is proposed to improve the accuracy and reliability of the monitoring. The effectiveness of the sensor is verified. The theoretical and practical analysis shows that the sensor can monitor and alarm the fixed-point liquid level more accurately and stably.

Aiming at the requirements of miniaturization and low profile of UHF RFID metal-mountable tag, this paper proposes a metal-mountable UHF RFID tag antenna with a size of 50 mm×20 mm×0.9 mm. The design uses CST MWS software for modeling and simulation. The effects of the changes of the size of the inset-feed structure and the size of the rectangular slot on the input impedance of the tag antenna are analyzed, and the corresponding parameters are adjusted to realize conjugate impedance matching between tag antenna and microchip. The measured results show that the input impedance of the tag antenna and the chip impedance are well matched. The tag antenna has a maximum measured read range of 4.3 m at 910 MHz, and has a small size and low profile. It can be applied to metal scenes in various fields such as logistics, medical treatment and retail.

An ultra-wideband antenna with four band-notched and reconfigurable characteristics is designed in this paper. The four notch characteristics of the antenna are realized by etching a U-shaped slot slit on the antenna radiation patch and the microstrip feed line, and adding an annular opening parasitic element on the modified floor. The trapping reconfigurable characteristic is realized by adding a PIN diode switch in the band-notch structure, and the three band-notch and four band-notch characteristics are respectively realized by the opening and closing of the switch, thereby the utilization ratio of the ultra-wideband frequency band are further improved. The principle of antenna band-notch generation is analyzed, and the influence of antenna size parameters on the notch is studied. The comparison between the simulation and measurement results shows that the antenna can effectively suppress the interference of narrow-band systems in the 3-11.74 GHz. The size of the antenna is 24 mm×16 mm×0.8 mm, and the structure is compact. It can be widely used in various UWB communication systems.

A method of frequency invariant near-field broadband beamforming is proposed in this paper. The output signals of a uniform concentric circular array (UCCA) are converted into phase mode signals by using inverse discrete Fourier transform (IDFT), and a far-field array with frequency invariant response is then approximately achieved by using the near-field correction and frequency compensation network. Therefore, the traditional far-field narrow-band beamforming methods can be extended to the proposed near-field broadband array. The simulation results show that the array response of the near-field broadband array is approximately frequency invariant, and its beam pattern is also similar to that of the far-field narrow-band array. In addition, compared with other beamforming methods, the performance of the proposed frequency invariant near-field broadband array is significantly improved with even lower computational complexity.