To further improve LTE B3 diplexer interband isolation, a high-isolation SAW duplexer module is designed using SIP technology in this study. The module is composed of two SAW duplexers and three couplers. It applies the phase cancellation of the TX-RX path and the isolation of the couplers to improve the isolation between the uplink and downlink of a single SAW duplexer. An impedance-element filter architecture is used to achieve an isolation degree of 51 dB for the proposed module. A broadside stripline multilayer helical coupler-line architecture is adopted to achieve miniaturized integrated 3 dB couplers with a wide operating bandwidth. The results of the developed module show that in the B3 band, for a SAW duplexer measuring 8.0 mm×8.0 mm×2.0 mm, the insertion loss is less than 3.2 dB, the return loss exceeds 13 dB, and the isolation degree exceeds 65 dB; furthermore, it can withstand instantaneous power levels up to 34 dBm.

To meet the increasing demand for Q-value and out-of-band suppression in narrowband surface acoustic wave filters, this paper proposes a design method based on a new type of piezo on insulator (POI) structure resonator.The purpose of changing the wave propagation angle is achieved by rotating the resonator, and accurate experimental data are obtained using a two-dimensional full model, which is compared with the original structure resonator in the filter design. The experimental results show that this method can effectively increase out-of-band suppression, with a 2-4 dB improvement in transition band suppression ability. Additionally, the design is simple and requires little space

The performance of small-volume surface acoustic wave (SAW) filters is significantly affected by packaging. To solve this problem, a new SAW trapezoidal filter circuit topology is proposed. By analyzing the phenomenon of the upturn of the remote rejection caused by the packaging of the filter at high frequency, the layout design is changed from the circuit structure to realize the on-chip inductance. The circuit topology that combines the conventional trapezoidal filter structure with the special grounding structure of the longitudinally coupled dual-mode resonator type filter (DMS) contributes to out-of-band rejection and design flexibility. The optimal topology of the high-order RF SAW filter with a center frequency of 2 580 MHz, bandwidth of 50 MHz, and an insertion loss of less than 2.5 dB is obtained via simulation analysis on a standard 42°Y-X lithium tantalate (LiTaO3) substrate.

To satisfy the demand for the miniaturization and universality of wideband-frequency synthesizers in radio-frequency and microwave circuits, SiP technology based on high-temperature co-fired ceramics (HTCC) is utilized to miniaturize wideband-frequency synthesizers in this study, and multifunctional circuits are utilized for signal amplification, frequency division, and frequency doubling. This design affords a miniature wideband-frequency synthesizer(0.1-40 GHz) measuring 15 mm×12 mm×3 mm, and its performance satisfies the demand of engineering applications. This design can promote the engineering application of wideband-frequency synthesizers.

To achieve spurious wave suppression and its simulation for piezoelectric surface acoustic wave(SAW) devices with arbitrary piezoelectric complex film structure, this study derived the equation of hierarchical cascade theory and a dispersion 2D-COM model of SAWs with a finite-length structure on the basis of rigorous mathematical analysis. The proposed approach can accurately and quickly calculate the influence of the propagation and aperture direction of the SAW device. The dispersion 2D-COM model facilitates the analysis of the suppression of spurious waves in SAW devices. Experimental results obtained from the design and implementation of the SAW filter with a 41°Y-X LiNbO3/SiO2/Si_poly/Si(111) structure were in good agreement with the simulation results, verifying the effectiveness and feasibility of the method.

Considering the electromagnetic parasitic parameters of the encapsulated tube shell and layout, the passband of an RF surface acoustic wave (SAW) filter narrows, and the standing wave increases. This paper proposes a method to quickly extract the electromagnetic parasitic effects in the package shell and layout and accurately simulate their influence on filter performance. First, FEM electromagnetic simulation software was used to extract the electromagnetic parasitic parameters of the encapsulated tube shell. Then, circuit simulation software was employed to co-simulate the designed filter with the extracted packaging parasitic parameters and filter layout. This approach eliminates the need for repeated electromagnetic simulations in FEM software, improving time efficiency.The method was verified on a SAW filter with a center frequency of 1 268 MHz, a passband insertion loss of less than 1 dB, an in-band standing wave of less than 1.6, an in-band fluctuation of 0.5 dB, and a bandwidth of 24 MHz(relative bandwidth of 1.8%). The SAW resonators used in this design were de-embedded, allowing for more accurate simulation of the measured filter results.

The microwave receiving front-end plays an important role in a channel receiver in the field of electronic surveillance. This paper presents a design scheme for an ultra-wideband, multi-channel, low-noise, low-sensitivity, and large dynamic range receiving front-end. Design simulation and prototype testing were used to verify the feasibility of the solution. Compared to traditional schemes, this receiving front-end optimizes the noise figure and switching isolation by 20%. The product size is 53 mm×115 mm×9 mm, and the performance indices meet the design requirements.

In this study, a B41 band SAW filter was designed, and SMD and CSP packages were modeled using 3D electromagnetic field simulation software. The acoustic-electromagnetic simulation results of the two packages were compared, leading to the preliminary conclusion that, for the topology of the filter circuit, the out-of-band rejection at high frequencies may increase (warping “upward”) when two different parallel branches are connected.This effect is due to the electromagnetic parasitic parameters of the bonding leads in the SMD package. SMD package models were established and simulated with varying numbers, diameters, and lengths of bonding wires to calculate the S-parameters. The simulation results indicate that as the diameter of the bonding wire increases and the length decreases, its equivalent inductance becomes smaller. Consequently, the electromagnetic parasitic parameters of the bonding wire decrease, reducing their influence on the performance of the SAW filter, and optimizing the outof- band rejection performance at high frequencies. Additionally, the ball-implanted inverted button of the CSP package exhibits smaller electromagnetic parasitic parameters, resulting in better joint acoustic-electromagnetic simulation outcomes, which align well with the measured results.

The fusion algorithm based on multi-state constrained Kalman filtering solely uses a single frame image for pose estimation. If the initialization is incorrect, then it can cause severe divergence in visual pose estimation.Furthermore, each visual feature point in the system state vector can easily lead to computational burden to the system. Given the aforementioned problems, an improved keyframe selection algorithm is proposed, which uses multiple visual keyframes to constrain the same feature points for reducing visual measurement errors and improving positioning accuracy. Simultaneously, only the camera pose calculated from keyframes is integrated into the system state vector, which can effectively reduce system computation. The experiment shows that the improved algorithm enhances positioning accuracy and computational efficiency by 29.09% and 32.2%, respectively, when compared to EKF. Additionally, the proposed algorithm increases computational efficiency by 35.48% when compared to that of Orb-slam2.

To address the issue of reduced filtering accuracy in integrated navigation systems caused by variable noise interference, an algorithm based on interactive multi-model (IMM) and square-root cubature Kalman filter(SCKF) is proposed. The IMM-SCKF filtering algorithm employs multiple model sets and adjusts the probability of the sub-model while fusing the output, allowing it to simulate the actual noise covariance to a certain degree. Simulation and road test results show that the root mean square (RMS) error of the IMM-SCKF algorithm is superior to that of the traditional single-model CKF algorithm, effectively enhancing the reliability of the integrated navigation system. Compared to the traditional CKF algorithm, the IMM-SCKF algorithm reduced the RMS error in eastward, northward, and up speed errors by 52%, 55%, and 30%, respectively, and the RMS error in position by 47%,60%, and 32%, respectively. The IMM-SCKF algorithm significantly improves the positioning accuracy and antiinterference ability of the system.

The output of quartz crystal microbalance (QCM) sensors is in the form of frequency signals. These sensors offer advantages such as low cost, fast response, and high sensitivity. This study utilized porous α-Al2O3, a moisture-sensitive material, to enhance the humidity detection sensitivity of QCM sensors. Simulations were performed using COMSOL, by applying the QCM sensing principle, to investigate the influence of various structural dimensions on the sensor’s resonant frequency, quality factor, and admittance, while optimizing its geometric parameters.Subsequently, the sensitivity and dynamic characteristics of the sensor were examined over a specific humidity range. The experimental findings demonstrate the remarkable humidity discrimination capability of the sensor,with a maximum frequency response of 13 kHz, sensitivity of 155 Hz/(%RH), and response and recovery times of 20 s and 8 s, respectively. These results demonstrate the reliability and accuracy of the QCM sensor, utilizing porous α-Al2O3 as the moisture-sensitive material, in humidity detection.

Piezoelectric deformable mirror is used as an actuator for adaptive optics system. In this study, a novel piezoelectric ceramic driving power supply is designed for high-precision and highly dynamic application of piezoelectric deformable mirror. The design adopts the linear correction network to ensure the stability of the amplification circuit. Furthermore, the reasons that affect the output accuracy and nonlinear distortion are analyzed. The experimental results show that when driving a capacitive load of 0.33 μF, the drive power supply exhibits a large signal bandwidth of up to 3 kHz, rise time of the step response greater than 80 μs, fall time greater than 130 μs, and output linearity of 99.6%.

High-frequency piezoelectric micromechanical ultrasonic transducers (PMUTs) are employed in various applications including fingerprint recognition, non-destructive testing, and medical imaging. In this study, the challenges associated with using lead zirconate titanate piezoelectric ceramics (PZT) in non-invasive vascular imaging and limitations of 1-D PMUT arrays are addressed by designing and fabricating a 2D PMUT array based on ScAlN piezoelectric film. To optimize output performance and minimize gate lobe influence, a parallel-hexagon array is designed with a spacing of half a wavelength (300 μm) to enhance the filling factor, reduce impedance, and improve output current. A silicon-on-insulator (SOI) wafer is utilized as the substrate for the PMUT, facilitating the MEMS process flow and wafer fabrication. The morphology and structure size of the PMUT are characterized using scanning electron microscopy and focused ion beam cutting. The measured resonant frequency in water is 2.36 MHz, with a simulation-test discrepancy of 9.2% and satisfactory displacement sensitivity, suggesting its suitability for non-invasive vascular imaging applications

In high-temperature pressure sensors, the E-type diaphragm offers advantages such as strong stability, minimal nonlinear error, and higher sensitivity under the same deflection compared to the C-type diaphragm.The preparation of thin films is crucial in the MEMS process, given that their morphology and structure greatly influence sensor performance. However, there are several challenges in preparing E-type thin films. To produce Etype(silicon island) thin films with good morphology, a DRIE deep reactive ion etching machine was used with SF6 as the main etching gas. The preparation process was optimized and improved using changing the mask material, and the morphology after etching was characterized using confocal microscopy and scanning electron microscopy (SEM). Experiments showed that using ROL-7133 negative adhesive and a SiO2 double mask, with pre-drying for90 s, mid-drying for 120 s, and developing for 50 s, resulted in E-type films with a silicon island height of 50 μm and a back cavity depth of 450 μm. These films exhibited high perpendicularity and good overall morphology, meeting the requirements for sensor production

Barium strontium titanate (BarSr1-rTiO3, BST) ferroelectric material is considered an important material in dynamic random access memory, microwave tuner, phase shifter, and other applications because of its good dielectric, ferroelectric, and pyroelectric properties. In this study, the (1-r)Ba0.6Sr0.4TiO3-rSnO2 (BST-Sn) ceramics were prepared via the solid-phase sintering method. The effects of different contents of SnO2 on the microstructure and dielectric properties of the BST system were examined via X-ray diffraction, scanning electron microscopy, and the LCR digital bridge test system. The theoretical calculation results show that the ratio of lattice constant c to lattice constant a of BST decreases and the band gap increases with an increase in the incorporation ratio of SnO2. When the doping ratio of SnO2 is 0.05, the band gap reaches a maximum of 1.889 eV. The results of band and state density show that an increase in band gap is caused by the movement of Ti atoms’ 3d orbitals towards high energy. Secondly, the dielectric constant of pure BST ceramics, prepared experimentally, is 3 227, and the introduction of SnO2 reduces the dielectric constant of BST ceramics.

The coupling-of-modes (COM) model is extensively used in the design of surface acoustic wave(SAW) filters. However, the conventional single-mode COM model is insufficient for accounting for spurious modes, such as higher-order horizontal shear waves and Sezawa waves at the far end. In this study, we first used the single-mode COM model and integrated it with a resonant branch similar to the MBVD equivalent circuit to establish the COM-MBVD model for accommodating the multi-modal acoustic response. Subsequently, an 8th-order ladder structure circuit was constructed for optimization simulation, following this model. The final configuration resulted in a SAW filter with a central frequency of 1 590 MHz, a passband insertion loss below 1.6 dB, an in-band fluctuation of 1 dB, and a bandwidth of 80 MHz (equivalent to a relative bandwidth of 5%). The alignment between the test and simulation data confirms the viability of the design approach.

In the process of developing the Chinese national standard “Micro-electromechanical systems technology-Bend testing methods of thin film materials”, cantilever beam structures with different sizes were designed and prepared to verify the accuracy and practicality of the method used. Their bending deformation processes were recorded by nanoindentation instrumentation, and the deformation-stress curves of the structures were obtained. The bending mechanical properties of thin-film materials can be effectively characterized based on this standard, and the measured data from the bending tests were analyzed. The experimental results show that the repeatability over 10 tests reached 0.32% using this testing method, and the same type of test structure exhbits strong regularity. The test point near the anchor of the cantilever beam exhibits high deformation stiffness, fully consistent with the theoretical prediction. Therefore, the bending test method used in this paper has good repeatability and can be used for testing the bending mechanical properties of thin-film materials.

The JGD single crystal furnace is a laser-based single crystal furnace featuring automatic diameter control for weighing. Unlike other single crystal furnaces that use power or temperature as control objectives, this furnace employs high-precision electronic scales as sensors and uses crystal weight as the control objective. The control software of the JGD single crystal furnace innovatively compares the theoretical weight of the crystal with the weight measured by the electronic scales to establish a closed-loop negative feedback system. By applying differential, integral, and PID theory, the software achieves intelligent control of the crystal growth process, automatically managing the growth of various high-quality crystals such as InSb, YAG, LYSO, TGG, and Ti: Al2O3 without human intervention. Additionally, the software collects growth process data using an SQLServer database for big data analysis and integrates remote monitoring functions, thereby improving production efficiency.

Laminated magnetoelectric(ME) energy harvesters, with the advantages of miniaturization, flexibility,and diversified functions, have wide application prospects in self-powered monitoring of low-power devices, such as implanted medicine, Internet of Things(IoT), and micro-electromechanical systems(MEMS). The latest research progress in harvesters is reviewed, introducing their magneto-mechano-electric(MME) coupled energy conversion mechanisms. The types and structural features of various high- and low-frequency magnetic energy harvesters and low-frequency hybrid energy harvesters are examined, and their performances are comprehensively compared and analyzed. The potential advantages of high-frequency magnetic energy harvesters in wirelessly powered medical diagnosis and treatment of implanted devices are highlighted. Further, the significant advantages of low-frequency harvesters in self-powered sensing and monitoring of current-carrying IoT devices are indicated. Finally, existing problems and future development directions for harvesting technology are summarized.

Lithium tantalate(LiTaO3) single-crystal thin films are utilized for high-Q and low thermal drift narrow-band RF filters based on crystal ion slicing(CIS) technology. However, defects and lattice damage caused by high-energy ion implantation in LiTaO3 films hinder the enhancement of device performance. In this study, we employed a thermal annealing process to repair the damage in LiTaO3 films and characterize the defects using Raman spectroscopy. Additionally, we analyzed the impact of annealing temperature on the composition and defects of LiTaO3 films. The results demonstrate that thermal annealing effectively repairs lithium vacancy defects and reduces oxygen vacancies in LiTaO3 films.

Equivalent self-noise is an important performance indicator for micro-electromechanical systems(MEMS) piezoelectric vector hydrophones, and the noise of the preamplifier circuit is an important consideration.This study entailed the design of a low-noise preamplifier circuit to reduce the self-noise of MEMS piezoelectric vector hydrophones. By using a circuit structure with dual junction field-effect transistors (JFETs) in parallel and supplementing it with appropriate bias circuits, a theoretical analysis of different noise sources was conducted to optimize the circuit parameters. The design and fabrication of a low-noise preamplifier circuit with superior noise performance were ultimately achieved. The test results show that, within the operating frequency band of the MEMS piezoelectric vector hydrophone, the low-noise preamplifier circuit amplifies signals without distortion, with a voltage gain of 43.8 dB and an equivalent input noise voltage spectral density of 0.7 nV/ Hz@1 kHz. This noise performance provides evident advantages over similar amplification circuits domestically and internationally.

To address the issues of limited stroke and significant coupling error in currently developed micro-positioning platforms, a two-degree-of-freedom micro-positioning platform, powered by piezoelectric actuators(PEA), is proposed. Additionally, a three-stage displacement amplifier is designed, which combines a two-stage lever amplification mechanism and Scott-Russell mechanism in series, to extend the operational stroke. The motion coupling error is eliminated by using a parallel-axis straight-circle flexible hinge and double-compound moving pair in parallel configuration. Finally, the performance of the platform is analyzed and tested via finite element simulation and experiment. The results show that the operating stroke of the designed micro-positioning platform is over 170 μm×170 μm, coupling error is within 1.2%, displacement resolution is 5 nm, and signal tracking error is 2.16%. This verifies the positioning accuracy and accuracy of the model.

Inchworm piezoelectric ceramic motors (IWPECMs), known for their small size, long stroke, nanopositioning,and large thrust characteristics, are widely used in integrated circuit equipment and precision motion platforms. However, current IWPECMs struggle to achieve high-precision positioning and controllable displacement and velocity over long-stroke movements with existing drivers. As a result, they cannot be applied to 7 nm technology integrated circuit (IC) chip testing equipment that requires high speed and nano-positioning. To address these issues, a dual-mode driver is proposed and developed. This dual-mode driver includes displacement-voltage and velocity- frequency modes, which are based on the principles of charge and stress effects, respectively. The sliding mode control (SMC) method is used to reduce the voltage ripple when the dual-mode driver outputs high voltage, thereby improving the displacement resolution of the IWPECM. Finally, the hardware performance and dual-mode control of the driver were verified through experiments, further testing the performance of IWPECM.

In this study, an optimization method for the orientation arrangement of antenna-array elements to achieve high gain and low sidelobe levels (SLL) based on weight coefficient regulation, is proposed. In the method, the fitness function is defined as the weighted sum of the maximum gain and the difference between the maximum gain and SLL. By introducing an appropriate weight coefficient, the design requirements of the antenna-arrays for high gain and low SLL are realized. The optimization results under different weight coefficients are discussed, and the radiation patterns are synthesized and summarized based on these coefficients. The full-wave method of moments(MoM) is adopted to adequately consider the coupling field of each array element. The optimization problem is solved via a genetic algorithm (GA), and two typical examples, including linear and planar dipole antennas, are presented. The results show that when weight coefficients of 0.45 and 0.9 are used, the established optimization method significantly reduces SLL and cross-polarization gain, while ensuring that the main beam gain in the desired direction is maintained. Thus, the results verify the effectiveness of the proposed method.

In a piezo inkjet system, the print head structure, driving waveform, and other factors directly influence the jetting characteristics and printing accuracy. In this study, the numerical simulation software COMSOL was employed to establish a model of piezoelectric inkjet printhead system. The influence of driving parameters— voltage amplitude, voltage residence time, and operating frequency—on jetting characteristics was investigated, specifically droplet velocity and volume. Additionally, a bipolar driving waveform was designed to suppress the residual oscillation. The results demonstrate that the damping waveform effectively suppresses the residual vibration of the pressure wave, significantly improving the working frequency and printing accuracy of the inkjet printhead.

In this study, an ultrasonic resonance-based method is proposed for solving full phase wind speed and wind direction. An equilateral triangular distribution of three ultrasonic transducers A, B, and C with an interval L is established. The initial phases of echo waves received by ultrasonic transducers A, B, and C are measured based on the obtained initial phases of echo waves. Furthermore, the wind speed and wind direction data under the conditions of direct wind blowing from the vertex without angle and wind blowing from the vertex with angle are calculated.Additionally, the full-phase wind speed and wind direction algorithm established in this study is continuous and singularity-free. Under the same input conditions, the proposed method exhibits smaller wind speed fluctuation and more accurate wind direction calculation when compared to other methods.

Traditional acoustic metamaterials face issues including narrow noise reduction frequency range, high cost, and difficulty in implementation. To address these problems, a Helmholtz resonant cavity acoustic metamaterial structure with a flexible thin film is proposed. Starting from the phenomenon of local resonance coupling effects, mathematical models of the Helmholtz resonant cavity and the flexible thin film are derived. These models are simulated and analyzed using COMSOL Multiphysics software. The results show that the structure produces two local resonance peaks. To achieve control over the noise reduction frequency band of the acoustic metamaterial,liquid is injected into the thin film. Experimental results show that when the injection volume increases from 0 to35 mL, the resonance frequency of the thin film shifts from 612 Hz to 446 Hz, resulting in a displacement of 166 Hz. The designed local resonance acoustic metamaterial effectively controls low-frequency noise within the specified frequency band, providing a novel approach for the design of acoustic metamaterials

Currently, surface acoustic wave filters urgently require high-quality lithium tantalate piezoelectric single crystal composite film substrates to improve performance. After ion implantation, wafer warpage and particle increase can easily occur, leading to defects such as irregular stripes and bonding voids during the subsequent bonding process, which seriously hinder the preparation of high-quality lithium tantalate piezoelectric single crystal composite films. The internal stress, damage, and particle changes caused by ion implantation were analyzed and characterized using X-ray diffraction (XRD), focused ion beam-transmission electron microscopy (FIB-TEM), particle tester, and other equipment. The reasons for the increase in warpage and particles were explained, and appropriate solutions were proposed. Finally, the implanted wafer was successfully prepared with low warpage and fewer particles.Further verification of the bonding process revealed that high-quality bonded wafers without defects such as stripes and voids can be obtained, laying the foundation for the efficient preparation of lithium tantalate piezoelectric single crystal composite films.

The hemispherical resonator gyro (HRG) is a new solid state vibrating gyro that offers high precision,high reliability, and a long life. It has broad application prospects in the aerospace field. This study analyzes the main factors affecting the working life of the HRG, proposes measures to improve the working life of gyroscopes,conducts long-term continuous gyroscope life tests, and verifies the long-term performance of the main indicators of the HRG. The results show that the HRG has a stable performance and a working life of as many as 20 years during long-term electrification, thus meeting the application requirements of long-term space missions, such as deep-space detectors.

To improve the range of quartz-flex accelerometers, this study analyzes the mechanism affecting this range and confirms that the primary reason for the restricted range is that the center of the electromagnetic feedback force is not superposed on the center of mass of the mass pendulum. Based on the analysis, methods for improving the range are presented by reducing the deviation of mechanical machining and assembly and increasing the torsion resistance of the mass pendulum, the efficiency of which is confirmed by prototypes.

The piezoelectric energy harvesters can convert the vibration energy into the electric energy and supply power for the low-power electronic equipment. In order to broaden the effective frequency band width of the piezoelectric energy harvester and reduce the resonant frequency of the system, a piezoelectric energy harvester with additional liguid mass is proposed in this paper. Guided by the piezoelectric effect, the mechanical model and electromechanical coupling model of piezoelectric energy harvester are established, and the dynamic characteristics of piezoelectric energy harvester with additional liquid mass are analyzed, and the study is carried out based on the theoretical model, simulation analysis and experimental verification. By making a prototype and building a vibration experiment platform, the energy harvesting characteristics of piezoelectric energy harvester are tested experimentally, The experimental results show that compared with the traditional cantilever piezoelectric energy harvester, the resonant freguency of the piezoeleetric energy harvester with five modes of the structure is signilicantly reduced, and the output voltage is increased. The AC-DC rectifier filter circuit is used to rectify and filter the electricity generated by the piezoelectric energy harvester, and the availability of the electric energy generated by the piezoelectric energy harvester is verified