A temperature compensated thin film bulk acoustic resonator(TC-FBAR) based on cavity structure is introduced in this paper, By growing a temperature compensation layer (SiO2) above the piezoelectric layer, the low temperature drift of resonator has been realized, The temperature coefficient of frequency of thin film bulk acoustic resonator without temperature compensation is about -25×10-6/℃, Through proper film structure design, the temperature coefficient of frequency can be controlled within ±3×10-6 /℃, It is found that the overall piezoelectric effect of the device is reduced by adding a temperature compensation layer, resulting in the reduction of the effective electromechanical coupling coefficient, The realization of the low temperature drift resonator can provide supports of effective design and process for developing the narrow band filter with low temperature drift,

The demand of surface acoustic wave(SAW) sensors for high temperature is increasing, Langasite provides high-temperature-resistant piezoelectric substrate because of good high-temperature characteristics, however, the electrode will lose its performance due to agglomeration at high temperature, In this paper, a surface acoustic wave resonator with grooved electrodes for high temperature is designed, Pt is used as electrode and langasite is used as piezoelectric substrate, The manufacturing process of the grooved electrodes is proposed and the morphology of the grooved electrode is characterized, The quality of Pt electrodes is improved by increasing the deposition temperature, Finally, a resonator with the wavelength of 8 μm and grooved IDTs of 240 nm in thickness is prepared which can work stably at 1 000 ℃,

In this paper, the effects of Al electrode thickness, interdigital duty ratio, reflector grating period and topology on insertion loss, out-of-band rejection and rectangle are investigated with a single layer and ladder structures based on 128 YX-LiNbO3 materials, In order to reduce the passband ripple and insertion loss, an interdigital transducer (IDT) reflector grating structure is designed, which can reduce the in-band peak loss of the resonator before and after optimization by 8, 84% and 0, 55%, respectively, Finally, a low interpolation loss high frequency surface acoustic wave (SAW) filter is designed based on this reflector grating structure, The results of the finite element simulation show that the center frequency of the filter is 2, 520 5 GHz, the insertion loss is -0, 502 12 dB, the out-of-band rejection is greater than 30 dB, and the -3 dB loss bandwidth is greater than 98 MHz,

This paper studied the COM parameters extraction method based on the hierarchical cascading technique, By simulating on a finite-length SAW single port resonator on 42° rotated Y-X LiTaO3 substrate, the COM parameters were extracted and the COM parameters datasets was established, A 1 200 MHz SAW filter with 3-IDT CRF hybrid structure has been developed, The results show that the amplitude-frequency response of the actual device is in good agreement with that of the simulated one,which verifies the feasibility of the method of extracting COM parameters in this article,and can be used to guide the design of SAW filters,

A film bulk acoustic wave resonator(FBAR) filter operating at 2, 4 GHz WiFi band (2 401~2 483 MHz) is designed in this paper, This design is a ladder filter based on the one-dimensional Mason circuit model of FBAR, which is built in ADS,the finite element electromagnetic model of packaging structure and test circuit is established in HFSS,and the joint simulation design is completed in ADS, Through MEMS process preparation and test,the insertion loss of the filter at 2 401~2 483 MHz frequency band, the insertion loss is ≤2, 2 dB,the out of band rejection at 2 520~2 900 MHz is ≥40 dB,and the volume of the filter is only 1, 1 mm×0, 9 mm×0, 65 mm,

The Chirp transform spectrometer(CTS) designed using surface acoustic wave(SAW) technology has the advantages of low power consumption and high stability,and is especially suitable for the field of deep space exploration, This paper proposes a large bandwidth CTS system, A 2 GHz bandwidth Chirp signal is generated by DAC and frequency multiplier,and its dispersion characteristics match those of a 1 GHz SAW delay line, A spectrum analyzer with a real-time processing bandwidth of 1 GHz and a frequency resolution of 100 kHz is built, and the unbalanced response of the CTS under large bandwidth is discussed, The influence of each part of the system on the CTS system is analyzed,and the reasons for the unbalanced response are verified through experiments, The test results show that the designed and built CTS system with a bandwidth of 1 GHz can reach a frequency resolution of 115, 512 kHz,

An S band surface acoustic wave(SAW) filter with center frequency of 3, 4 GHz was developed in this work, The filter adopted an impedance element structure composed of a new type of resonator, which can improve the resistance to electrostatic damage(ESD) protection of pyroelectric effect, and improve the power handling ability to a certain extent, Furthermore,a kind of chip scale packaging(CSP) substrate with size of 2, 0 mm×1, 6 mm was developed, The electric connection between the chip and CSP substrate was realized by the flip-chip process, thus the electromagnetic parasitic influence was reduced, The developed S band SAW filter has center frequency of 3, 408 GHz,insertion loss of 2, 23 dB, above 30 dB the stopband suppression of greater than 30 dB at 8 GHz at the far end, the measured power handling ability of 30 dBm,

The Cu/15°YX-LiNbO3 surface acoustic wave(SAW) resonator is a key element of the wide band SAW filter, The existence of spurious transverse modes of the resonator will greatly deteriorate the passband performance of the SAW filter,which will cause the passband ripples and increase the insert losses, so as to reduce the signal-to-noise ratio of the system and cause signal misreading, The transverse modes suppression of the Cu/15°YX-LiNbO3 SAW resonator with the Piston technique was studied in this paper, The end size of the finger was optimized by the finite element method, The simulated results show that the spurious transverse modes around the main mode can be completely suppressed when the duty ratio and the length of the slow region are 0, 692 and 0, 65λ, respectively, The effectiveness of the simulation was verified experimentally, This offers a foundation for the application of the Piston technique to the transverse modes suppression of the wide band SAW filter with a structure of Cu/15°YX-LiNbO3,

In this paper, the AlN/PZT composite piezoelectric thin film layer SAW device on the monocrystalline silicon substrate was designed, The finite element method was used to study the influences of the thickness of composite piezoelectric material (the PZT thickness hPZT and AlN thickness hAlN) on the phase velocity of zero-order SAW and first-order SAW, electromechanical coupling coefficient and electrode reflection coefficient in AlN/IDT/PZT/Si structure, According to the dispersion characteristics, the optimum film thickness was obtained, The results show that when hPZT=0, 025λ and hAlN =λ in AlN/IDT/PZT/Si structure, the highest phase velocities of the zero-order and first-order SAW are 5 582 m/s and 5 711 m/s respectively, which are suitable for the design of high frequency devices, When hPZT=0, 2λ,hAlN =0, 1λ, the electromechanical coupling coefficient of zero-order SAW wave is the highest of 21, 55%, but the phase velocity is the smallest of only 2 890 m/s, which is suitable for the design of the signal processing devices of wideband low loss surface acoustic wave filter and delay linear structure in the mobile communication field,

A development method of B34 & B39 SAW dual filter for 5G communication carrier aggregation is present in this article, First, according to the product index, the design is determined by the topology design and the isolate of the signal of the dual channel filters; then the product is simulated and optimized through the coupling-of-mode model combined with the electromagnetic full-wave simulation, and finally the FEM/BEM is used to verify the performance of device, According to the comparison between the production and the simulation results, the graphs are in good agreement and fully meet the requirements of market, which proves the feasibility of the research method in this paper,

In order to correctly analyze and design thin film bulk acoustic wave resonator(FBAR), it is necessary to accurately extract the parameters(such as electromechanical coupling coefficient, dielectric parameters and viscosity coefficient etc, ) of FBAR resonator in the Mason model, Through the simple harmonic approximation, the transverse component of the displacement in the thickness direction is introduced into the Mason model to improve the accuracy of the model, Using the scattering parameters of open and short graphics, the equivalent circuit parameters of probe and test pad are extracted to de-embed the resonator, The filter with center frequency of 5, 43 GHz is simulated with the fitted model parameters, The results show that the simulation results of the mode parameters extracted by this method are in good agreement with the passband shape of the probe test curve of the filter,

Using polyaniline as a sensitive material, a highly sensitive and fast-response surface acoustic wave (SAW) ammonia gas sensor device was experimentally prepared, and a sensing system was constructed by combining with a phase-detecting sensing circuit, The mass load and the acoustic-electric coupling effect generated by the selective adsorption of polyaniline to ammonia cause the change of the sound propagation velocity, and then the voltage signal output by the phase detector is used to characterize the volume concentration of ammonia to be measured, The experimental results show that the sensor exhibits high sensitivity (0, 11 mV/10-6 mV), low detection limit (0, 5×10-6) and fast response time (T90<20 s) at room temperature,

As an emerging piezoelectric micro-electro-mechanical system(MEMS) acoustic device, the Lamb wave resonator has the features of high operating frequency, high k2t, high Q and low power consumption simultaneously, Its process is compatible with the integrated circuits and is promising to realize multi-frequency devices on a single wafer, The acoustic filter based on the Lamb wave resonator is one of the effective solutions to realize high-performance RF front-end modules, which can meet the development requirements of multi-frequency and integration of communication equipment in the future, thus the research on the Lamb wave devices has become a hot spot in the field of micro-acoustic devices, In this paper, the basic principle of the Lamb wave is introduced, The latest achievements in the research on piezoelectric MEMS Lamb wave devices based on AlN thin films and lithium niobate thin films (LNOI) in recent years are reviewed, Finally, the development trends of piezoelectric MEMS Lamb wave devices are discussed,

This paper introduces the development process of a surface acoustic wave(SAW) filter for Band3 receiver, In order to satisfy the large-bandwidth performance of the filter and the high selectivity at the low end of the stopband, a 7-interdigital transducer(7-IDT) hybrid structure is used, and the coupling of mode model is used for automatic optimization design and multiple optimization iterations, And use finite element method/boundary element method(FEM/BEM) software to carry out accurate acoustic verification, and finally through the test to verify the effectiveness of the simulation results,

In order to analyze the surface acoustic wave (SAW) devices with arbitrary complex structure, and accurately and quickly characterize the multi-physical fields in SAW devices, the finite element model of the finite-length SAW device is derived by using the finite element hierarchical cascading technique(HCT) algorithm, Based on the full-wave simulation technology, the compensated-temperature leaky surface acoustic wave(TC-SAW) device with 42°Y-X LiTaO3 is calculated considering the electromagnetic effects of the package models such as the tube holder and the bonding wire, The accuracy of the HCT model is verified by comparing with the experimental results, This work can provide support for accurate and rapid design of high performance SAW devices,

A wideband and low-loss SAW filter based on the excited Love wave mode of materials with large electromechanical coupling coefficient of LiNbO3 designed in this paper。The electromechanical coupling coefficient of LiNbO3 materials with different cuts and the Rayleigh wave excitation of 15°YX-LiNbO3 materials with different film thickness and cut were studied, The results show that by using the Cu electrodes to apodize and weight the resonator to suppress the transverse mode, the proposed wideband filter can realize lower insertion loss and better passband characteristics,

The temperature coefficient of the conventional thin film bulk acoustic wave resonator(FBAR) filters is around (-30~-25)×10-6/℃, and the electrical performance varies with the environment temperature, This property degrades the electrical performance of the filter which works in a broad temperature rage, and further confines the applications, especially the applications with stringent requirements in insertion loss in the pass band and roll-off in the transitional band, In this paper,a silicon oxide(SiO2) layer with positive temperature coefficient is introduced in the conventional FBAR filters, Filter stack position technique and filter fabrication technique are researched,and a S-band temperature compensated FBAR filter device is developed, whose operation frequency is 3, 1 GHz, the insertion loss is 2, 0 dB, out of band rejection is better than 30 dB, and the temperature coefficient of frequency is -0, 02×10-6/℃,

In the process of surface acoustic wave(SAW) device photolithography, the line width of the photoresist is inconsistent with the photomask, especially, the line width variation of the non-uniform lines with different widths has a deviation after photolithography, The influence of proximity exposure diffraction effect on the line width is studied in this paper, The relationships among the parameters such as line and gap widths on the photomask, diffracted light intensity, spacing between photomask and photoresist, etc are analyzed, The results show that the precise control of the non-uniform line width of SAW devices can be realized by using the method of calculating the variation value of different line widths after exposure by establishing an optical model, and by using the programming method to compensate the lines with different sizes and the gap widths in the photomask data file,

Based on the traditional withdrawal weighted technique, an adaptive withdrawal weighted technique is proposed in this paper, The withdrawal weighting of part fingers of the apodized transducer can be carried out by calculation to determine the starting position of the withdrawal weighting and the withdrawal weighted value, The results show that the developed filter based on the proposed method has frequency of 61, 60 MHz , -1 dB relative bandwidth of 3, 7%, out-of-band rejection of greater than 45 dB， rectangle factor of 1, 4, The comprehensive performance of the device is superior to the traditional one,

An improved double-mode surface acoustic wave(DMS) structure is used to design an extreme narrow band SAW filter at 1, 5 GHz, The reflectors at both ends of the DMS structure adopt a distributed multi-period weighting structure,which can eliminate a variety of acoustic reflection modes propagating on the acoustic channel, A reflector is added between two interdigital transducers(IDT) in DMS structure to flexibly design the stopband suppression and bandwidth index of the filter, The results show that the developed extreme narrow band SAW filter has a center frequency of 1, 5 GHz, a measured bandwidth of 878, 75 kHz,insertion loss of 5, 8 dB, and stop-band suppression of 45 dB,

SAW delay line, used as sensor, can be encoded to enable multi-point distributed measurements, and thus have been widely studied, In this paper, the SAW delay lines with different pairs of IDT were prepared on 128°Y-X cut LiNbO3 piezoelectric substrate, and the strain characteristics of the prepared SAW delay lines were investigated, The results show that the sensitivities of the SAW delay lines with 10, 20 and 30 IDT pairs were 1, 727 5 ps/με, 2, 046 7 ps/με and 3, 256 6 ps/με, respectively, The strain characteristics of the SAW delay lines are closely dependent on the angle between the directions of the applied strain and SAW propagation, namely, the delay time increases as the strain increases at 0° and the delay time decreases as the strain increases at 90°, Two SAW delay lines with different angles (0° and 90°) are combined to constitute strain sensor with differential structure, The experimental results show that this structure can cancel the effect of temperature, and that the accurate strains can be acquired even if the temperature fluctuates, The SAW delay line with differential structure demonstrated in this paper is expected to be applied to sense strain in environment with temperature fluctuations,

A C band thin film bulk acoustic resonator(FBAR) filter packaged by WLP was developed in this paper, The one-dimensional Mason equivalent circuit model was used to design the resonator, the HFSS was used to optimize the electromagnetic packaging model, and then the filter was simulated and optimized in ADS to obtain the stepped FBAR filter, FBAR filter chip was fabricated by cavity structure, and WLP was carried out by taping and electroplating on FBAR bare chip, The test results showed that the center frequency of the filter was 6, 09 GHz, the center insertion loss was 2, 92 dB, the passband insertion loss was 3, 4 dB, the bandwidth was 112 MHz, and the out-of-band rejection was greater than 40 dB,

In order to investigate the influence law of pump chamber structure parameters on the performance of piezoelectric gas diaphragm pump, a pump chamber structure of piezoelectric gas diaphragm pump was designed, Firstly, the structural design and working principle of the pump chamber are briefly described, and the expression of the relationship between the airflow velocity at the outlet of the pump chamber is derived, and the relationship between the height of the pump chamber and the diameter of the air hole on the instantaneous air pressure, airflow velocity and gas flow in the chamber is obtained through simulation, Finally, a pump cavity is machined and applied to a piezoelectric gas diaphragm pump, and experimental tests and the theoretical analysis are conducted, and experimental results are consistent with the theoretical analysis, The output flow rate decreases with increasing cavity height and increases with increasing orifice diameter, Provides a theoretical reference for the design of the cavity of the piezoelectric gas micropump,

The resonance frequency of the piezoelectric resonator will drift due to environmental factors, The tuning technology actively adjusts the resonance frequency by using specific means, which has a wide range of applications, Traditional mechanical tuning techniques such as additional masses attachment and laser ablation are time-consuming and labor-intensive, and have poor flexibility, For the cuboid piezoelectric resonator, an electrical tuning method of excitation signal amplitude tuning and DC tuning is proposed, This method can precisely adjust the resonance frequency of the resonator, A digital measurement and control circuit based on ZYNQ is designed, which realizes the frequency sweep excitation of the vibrator, The circuit also detects the amplitude and phase of the output signal, providing an experimental hardware platform for the excitation signal amplitude tuning and DC tuning, The experimental results show that the resonance frequency adjustment range of excitation signal amplitude tuning is about 347, 850~348, 000 kHz, and the adjustment range of DC tuning is about 347, 720~347, 820 kHz, This technology provides a reliable theoretical and practical approach for the precise adjustment of the resonance frequency of piezoelectric resonators,

The matching layer material and structure play an important role in improving the bandwidth, sensitivity and axial resolution of the array transducer, To investigate the effects of different matching layer materials on the performance of array transducers, this paper simulated array transducers with different matching layer materials including polymer, 0-3 composite materials and magnesium alloy through finite element method, The frequency domain and time domain characteristics of each transducer models were compared, The simulation results show that the array transducer model using AZ31B magnesium alloy as the first matching layer and Epo-Tek 301 epoxy as the second matching layer has the best performance, providing a new matching layer design scheme for developing high-performance array piezoelectric ultrasonic transducers,

The transducers with traditional structure are difficult to adapt to underwater high-speed movement, This paper proposes a design scheme of ultrasonic array transducer with conical structure based on the design of ordinary array transducer with circular or elliptical head, The proposed transducer can be suitable for underwater high-speed aircraft, The size and structure of the array element are determined by finite element simulation, the overall sound field distribution of the transducer is analyzed, A prototype of the transducer is developed and its electroacoustic performance is tested, The test results of the prototype are in good agreement with the simulation results, The directivity and emission voltage response of the transducer meet the application requirements, The results show that the structure of the transducer is practical and feasible,

A flexoelectric sensor model of cylindrical shell panel due to direct flexoelectric effect was established, Firstly, dynamic response of the panel was derived, Then, flexoelectric sensing theory due to the direct flexoelectric effect was employed, and modal voltage and power, Flexoelectric sensing signal induced by the flexoelectric effect contains two parts: the flexoelectric signal induced by the longitudinal bending strain and the flexoelectric signal induced by the circumferential bending strain, When the flexoelectric patch is infinite, the sensing characteristics of flexoelectric patch is the distributed sensing characteristics of each point, Finally, effects of different parameters on the sensing characteristics, such as mode shape, natural frequency, flexoelectric signal components, were analyzed to optimize the sensing signal, which was significant in engineering application,

Aiming at the problem that the internal space constraints and motion parameters of guided munitions are difficult to accurately measure in the high overload environment, a frame-type embedded micro inertial measurement unit (MIMU) structure is designed, The MIMU is composed of a three-axis MEMS gyroscope and a three-axis MEMS accelerometer, The weight and volume of the MIMU are greatly reduced by reasonably configuring the installation method of the sensor and optimizing the internal space layout, The overall structure of the MIMU adopts the high strength metal material and special potting process, which ensures its high overload resistance performance, Through finite element simulation and analysis, the results show that the structure of MIMU can meet the overload impact of not less than 20 000g(g=9, 8 m/s2), Finally, the penetration overload test has been carried out by carrying the MIMU on the certain type of test projectile in the shooting range, The test results also show that the designed MIMU has the ability to resist high overload and meet the high overload requirements of guided munitions,

In order to improve the sound pressure level(SPL) of piezoelectric micro-electro-mechanical systems(MEMS) speakers, a novel speaker diaphragm structure is proposed in this paper, The structure consists of four identical fan-ring driving units and a circular mass block in the middle, and the upper surface is covered with a layer of flexible material, forming a rigid-flexible-coupling sealed vibration membrane, The parameters such as radius r2 of the circular mass block and angle θ of adjacent fan rings were optimized, It was found that the maximum SPL was obtained when θ=50° and r2 =700 μm, The sound pressure level of the novel structure proposed in this paper is 5 dB higher than that of the optimized clamped circular multilayer diaphragm under the condition that the diaphragm area is the same and the resonant frequency is basically the same,

In this paper, the high-overtone bulk acoustic resonators (HBAR) were fabricated based on the scandium-doped AlN thin films, and the effect of scandium(Sc) doping concentration on the material properties of AlN piezoelectric thin films as well as the performance of devices were investigated, The results showed that, as the Sc mole fraction increased from 0 to 25%, the piezoelectric stress coefficient e33 increased and the stiffness constant CD33 decreased, resulting in an increase of the electromechanical coupling coefficient k2t of Al1-xScxN piezoelectric film from 5, 6% to 15, 8%, thereby increasing the effective electromechanical coupling coefficient (k2eff) of HBAR device by a factor of three, At the same time, when the Sc mole fraction was up to 25%, the sound velocity of the Al1-xScxN film piezoelectric film was reduced by 13%, and the acoustic loss was increased, resulting in a decrease of the resonant frequency and quality factor Q of the HBAR device,

An infrared optical fiber evanescent wave sensor for on-line and accurate detection of vinylidene chloride in water is fabricated in this work, The sensor is composed of a U-shaped mid-infrared optical fiber sensing probe, a vinylidene chloride selective sensitive membrane and a superhydrophobic membrane, The tetrafluoroethylene sensitive membrane was coated on the surface of the U-shaped area, and the superhydrophobic membrane was coated on the surface of the vinylidene chloride sensitive membrane, The U-shaped sensing region can enhance the intensity of the evanescent wave on the surface of the optical fiber, thereby improving the sensitivity of the sensor, The sensitive membrane can selectively detect the vinylidene chloride in water and improve the accuracy of the measurement results of the sensor, The superhydrophobic membrane can eliminate the negative influence of the water molecules on the measurement results, The characteristic absorption spectrum of vinylidene chloride, the response sensitivity, response time and selectivity of the sensor to the vinylidene chloride are studied experimentally, A theoretical model for measuring the vinylidene chloride by sensor is established, The results show that the sensor has high selective sensitivity to vinylidene chloride, the sensitivity is up to 0, 002 1 abs/(mg·L-1)) and the response time is 230 s,

The application of intelligent manhole covers greatly reduces the difficulty of manual inspections and reduces the safety risks of people's lives and properties, The article studies a cymbal piezoelectric energy harvester, which effectively improves the battery life of the smart manhole cover wireless monitoring node battery and reduces the cost of manual inspections, The paper analyzes the working principle of the collector, and uses ANSYS Workbench software for simulation optimization, and also studies the key factors affecting the output performance, The prototype of the cymbal-type power generation device was processed and assembled, and the test was completed, The results show that the prototype has an output open circuit voltage of 102 V and an output power of 4, 11 mW under an impact load of 250 ms pulse width and 0, 5 MPa, which can effectively improve the endurance of the manhole cover monitoring node,

Based on the flexural beam theory proposed by Timoshenko, this paper establishes a transfer matrix theory of the dual excitation stepped sandwich piezoelectric transducer in flexural vibration, The analytical theoretical model and FE simulation are used to calculate and analyze the first four order flexural vibration characteristics of the transducer, The results of the analytical theoretical calculation and the FE simulation are consistent in all flexural vibration modes of the transducer, The effective electromechanical coupling coefficient of the transducer is large in low order (first and second order) flexural vibration mode, and small in high order flexural vibration mode, The diameter ratio of the stepped front cover has a greater impact on the flexural resonance frequency and the amplification factor of the transducer, the larger the diameter ratio, the lower the flexural resonance frequency and the greater the amplification factor,

In order to decrease microfluidic analysis cost, a smartphone-based method for detecting the position of a droplet on piezoelectric substrate is presented, An application soft is developed for sensing droplet position, which can be obtained by analyzing its color information and geometry information, In the meantime, transportation velocity of the droplet is calculated by help of the interesting time, A 5 μL black ink solution droplet is used to demonstrate the utility of the presented method, The results show that the droplet on the piezoelectric substrate can be identified and its position can be determined using the self-developed app, The average transportation velocity of the droplet is 0, 416 mm/s from 2 s to 10 s at 27, 5 dBm of signal power,

The fast servo tool post with piezoelectric ceramic driver as the power input owns the obvious advantages of large output force and high frequency response, However, the inherent hysteresis of the piezoelectric ceramic driver seriously affects the output positioning accuracy of the fast servo tool post, In order to solve this problem, a feedforward control compensator is established by introducing a normalized Bouc-Wen model, The normalized Bouc-Wen model solves the problem of parameter redundancy in the classic Bouc-Wen model, After obtaining the model parameters, a feedforward compensator is built based on its inverse model, The single/double degree of freedom trajectory tracking performance test is carried out on the built test platform, The test results show that for a constant amplitude sine wave voltage signal, the maximum trajectory tracking error under the compensation of the feedforward control link is 1, 18%, and the maximum trajectory tracking deviation is 2, 61%, It proves that the proposed feedforward control compensator can significantly improve the positioning accuracy of the fast servo tool

Aiming at the problem that the echo of coherent laser wind lidar is very weak and the frequency domain amplitude of the echo cannot be obtained after direct fast Fourier transform(FFT), a digital intermediate frequency signal processing method embedded in field programmable gate array(FPGA) is proposed to effectively extract the frequency domain amplitude of the echo, The echo of laser wind lidar is the backscattered signal of coherent laser pulse through aerosol in the air, Due to the small aerosol concentration in the air and the limitation of laser emission power, the echo is extremely weak, Firstly, the analog signal of echo is amplified through the intermediate frequency(IF) amplifier, and then enters the analog-to-digital converter(ADC) for sampling, Then digital IF signal processing methods such as zero padding FFT and FFT spectrum accumulation are used to improve the signal-to-noise ratio of weak echo, so as to effectively identify the frequency domain amplitude of wind speed information in echo, Through the test, the stable wind speed within 2 km is obtained, and the accuracy is 0, 1 m/s,