35 results about "Single-sideband modulation" patented technology

This invention discloses a simple, multifunctional, integrated 5G analog fronthaul in-band full-duplex communication method for remote units (RUs). This method primarily relates to the fields of optical communication technology and microwave technology. The system structure of the method, as shown in Figure 1 of the specification, includes a laser, downlink vector signal, electrical local oscillator signal, downlink interference signal, target signal, reference signal, 90° electrical coupler, dual-polarization quadrature phase-shift keying modulator, phase modulator, single-mode fiber, optical coupler, polarization beamsplitter, polarization beam combiner, polarization controller, polarizer, and photodetector. The remote unit (RU) uses a single phase (PM) modulator to achieve self-interference cancellation (SIC) combined with anti-fiber dispersion transmission and down-conversion, eliminating the need for bias control and additional local oscillator (LO) branches, resulting in a simple structure. At the central office (CO), the carried downlink signal and local oscillator signal are single-sideband modulated to achieve anti-fiber dispersion transmission. The RU uses wavelength reuse technology to perform PM cascaded down-conversion on the signal received from the uplink, and the SIC is moved from the RU to the CO to simplify the RU. The entire link has no optical filter and is reconfigurable.

The application discloses a kind of bandwidth saving coherent transmission method and PON system, it is related to optical access network technical field, including: in downlink transmission direction, OLT sending end generates M digital subcarriers, after digital-analog conversion, it is carried out double polarization modulation, as downlink signal is sent to ONU receiving end;Each subarea ONU receiving end carries out heterodyne coherent detection to the partial spectrum of downlink signal, and downlink signal occupies the single sideband spectrum of ONU end light source;In the direction of uplink transmission, the data of corresponding digital subcarrier is generated by ONU sending end, and single sideband modulation is carried out based on ONU end light source, as uplink signal is sent to the OLT receiving end of corresponding subarea, and uplink signal occupies another single sideband spectrum of ONU end light source;OLT receiving end carries out analog-digital conversion and digital signal processing after heterodyne coherent detection.The application selects subcarrier by configuring light source of different wavelength at ONU end to reduce device bandwidth, so that PON system reduces cost while maintaining transmission capacity, sensitivity and flexibility.

The invention belongs to the technical field of optics, and particularly relates to an unequal-interval frequency comb generation and detection device and method based on a single side band modulator. In order to improve phase coherence between comb teeth, an arbitrary waveform generator generates a modulation signal, the modulation signal is amplified by a power amplifier and then input into a single-side-band phase modulator, a laser is connected with an optical signal input end of the single-side-band phase modulator, and an output end of the single-side-band phase modulator is connected with an optical beam splitter. The light beam splitter divides light into two paths, one path serves as reference light to enter the first detector, the first detector converts the reference light into an electric signal and then carries out FFT observation, the other path serves as detection light, is absorbed by the gas chamber and then is input into the second detector, and the second detector converts the detection light into an electric signal and then carries out FFT observation.

The application provides a wireless signal generation device and method based on integrated optical comb synchronization. The device comprises: an integrated optical comb repetition frequency signal generation unit: generating an optical comb signal, filtering the optical comb signal to obtain first and second optical signals adjacent to the beam, and third and fourth optical signals with different frequencies, and obtaining a high-frequency clock signal with the same frequency as the optical comb signal by combining, amplifying and frequency mixing the first and second optical signals; a standard microwave clock signal generation unit: after amplification and filtering of the high-frequency clock signal, the microwave clock signal with a standard frequency and synchronized with the high-frequency clock signal is obtained by integer frequency division and decimal frequency division in turn; a wireless signal generation unit: converting the microwave clock signal into a low-frequency baseband signal, generating an optical carrier microwave signal by single sideband modulation of the fourth optical signal through the low-frequency baseband signal, and obtaining a high-frequency coherent wireless signal by combining and frequency mixing the optical carrier microwave signal and the third optical signal.

The invention provides a signal generation system. The signal generation system comprises an external modulation laser, an optical splitter, a Mach-Zehnder modulator, a phase shifter, an attenuator, a coupler and a photoelectric conversion unit. According to the invention, Mach-Zehnder modulation is carried out on optical carriers through asymmetric double single side band signals, and millimeter wave / terahertz signals in the form of optical signals are obtained through destructive interference between output signals of a phase shifter and an attenuator and optical signals subjected to Mach-Zehnder modulation. And finally, millimeter wave / terahertz signals in an electric signal form are obtained through the photoelectric conversion unit. Millimeter wave / terahertz signals are generated by adopting a single push-pull Mach-Zehnder modulator and attenuator optical double-single-side-band modulation, transmitter precoding and a complex and expensive I / Q modulator are avoided, the complexity and cost of the system can be effectively reduced, meanwhile, the frequency interval can be flexibly adjusted, and the system performance is improved. And the tunable range of the system is increased.

This invention discloses a coherent transmission method and PON system based on digital subcarrier multiplexing, relating to the field of optical access network technology. The method includes: in the downlink transmission direction, the OLT transmitter generates an Alamouti-coded signal of M digital subcarriers, performs digital-to-analog conversion and dual polarization modulation, and transmits it as a downlink signal to the ONU receiver; the ONU receiver performs heterodyne coherent detection, analog-to-digital conversion, and digital signal processing, with the downlink signal occupying a single-sideband spectrum of the ONU's light source; in the uplink transmission direction, the ONU transmitter generates data of M digital subcarriers, performs digital-to-analog conversion, and then performs single-sideband modulation based on the ONU's light source, transmitting it as an uplink signal to the OLT receiver, with the uplink signal occupying another single-sideband spectrum; the OLT receiver performs analog-to-digital conversion and digital signal processing after coherent reception. This application enables bidirectional high-speed transmission, and uses the same light source for both transmission and reception at the ONU, which increases the capacity of the PON system, simplifies the ONU's structure and algorithm, and reduces system costs.

This invention relates to an optical frequency domain reflection system and method based on a voltage-controlled oscillator (VCO). The system mainly includes an arbitrary function generator, a laser, a VCO, a single-sideband modulator, an auxiliary interferometer, a main interferometer, and a polarization beam splitter. The arbitrary function generator, laser, VCO, and VSB modulator work together to generate the sweeping light required for measurement. This sweeping light is split into two paths: one path enters the main interferometer as probe light, and the other path enters the auxiliary interferometer to obtain the instantaneous frequency of the probe light. Based on the instantaneous frequency, the signal from the main interferometer is resampled using a one-dimensional interpolation method. This invention uses a low-cost, small-sized VCO as the radio frequency signal generator to generate a sweeping signal with fast frequency modulation performance, and compensates for phase noise caused by the nonlinearity of the sweeping signal by designing the optical path of the auxiliary interferometer and using a linear interpolation algorithm.

This invention discloses a method for generating broadband microwave signals based on microwave photonics technology. A reference microwave signal and an excitation microwave signal are simultaneously passed through a 90° microwave bridge to obtain two orthogonal microwave signals. These two orthogonal microwave signals are then used to perform carrier-suppressed single-sideband modulation on an optical carrier using a dual parallel intensity modulator. The generated modulated optical signal is then optically amplified and filtered before photoelectric conversion to generate a frequency-converted microwave signal. This frequency-converted microwave signal is split into two paths: one is used as the system output, and the other is electrically amplified and filtered before being fed back to the 90° microwave bridge, thus forming a closed frequency conversion loop. After multiple frequency conversions, the system outputs an ultra-wide bandwidth microwave signal. This invention also discloses a broadband microwave signal generation device based on microwave photonics technology. Compared with existing technologies, this invention can generate ultra-wide bandwidth microwave signals in different frequency bands and multiple formats.

The invention relates to the technical field of distributed optical fiber sensing, in particular to an optical fiber Rayleigh scattering signal enhancement device based on a chaotic Brillouin dynamic grating, which comprises a chaotic laser, chaotic laser from the first output end of the first coupler is subjected to sideband modulation through a single sideband modulator, passes through a first polarization controller and a first polarizer, and enters a sensing optical fiber as first pump light; a chaotic laser signal output from the second output end of the first coupler passes through a second polarization controller, a second polarizer and a polarization beam splitter and then enters the sensing optical fiber from the other end of the sensing optical fiber as second pump light; the two paths of pump light meet in the sensing optical fiber and generate a stimulated Brillouin effect to form a chaotic Brillouin dynamic grating; according to the invention, the chaotic laser is adopted to form the chaotic Brillouin dynamic grating, so that the Rayleigh scattering response bandwidth of a detection signal is obviously widened, and the bandwidth of a Rayleigh scattering enhanced signal is improved.

The invention discloses an optical carrier suppression single side band modulation device and method based on a variable optical coupler. The device comprises a laser, a first adjustable optical coupler, an optical single side band modulation module, a second optical phase shifter and a fourth adjustable optical coupler. And the first adjustable optical coupler divides the optical carrier into two paths according to a preset proportion, and the two paths are respectively input into the optical single side band modulation module and the second branch, so that the power matching of the two paths of carriers is ensured. The optical single side band modulation module comprises a second adjustable optical coupler, a first optical phase shifter and a third adjustable optical coupler, and accurate splitting ratio control and phase adjustment are achieved. And the second optical phase shifter performs phase adjustment on the second branch optical carrier to enable the second branch optical carrier to be opposite to the carrier phase in the modulation signal, and a high-purity optical carrier suppression single side band signal is output through combination of a fourth adjustable optical coupler. According to the invention, through cooperative configuration of the multi-stage adjustable device, process errors are effectively overcome, the carrier-to-sideband suppression ratio and the system power efficiency are improved, and the method can be applied to the fields of radio over fiber communication and the like.

The application relates to the field of distributed optical fiber sensing, and discloses a high-speed chaotic Brillouin sensing device and method based on a correlation method multi-address positioning method, wherein strong periodic broadband chaotic laser is divided into two beams through a first beam splitter, one beam is used as probe light and sequentially enters a sensing optical fiber after passing through a single sideband modulator and an erbium-doped fiber amplifier; the other beam sequentially passes through an optical delay line, an erbium-doped fiber amplifier, and a second beam splitter to be divided into pump light and reference light, the pump light passes through an optical circulator and occurs stimulated Brillouin amplification with the probe light at different positions in the sensing optical fiber; the signal in the sensing optical fiber is output after passing through the optical circulator, Stokes light is filtered out by a tunable optical filter and is detected by a first photodetector, the reference light is detected by a second photodetector, a data acquisition unit collects two-way signals and sends the two-way signals to a computer for data processing; the application improves the signal-to-noise ratio of the system, widens the sensing distance, and realizes high-speed and accurate positioning of multiple sensing points.

The invention discloses an information processing method, and the method comprises the steps: detecting a single side band modulation SSB signal after the SSB signal is received, and obtaining a first peak value of a main synchronization signal and a second peak value of an auxiliary synchronization signal which are included in the SSB signal; determining the position of a time slot head of the SSB signal based on the first peak value and the second peak value; and performing downlink beam synchronization based on the position of the time slot head. The invention further discloses an information processing device and equipment, a computer readable storage medium and a computer program product.

The present disclosure relates to a device and a communication method with which it is possible to perform appropriate filtering / image suppression when single side band modulation is used for D2R transmission of an A-IoT device. A device that has a lower complexity than an NB-IoT device comprises: a transmission unit that transmits to a wireless base station by using single side band modulation; and a control unit that selects either an upper side band or a lower side band in the single side band modulation, and uses the selected side band to perform transmission control of a transmission signal to the wireless base station.

The application discloses an encryption communication method and system based on probability shaping and double single sideband modulation, and the method comprises the following steps: receiving an original bit stream and an initial key, generating a chaotic sequence according to the initial key by using a hyperchaotic model; calculating a mask factor according to the chaotic sequence; performing constellation mapping processing on the original bit stream to obtain a constellation diagram; performing rotation encryption on the constellation diagram according to the mask factor to obtain an encrypted signal; performing QPSK modulation on the encrypted signal to obtain a left sideband carrier signal; performing constellation mapping on the initial key after repeating and superimposing to obtain a key signal; performing probability shaping and QPSK modulation on the key signal to obtain a right sideband carrier signal; superimposing the left sideband carrier signal and the right sideband carrier signal to obtain a mixed signal, and transmitting the mixed signal to a receiver through a transmitter; and the safety and reliability of key transmission are improved while the signal transmission efficiency is ensured.

To provide a device and a communication method that can perform appropriate filtering / image suppression when single sideband modulation is used for D2R transmission of an A-IoT device.SOLUTION: A device with lower complexity than an NB-IoT (Narrow Band Internet of Things) device includes a transmitter that transmits to a wireless base station using single sideband amplitude modulation, and a controller that selects either an upper sideband or a lower sideband in the single sideband modulation and controls transmission of a transmission signal to the wireless base station using the selected sideband.SELECTED DRAWING: Figure 11

The invention discloses an optical fiber scattering sensing system and method for satellite structure temperature measurement, and belongs to the technical field of optical fiber sensing. The system comprises a narrow linewidth semiconductor laser, an optical fiber coupler, a detection light path, a pump light path, a sensing optical fiber, a circulator, a photoelectric detector and a data processing module. A polarization controller is independently arranged in the detection light path so as to accurately regulate and control the polarization state of the detection light and realize optimal polarization matching with the pump light; a single side band modulator and a microwave source are adopted in a pump light path to accurately control the frequency shift amount, and high-selectivity amplification of a target sound mode is achieved in combination with an erbium-doped optical fiber amplifier. The measurement method comprises the following steps: selecting a target acoustic mode, calibrating frequency shift-temperature sensitivity coefficients in non-amplification and amplification states, and resolving the temperature variation by using the amplified high sensitivity coefficient. According to the invention, the signal-to-noise ratio and the measurement precision of the signal are remarkably improved through the Brillouin amplification technology, and the device has the advantages of light weight, simple structure and high environmental adaptability.

The invention provides a broadband phased array system based on an optical frequency comb and channelization processing. The broadband phased array system comprises an optical frequency comb generator, a single sideband modulator, a first periodic narrow-band filter array, a second periodic narrow-band filter array, a delay line array, a dense wavelength division multiplexing module, a photoelectric detector array and an antenna array. The system generates equally spaced optical carriers through an optical frequency comb, loads broadband signals through single side band modulation, and carries out channelized segmentation by using a narrow-band filter; delay is applied to each channel signal by an independent delay line, and an equal difference phase between array elements is generated based on the equal interval characteristic of the optical frequency comb; and after being recombined by the narrow-band filter array and decoupled by wavelength division multiplexing, the light is converted by the photoelectric detector and radiated by the antenna array, and finally a directional wave beam is formed. According to the invention, multiple array element phases can be controlled through a single delay line, independent beam pointing of signals with different frequencies is supported, and the stability and the flexibility are extremely high.

This invention discloses a dispersion measurement system based on microwave photonics technology. It uses a microwave signal generated by a first signal generator to perform carrier-suppressed single-sideband modulation (CSSM) on an optical signal generated by a laser. Then, the primary modulated optical signal is used as the carrier signal of a second electro-optic modulator. The microwave signal generated by the second signal generator is then used to perform carrier-unsuppressed CSSM on this optical carrier signal, and the modulated signal is split into two paths. One CSSM-modulated optical carrier microwave signal is used as a probe light to sense the dispersion of the dispersive element under test (DIST), and the other path is used as a reference light. The probe light signal passing through the DIST is converted into a corresponding dispersion-sensing electrical signal, while the reference light signal not passing through the DIST is converted into a corresponding reference electrical signal. The phase difference between the two electrical signals is detected to obtain a voltage value related to the phase difference, and the dispersion coefficient of the DIST corresponding to the current optical carrier wavelength is calculated based on the voltage value.

The invention discloses an optical fiber sensing integrated system based on a Kramers-Kronig receiver, and the specific structure is as follows: a narrow linewidth laser and a single sideband modulator generate a linear frequency modulation optical signal as a common optical carrier, and the optical carrier is divided into two paths through a polarization-maintaining coupler; one path of optical carrier carries a single-side-band communication signal through an IQ modulator to generate an optical single-side-band signal; the other linear frequency modulation optical carrier is coupled with the generated optical single side band signal through an optical fiber coupler to generate a sensing integrated optical signal; a communication receiving end (far end) adopts a high-speed photoelectric detector to convert an optical signal into an electric signal, and a Kramers-Kronig relation is utilized to recover a field signal; and a sensing receiving end (local end) adopts a linear frequency modulation optical signal generated by the sending end as local oscillator laser, and obtains a sensing signal by using coherent detection. The system is simple and efficient, can realize communication enhancement, and has high spectrum efficiency and high system flexibility.

The invention relates to the technical field of distributed optical fiber sensing, and discloses a rock burst prediction device and method based on a Brillouin dynamic grating, and the device comprises a narrow linewidth laser and a tunable laser. After narrow-linewidth laser output by the narrow-linewidth laser device is divided into two beams, one beam is subjected to Brillouin frequency shift through the single-sideband modulator, is adjusted to be x-axis polarization through the first polarization controller and then enters the polarization-maintaining sensing optical fiber, and the other beam is adjusted to be x-axis polarization through the second polarization controller and the polarization-maintaining beam splitter in sequence and then enters the polarization-maintaining sensing optical fiber. The two beams of light enter the polarization-maintaining sensing optical fiber from the other end, meet in the polarization-maintaining sensing optical fiber and form a Brillouin dynamic grating; after being subjected to pulse modulation, probe light output by the tunable laser is adjusted into y-axis polarization through the polarization-maintaining beam splitter, then enters the polarization-maintaining sensing optical fiber from the other end and is reflected by the Brillouin dynamic grating, and reflected light is collected by the spectrograph and subjected to data processing through the control terminal to achieve prediction of impact low pressure. According to the method, the flexibility and adaptability of rock burst prediction are remarkably improved.

The application discloses a single sideband modulation gas detection method and system based on TDLAS and an electro-optic modulator, and belongs to the technical field of gas concentration detection. The method comprises the following steps: inputting a laser beam of a specific wavelength emitted by a laser into an electro-optic modulator, and driving the electro-optic modulator by a radio frequency signal; inputting the laser beam is modulated into output light containing a carrier frequency and two sideband frequencies by the electro-optic modulator; the output light is subjected to single sideband modulation by an optical filter to obtain single sideband laser corresponding to an absorption line of a gas to be detected; the single sideband laser is guided into a gas region to be detected and reflected to a detector; the reflected light signal is converted by an electronic circuit, and the output electric signal is subjected to data processing to obtain the gas concentration of the gas to be detected. The application can realize fast modulation and response, and has the advantages of high precision and high reliability.

The invention discloses a single side band modulation Raman light generation device and method for cold atom interference. The device comprises a microwave source, a radio frequency source, a frequency mixer, a radio frequency switch, a voltage-controlled attenuator, a band-pass filter, a phase shifter, a power divider, an IQ modulator, a phase adjusting power supply, a seed laser, a laser amplifier and a frequency doubling crystal. The microwave source is connected with the mixer; the radio frequency switch is connected between the radio frequency source and the frequency mixer; the frequency mixer is connected with the voltage-controlled attenuator; the band-pass filter is connected between the voltage-controlled attenuator and the power divider; the power divider is also connected with the IQ modulator, and the phase shifter is connected between the power divider and the IQ modulator; the phase adjusting power supply is connected with the IQ modulator; the seed laser is connected with the IQ modulator, and the laser amplifier is connected between the IQ modulator and the frequency doubling crystal. According to the invention, the generation and modulation of Raman light can be realized by adopting one seed laser and one IQ modulator, the system structure is compact, and the interference measurement precision can be improved.

This invention discloses a microwave photonic filtering method. The method includes: splitting an optical frequency comb into two paths; performing dispersion compensation on the first optical frequency comb and then splitting it into two local oscillator optical frequency comb signals; using the radio frequency signal to be filtered to perform carrier-suppressed single-sideband modulation on the second optical frequency comb, and performing the same dispersion compensation on the generated modulated optical signal before splitting it into two radio frequency modulated optical frequency comb signals; performing a 90° optical phase shift on one of the local oscillator optical frequency comb signals / radio frequency modulated optical frequency comb signals and coupling it with the other radio frequency modulated optical frequency comb signal / local oscillator optical frequency comb signal, and performing photoelectric detection on the coupled signal to obtain a first electrical signal; coupling the other local oscillator optical frequency comb signal with the other radio frequency modulated optical frequency comb signal and performing photoelectric detection to obtain a second electrical signal; and performing an electrical phase shift on the first electrical signal and then coupling it with the second electrical signal. This invention also discloses a microwave photonic filtering device. Compared with the prior art, this invention can significantly expand the frequency tunable range.

FIELD: communications.SUBSTANCE: devices for generating amplitude modulation (AM) signals, used in communications equipment. A low-frequency modulating signal source, an analog-to-digital transducer, a first additional adder, a third multiplier, an inverter, a third adder, an additional Hilbert transducer, a second additional adder, a fourth multiplier, a fourth adder, and an additional phase shifter are additionally introduced into the single-sideband modulator.EFFECT: formation of an AM signal, the sidebands of the spectrum of which contain information from a discrete information source and an analog information source.1 cl, 2 dwg

The invention belongs to the technical field of distributed optical fiber sensing, and discloses a Brillouin dynamic grating reflection spectrum measuring device based on spectrum demodulation, which comprises a pump light source and a tunable laser, the pump light source is connected with the optical fiber coupler, a first output port and a second output port of the optical fiber coupler are respectively connected with input ports of the single side band modulator and the second polarizer, and an output port of the single side band modulator is connected with one end of the polarization maintaining optical fiber through the first polarizer; the output port of the second polarizer is connected with the first input port of the polarization beam splitter; an output port of the tunable laser is connected with a second input port of the polarization beam splitter through the third polarizer and the optical circulator, and a combined beam output port of the polarization beam splitter is connected with the other end of the polarization maintaining optical fiber; and a reflection port of the optical circulator is connected with an input port of the spectrograph. According to the invention, rapid, high-precision and low-cost measurement of the BDG reflectance spectrum is realized, and the method is especially suitable for dynamic distributed optical fiber sensing.

The invention discloses an automatic bias control device and method for optical carrier suppression single side band modulation, and the method comprises the steps: receiving a laser signal and a phase-shifted radio frequency signal through an IQ modulator, carrying out the optical modulation, collecting a feedback optical signal with a small part of power from the optical signal outputted by the IQ modulator, and transmitting the feedback optical signal to the IQ modulator; pilot signal harmonic information with a high signal-to-noise ratio is obtained by using a correlation integral extraction and adaptive extended Kalman filtering technology, direct current bias voltages of I, Q and P bias voltage ports of an IQ modulator are adjusted through an adaptive PID algorithm, and dynamically updated pilot signals are generated and injected into the I, Q and P bias voltage ports of the IQ modulator at the same time. Therefore, dynamic tracking and drift compensation of a bias point are realized. According to the invention, the four requirements of low pilot signals, high control precision, accurate control of positive and negative sidebands and strong environmental robustness are met cooperatively, long-term stable output of high-quality optical carrier suppression single sideband signals is effectively guaranteed, and technical support is provided for high-reliability optical modulation application.

The invention discloses a microwave photon fast frequency hopping signal generation system and method. The system comprises a master laser, a light beam splitter, a slave laser, a semiconductor optical amplifier, an IQ modulator and a photoelectric detector. The main laser generates a single-frequency optical signal, and the single-frequency optical signal is modulated by the low-carrier-frequency radio-frequency signal gain switch to generate a wide-spectrum optical frequency comb; the method comprises the following steps of: dividing an optical signal into an upper branch and a lower branch through an optical beam splitter, injecting the optical signal into a slave laser through a polarization controller and a circulator to perform frequency-selecting filtering, then increasing the rejection ratio through a semiconductor optical amplifier, and loading the lower branch to a communication signal to control the phase difference between an I path and a Q path in a modulator, when carrier suppression single sideband modulation is realized, a + 1 order sideband and a-1 order sideband can be flexibly selected; and finally, beat frequency is carried out on the upper and lower branches through a photoelectric detector to realize communication signal output in a double-frequency coverage range. According to the invention, the difficulty of realizing a frequency hopping signal in a high carrier frequency and broadband range by a direct digital synthesizer in an electronic domain is greatly reduced.

The application discloses a kind of device and method based on atomic transition adjustment laser output frequency, comprising: laser, for outputting to be stabilized frequency shift laser;Modulation module, for receiving the stabilized frequency shift laser output by laser, and after using radio frequency signal to modulate the frequency of stabilized frequency shift laser, output single sideband modulation laser;Frequency stabilization module, for receiving single sideband modulation laser and generating frequency discrimination signal, frequency stabilization module is electrically connected with laser, and frequency discrimination signal is fed back to laser, to adjust the frequency of laser output laser, so that single sideband modulation laser is locked on selected atomic transition spectrum line.The application combines the modulation module and frequency stabilization module of laser, and acoustooptic modulator and fiber electro-optic modulator in modulation module are sequentially connected, so that wide-range high-precision adjustment of laser frequency can be realized.The application has the characteristics of simple device, strong robustness and wide applicability, so that it can be widely applied in different fields.