259 results about "Microwave photonic" patented technology

The invention discloses a DP-MZM-based reconfigurable mixer with phase shift and image rejection functions, and belongs to the field of microwave photon signal processing. By adjusting an input radio frequency signal and a direct current bias voltage of the DP-MZM1, four different LO frequency doubling and mixing functions can be realized. By controlling the angle alpha between the polarization direction of the polarization analyzer and one axis of the modulator, the phase of the generated signal can be flexibly tuned in the range of 0-360 degrees. When combined with the optical frequency comb, the multi-channel multi-band frequency conversion system can be expanded into a multi-channel multi-band frequency conversion system with independent phase tuning capability by utilizing the channel switching and frequency slot selection functions of the wavelength selection switch, and parallel output of various frequency mixing results can be realized. By adjusting the phase difference between the two-channel output signals, I / Q mixing, double-balanced mixing and image rejection mixing can be configured. The scheme is not influenced by direct current bias drift, the system complexity is reduced, and the frequency conversion efficiency is improved.

The invention discloses a software-defined multi-system satellite communication load system which comprises a satellite-borne routing unit, a microwave photon frequency conversion switching unit, a comprehensive antenna microwave antenna, a comprehensive ground microwave antenna, a high-performance computing power unit, a low-speed AD / DA conversion unit, a high-speed waveform processing unit and a laser / W-frequency-band microwave common-aperture inter-satellite satellite-ground terminal. According to the invention, on-demand expansion of load capacity and miniaturization of a load system are realized, and the system integration degree is improved.

The invention belongs to the technical field of microwave photon links, and particularly relates to a high-resolution microwave photon frequency measurement system based on real-time Fourier transform. The link comprises a mode-locked laser, a first dispersion compensation module, a second dispersion compensation module, a dual-drive Mach-Zehnder modulator, a Mach-Zehnder modulator, a dispersion optical fiber, a time lens, an erbium-doped optical fiber amplifier, a photoelectric detector and an oscilloscope; the mode-locked laser outputs femtosecond Gaussian light pulses, and the femtosecond Gaussian light pulses are injected into the first dispersion compensation module and then stretched into chirp light pulses; modulating the chirp light pulse through electro-optical modulators which are connected in parallel; the modulated optical signal is subjected to time amplification processing through a dispersion optical fiber, a time lens, a second dispersion compensation module and an erbium-doped optical fiber amplifier in sequence; and the optical signal after time amplification processing is converted into a microwave pulse carrying frequency information of the signal to be detected by a photoelectric detector, and the microwave pulse is observed by an oscilloscope.

The invention discloses a distributed MIMO (Multiple Input Multiple Output) integrated system and method based on a reconfigurable notch chaotic optoelectronic oscillator, belongs to the field of microwave photons, and solves the problems of spectrum resource conflict, difficulty in multi-node synchronization, discrete inductance functions and the like. According to the system, a plurality of independent chaotic OEOs are combined with an optical frequency comb to drive an FIR filtering effect, MIMO chaotic signals with reconfigurable notch frequency points and quantity are generated, and dynamic allocation of spectrum resources is realized. The notch frequency band is used as a communication channel embedded modulation signal, and supports multi-spectrum sharing with 2.4 G, 5G, Wi-Fi and the like; a non-notch frequency band is reserved as a radar signal, and the range resolution is improved by using the broadband characteristic of the chaotic waveform. The star topology optical network expands the coverage area of a distributed system, and a centralized processing architecture reduces the complexity of multi-node collaboration. The invention provides an integrated solution of high-precision environment perception and high-reliability communication for smart cities, Internet of Vehicles and the like, and is suitable for dense urban areas with resource shortage and dynamic multi-service environments.

The invention discloses a microwave photon radar strong maneuvering target identification method based on small sample incremental learning, and belongs to the field of microwave photon radar maneuvering target identification. Time-frequency dynamic, polarization space and geometric topological features are extracted through a deep learning model, and multi-dimensional joint characterization is realized in combination with a cross-domain attention mechanism; designing a polarization-time frequency adversarial generative network, generating synthetic data conforming to an electromagnetic scattering rule under the physical constraint of a Maxwell equation, and constructing a prototype feature support set through meta learning; a dynamic knowledge distillation framework is introduced, physical consistency loss is utilized to align motion parameters and classification probability distribution of the teacher model and the student model, and lightweight increment updating is realized in combination with gradient importance masks. According to the method, the recognition precision and real-time performance of the strong maneuvering target in a complex electromagnetic environment are remarkably improved, and the method is suitable for high and overspeed maneuvering target recognition.

The invention discloses a dual-wavelength mode-locked laser generating device and a dual-wavelength mode-locked laser generating method, and belongs to the technical field of optical communication, and the dual-wavelength mode-locked laser generating device comprises a pumping source, an optical integration module, a gain optical fiber, a saturable absorber and a dual-wavelength pulse independent polarization mode linear coupling regulation and control structure, linear coupling strength of cross-polarization components in two wavelength pulses is independently regulated and controlled by using a structure of a polarization controller and a polarization maintaining optical fiber, and dual-wavelength mode-locked pulse laser of different types of pulse combinations can be obtained. The coherent pulse light source with unique spectral characteristics can provide a low-cost light source for the fields of high repetition frequency optical combs, all-fiber architecture high repetition frequency soliton sequences and microwave photonics.

The invention relates to the technical field of microwave photonics, and discloses a full-band noise microwave source system and a microwave signal generation method. An optical reference unit is used for generating an optical reference signal; the photoelectric phase detection unit is connected with the optical reference unit and is used for receiving the optical reference signal and a feedback signal sent by the microwave oscillation unit and outputting a beat frequency electric signal for reflecting a phase error; the servo control unit is connected with the photoelectric phase detection unit and the microwave oscillation unit and is used for separating the beat frequency electric signal into a low-frequency control signal and a high-frequency control signal; the microwave oscillation unit is connected with the servo control unit and outputs a target microwave signal in response to the low-frequency control signal and the high-frequency control signal. A beat frequency electric signal is separated into a low-frequency path and a high-frequency path by using the servo control unit, so that targeted suppression of phase noise of different frequency bands in a single signal source is realized.

The invention discloses a microwave photon channelization receiving device and method based on a photoelectric oscillation loop structure. The device comprises an optical signal generation unit, a photoelectric modulation unit, an optical filtering unit, a photoelectric branching unit and a signal receiving unit. The optical signal generation unit is connected with the photoelectric unit; the photoelectric unit is connected with the optical filtering unit; the output end of the optical filtering unit is connected with the input end of the photoelectric branching unit, and the signal receiving unit is connected with the output end of the photoelectric branching unit. According to the invention, the sensitivity of the microwave photon channelized receiver can be effectively improved.

The invention discloses a microwave photon beam forming network architecture based on a switch switching type optical adjustable true delay line and a phased array radar system thereof. According to the framework, microwave signals are modulated in an optical domain, and the characteristics of a plurality of adjustable delay paths in a single-channel switch switching type delay line are utilized, so that delay difference adjustment of multiple paths of optical signals is realized, the number of delay lines and delay units is greatly reduced, and meanwhile, high-precision and broadband beam-strabismus-free beam forming is supported; through two-stage or multi-stage delay configuration, the network can flexibly meet the broadband delay compensation requirements of different array antenna units, has low complexity and strong dynamic reconfigurable capability, is suitable for realization of a large-scale photonic integrated chip, reduces the number of delay lines by about 50%, does not generate frequency dispersion, and is suitable for large-scale photonic integrated chips. The system complexity, the cost and the power consumption can be remarkably reduced, and the method is particularly suitable for broadband phased array systems of millimeter waves, satellite communication, radar detection and the like.

The invention discloses a multi-frequency-band signal fusion microwave photon radar system and an implementation method thereof, and relates to the technical field of optical signal processing, and the system comprises a multi-frequency-band signal transmitting module which is used for generating a multi-frequency-band bandwidth radar signal; the m microwave photon dechirp receiving modules are used for receiving echo signals of three or more multi-band bandwidth radar signals in an optical domain; the multi-frequency-band signal fusion processing module is used for carrying out interpolation and filling of spectrum gaps on missing frequency bands among multiple frequency bands through a coherent fusion technology so as to realize fusion splicing of multi-frequency-band signals; m is the number of multi-band channels; according to the method, the broadband characteristic of the photon technology can be fully utilized, and the distance resolution of target detection is effectively improved under the condition that the bandwidth requirement of the radar waveform electrical generator is not increased through fusion processing of multi-band bandwidth radar signals.

The invention provides a terahertz generation chip based on a thin film lithium niobate platform and a preparation method of the terahertz generation chip, and belongs to the field of integrated optics and microwave photons. According to the chip, terahertz waves are generated by utilizing a second-order nonlinear difference frequency effect on thin-film lithium niobate, and phase matching of an optical field and a terahertz field is realized through parameter design of an optical waveguide structure of the lithium niobate layer and a terahertz waveguide structure of the silicon layer. The device comprises a nonlinear action layer, an isolation layer, a terahertz transmission layer and a substrate layer. Firstly, a silicon layer is thinned through a mechanical polishing process, then polytetrafluoroethylene is bonded to the bottom of the thinned silicon layer, finally, waveguide structure etching is carried out, a specific waveguide shape and size are constructed, and efficient generation and transmission of terahertz waves are achieved. The method has strong practical operability, and has wide application prospects in the fields of terahertz communication, spectroscopy, remote sensing and the like.

The present invention discloses a quartz substrate lithium niobate mode spot converter, which relates to the fields of optical communication and microwave photonics. The present invention includes a quartz substrate layer, a silica cladding layer, a lithium niobate waveguide layer, an oxide interlayer and an oxide upper cladding layer. The lithium niobate waveguide layer is a three-layer stepped structure, and the cross-sections of the fiber coupling ends of the three-layer lithium niobate waveguide layers are all isosceles trapezoids. The cross-sections of the fiber coupling ends of the oxide interlayer and the oxide upper cladding layer are both provided with notches at the lower part and isosceles trapezoidal protrusions at the upper part, and the oblique side angles of the isosceles trapezoidal protrusions of the oxide interlayer and the oxide upper cladding layer and the isosceles trapezoidal cross-sections of the lithium niobate waveguide layer do not exceed 70°. The present invention can achieve high coupling and low transmission loss when optical signals are coupled between an integrated lithium niobate photonic chip and an optical fiber, and reduces the process processing difficulty, and has high practicability.

The invention provides a broadband linear frequency modulation microwave source based on ultra-short external cavity modulation light feedback, and relates to the field of microwave photonics. Continuous light generated by the main semiconductor laser is injected into the slave laser after being adjusted, so that the slave laser works in a periodic oscillation state; the slave laser, the electro-absorption modulator and the reflector are integrated to form an ultra-short outer cavity, and the intensity of feedback light is regulated and controlled by an external signal source so as to realize linear scanning of cavity mode frequency. After beam splitting of light output from the laser, one path forms a long external cavity feedback stable signal through the adjustable optical fiber delay line, and the other path outputs a target signal after beat frequency of the photoelectric detector and filtering of the band-pass filter. A high-speed modulator and a high-frequency microwave source are not needed, the broadband advantage of a photonics scheme is reserved, the frequency sweeping bandwidth is further improved to 60 GHz or above, the center frequency and the frequency sweeping range are independently adjustable, the structure is simple, cost is low, integration is easy, and the device is suitable for scenes such as photoelectric radars.

The application belongs to the technical field of optical communication and relates to a frequency-shift-free microwave photonic channelized receiving device, which comprises a carrier light frequency comb generating unit, a local light frequency comb generating unit, an electro-optical modulation unit, an optical phase shift unit, a channel selection and spectrum processing unit and a plurality of photoelectric conversion units. The received broadband radio frequency signal is modulated on each comb tooth of the carrier light frequency comb through the electro-optical modulation unit, and the frequency alignment between the optical local oscillator and the required receiving sub-channel can be realized based on the "vernier" effect caused by the different free spectral ranges of the carrier light frequency comb and the local light frequency comb and the inherent frequency alignment of the same pump laser. The mirror image sub-channel suppression is realized based on the opposite optical phase shifts on both sides of the pump light. The application has a simple structure, omits the frequency shift and special modulation structure required for frequency alignment, effectively suppresses the inter-channel crosstalk problem in the channelized receiving process, and can flexibly increase the channelization quantity according to actual needs.

The technology described herein is directed towards a cryogenic magnet-less circulator device, in which the circulator device is based on the spatiotemporal modulation of angular momentum for microwave photons, controlled using a modulated control signal. The circulator device is configured for integration with a quantum computer, e.g., to facilitate qubit measurements. The circulator topology and design are based on tank circuits, e.g., arranged in a star topology with different sets of radio frequency superconducting quantum interference devices (rf-SQUIDS) per tank circuit, that resonate out-of-phase based on the modulated control signal. A single control line can be used to operate the circulator. The circulator can be fabricated using standard semiconductor processes, allowing one or more circulators to be integrated on the same superconducting chip as the qubits. A classical computer can be used to output the modulated control signal, and adapt the modulated control signal as needed under varying conditions.

The application provides a photon-assisted ultra-wideband millimeter wave multi-channel receiver, and the ultra-wideband millimeter wave multi-channel signal is channelized and divided by adopting the radio frequency local oscillator microwave photon frequency conversion, high-frequency stable multi-channel channelization local oscillator generation and multi-channel parallel coherent detection technology; under the constraint of a low-cost analog-digital converter, the function of high-sensitivity parallel narrowband reception of the ultra-wideband millimeter wave signal is realized through parallel channel analog-digital conversion and reception processing, and large capacity and long-distance transmission of millimeter wave wireless communication are supported. The application solves the problems of ultra-wideband signal reception, analog-digital conversion and processing in millimeter wave wireless communication, supports large capacity and long-distance transmission of millimeter wave wireless communication, and can be applied to an ultra-wideband millimeter wave wireless communication system; the principle is simple, the scheme is simple and efficient, and the application value is high.

This invention discloses a microwave photonic link signal transmission analysis method based on device models. The method first establishes the input-output relationships of different devices based on the physical mechanisms of the devices in the microwave photonic link, forming a device model. Then, according to the actual situation of the microwave photonic link, the devices are connected to analyze the signal conditions at different locations in the link. Finally, based on the RF input and RF output of the link, the method achieves rapid prediction of the RF performance of the microwave photonic link and dynamic analysis of its impact on device parameters. This invention divides the RF signal transmission process in the microwave photonic link into three steps: electro-optical conversion, optical signal processing, and photoelectric conversion. By adjusting the device layout and device parameters, dynamic design analysis of the microwave photonic link is achieved.

The invention discloses a broadband microwave photon system frequency adaptive beam amplitude weighted optimization method, which comprises the following steps: firstly, connecting different array channels of a microwave photon system by using a detector, and obtaining single-channel antenna array directional diagrams of different channels through testing, thereby constructing a broadband microwave photon system comprehensive antenna directional diagram equation; based on a vector network analyzer, amplitude weighting response conditions of each channel amplitude weighting module under different frequencies are obtained, and a broadband amplitude weighting factor function is constructed; according to a beam pointing demand, beam pointing control is realized through optical true delay, and a current antenna pattern amplitude phase equation of each channel is constructed; and finally, according to the antenna beam width and sidelobe level requirements, adaptively constructing a microwave photon system amplitude weighting optimization model of the key concerned frequency, and solving the microwave photon system amplitude weighting optimization model to obtain the optimal amplitude weighting. According to the scheme, free adjustment of the whole wave beam is realized through actually measuring limited sampling data, wave beam amplitude weighting can be adaptively carried out according to the frequency of a key signal, and the performance of the broadband microwave photon array in different directions is improved.

The invention discloses a distributed radar and laser radar system based on a chaotic optical comb, and belongs to the technical field of microwave photonics and laser. The distributed radar and laser radar system comprises a chaotic optical comb signal generation module, a wavelength division multiplexer, N optical fibers and N radar and laser radar modules. A chaotic optical comb signal generated by the chaotic optical comb signal generation module is divided into N single chaotic optical signals with different wavelengths in the wavelength division multiplexer; the N single chaotic optical signals with different wavelengths are respectively transmitted to the N radar and laser radar modules at different spatial positions through the N optical fibers, so that spatial distribution of the signals is realized. The single chaotic optical comb signal source is combined with the wavelength division multiplexer and the optical fiber, sensing signals are provided for a plurality of radar and laser radar modules which are arranged in a distributed mode, generation and distribution of multi-path distributed sensing signals are achieved, a traditional multi-source scheme is replaced, system cost, size and complexity are reduced, and compact 360-degree annular sensing array deployment is supported.

The invention relates to the field of signal frequency detection in microwave photonics, and discloses a broadband instantaneous frequency measurement receiving system based on Brillouin spectrum compression, which utilizes a dual-tone pump optical carrier signal carried on an intensity modulator and an optical filter to generate a single Brillouin pump source regulated and controlled by unknown radio frequency. A stimulated Brillouin structure narrowed by an optical fiber ring cavity and a single-pumping reference source subjected to phase shift beat frequency, a signal in a 45GHz range can be compressed to a bandwidth of 2.5 MHz, and meanwhile, an original signal can be subjected to optical domain down-conversion processing by a reference source signal, so that a low-frequency signal easy to process electronically is obtained; besides, a double-fiber annular cavity design is adopted, the line width of the Brillouin resonant laser is further compressed through mode matching of interference of light waves in the cavity, test precision reduction caused by frequency spectrum compression is made up, the resolution ratio can reach + / -2.2 MHz, and finally the Brillouin broadband instantaneous frequency measurement receiving technology is achieved.

The invention discloses a multi-modal information network system based on microwave photon energizing enhancement and an operation method. The system comprises a high-precision time-frequency synchronization subsystem, a broadband parallel processing subsystem and a broadband high-speed frequency hopping subsystem which are connected in sequence. According to the invention, the advantages of broadband, low loss and high precision of the microwave photon technology are utilized to enable and enhance information network node equipment, so that the communication capabilities of high-precision time-frequency synchronization, broadband signal parallel processing and large-bandwidth anti-interference interception frequency hopping are realized; therefore, the problems that multi-frequency, multi-form and large-capacity signal receiving and processing are difficult to realize by the existing electronic technology, and high real-time, high-speed, high-precision, high anti-interference and anti-interception requirements of a communication network in a complex electromagnetic environment in the future cannot be met are solved.

The application discloses a microwave photon frequency hopping signal generation device and method based on an optical switch and belongs to the technical field of optical communication. The application is composed of a light source, a beam splitter, an optical frequency comb generator, an electro-optical frequency shifter, an acousto-optic modulator, a digital frequency synthesizer, a filter array, a signal control unit, an electrically controlled high-speed optical switch, a beam combiner and a photoelectric detector. The application separates optical frequency comb teeth by using an ultra-narrow bandwidth optical filter, selects and opens the frequency hopping signal generated by the local light beat frequency through the optical switch, and can generate a high-speed high-order high-stability frequency hopping signal compared with the prior art.

This invention proposes a random microwave pulse generation system and method based on an optoelectronic oscillator, belonging to the field of microwave photonic signal generation and processing technology. The system includes a laser, a polarization controller, a closed-loop optoelectronic oscillator (OEO) loop, a random fiber grating string, and a function generator; wherein the closed-loop optoelectronic oscillator (OEO) loop mainly consists of a Mach-Zehnder modulator, a circulator, an erbium-doped fiber amplifier, a photodetector, an electrical amplifier, and a directional coupler.

This invention discloses a method and system for determining the type and parameters of interference signals based on microwave photonics technology. The method utilizes microwave photonics technology to modulate broadband interference signals into the optical domain. By dynamically matching the LCT transform kernel function with the reference signal parameters, the LCT operation is directly performed in the analog domain, focusing the interference signal in the optimal LCT domain. Based on the time-frequency characteristics after focusing, real-time type judgment and parameter estimation of the interference signal are achieved, completely avoiding the digital domain iterative operations of existing electronic methods. The computational complexity is reduced to microseconds, and the parameter estimation delay reaches the microsecond level, without any broadband throughput bottleneck. The parameter tuning delay depends only on the control rate of the reference signal, adapting to the type identification and parameter estimation requirements of various types of broadband interference signals, such as linear frequency modulation, frequency hopping, slice combination, and intermittent sampling and forwarding. The resistance to environmental interference and stability are significantly enhanced.

This invention discloses a shell structure and fabrication method for a laser control module in a microwave photonics system. The structure includes a ceramic component with a first metal frame and a second metal frame disposed on its upper and lower surfaces, forming a double-sided cavity structure for encapsulating multiple components. Several lead pads are arranged around the ceramic component, with a metal lead soldered onto each lead pad. Several metallized patterns are formed on each layer of the ceramic component's surface and interior. The metallized patterns on the surface of the ceramic component are connected to the metallized patterns inside the ceramic component through metal holes, forming multiple signal networks. Signal networks not connected to the lead pads are called island networks. Electroplated interconnects are distributed on the surface of the ceramic component, connecting the island networks to the lead pads for nickel-gold plating of the island networks. This invention effectively improves the integration of the circuit module and also improves electroplating efficiency, ensuring a high plating yield.

A scattering parameter measurement device based on microwave photonic mixing includes a microwave generation module 1, a signal loading module 2, a local oscillator frequency generation module 3, a multi-channel microwave photonic mixing module 4, an analog-to-digital converter (ADC) module 5, and a signal processing module 6. Along the signal output direction of the multi-channel microwave photonic mixing module 4, the ADC module 5 and the signal processing module 6 are sequentially arranged. This invention utilizes microwave photonic mixing technology and a local oscillator source with relatively small bandwidth to down-convert a high-frequency microwave signal to a fixed-frequency intermediate frequency (IF) signal. This reduces the bandwidth requirements of the receiver's electronic components and the sampling rate requirements of the ADC. It abandons the traditional superheterodyne structure and / or direct conversion structure, using a miniaturized continuous optical module as the light source for microwave photonic mixing, simplifying the system structure and reducing cost and power consumption.

The invention discloses a microwave photonic link-oriented offset angle insensitive rapid adaptive linearization method. The method specifically comprises the following steps of: injecting a continuous optical carrier output by a laser into a Mach-Zehnder modulator; an optical carrier in the Mach-Zehnder modulator is modulated by an input electric signal x; after the modulated optical signal is transmitted through an optical fiber, the signal is completely received through a photoelectric detector and is converted into an electric signal y; performing data sampling on the electric signal y output by the photoelectric detector through an analog-to-digital conversion module, and sending the electric signal y into a DSP (Digital Signal Processor); the method comprises the following steps: firstly, finishing suppression of second-order distortion in a DSP; and the suppression of the third-order distortion is further completed in the DSP. The method can flexibly adapt to the change of the offset angle, can be quickly and adaptively applied to various microwave photon links which have different input signals and are based on the Mach-Zehnder modulator, only needs to know the upper cut-off frequency and the lower cut-off frequency of the bandwidth of the input electric signal, does not need other prior parameters of the link or the input electric signal, and does not need complex training or iterative optimization.

Disclosed is a method for characterising a sample (E), said method comprising magnetically coupling the sample to a microwave resonator (RHS) such that the coupling dominates the relaxation dynamics of an electron spin (SEL) of a paramagnetic centre of the sample, and determining, by nuclear-magnetic-resonance spectroscopy, coefficients Cij of coupling between a nuclear spin of the sample, called the probe nuclear spin (SNi), and other nuclear spins (SNj, SNk) of the sample, said method employing indirect detection of a state of said probe nuclear spin (SNi), through counting of microwave photons, of respective noise signals (SBS) produced by the return to equilibrium of said electron spin (SEL). An apparatus for implementing such a method is also disclosed.

This invention relates to the fields of optical fiber communication and microwave photonics. Existing tunable dual-passband microwave photonic filters suffer from poor passband stability and cannot meet practical application requirements. This invention provides a narrow-band tunable dual-passband microwave photonic filter using a Brillouin fiber laser. It generates dual-tone pump light to excite the Brillouin using a tunable laser source and an intensity modulator. Combined with a Brillouin fiber oscillator and a cascaded Fabry-Perot cavity, the Brillouin gain spectrum is narrowed to the kHz level. Simultaneously, the different periodic resonant frequencies of the two ring cavities effectively suppress side modes, filtering out the desired frequency band signal. Furthermore, by synchronously tuning the center frequencies of the two passbands of the filter by changing the pump light wavelength, and simultaneously controlling the output frequency of the signal generator, the frequency interval between the two passbands is changed, ultimately realizing a narrow-linewidth tunable dual-passband microwave photonic filter.

The invention provides an on-chip integrated microwave photon-assisted channelized frequency measurement system, which is applied to the technical field of microwave photons. The system comprises a light source module used for emitting optical carriers with different wavelengths through N laser channels; the beam combining module is used for combining the N optical carriers with different wavelengths through N first channels to obtain a multi-wavelength optical carrier signal; the modulation module is used for receiving a radio frequency input signal and loading the radio frequency input signal to the multi-wavelength optical carrier signal to obtain a multi-wavelength radio frequency modulation optical signal; the filtering module is used for filtering the multi-wavelength radio frequency modulation optical signal so as to extract a single sideband of the radio frequency modulation optical carrier signal of each wavelength; the beam splitting module is used for separating the filtered multi-wavelength radio frequency modulation optical signals and distributing the multi-wavelength radio frequency modulation optical signals to N second channels; and the detection module is used for detecting the power of the output signals of the N second channels so as to determine the frequency range of the radio frequency input signal.