71 results about "Microwave signal processing" patented technology

The invention discloses a photon microwave down conversion device and method, and belongs to the technical field of microwave signal processing. In the device, an electro-optic modulator, an optical narrow band notch filter, a photoelectric detector and an electric mixer form an oscillating loop, the device has a function of generating microwave local oscillation, and the frequency of a local oscillation signal can be flexibly adjusted by changing the frequency of output optical waves of a variable length adjustable laser. Due to a phase modulation function of the electro-optic modulator, a radio frequency signal is output from an output end of the down conversion photoelectric detector, thus having complete radio frequency isolation advantages. The down conversion device has flexible regulation and control ability, can not only perform down conversion on the radio frequency signals with different frequency to intermediate frequency signals with the same frequency, but also can performdown conversion on the same radio frequency signal to the intermediate frequency signals with different frequency. The photon microwave down conversion device solves the problems of complex structure, poor radio frequency isolation, flexible tuning difficulty and the like of microwave down conversion in the prior art.

The invention relates to the fields of radar microwave signal processing technologies and life medicine, and in particular relates to a method for measuring the respiratory rate and the heart rate ofthe human body based on ultra-wideband radar. The technical key points of the scheme are as follows: the method comprises the following steps: S1, carrying out initialization on the ultra-wideband radar; S2, acquiring echo signals; S3, calculating the position information of the person according to the echo signals; S4, carrying out Butterworth band-pass filtering on one-dimensional time series signals in S3; S5, enhancing the signals by adopting a Min-Max normalization method; S6, smoothing the enhanced signals by adopting the Harming window; S7, carrying out fast discrete Fourier transform on the signals after smoothing processing; and S8, searching the peak values of the signals in the breathing zone and the heart rate zone, wherein the searched peak values are adopted as the parametersof respiration and heartbeat. The method is applicable to the non-contact measurement for respiration and heartbeat, can be applied to the special human body and environment, and has the relatively high precision and relatively low computation complexity.

The invention discloses a microwave photon filter of a multi-wavelength light source and a tuning and reconfiguring method of the microwave photon filter. The microwave photon filter of the multi-wavelength light source comprises a multi-wavelength light source generator and a microwave filter device. The microwave filter device comprises a phase modulator, an adjustable dispersion compensator, a first erbium-doped optical fiber amplifier, a photoelectric detector and a vector network analyzer. A comb-shaped optical fiber of the multi-wavelength light source generator is a programmable optical filter. By observing response curve of the network analyzer, dispersion value of the adjustable dispersion compensator is adjusted, time delay between adjacent optical wavelengths of adjacent multi-wavelength light is changed continuously, and central continuous tuning of the microwave photon filter can be realized. The number of comb-shaped pass bands is set by the programmable optical filter to change the number of emitting wavelengths, and adjustment of the bandwidth of the microwave photon filter is realized. Tunable capacity and reconfigurability of the microwave photon filter are realized, and the microwave photon filter can be more flexibly used for the microwave signal processing system.

A microwave sensor used for steam humidity detection belongs to the technical field of testing and is used to solve the problem of steam humidity detection. The technical solution is that it includes a cylindrical cavity with openings at both ends and a microwave signal transmission interface in the middle, and a ring divider is respectively arranged at both ends of the cylindrical cavity, and the ring divider is composed of It consists of 1 to 4 cylinders coaxial with the cylindrical cavity, one end of which is close to the port of the cylindrical cavity is connected with the cylindrical cavity, and the expansion coefficient of the ring separator is larger than that of the cylindrical cavity. The invention has the advantages of simple structure, convenient use and low requirements on the environment, and can realize high-precision online measurement of the humidity of flowing wet steam by cooperating with the microwave signal processing circuit.

The invention relates to a microwave same-frequency signal interference suppression and down-conversion receiving device and method, and belongs to the technical field of microwave signal processing.The microwave same-frequency signal interference suppression and down-conversion receiving device comprises a laser, polarization multiplexing DP-MZMs (dual-parallel Mach-Zehnder modulators) , a received signal simulator, an interference signal simulator, a local oscillator signal generator, a DC power supply, a polarization controller, a polarizer, an optical amplifier and a photoelectric detector, wherein the DP-MZMs are DP-QPSK (dual-polarization quadrature phase shift keying) modulators, one DP-MZM of the DP-QPSK modulators is used for suppressing an interference signal in received signalsin an optical domain and coupled with a local oscillator light signal generated by the other DP-MZM of the DP-QPSK modulators, and photovoltaic conversion is conducted at the photoelectric detector so that optical down conversion of the received signals is achieved. Same-frequency interference suppression and optical down-conversion of the received signals can be achieved simultaneously, and influence of optical fiber dispersion on same-frequency interference suppression level and power of the received signals in the signal optical fiber transmission process is reduced.

The invention provides an online microwave moisture detection method and system for a tobacco bale. The method comprises the following steps of: (1) obtaining internal moisture of tobacco bale leaves; (2) obtaining attenuation A and phase difference P measurement components of an online microwave moisture detection device; and (3) establishing a mathematic model of the internal moisture and the attenuation A and phase difference P measurement components; predicating the internal moisture of the tobacco bale by utilizing the mathematic model. The system provided by the invention is used for complementing the method and comprises an analyzer enclosure, and a power supply unit, a control unit, a moisture predication module, a microwave signal transmitter, a transmitting antenna, a receiving antenna and a microwave signal processing unit, which are mounted in the analyzer enclosure. The online microwave moisture detection method and system provided by the invention have the advantages of capability of detecting the whole moisture in the tobacco bale, high detection precision, simplicity in detection, stability in operation, wide applicable range and the like.

The invention discloses an atomic time signal receiving system and method. The system comprises a microwave detection part and a microwave signal processing part, wherein the microwave detection part is used to couple an optical signal at an atomic time signal receiving position at any position in an optical fiber link and then demodulate a microwave signal on the optical signal; the microwave signal processing part is used to reproduce an atomic time signal of which the phase is locked on a reference clock on the basis of the demodulated microwave signal; and the microwave detection part can respectively couple parts of the optical signals transmitted along the opposite directions in the optical fiber link and then perform a demodulation process. According to the atomic time signal receiving system, atomic time signal of which the phase is locked on the reference clock can be reproduced at any position in the compensated signal transmission system of the optical fiber link, thus the application range of the atomic time signal fiber transmission system can be enlarged.

The invention relates to the field of microwave signal processing, and particularly relates to a multi-channel phase and amplitude correction device and correction method for a receiving channel. According to the scheme of the invention, a standard waveform is generated by a correction module, an AD module acquires a signal and calculates phase and amplitude offsets, and thus the correction of theamplitude and phase of the channel can be performed. The method disclosed by the invention has the advantages of small calculation amount, timing compensation, high accuracy and the like.

The embodiment of the invention provides a microwave signal processing system and method, and relates to the technical field of communications. The system comprises an optical frequency comb, a firstintensity modulator, a filter, a pulse shaper, a time lens and a dispersing component; the first intensity modulator receives an external input microwave radio frequency signal and a comb-like ultra-short pulse laser signal generated by the optical frequency comb, and modulates the microwave radio frequency signal to the comb-like ultra-short pulse laser signal to obtain a radio-over-fiber signal;the bandwidth of the radio-over-fiber signal is filtered and amplified by the optical filter; a first optical pulse signal is obtained after the radio-over-fiber signal with the amplified bandwidth passes through the pulse shaper; the time lens modulates a chirped phase to the first optical pulse signal to obtain a chirped optical pulse; and the dispersing component de-chirps the chirped opticalpulse to obtain a delayed optical pulse signal. The scheme provided by the embodiment of the invention can improve the frequency resolution of the microwave radio frequency signal that can be processed by the microwave signal processing system.

The invention relates to a high-spectral-efficiency microwave same-frequency signal interference suppression device and method, and belongs to the technical field of microwave signal processing. The device comprises a laser, a polarization multiplexing Mach-Zehnder modulator, namely a DP-BPSK modulator, a received signal simulator, an interference signal simulator, a first 90-degree electric mixer, a second 90-degree electric mixer, a direct-current power supply, a polarization controller, a polarizer and an optical receiver. A dual-drive Mach-Zehnder modulator (DD-MZM) of a DP-BPSK modulator is used for carrying out single sideband modulation on a received signal, and the other DD-MZM performs single sideband modulation on the interference signal, the interference signal is suppressed in an optical domain after the two paths of optical signals are coupled, and meanwhile, the useful signal is subjected to suppression carrier single sideband modulation. Due to the fact that interference is eliminated in an optical domain, dispersion in signal optical fiber transmission will not enable interference signals to appear again, in addition, system spectral efficiency is improved through suppression carrier single-sideband modulation of useful signals, and meanwhile the influence of dispersion on useful signal transmission is greatly reduced.

The invention discloses a tactical air navigation system external field beacon simulator, which consists of a frequency synthesizer module, a microwave modulation module and a display control and video processing module, wherein the frequency synthesizer module and the microwave modulation module finish generating and receiving five paths of radio frequency signals on the basis of microwave signalprocessing and a microstrip technology; the display control and video processing module takes a large-scale integrated circuit FPGA (Field Programmable Gate Array) and a high-speed MCU (Single Chip Microcomputer) as the center; and a bell shaped pulse and a PIN (Personal Identification Number) modulation technology are adopted to effectively improve frequency spectrum performance, and the full-frequency-band and full-channel coverage function of the tactical air navigation system external field beacon simulator is realized. A multi-channel parallel technology and the microwave modulation module with a microwave signal processing function are adopted to generate the simulation signals of a plurality of beacon stations, and a one-machine multiple-station function can be realized.

A gain compensation circuit comprises a first amplifier, a second amplifier, a filter, a first attenuator, a second attenuator and a third attenuator. The first amplifier is configured to amplify an input signal of the microwave signal processor. The filter is disposed between the first and second amplifiers. The first attenuator is disposed between the first amplifier and the filter for reducing return loss of the microwave signal processor. The second attenuator is disposed between the second amplifier and the filter for reducing return loss of the microwave signal processor. The third attenuator is electrically connected to the output of the second amplifier for reducing noise figure of the microwave signal processor and providing first and second gain compensations. The first gain compensation keeps the gain of the microwave signal processor constant under various temperatures, and the second gain compensation adjusts a nominal gain of the microwave signal processor.

The invention relates to a quantitative detection method of glyceryl triacetate in a filter stick. The method comprises the following steps: (1) preparing a gradient filter stick sample having a glyceryl triacetate content of 0%-15%; and (2) measuring the accurate content of the glyceryl triacetate in the filter stick by using a gas chromatographic method; (3) placing the filter stick sample in amicrowave detector for detection to obtain a microwave detection signal of the sample; (4) after the microwave signal of the sample is processed, correlating the microwave signal of the sample with the accurate content obtained by using the gas chromatographic method, establishing a model, and storing the model; and (5) randomly taking the filter stick sample, measuring the filter stick sample byusing the microwave detector to obtain the microwave detection signal of the sample, and comparing the microwave detection signal of the sample with the model in a memory to obtain a content value ofthe glyceryl triacetate of the sample. The detection method provided by the invention can be used for quickly and accurately measuring the content of the glyceryl triacetate in the filter stick, and can be promoted to the online control of the adding of the glyceryl triacetate in the filter stick forming process.

The invention belongs to the photon microwave signal processing technical field and provides an optical domain reflection-based miniaturized tunable photoelectric time delay network structure. The objective of the invention is to effectively reduce the size of a whole photoelectric delay network. According to the technical schemes of the invention, the optical domain reflection-based miniaturized tunable photoelectric time delay network structure comprises one or more time delay modules which are connected in series between an optical microwave signal input end and an optical microwave signal output end; each time delay module includes a circulator (1), an optical switch (2), time delay devices (3) and reflectors (4); input optical microwave signals are connected with the input end of the circulator (1); the bi-directional port of the circulator (1) is connected with the common port of the optical switch (2); two switchable ports of the optical switch (2) are respectively connected with the time delay devices (3) enabling different time delay length; one end of each time delay device (3) is connected with one reflector (4); and the output end of the circulator outputs optical microwave signals.

A microwave photon trap wave apparatus with a silicon-based self-coupling micro ring resonant cavity relates to the technical field of optical fiber communication and comprises a to-be-processed signal generation module, a microwave photon trap wave module and a processed-signal feedback module. A to-be-processed photon signal is generated by the to-be-processed signal generation module and then input by an input end of the microwave photon trap wave module; and an output end of the microwave photon trap wave module outputs a processed signal via the processed-signal feedback module.. Limitations on processing speed and adjusting range can be removed and a solution scheme is provided for realization of a filtering function of a dynamic broadband microwave signal processing system.

The present invention relates to a microwave scanning brain imaging device and method. The microwave scanning brain imaging device comprises a microwave signal processing unit, microwave antennas, a ring bracket and a rotating unit, the microwave signal processing unit comprises a microwave transmitting module and a microwave receiving module, the microwave antennas are arranged inside the ring bracket, the ring bracket is connected with the rotating unit, the microwave antennas are connected with the microwave signal processing unit, the rotating unit drives the ring bracket to rotate, by rotating and changing positions of the microwave antennas to work, the microwave antennas are connected with the microwave signal processing unit, the microwave signal processing unit controls and drivesthe microwave antennas to transmit microwave signals or receive the microwave signals, and the microwave signal processing unit conducts an imaging treatment according to the signals received by themicrowave receiving module. By using a plurality of the microwave antennas to conduct rotary and movable scanning, the microwave scanning brain imaging device improves scanning density on a horizontalplane, also increases the scanning density in a vertical direction, and thus greatly improves imaging accuracy.

The invention, which belongs to the field of microwave systems, discloses a microwave sensor, a microwave signal processing system and a detection method thereof, thereby solving problems of high manufacturing cost and high manufacturing difficulty of the existing microwave sensor made based on the oft lithography technology in the prior art. The microwave sensor made based on a PCB has the highereconomic effect than the glass-based microwave sensor and is suitable for mass production. The sensor and system are easy to combine with a microfluidic channel and capillary tube. And thus the microwave sensor, the microwave signal processing system and the detection method thereof have the broad application prospects in fields of component analysis in food and beverage production and pathogen detection in the food and drinking water. Besides, the sensor and the system can be made simply; the detection is accurate; and the cost is reduced substantially.

The invention relates to a thermal control phase modulator based on a sub-wavelength grating metasurface. The thermal control phase modulator comprises a transparent medium substrate of a first bottomlayer, a second metal film layer, a third medium film layer, a fourth medium grating layer, a fifth high-refractive-index medium grating layer and a sixth thermo-optical medium layer. The medium grating layer and the high-refractive-index medium grating layer are periodic grating arrays, the grating periods are p, the grating duty ratios are q, the thicknesses are t1 and t2 respectively, and t1 <t2. The thermal control phase modulator based on the sub-wavelength grating metasurface structure has a high Q value formant, the high Q value formant is accompanied by violent phase mutation, and aphase mutation curve drifts along with the change of the external refractive index. High-sensitivity thermal control phase modulation can be realized based on the spatial light modulator, so that thefunction of the spatial light modulator is realized, and the thermal control phase modulator can be applied to the fields of optical communication, display and imaging, optical signal processing, automatic driving, microwave signal processing and the like.

The invention provides a modulation laser ranging method for underwater ranging, relating to the technical field of underwater detection. The method comprises specific steps that a light emitter emitsGaussian pulse, performs cosine modulation on the Gaussian pulse, adjusts pulse width, modulation frequency and modulation depth and other parameters, and selects a proper parameter according to actually detected seawater depth; and modulated Gaussian pulse passes a transfer medium and then arrives at a target, is reflected by the target and returns through the same medium, an echo signal is received by a high-speed detector, the modulated signal is extracted and undergoes microwave signal treatment, and a treatment result peak is corresponding to target distance information. The method solves problems of low signal to noise ratio of an underwater signal, poor target contrast, short distance measurement range and low accuracy caused by underwater backward scattering. The method effectively suppresses underwater backward scattering, improves signal to noise ratio of the signal greatly, is suitable for various complex underwater environments, and improves underwater distance measurementaccuracy and prolongs distance measurement range.

The invention provides a flexible microwave device and a preparation method thereof. The device includes a flexible waveguide and flexible ferrite films; the flexible ferrite films are formed on the upper surface of the flexible waveguide. The surface of the flexible waveguide is provided with two parallel S-shaped channels, the flexible ferrite films are located in the middles of the S-shaped channels, and one end of each S-shaped channel is externally connected with an electromagnetic wave generator. The flexible microwave device is simple in structure, small in size, low in cost and good inperformance, can be used for preparing flexible microwave signal processing devices such as isolators, circulators, phase shifters, diplexers, filters, microwave dielectric antennas and ferrite switches, and has important application prospects in microwave communication, the Internet of Things, intelligent household appliances and other fields.

The invention provides an ablation catheter and a method using the same to implement ablation. The ablation catheter comprises an ablation electrode, a catheter body, an operation handle and a control processing system which are connected sequentially, the control processing system comprises a radio frequency transmitting system and a microwave signal processing system, the radio frequency transmitting system sends out an ablation radio frequency signal which is transmitted to ablation tissue through the ablation electrode, the ablation electrode receives a microwave signal from the ablation tissue and transmits the microwave signal to the microwave signal processing system, and the ablation electrode can serve as a transmitting antenna of the ablation radio frequency signal and a receiving antenna of the microwave signal, so that temperature change of the ablation tissue can be presented truly and timely without affecting controllability of the catheter. The ablation catheter is simple in machining process and low in cost, and operating safety is improved to some extent.

The invention relates to a multi-frequency pulse laser radar signal processing method and a wind finding radar system. The method comprises the following steps: detecting a target by emitting a plurality of laser pulse signals with coherent frequencies, correspondingly receiving a plurality of multi-frequency echo signals reflected by the target at different distances, and processing the multi-frequency echo signals by adopting a microwave signal processing mode to obtain the moving speed of the target. By adopting the method, the problem that speed/distance resolution of a traditional single-frequency laser radar is dilemma can be solved, that is, distance resolution can be reduced when speed resolution of the traditional laser radar is improved, and speed resolution can be reduced when distance resolution is improved, so that fine detection of a complex wind field is realized under a lower signal-to-noise ratio; moreover, the frequency difference among the multi-frequency signals is adjusted to adapt to various detection conditions.

The invention relates to a multi-channel portable microwave scanning brain imaging device and method. The multi-channel portable microwave scanning brain imaging device comprises an elastic loading module, a coupling fluid storing module for storing coupling fluid, a vacuum negative pressure generating module for producing vacuum negative pressure, and a microwave signal processing unit, wherein the elastic loading module cooperates with the shape of the brain, consists of an arc-surface antenna array, a skull hood and a ventilation pipe, can be penetrated by microwaves and is used for loadingcoupling fluid, the arc-surface antenna array comprises a plurality of microwave antennas, and the microwave antennas are arrayed in an arc surface; the microwave signal processing unit comprises a microwave transmitting module and a microwave receiving module; each microwave antenna is connected with the microwave signal processing unit; and an opening at one end of the ventilation pipe is connected to the skull hood and communicates with an inner cavity of the skull hood, and the other end of the ventilation pipe is connected with the vacuum negative pressure generating module. According tothe multi-channel portable microwave scanning brain imaging device and the method disclosed by the invention, the ventilation pipe and the elastic loading module are arranged, so that the elastic loading module loaded with the coupling fluid can be tightly attached to the microwave antennas, a microwave signal is less influenced, and the imaging effect is good.

The invention discloses a multi-service wireless communication system and method. The multi-service wireless communication system comprises a plurality of access units, at least one expansion units connected with the access units, and at least one far-end unit connected with the expansion units; each access unit supports a plurality of communication modes of different server providers, and each far-end unit supports the communication modes of the different server providers; in a down link, each access unit adds a corresponding communication mode label to a received radio-frequency signal and then sends the radio-frequency signal to the corresponding expansion unit through a microwave; each expansion unit processes the received microwave signal according to the communication mode label in the received microwave signal and then sends the processed microwave signal to the corresponding far-end unit supporting the communication mode through an optical fiber; and the corresponding far-end unit processes a corresponding received optical signal to convert the corresponding received optical signal into a radio-frequency signal in a corresponding communication mode and to transmit the radio-frequency signal in the corresponding communication mode to a user.

The invention discloses a microwave heating triaxial test device and a sample heating method. The device comprises a novel triaxial pressure chamber, a microwave heating device, a temperature controller and a microwave modem, wherein a columnar heating cylinder is attached to the inner wall of a pressure chamber cylinder, the space between the pressure chamber cylinder and the columnar heating cylinder is filled with glass fibers, and the pressure chamber cylinder, the glass fibers and the columnar heating cylinder form a lifting integrated structure, so that disassembling is not needed, and operation is easy; and the microwave heating device is embedded into a sample cap on the upper portion of the pressure chamber, the microwave device is connected with a microwave signal processor through a wire, the microwave signal processor is connected with the microwave modem through a wire, the microwave modem is connected with a temperature sensor through a wire, and the temperature sensor isconnected to the interior of the pressure chamber and the upper portion of a sample through wires, so that a closed loop is formed. Through the device and the method, direct overall heating of the sample itself can be realized, internal temperature and external temperature of the sample are consistent, the influence of non-uniform heating on a test result is avoided, and the accuracy of the triaxial test result is ensured.

The invention discloses a double frequency conversion optical orthogonal demodulation method and system for microwave signals, and belongs to the field of microwave signal processing, and the method comprises the following steps: S1, inputting a high-frequency local oscillator signal, and loading the local oscillator signal to an optical carrier by using a modulator; S2, generating a local oscillator optical signal capable of covering a low frequency band and a high frequency band; and S3, mixing the local oscillation optical signal with the signal light loaded with the radio frequency signalto realize zero intermediate frequency optical orthogonal demodulation of the microwave signal. According to the method, a secondary frequency conversion thought is utilized, and microwave signal processing of a low frequency band is also moved to a high frequency band. The two-stage modulator carries out optical mixing to generate broadband local oscillation optical signals covering a low frequency band and a high frequency band, so that zero intermediate frequency optical orthogonal demodulation of microwave signals is realized, orthogonal demodulation of microwave signals covering a full frequency band can be conveniently realized, and requirements on optical signal processing in a broadband signal optical orthogonal demodulation scheme can be reduced.