156 results about "Microwave reflection" patented technology

The invention belongs to the technical field of microwave measurement, and discloses an outer wall hollowing microwave reflection detection method based on multi-modal fusion, which comprises the following steps: carrying out multi-modal scanning on a building outer wall to be detected, obtaining visible light image data and infrared temperature distribution data of the outer wall surface, and carrying out space registration and coordinate mapping; a unified multi-modal fusion data set is formed; performing anomaly screening on the multi-modal fusion data set, and identifying a thermal anomaly region by analyzing infrared temperature distribution data; detecting a bump or crack area in combination with texture and morphology anomaly features of the visible light image data; performing information fusion on the thermal anomaly region and the bump or crack region, and extracting candidate detection regions of suspected hollowing; high-precision recognition and quantitative evaluation of the outer wall hollowing are achieved, and the precision and stability of outer wall hollowing detection are improved.

The invention discloses a microwave-based polyethylene pipe hot-melt welding defect detection system, and relates to the technical field of polyethylene pipe hot-melt welding joint defect detection, and the method comprises the following steps: firstly, collecting microwave reflection signals of normal and defect-containing hot-melt welding joints, and carrying out normalization; the processed signals are sliced, sliced fragments are labeled, time domain and frequency domain features are extracted, and a defect sample data set is constructed; carrying out feature selection on the extracted features, and selecting 10 features with the highest contribution to the recognition accuracy; constructing a support vector classifier model, performing training by using the data set after feature selection, and performing hyper-parameter optimization on the model to obtain an optimal classification model; designing and realizing a polyethylene pipe hot-melt welding defect detection system, and detecting whether a welding position contains defects and defect positions or not; according to the invention, accurate detection of polyethylene pipe hot melting welding defects can be realized, defects and positions can be rapidly identified, and technical support is provided for quality safety detection of polyethylene pipes.

The invention discloses a vital sign monitoring method based on multilayer variational mode decomposition and reconstruction, which comprises the following steps: sending a radar microwave signal to a target human body, receiving a path of returned radar microwave reflection signal, and extracting frequency domain characteristics of the radar microwave reflection signal; judging whether the current human body is in a resting state or not according to the radar microwave reflection signals, and if so, extracting the radar microwave reflection signals in the resting state; carrying out respiratory signal and heart rate signal separation reconstruction on the radar microwave reflection signal in the resting state to obtain a reconstructed respiratory signal and a reconstructed heart rate signal; phase data of the reconstructed respiration signals and the reconstructed heart rate signals are extracted respectively, wavelet transformation is conducted on the phase data of the respiration signals and the phase data of the heart rate signals respectively, respiration phase characteristics and heart rate phase characteristics are obtained, and the respiration frequency and the heart rate are calculated according to the respiration phase characteristics and the heart rate phase characteristics.

The invention discloses a 10kV XLPE cable insulation aging state evaluation method based on a microwave reflection signal transmission factor, and the method comprises the following steps: transmitting high-frequency microwave signals with different frequencies to a to-be-evaluated cable through a high-frequency microwave signal source, and measuring the reflected wave power absolute value and the reflection coefficient of the high-frequency microwave signals after the high-frequency microwave signals are reflected in a cable medium; and respectively calculating a cable distortion coefficient alpha, an electromagnetic disturbance coefficient beta and a microwave reflection signal transmission factor sigma of the to-be-evaluated cable, and evaluating the aging state of cable insulation through the microwave reflection signal transmission factor sigma. The method has the advantages that the high-frequency microwave signal is applied to the XLPE cable, the receiving antenna is used for obtaining the reflected wave, the power absolute value and the reflection coefficient of the reflected wave are detected through the spectrum analyzer, the distortion coefficient and the electromagnetic disturbance coefficient of the cable are calculated, and the microwave reflection signal transmission factor is extracted to evaluate the insulation aging state of the XLPE cable. According to the method, the insulation aging state of the 10kV XLPE cable can be accurately evaluated efficiently and safely, power failure faults caused by serious insulation aging of the cable are reduced, guiding significance can be provided for operation and maintenance personnel to evaluate the service performance of the cable, and safe operation of a power grid is guaranteed.

The polarization-insensitive dynamic adjustable metasurface invisible cloak is suitable for different target terrain backgrounds, independent adjustment of polarization-insensitive amplitude and phase is achieved through innovative design, and the polarization-insensitive dynamic adjustable metasurface invisible cloak is suitable for dynamic invisibility and electromagnetic wave control in a complex environment. The cloak is composed of a plurality of metasurface units arranged in an array mode, each unit comprises a multi-layer metal structure and a dielectric substrate and is integrated with an active adjustable device, and real-time regulation and control over the phase and amplitude of electromagnetic waves are achieved. And by adopting the 90-degree rotational symmetry design, the good adaptability to horizontal polarization and vertical polarization radar waves is ensured. By adjusting the bias voltage, the device can simulate microwave reflection characteristics of different target terrains, and an efficient solution is provided for military stealth, terrain detection and electromagnetic environment simulation. Compared with the prior art, the electromagnetic wave control flexibility and environmental adaptability of the metasurface are remarkably improved.

The invention belongs to the cross technical field of artificial intelligence and environmental protection engineering, particularly relates to a denitration catalyst microwave regeneration optimization method based on machine learning, and aims to solve the problems of inaccurate energy matching, large structural damage and low efficiency of a traditional regeneration method. The method comprises the following steps: constructing a catalyst multi-dimensional feature database, establishing a microwave regeneration multi-physics field coupling simulation model, and training an integrated learning prediction model to associate input features with a regeneration effect; in the regeneration process, infrared thermal imaging, microwave reflection and gas sensing equipment are integrated, temperature field, energy absorption and tail gas data are collected in real time, and microwave power, frequency and atmosphere parameters are dynamically regulated and controlled. Accurate energy release and closed-loop intelligent regulation and control are achieved, the activity recovery rate after regeneration exceeds 92%, the specific surface area retention rate exceeds 85%, the regeneration period is shortened to one third of that of a traditional method, energy consumption is reduced by 40%, full-life-cycle intelligent management of the catalyst is supported, and economical efficiency and sustainability of environmental protection equipment are remarkably improved.

The invention relates to a method and a device for measuring a soil disturbance profile of an agricultural soil touch component, and belongs to the technical field of soil disturbance measurement. The method comprises the following steps that microwaves are emitted to soil of the cross section of an operation area after the agricultural soil touch component operates, reflected waves reflected by the soil are measured, the area with the large microwave reflection loss is determined from the reflected waves, and the boundary of the area serves as the soil disturbance outline. Microwaves are emitted to the soil of the cross section of the working area after the agricultural soil touching component works, reflected waves reflected by the soil are measured, the area with the large microwave reflection loss is determined from the reflected waves, when the soil bulk density corresponding to the microwave reflection loss is reduced by 20% or above, it is considered that the microwave reflection loss is large, and the area with the large microwave reflection loss is determined. According to the method, the boundary of a large area in microwave reflection loss serves as the soil disturbance contour, accurate measurement of the soil disturbance contour is achieved, manual repeated measurement is not needed, and accurate measurement can be conducted on the complex shape of the disturbance area after operation.

The invention relates to the technical field of fireproof heat preservation plate machining, and discloses a fireproof heat preservation plate machining device and method.The fireproof heat preservation plate machining device comprises a microwave drying box, a sealing door is hinged to the outer portion of the microwave drying box, a containing groove is formed in the bottom of the microwave drying box, and a microwave emitting device is fixed in the containing groove; according to the fireproof heat preservation plate machining device and method, a microwave emitting device is started to conduct microwave drying on a fireproof heat preservation plate, a first motor is started to drive a belt and a ceramic screw to rotate, a belt drives metal fan blades to rotate, and then the microwave emitting device is started to conduct microwave drying on the fireproof heat preservation plate; and the ceramic screw drives the aluminum pipe screw to move, the aluminum pipe drives the ceramic cover plate to push the fireproof heat preservation plates, the interval gaps of the fireproof heat preservation plates are enlarged, the microwaves can irradiate the fireproof heat preservation plates more easily, and the drying efficiency of the fireproof heat preservation plates is improved.

The invention discloses a polyethylene pipe microwave defect detection system based on a multi-dimensional movement mechanism. The method comprises the steps that firstly, full-coverage scanning of a welding area is achieved through a clamp and a control device, and microwave reflection signals of a welding joint are collected and subjected to amplification, filtering and normalization processing; converting the frequency domain signal into a time domain B-scan image by using inverse fast Fourier transform (IFFT), and effectively inhibiting direct waves and high-frequency noise by using a wavelet transform threshold denoising method so as to enhance defect reflection characteristics; on the basis, the system can identify and position typical defects such as holes, slag inclusion, incomplete fusion and the like, and visual visualization of defect positions and forms is realized through the information display module. The system is compact in structure and high in detection precision, has the advantages of high automation degree, wide application range, simplicity and convenience in operation and the like, can realize rapid and accurate detection of weld defects of the polyethylene pipeline, and provides reliable technical guarantee for pipeline quality evaluation and safe operation.

The invention discloses a double-probe film thickness and defect collaborative decoupling method. The method comprises the steps that microwave reflection signals of a thermal barrier coating are synchronously collected through a coaxial resonance probe and a CSRR resonance ring probe; the microwave reflection signal comprises reflection coefficient amplitude, reflection coefficient phase and resonant frequency; constructing a frequency deviation model based on the microwave reflection signal; training the dual-channel deep learning network based on the frequency deviation model to obtain a trained dual-channel deep learning network; and obtaining film thickness information and a defect positioning result based on the trained dual-channel deep learning network. According to the method, collaborative decoupling of the film thickness and the defect signal is achieved through a physical-data fusion method, effective decoupling and independent recognition of the coating film thickness change and the defect response signal are achieved, and the resolution ratio, the accuracy rate and the practicability of a detection system are improved.

The invention discloses a preparation method of a magnetic doped nanofiber derived carbon aerogel wave-absorbing material with a gradient pore structure and application of carbon aerogel, and belongs to the field of microwave wave-absorbing materials. The aerogel microstructure is controlled by regulating and controlling the parameters of the arched ice template and the content of the magnetic material precursor, and the lightweight carbon aerogel material is obtained through arched ice template freezing, freeze drying and carbonization. The gradient pore structure of the carbon aerogel improves impedance matching and promotes microwave reflection and scattering; the nano cellulose, the aramid nano fiber and the metal organic framework cooperatively optimize the polarization loss and magnetic loss performance by constructing a multi-element heterogeneous interface. Due to the characteristics, the carbon aerogel has excellent wave absorbing performance. According to the present invention, the carbon aerogel has the optimal reflection loss value of-57.03 dB when the frequency is 2-18 GHz and the thickness is 2.8 mm, and the effective absorption bandwidth (RL < =-10 dB) of the microwave absorption is 6.76 GHz, such that the carbon aerogel has the good application prospect in the electromagnetic wave field, and can simultaneously achieve the broadband and the strong absorption of the microwave under the low thickness.

A center shaft of a feed source and an X-axis stator of a base are coaxial and jointly fixed on an X-axis base, an X-axis drives an auxiliary reflector, a Y-axis and a main reflector to rotate jointly, the Y-axis drives the main reflector to rotate relative to the auxiliary reflector, microwave signals are emitted from the feed source and reflected to the main reflector through the auxiliary reflector with an included angle of 45 degrees, and the microwave signals are reflected to the main reflector through the auxiliary reflector with the included angle of 45 degrees. The first reflection microwave direction rotates along with the X axis, and the second reflection microwave direction rotates along with the Y axis; the microwave signal receiving process is opposite; when the antenna is launched, the antenna is folded, and the Y-axis driving shaft and the main reverse fixed assembly rotate reversely together, and are pressed on a satellite deck by a pressing point. A plurality of rotating joints and connecting waveguides of a two-dimensional mechanism are omitted, feed line loss is greatly reduced, efficiency is improved by more than 30% under the same caliber, weight is reduced by more than 40%, control over main and auxiliary reverse installation precision of the mechanism is greatly simplified, and the mechanical environment of a satellite launching section can be met.

The invention discloses a plasma field three-dimensional chromatography reconstruction method based on microwave reflection and probe combined measurement, which comprises the following steps: firstly setting the frequency of a microwave antenna and the measurement position of a probe, and then realizing high-precision combined diagnosis of electron density distribution by combining the global non-contact measurement advantage of a microwave reflection method and the local fine measurement capability of an electrostatic probe; and then realizing high-precision fitting of the electron density based on a physical constraint Gaussian process regression model, establishing a mapping relation between the electron density and an emission coefficient, and finally reconstructing a three-dimensional electron density field with millimeter-level resolution.

This invention discloses a microwave detection method for wellbore rock humidity in gas drilling, comprising the following steps: S1: Establishing a near-bit annular space microwave propagation model based on the annular structure of the gas drilling well and the properties of the rock wall interface; S2: Establishing a microwave reflection coefficient calculation model for the wellbore rock wall interface based on the near-bit annular space microwave propagation model; S3: Establishing a quantitative calculation model for the change in microwave reflection coefficient of the wellbore rock wall under low humidity conditions near the drill bit, based on the microwave reflection coefficient calculation model; S4: Establishing a simulation model for microwave reflection of the wellbore rock wall under low humidity conditions based on the quantitative calculation model; S5: Performing simulations across the entire frequency band according to the simulation model to determine the most reasonable band for the microwave detection method of wellbore rock humidity in gas drilling. This invention enables effective ultra-fast dynamic monitoring of humidity changes during drilling in low humidity ranges.

The composition includes a thermoplastic resin comprising a polypropylene polymer and about 0.15% to about 4.75% by weight of a filler comprising carbon nanotubes. The carbon nanotubes have an average diameter of about 5 to 15 nanometers (nm) and a density of at least about 100 square meters per gram (m 2 / gr) surface area, and 10 -3 The composition has a volume resistivity of 0.01E+1.0 Ohm.cm or less. The composition exhibits a volume electrical resistivity of 2.0E+14 Ohm.cm to 1.0E+03 Ohm.cm, and molded samples of the composition exhibit a percent power absorption of at least 65% measured in transmission mode at frequencies of about 75 GHz to about 110 GHz. Molded articles containing micron-sized features that provide the article with high absorption and low reflection properties are also described.

A cap feed source structure disclosed by the present invention comprises a protective cap, a medium support member and a circular waveguide, the circular waveguide and the medium support member are fastened through a triangular step, and the medium support member and the protective cap are fastened through a thread. The medium supporting piece is made of cross-linked polystyrene, so that the stable wave-transparent performance of the whole material is ensured; the upper end surface of the dielectric support member is metalized to ensure the microwave reflection efficiency of the end surface; metallization treatment is carried out on the upper end surface of the medium supporting piece, a mature vacuum plating process is adopted, copper plating and nickel plating are carried out on the material, and a plating layer is firm and reliable; the circular waveguide and the dielectric support member are assembled by a process of first partial assembly and then welding forming, so that the connection quality of the two devices is effectively ensured; the protective cap is made of a cross-linked polystyrene material and protects the metalized surface of the upper end of the supporting medium piece.

The invention relates to the technical field of electrical equipment monitoring, and discloses a multi-band microwave sensing electrical equipment on-line fault positioning method, which comprises the following steps of: acquiring microwave reflection / scattering signal data of electrical equipment as original data by adopting a multi-band sensor array; de-noising processing is carried out on the original data of each multi-band sensor to obtain de-noised data; performing data fusion processing on the de-noised data to obtain fused data; and establishing a visual map according to the fused data, extracting feature vectors from the visual map to perform node fault identification, obtaining fault identification results of a plurality of nodes, and predicting a fault development trend of each node of the electrical equipment so as to redeploy the multi-band sensor array. Through multi-band sensor array acquisition, data denoising fusion, visual map feature extraction and fault trend prediction, electrical equipment fault accurate positioning and sensor dynamic deployment are realized, the reliability and operation and maintenance efficiency of a power system are improved, and the fault risk and cost are reduced.

The invention relates to the technical field of materials, discloses a preparation method and device of a visible-light-transparent metamaterial wave absorber, and solves the problems that an existing preparation method and device of the visible-light-transparent metamaterial wave absorber are narrow in wave absorbing bandwidth, poor in visible light transparency and difficult to achieve an infrared camouflage effect. The infrared stealth layer, the first PMMA layer, the microwave absorption layer, the second PMMA layer and the microwave reflection layer are combined and arranged by utilizing the visible light transparency characteristic of the indium tin oxide thin film and the polymethyl methacrylate or the polyvinyl chloride plate, the indium tin oxide with resistance loss is used as an absorbent, electromagnetic resonance loss is introduced, and meanwhile the resistance loss is increased; the adjustable resistance and patterning characteristics of the indium tin oxide are fully utilized, the duty ratio of the high-conductivity indium tin oxide thin film in the infrared stealth layer is improved, the infrared emissivity can be reduced, and the transparent indium tin oxide thin film with different surface resistivity is utilized to realize broadband strong absorption of visible light transparency and infrared disguise.

The invention provides substrate table system MPCVD equipment. The substrate table system MPCVD equipment comprises a microwave reflection table and a large molybdenum table which are arranged in a stacked mode. The substrate table is arranged on one side, far away from the microwave reflection table, of the large molybdenum table; wherein one side, far away from the microwave reflecting table, of the large molybdenum table is provided with an annular bulge, and the annular bulge is coaxial with the substrate table and surrounds the periphery of the substrate table. By means of the arrangement, the annular boss is arranged on the periphery of the substrate table, plasma formed above the substrate table can be evenly distributed, the temperature difference between the center and the edge is further reduced, it is guaranteed that the diamond growth rate is consistent, the stress of diamond crystals is reduced, and the cracking rate is reduced.

The utility model relates to the technical field of integrated circuit manufacturing, in particular to a quartz lens assembly for a polycrystalline silicon reduction furnace, which comprises an upper quartz lens and a lower quartz lens which are arranged in an upper sight glass opening of the reduction furnace and are respectively fixed on the inner wall of the sight glass opening of the reduction furnace through an upper flange and a lower flange. A metal coating is arranged on the side face of the quartz lens, and the upper surface and the lower surface of the quartz lens are planes. According to the quartz lens assembly, by optimizing the structural design, a metal coating with a specific thickness is sprayed on the outer side of the quartz lens and the surface of the plane edge of the upper surface, and the good microwave reflection performance of the coating is utilized, so that microwave energy is effectively prevented from leaking from the side wall of the quartz lens; the thickness and distribution of the metal coating are accurately calculated and controlled, so that most of leaked microwave energy can be reflected back into the reduction furnace, the microwave energy efficiency utilization rate is improved, and meanwhile, the influence of microwaves on the external environment and potential safety hazards are reduced.

The utility model provides an air inlet structure and a graphene preparation device, and relates to the technical field of graphene production and manufacturing. The air inlet structure comprises a fixing assembly, an air inlet assembly, an air outlet pipe and a rectifying assembly. The air inlet assembly is arranged on the fixing assembly in a penetrating mode and provided with an air inlet. The air outlet pipe penetrates through the fixing assembly, and the air outlet pipe and the air inlet assembly are arranged on the two sides of the fixing assembly in the axial direction of the fixing assembly correspondingly. One end of the rectifying assembly is connected to the air inlet assembly and communicates with the air inlet assembly, and the other end of the rectifying assembly is provided with an air outlet; the rectification assembly is configured to move in the axial direction of the fixing assembly and used for adjusting the position of the air outlet relative to the air outlet pipe. The rectifying assembly can move relative to the position of the fixing assembly, and the position of the air outlet can be freely adjusted, so that the adjustability of the microwave reflecting surface is realized, the length of the plasma torch and the local plasma density can be adjusted, and the purpose of enhancing the microwave plasma torch is achieved.

This invention relates to the field of optical imaging technology, specifically providing an optical radar co-aperture off-axis imaging system, comprising: an off-axis mirror assembly, a frequency-splitting device, a radar transceiver system, and an optical imaging system. The frequency-splitting device is disposed in the rear optical path of the secondary mirror and is used to reflect light waves and transmit microwaves. The frequency-splitting device includes a frequency-selective surface, which comprises an FSS pattern layer and a bias line layer. The FSS pattern layer includes periodically arranged FSS units. Nonlinear capacitors are electrically connected to the FSS units. The bias line layer applies a voltage to the nonlinear capacitors according to the received microwave band. By changing the voltage applied to the nonlinear capacitors, the resonant frequency of the FSS units is tuned, thereby changing the microwave passband frequency of the frequency-splitting device. This invention not only achieves a reflective wave-transmitting microwave design but also solves the problem that transmitting only a single band of microwaves in microwave-transmitting and light-reflecting methods is difficult to adapt to different task requirements.

The utility model relates to seasoning powder drying and processing equipment which comprises a screw conveyor and a semicircular fixed cover fixedly arranged above the screw conveyor, the screw conveyor comprises a shaftless screw blade, a coating capable of reflecting microwaves is arranged on the inner wall of a cavity between the screw conveyor and the fixed cover, and the coating is provided with a plurality of blades. A plurality of microwave drying assemblies are arranged at the top end of the fixing cover, and the output ends of the microwave drying assemblies face the axis of the shaftless spiral blade. The two end faces of the fixing cover are provided with dehumidification fans, and the axes of the dehumidification fans are parallel to the axes of the shaftless spiral blades. The cavity between the screw conveyor and the fixed cover can effectively reflect microwaves, the materials can be fully covered by the microwaves, the materials are turned over in cooperation with the shaftless screw blade, the microwave utilization rate is high, and energy consumption can be reduced. And the shaftless spiral blade turns over the materials to enable water vapor to effectively overflow, meanwhile, the dehumidifying fan efficiently pumps away the water vapor, and the drying efficiency is high.

The present application provides a die-casting method, comprising: providing a compression molding device, comprising a mold, a microwave generator and a waveguide, the mold comprising a wall body, an upper pressure head, a lower pressure head and a seal, the wall body encloses a mold cavity, and the wall body comprises a microwave reflecting material, the seal comprises a microwave penetrating material, the upper pressure head and the lower pressure head are arranged opposite to each other on the wall body, at least one mounting hole passes through the wall body, and the seal seals the mounting hole toward the opening of the mold cavity, and the waveguide connects the mounting hole and the microwave generator; placing powder in the mold cavity; turning on the microwave generator to heat the powder in the mold cavity to a preset temperature by microwaves and then turning it off; driving the upper pressure head and the lower pressure head to press the heated powder; turning on the microwave generator to heat the pressed powder to another preset temperature and then turning it off; opening the mold after cooling down to take out the molded product. The above method can shorten the heating time and improve the situation where the powder is heated unevenly. The present application also provides the above mold and the above compression molding device.

The invention relates to a system and a method for measuring ballistic trajectories in a light-gas gun and an artillery, and the system comprises a first microwave source assembly, a first power amplifier, a first circulator, a horn antenna, a second microwave source assembly, a second power amplifier, a second circulator, a linear polarization antenna and a microwave reflection and transmission plate, the directions of microwaves emitted by the horn antenna and the linearly polarized antenna form an angle of 90 degrees, the microwave reflection and transmission plate is arranged on an angular bisector of the angle formed by the horn antenna and the linearly polarized antenna, and the microwave reflection and transmission plate enables short-wavelength microwaves emitted by the horn antenna to be directly transmitted to a target to be measured. And long-wavelength microwaves emitted by the linear polarization antenna can be reflected to a to-be-measured target according to an angle of 45 degrees. According to the system for measuring the ballistic trajectory in the light-gas gun and the artillery, long-wave microwaves are reflected on the front surface of forward gas, short waves are reflected on the surface of a projectile, and therefore long-distance, continuous and simultaneous measurement of the speed of the forward gas and the speed of the projectile is achieved.

The present invention relates to the technical field of material performance detection, and particularly to a microwave performance improvement system based on activated crumb rubber modified asphalt materials. The system includes a microwave irradiation condition design module, a performance detection and heat generation analysis module, a material microscopic influence evaluation module, and a material microwave performance improvement module. It can obtain different microwave irradiation powers and nano-zinc oxide compounding ratios, design microwave irradiation conditions, and detect microwave performance parameters to obtain microwave reflection coefficients, microwave transmission coefficients, and microwave absorption coefficients. By monitoring the microwave heat generation uniformity index in real time, analyzing the microscopic structure characteristics, and evaluating the influence on microwave performance, the corresponding material microscopic performance influence factors can be obtained. The microwave performance evaluation calculation and adaptive optimization adjustment are carried out on the microwave reflection coefficient, microwave transmission coefficient, and microwave absorption coefficient to generate a microwave performance improvement adjustment strategy corresponding to the modified asphalt material. The present invention can improve the microwave performance of the modified asphalt material.

The invention relates to a microwave apparatus (1) for continuous treatment of a flowing fluid medium. It comprises an enclosure (2) made of a microwave-reflective material and internally defining a microwave cavity (3) in which the fluid medium flows along a flow axis (A1); an input waveguide (4) extending along a propagation axis (A2) orthogonal to the flow axis and coupled to an input window (41) provided in the enclosure for propagation of microwaves entering the microwave cavity. The invention is characterised in that it comprises a measurement system for determining a symmetry indicator representing a symmetry of an electric field relative to the flow axis inside the microwave cavity, thus representing a centring of the electric field in the fluid medium. Knowledge of this symmetry indicator advantageously allows the symmetry of the electric field in the fluid medium to be controlled.

The application discloses a microwave intrusion detector testing system, method, equipment, medium and product, and relates to the technical field of nuclear security physical protection effectiveness testing. The system comprises a robot moving device, which is used for carrying a testing tool and a central control module, and performing a preset test motion track in a test site. The testing tool comprises a microwave reflector simulation unit, a posture monitoring module and a signal source unit, which are respectively used for simulating electromagnetic reflection characteristics, collecting real-time posture data of the microwave reflector simulation unit and transmitting microwave signals. The central control module is used for controlling the robot moving device and the testing tool, and sending the acquired test data to a data analysis module. The data analysis module is in communication connection with the central control module, and is used for analyzing the test data acquired by the central control module and generating a test report. Therefore, the application improves the accuracy of the test result of the microwave intrusion detector.

The utility model provides a device for reducing microwave reflectivity and protecting a magnetron and microwave heating equipment, the device comprises an integrated shell, a microwave excitation mechanism, a microwave circulator mechanism and a microwave water load mechanism, the integrated shell comprises a circulator shell, an excitation cavity shell and a water load shell which are integrally arranged; a microwave excitation cavity is arranged in the excitation cavity shell, and a magnetron of the microwave excitation mechanism is arranged on the excitation cavity shell; a water load mounting cavity for mounting the microwave water load mechanism is formed in the water load shell; a circulator mounting cavity for mounting a microwave circulator mechanism is formed in the circulator shell; according to the integrated shell, the microwave excitation mechanism, the microwave circulator mechanism and the microwave water load mechanism are integrated, the integrated shell is compact in overall structure, small in occupied space, light in weight and low in cost, assembling operation can be effectively simplified, the production process can be simplified, and meanwhile compared with an assembled structure, the integrated shell can unify resistance design and reduce resistance difference.

The present invention discloses a microwave reflection diagnosis method and system for non-uniform plasma sheath distribution based on the multi-peak point phenomenon. The method constructs a non-uniform plasma sheath electron density spatial distribution model by adopting a multi-layer double Gaussian distribution, establishes a reflection function of the plasma sheath using an equivalent transmission matrix, performs multi-Gaussian fitting on the reflection function and extracts key features in the fitting curve, and uses the key features as inputs of a neural network to diagnose the spatial distribution parameters of the plasma sheath. The system is used to implement the method. The present invention not only achieves dimensionality reduction of reflection data, removes redundant information and noise, and improves data processing efficiency through feature extraction technology, but also, by constructing a back-propagation neural network, only needs to focus on the most critical features, reduces training time and computational burden, and improves the accuracy and robustness of prediction results.