120 results about "Microwave anechoic chamber" patented technology

The invention provides a microwave anechoic chamber performance measuring method, which comprises the following steps of: adopting a microwave anechoic chamber performance measuring system, and setting a dead zone parameter, a measuring frequency, a signal source power, a scanning trace and a kinematic velocity of a receiving antenna, and a rotation direction and a rotation velocity of a transceiving antenna according to the requirements of a microwave anechoic chamber performance analysis test; driving a signal source according to the signal source power; driving each stepping motor to control each moving part to move according to the scanning trace and the kinematic velocity of the receiving antenna, and the rotation direction and the rotation velocity of the transceiving antenna; and controlling a signal receiver to receive a signal of the receiving antenna according to the measuring frequency, and storing the signal. The method can be adopted to be applied in a microwave anechoic chamber flexibly so as to measure along different scanning traces; and a computer is adopted to realize automatic measurement of microwave anechoic chamber dead zone reflectivity level, cross polarization character, multi-path loss uniformity, and field uniformity performance indexes, so that the measuring efficiency is improved.

The invention discloses a compact range antenna measuring system which comprises a feed source which is arranged in a microwave anechoic chamber and a planar wave generation unit formed by a plurality of meta-material layers which are overlapped with one another, wherein each meta-material layer comprises a substrate and a plurality of artificial hole micro-structures on the substrate; and electromagnetic waves generated by the feed source are converted into planar electromagnetic waves after passing through the planar wave generation unit. A reflecting surface in the prior art is replaced by the planar wave generation unit made from meta-materials, and the refraction characteristics of the planar wave generation unit are simulated by a computer according to test requirements, so that an antenna testing turntable is provided with a quasi-plane-wave testing area with excellent performance after the electromagnetic waves generated by the feed source are refracted by the planar wave generation unit. Thereby, the manufacturing of a high-precision reflecting surface and a high-difficulty processing technique are omitted, and thus the manufacturing cost of the compact range antenna measuring system is greatly reduced.

The invention provides a wireless performance test method for an MIMO (Multiple-Input Multiple-Output) wireless terminal. The method comprises the steps of obtaining antenna pattern information of a plurality of antennas of a tested MIMO wireless terminal tested in a microwave anechoic chamber; obtaining test signals according to the antenna pattern information of the tested MIMO wireless terminal; calibrating the test signals through utilization of an error calibration joint matrix of the tested MIMO wireless terminal and obtaining test transmission signals; and feeding the test transmissionsignals in a plurality of test antennas of the microwave anechoic chamber, and transmitting the test transmission signals to the wireless terminal through the test antennas, thereby testing the wireless terminal. The test signals are calibrated through adoption of the error calibration joint matrix to obtain the test transmission signals, so a test error is eliminated, and the technical problem oftest accuracy and repeatability of the MIMO wireless terminal in the prior art resulting from the fact that the test error cannot be quantized is solved.

The invention provides a system and a method for testing stray radiation of a radio frequency transmitter. The system is a near-field test system, and a test field is a microwave anechoic chamber; a servo system is a one-axis precision rotary table installed in the microwave anechoic chamber, and an antenna of a radio frequency transmitter to be tested is arranged on the precision rotary table. Aradio frequency subsystem comprises a vector network analyzer. The vector network analyzer receives radiation signals of a radio frequency transmitter antenna to be tested through a test probe to complete amplitude and phase parameter test of the radio frequency transmitter antenna to be tested. The test method adopts a field test method. According to the invention, spherical near-field sampling of an electromagnetic field is realized by using a one-axis rotary table in cooperation with a probe array.

The invention discloses a method of solving the inverse matrix of an electromagnetic wave propagation matrix based on antenna pattern information of a wireless terminal. A microwave anechoic chamber comprises n test antennas inside, a wireless terminal comprises m receiving antennas, and the m receiving antennas and selected m test antennas carry out data transmission in the form of electromagnetic wave, wherein m>=2, and n>=m. The method of solving the inverse matrix of an electromagnetic wave propagation matrix comprises the following steps: getting the pattern information of the m receiving antennas; calculating out coordinate points suitable for solving the inverse matrix of an electromagnetic wave propagation matrix according to the pattern information; and solving the inverse matrix of a corresponding propagation matrix at the suitable coordinate points. Through the solving method, an inverse matrix meeting requirements can be solved quickly during calculation based on a radiation two-step approach (one of the international standards for MIMO test), no human intervention is needed, and time and effort are saved.

The invention discloses a method for testing and evaluating LPI performance of a data link. By adopting the method disclosed by the invention, the strength of radio signals that are transmitted externally can be reduced, the radiation characteristics can be optimized, and the anti-interception capability of test equipment can be improved. The method is implemented through the following technical schemes: in a microwave anechoic chamber environment, a data link antenna 1 and a data link antenna 2 complete a data link communication function, and a microwave antenna completes the detection of a communication signal of the data link antenna 1, and simultaneously eliminates an interference signal of the data link antenna 2; a scenario driving system of an industrial control computer sets a value that meets a power control range and stepping requirements of the data link, and automatically simulates discrete track points and continuous track segments; and an analysis and evaluation system ofthe industrial control computer equivalently converts a communication distance and an interception distance obtained under existing site sizes and test conditions to a real aerial test flight scene,obtains a power control range and a stepping value of the data link, and calculates a communication LPI quality factor of the data link.

The invention discloses a shielding case assembly structure of a microwave anechoic chamber and the microwave anechoic chamber with the shielding case assembly structure. The shielding case assembly structure comprises one or more pairs of first splicing units and second splicing units all with the electromagnetic shielding property, wherein the first splicing units and the second splicing units are mutually spliced, at least the outer surfaces of the first splicing units and the outer surfaces of the second splicing units are made of non-ferromagnetic metal material, and the joints of the first splicing units and the second splicing units are spliced in a non-conduction mode. The inner sides of the joints are covered with loss layers, the outer sides of the joints are covered with shielding layers, the loss layers are made of non-magnetic wave-absorbing material, and the shielding layers are used for shielding external electromagnetic waves. The shielding case assembly structure can reliably avoid intermodulation interference and improve the property of shielding the electromagnetic waves.

The invention discloses a microwave anechoic chamber for intermodulation test, which is composed of a chamber main body and a wave absorbing material arranged in the chamber main body. The chamber main body is a closed space composed of a keel frame and blocky wall faces fixed on the keel frame and capable of accommodating workers to walk inside. The chamber is characterized in that a shield layer is arranged on the surface of the side of the blocky wall faces facing the closed space, the wave absorbing material is fixed on the shield layer, and an operation platform for workers to walk on is arranged inside the chamber main body. The inventive chamber adopts an aluminum alloy plate adhered to a fireproof flame-retardant plate, and uses an insulating shielding aluminum foil to cover a joint to effectively avoid formation of large-area strong intermodulation source in the chamber and ensure that the interference source prone to excitation and intermodulation in the shield body structure is weakened, to the maximum extent.

The invention relates to a narrow-band antenna test method based on return loss compensation. The narrow-band antenna test method is characterized by comprising the following steps of: constructing an antenna test system, wherein an auxiliary antenna at a transmitting end and a tested antenna at a test end are positioned at the same height and on the same axial line; and according to a reflection coefficient of a certain frequency point, calculating radiation energy loss of a frequency point corresponding to the antenna, and performing value compensation, so that a time domain waveform is free of distortion after time-frequency conversion is performed. By the narrow-band antenna test method, a test bandwidth is expanded, so that an ideal time domain resolution is obtained, and the influence of multipath interference can be effectively suppressed, a test technology is applied to antenna test at a low frequency band (less than 300 MHz) in a microwave anechoic chamber and open area test with a near-end strong reflector, and therefore, the precision of a direction graph of a low-frequency and narrow-band antenna is improved by 2 dB or so, and a high-precision antenna test result can be obtained.

The invention discloses a microwave anechoic chamber which comprises an electromagnetic shielding room and also comprises a wave absorbing material and a measurement antenna installed at the inner wall of the electromagnetic shielding room. At least the upper part of the wave absorbing material is a periodic pyramid. The microwave anechoic chamber is characterized in that at least the edge direction of the pyramid of the wave absorbing material in the main reflection area of non-vertical incidence faces a main incoming wave direction in the microwave anechoic chamber. Through a simple mode with easy operation and low cost, under the condition of not changing an anechoic chamber structure or the height of the wave absorbing material, only through changing the layout of the wave absorbing material, can the anechoic chamber reflection, can the anechoic chamber reflection be reduced greatly, a more pure measurement environment is created, and the measurement precision is improved.

The invention discloses a reliability test verification system applied to a radar microwave product. According to the system, a temperature and humidity stress test subsystem and a vibration stress test subsystem are organically connected with a microwave anechoic chamber, a combined environment test capable of simulating temperature, humidity, vibration and other stress is set up, the problem that reliability verification of the product is insufficient because an existing test system cannot comprehensively test function and performance indexes of the radar microwave product is solved, a testverification means is provided for increasing the reliability level of the radar microwave product and meeting the new requirement of approaching practical examination, therefore, the development cycle of the product is shortened, and the system has huge economic benefit.

A mechanical multi-frame RF/infrared composite interference semi-physical simulation system includes a microwave anechoic chamber, a three-axle table, a table control system, a RF interference simulator, an infrared interference simulator, a mechanical multi-frame moving system, a servo system, and an integral real-time simulation control system. The three-axle table, the table control system, the RF interference simulator, the infrared interference simulator, and the mechanical multi-frame moving system are arranged inside the microwave anechoic chamber, and the integral real-time simulation control system is arranged outside the microwave anechoic chamber. The RF interference simulator and the infrared interference simulator are mounted on a moving platform of the mechanical multi-frame moving system. The integral real-time simulation control system is composed of a multi-node real-time computer network including a master control computer, an acquisition computer, a RF interference control system, an infrared interference control system, a real-time communication network, a simulative master control system and a monitoring system. The real-time communication network is built up by the utilization of reflective memory networking, and information transmission and real-time control among devices of the simulation system are realized.

The invention belongs to the field of researches on an electromagnetic biological effect and particularly relates to a living animal electromagnetic irradiation system and an application method thereof. The living animal electromagnetic irradiation system consists of an electromagnetic irradiation control system, a microwave device, a three-dimensional object carrying platform and a microwave anechoic chamber, wherein the electromagnetic irradiation control system at least comprises a hardware setting module, an electromagnetic irradiation parameter setting and output module, a microwave emission control module and an irradiation method and irradiation dose display module. All modules are mutually connected. The living animal electromagnetic irradiation system and the application method thereof have the advantages that multiple irradiation parameters which influence irradiation dose in animal bodies can be set through the electromagnetic irradiation control system, the placing posture of the living animals relative to the emitting direction of microwaves can be intuitively given out and can be adjusted through the three-dimensional object carrying platform, the irradiation dose of up to eleven important organs can be given out after the irradiation parameters are set, data is provided for establishing an accurate dose-effect relationship between the irradiation dose and the animal effect and the goal of remotely controlling the microwave device to emit microwaves is realized.

A compact range antenna test system provided by the present invention comprises a microwave anechoic chamber, and a first manipulator, a second manipulator, a reflector and a feed source which are all arranged in the microwave anechoic chamber, the reflector is arranged on the first manipulator, the feed source is arranged on the second manipulator and faces the reflector, the reflector is used for focusing emergent waves emitted by the feed source into plane waves and reflecting the plane waves to a to-be-tested piece to form a quiet zone, the first manipulator can drive the reflector to move, and the second manipulator can drive the feed source to move according to the moving position of the reflector so as to translate the quiet zone. According to the compact range antenna test system provided by the invention, the reflector and the feed source are respectively driven by the first manipulator and the second manipulator to move, and translation of the quiet zones can be realized by combining real-time matching and alignment of the reflector and the feed source, so that a plurality of quiet zones which can be mutually spliced are formed, the space of the quiet zones is multiplied, and the test performance is improved.

The invention discloses a comprehensive system for measuring conduction and radiation characteristics of a packaged antenna. The comprehensive system comprises a microwave anechoic chamber, radio frequency measurement equipment, a feed source antenna, a chip suction device and a packaged test base, wherein the package testing base comprises a first base part and a second base part which can be jointed or separated; the first base part is fixedly arranged above a top plate of the microwave anechoic chamber; the chip suction device penetrates through a through hole defined by the second base part; the chip suction device is linked with the second base part; when the second base part is jointed with the first base part, the radio frequency measurement equipment is electrically connected withthe packaged antenna by means of the first base part and the second base part in sequence, so as to measure radio frequency conduction characteristic parameters of the packaged antenna; and the radiofrequency measurement equipment is further electrically connected with the feed source antenna so as to measure the radiation characteristics of the packaged antenna.

The invention discloses a satellite stealth performance ground test and in-orbit integration verification method, and belongs to the technical field of spacecraft stealth performance testing. The method comprises the following steps that a stealth satellite is arranged to be in a non-stealth state and a stealth state, and theoretical simulating calculation is performed on the stealth performance of the satellite; stealth performance testing is performed for the non-stealth state and the stealth state of the satellite through ground microwave anechoic chamber test equipment; after the satellite is injected into an orbit, in-orbit comparative measurement is performed on the stealth performance achieved when the satellite is in the in-orbit non-stealth state and the stealth performance achieved when the satellite is in the in-orbit stealth state; quantitative evaluation is performed on the satellite stealth performance according to the specific indexes of the satellite stealth design by analyzing in-orbit satellite measurement data; comparative analysis is performed on theoretical simulating data, ground test data and in-orbit test data of satellite RCS sequence values. Accordingly, a specific technical scheme and a quantitative test analysis method are supplied to satellite stealth performance testing in future, and the method can be applied to radar stealth satellite platforms, optical stealth satellite platforms, infrared stealth satellite platforms and the like.

The invention provides an equivalent far-field testing device and method for a large-scale cylindrical phased-array antenna. The equivalent far-field testing device comprises a microwave anechoic chamber, a turntable, a signal transmitting module, a signal transmitting module and a control unit, wherein the microwave anechoic chamber is used for providing an electromagnetic wave free propagation space which is not reflected by an internal electromagnetic signal and is not interfered by an external electromagnetic signal; the turntable is used for adjusting the attitude of the measured cylindrical phased-array antenna so as to measure the radiation characteristics of the measured cylindrical phased-array antenna in different directions; the signal transmitting module is used for generatingan excitation signal for antenna testing; and the control unit is used for controlling the excitation signal of the signal transmitting module and the rotation angle of the turntable, and acquiring and processing the radiation characteristics of the measured cylindrical phased array antenna in different directions. The equivalent far-field testing device and the method are suitable for testing thelarge cylindrical phased-array antenna, the construction cost of a test system can be effectively saved, the adaptability is high, and the test result is more accurate.

The invention belongs to the technical field of electromagnetic compatibility testing, and discloses a method for monitoring the angle simulation precision of a radio frequency simulation test systemin real time. A system for monitoring the angle simulation precision in real time comprises a calibration control computer, a three-axis calibration turntable, calibration equipment and a total station, the calibration equipment located in the middle in a simulation microwave anechoic chamber is fixed to a lifting column through the three-axis calibration turntable, the total station is arranged in the simulation microwave anechoic chamber on one side of the calibration equipment, tested equipment is arranged in the simulation microwave anechoic chamber on one side of the calibration equipment, and the tested equipment is higher than the calibration equipment; the calibration control computer is arranged outside the simulation microwave anechoic chamber; the phase difference and the amplitude difference generated by the transmission path difference are corrected through the full-path phase compensation technology, the measurement of the angle simulation precision is realized, and the real-time monitoring of the angle simulation precision of a simulated antenna array is realized; therefore, the confidence degree of the test can be ensured. The method can be applied to far-field measurement of the radiation characteristics of a phased-array antenna.

The invention provides a wide-frequency-band vacuum microwave darkroom for near space high-speed target plasma environment ground simulation, which comprises a vacuum tank body, a microwave anechoic chamber framework, a support mechanism and a composite electromagnetic wave absorber, the microwave anechoic chamber framework is arranged in the vacuum tank body, and one end of the vacuum tank body is provided with a vacuum end socket flange; the anechoic chamber framework comprises a plurality of connecting sections which are connected in sequence, and the connecting sections are connected to form a cylinder structure; a multistage nested flange is arranged at one end of the anechoic chamber framework, a wave-absorbing shielding door is arranged at the other end of the anechoic chamber framework, a plurality of composite electromagnetic wave absorbers are installed to completely cover the inner wall of the anechoic chamber framework, and each composite electromagnetic wave absorber is formed by compounding a ferrite tile, a matching layer and a pyramid wave-absorbing material through impedance matching. The ferrite tile, the matching layer and the pyramid wave-absorbing material are sequentially arranged from bottom to top. The wide-frequency-band vacuum microwave anechoic chamber can be provided and can be used for near space high-speed target surface plasma environment and electromagnetic communication research.

The invention discloses an equivalent device for millimeter wave radiometer test. The device comprises a microwave anechoic chamber, a millimeter wave radiometer detector, a dielectric attenuation module, a target jammer, a three-dimensional test platform, a detector output signal acquisition module, a chopper wheel, a chopper wheel control and rotation speed monitoring module and a test platform servo control module. The transmitting antenna of the target jammer, the chopper wheel, the dielectric attenuation module and the receiving antenna of the millimeter wave radiometer detector are on the same straight line. The target jammer is arranged on the three-dimensional test platform. The test platform servo control module is used for controlling the height, the pitch angle and the azimuth angle of the target jammer through the three-dimensional test platform. The chopper wheel control and rotation speed monitoring module is used for controlling the rotation speed of the chopper wheel. The detector output signal acquisition module is used for acquiring a millimeter wave signal detected by the detector. According to the invention, static and dynamic performances of a millimeter wave radiometer can be tested; the detection cost of a product is reduced; and the test efficiency is improved.

The invention provides a coating type wave-absorbing component used in high-vacuum condition. The wave-absorbing component comprises a structuralized base plate and a wave-absorbing coating, wherein the wave-absorbing coating is sprayed on the outer surface of the structuralized base plate; the structuralized base plate is made of an aluminum material in a die-cast formation mode, so that good heat conduction property is achieved; the wave-absorbing coating has good wave-absorbing property and can be used in a high-vacuum environment. By optimizing the wave-absorbing coating ratio and reducing the volatility of the material, the vacuum application requirements can be met, and the wave-absorbing component can be applied to construction of a vacuum-resisting controllable temperature microwave anechoic chamber. By optimizing the substrate size in structural design, adjusting the ratio of the wave-absorbing coating and the coating thickness, and spraying for multiple times, the wave-absorbing property of the structuralized coating type wave-absorbing component is optimized within a target frequency band. Through the optimized structural design, a metal material with high heat conduction rate is adopted inside, and the wave-absorbing coating is sprayed on the surface of a metal substrate, the wave-absorbing component has good wave-absorbing property and excellent heat conduction property, and precise external heat flow analog can be achieved.

The invention belongs to the technical field of microwave measurement, and particularly relates to test equipment and a test method for equivalent flat plate power reflection. The test equipment comprises a test instrument, a microwave anechoic chamber, an arc guide rail, rotary tables, test antennas and a tested piece, wherein the test instrument, the arc guide rail, the rotary tables, the test antenna and the tested piece are installed in the microwave anechoic chamber; the two rotary tables are symmetrically installed on the arc guide rail, the test antennas are installed on the rotary tables, the center of the tested piece is located on the axis where the circle center of the arc guide rail is located, the test instrument is connected with the two test antennas through the radio frequency cable, and the extension lines of the axes of the two test antennas intersect on the axis of the circle center of the arc guide rail. The test equipment provided by the invention can effectively save the volume of the microwave anechoic chamber, and the equivalent flat plate power reflection test method can effectively improve the test efficiency.

The invention discloses an array antenna near field calibration system and method, and the system comprises a to-be-tested array antenna, the array antenna is provided with N antenna units, each antenna unit is provided with a digital phase shifter for phase control, and a plane wave generator is disposed at the near field of the to-be-tested array antenna. The plane wave generator is used for generating quasi-plane waves at a to-be-tested array antenna, each channel of the array antenna is connected with one end of the vector network analyzer, and the other end of the vector network analyzer is connected with the plane wave generator. The quasi-plane waves are generated in the near field of the to-be-tested antenna through the plane wave generator, the size of a microwave anechoic chamber needed by testing is remarkably reduced compared with a far-field testing method, errors caused by path loss due to the fact that the propagation distance of electromagnetic waves is long are avoided, the plane wave generator is regarded as an equivalent far-field single-probe measuring system, the method has the characteristics of short measurement time, small occupied space and low cost.