47 results about "Microwave anechoic chamber" patented technology

The utility model relates to a control device for a microwave anechoic chamber test system. Comprising a shielding box which is a sealed cavity provided with a cover plate, and the shielding box is provided with a power supply socket, a data socket and an optical fiber coupler; a control circuit board, an AC-DC power supply module, a data optical fiber transceiver and other modules are installed in the shielding box. A plurality of motor control units, a power supply interface and a communication interface are integrated on the control circuit board, and a first output end of the AC-DC power supply module is connected with the control board and is used for supplying power to the control board; one end of the data optical fiber transceiver is electrically connected with the optical fiber coupler, and the other end is electrically connected with the communication interface for converting the signal into an optical signal and outputting the optical signal. The control circuit board is placed in the shielding box, so that the size of the rotary table or antenna tower equipment is reduced, and the electromagnetic interference risk of a motor and a darkroom environment is reduced; the control circuit board integrates the servo motor control unit and the stepping motor control unit for modular design, serves as an independent unit of the darkroom test system, and is high in universality.

The invention relates to an electronic equipment antenna port high-power microwave coupling effect test system and method, and the system comprises a microwave anechoic chamber, a polarization characteristic test turntable, a directivity test turntable, a transmitting antenna, a power amplifier, a radio frequency signal source, a turntable controller, and a main control computer. The polarization characteristic test turntable and the directivity test turntable are arranged in the microwave darkroom, the polarization characteristic test turntable is connected with a transmitting antenna, and the directivity test turntable is used for placing electronic equipment; the power amplifier, the radio frequency signal source, the turntable controller and the main control computer are arranged outside the microwave darkroom; the power amplifier is connected with the transmitting antenna and the radio frequency signal source, and the turntable controller is connected with the polarization characteristic test turntable and the directivity test turntable; the main control computer is connected with the radio frequency signal source; and the main control computer is connected with the turntable controller.

The application relates to a navigation terminal comprehensive performance test evaluation method based on a microwave darkroom, and belongs to the technical field of satellite navigation. The application simulates the use conditions and various scenes possibly encountered by a navigation terminal in actual use for testing by constructing a navigation terminal comprehensive performance test platform based on a microwave darkroom and constructing a navigation terminal comprehensive performance test scene, and performs comprehensive performance evaluation according to positioning / short message communication information reported by the navigation terminal. The application simulates the scenes possibly encountered by the tested terminal in actual application through a comprehensive test scene formed by multiple application scenes, the test result is closer to the actual application, and the application has good actual application value.

This invention discloses a near-field scanning detection method based on active learning to obtain conducted coupling paths. The method includes: constructing a near-field scanning detection platform; placing the circuit board under test (PCB) in a microwave anechoic chamber; and using the near-field scanning detection platform directly above the PCB to perform detection; obtaining the detection results using an active learning-based near-field scanning method; and obtaining a near-field current distribution map on the PCB at continuous time intervals based on the detection results, thereby realizing the detection of conducted coupling paths. This invention utilizes active machine learning methods to achieve more efficient near-field scanning detection, concentrating scanning points in areas with strong currents and accurately reconstructing the actual current changes of the PCB using the scan results of sparse points, greatly improving detection efficiency. By using near-field scanning detection to reconstruct the current changes on the circuit board, the coupling paths of conducted interference currents on the PCB can be quickly analyzed, meeting the requirements for detecting electromagnetic interference in systems in practical engineering.

This invention relates to an automatic two-dimensional beam measurement system and method for multi-band phased array antennas, belonging to the field of phased array measurement technology. The system includes a PC main controller, an automatic beam controller, a vector network analyzer, a switch, a servo control system, a robotic arm, a microwave anechoic chamber feed, and the phased array antenna under test. The automatic beam controller is connected to the PC main controller, the switch, the vector network analyzer, the servo control system, and the phased array antenna under test. The switch is connected to the PC main controller, the vector network analyzer, and the servo control system. The vector network analyzer is also connected to the phased array antenna under test. The servo control system controls the robotic arm, which is equipped with a microwave anechoic chamber feed. The signal from the microwave anechoic chamber feed flows to the phased array antenna under test. This invention only requires completing one full scan within a set range to test the entire two-dimensional phased array antenna beam, greatly shortening the required measurement time.

This invention discloses a method for distinguishing parallel and vertical insects based on multi-frequency differential eigenvalues. First, based on simulations and microwave anechoic chamber measurements of insect multi-frequency differential eigenvalue characteristics, the relationship between insect multi-frequency differential eigenvalues ​​and polarization patterns, as well as insect category (parallel or vertical), was discovered. Then, based on three conditions—"differential eigenvalue relationship," "polarization pattern type," and "whether the maximum RCS direction is consistent"—the insect categories at 9.5 GHz and 11.5 GHz were classified and discussed in five cases. Finally, based on the above classification and discussion results, a new method for distinguishing parallel and vertical insects is proposed.

The invention relates to a small broadband microwave anechoic chamber based on a non-uniform artificial surface, the small broadband microwave anechoic chamber comprises a 36-polygon cylindrical shell, a broadband artificial medium wave-absorbing unit and a transmitting antenna, the broadband artificial medium wave-absorbing unit is attached to the inner wall of the 36-polygon cylindrical shell, edges are uniformly arranged on the 36-polygon cylindrical shell at intervals along the perimeter direction of the outer side of the 36-polygon cylindrical shell, and the transmitting antenna is arranged on the outer side of the 36-polygon cylindrical shell. A transmitting antenna is attached between every two adjacent edges, and the transmitting antennas are microstrip patch antennas. The broadband artificial medium wave-absorbing unit can effectively absorb 8-12 GHz electromagnetic waves incident at 0-70 degrees, has the advantages of multiple angles, broadband and high absorptivity, and provides a high-quality low-reflection test environment for scenes such as antenna measurement and microwave imaging which have strict requirements on the electromagnetic environment; the device is small in size, compact in structure and easy to install and integrate, the used materials are common materials, large-scale expansion is easy, and the device has the advantages of being passive, easy to machine and low in cost.

The utility model discloses a calibration tool for a microwave anechoic chamber test of a radio direction finder, which relates to the technical field of direction finders and comprises a fixing plate, a boss is arranged in the middle of one side of the fixing plate, a plurality of first bolt holes penetrating through the boss and the fixing plate are arranged on the boss, and the first bolt holes are used for connecting the tool and a bottom plate of a mechanical arm. The boss is provided with a plurality of first hollow areas for wiring, the other side of the fixing plate is provided with a plurality of second bolt holes, and the second bolt holes are used for connecting a tool and a radio direction finder. When the microwave darkroom test of the radio direction finder is carried out, the calibration tool and the bottom plate of the mechanical arm are firstly fixed through the first bolt hole to complete the calibration adjustment of the calibration tool, and then the radio direction finder is fixed on the calibration tool through the second bolt hole. The radio direction finder does not need secondary calibration, and at the same time, the boss is also provided with a plurality of first hollow areas, which is convenient for wiring.

This invention relates to a miniature dual-frequency microwave anechoic chamber based on spatially distributed ultrathin absorbing materials. It includes a rigid cylindrical shell mounted on a support. An ultrathin dual-frequency electromagnetic wave absorbing unit and a transmitting antenna are attached to the inner wall of the rigid cylindrical shell. The ultrathin dual-frequency electromagnetic wave absorbing unit and the transmitting antenna are integrally formed, and the transmitting antenna is a microstrip patch antenna. This invention, through research on spatially distributed ultrathin electromagnetic wave absorbing materials, realizes a wavelength-scale miniature dual-frequency microwave anechoic chamber. The shape and size of the microwave anechoic chamber can be customized according to actual application requirements, and it is expected to be widely used in antenna measurement, microwave imaging, and other fields. This invention features low cost, simple construction, and portability.

The present application relates to a kind of electromagnetic propagation characteristics characterization and reconstruction method of heterostructure, belong to wireless communication technical field.The method adopts the thought of single layer to multiple layers, first study single layer material propagation characteristics, clear single layer material reflection and transmission ability, in combination with measured inversion material electromagnetic parameter;Then, using single layer material electromagnetic parameter, reconstruct heterostructure model by full-wave simulation, simultaneously construct multiple layer iterative propagation model based on Fresnel theory;Finally, the simulation value of reconstructed structure model propagation characteristics, the theoretical value of multiple layer iterative model and the microwave anechoic chamber measured value are compared, verify the accuracy and effectiveness of structure model and propagation model.The present application can be extended to characterize the electromagnetic propagation characteristics of various flat plate-shaped heterostructure complex structures in full-band range, and lay a theoretical foundation for structure material classification, target perception and environment twin.

The invention relates to the technical field of communication testing, in particular to a microwave anechoic chamber testing system which comprises a detection box, a wave absorbing material and a testing antenna, the top end of the detection box is provided with a top cover in an up-down adjustable mode through a linear driving piece, a supporting partition plate is horizontally arranged in the detection box, and the testing antenna is installed in the middle of the top end of the supporting partition plate. A plurality of placing seats for placing test terminals are arranged at the top end of the supporting partition plate, the distances between the placing seats and the test antenna are equal, a plurality of movable plates in one-to-one correspondence with the placing seats are movably arranged at the bottom end of the supporting partition plate, a driving seat is arranged under the test antenna, and the driving seat is fixedly connected with the top cover through a plurality of connecting rods; the driving seat is connected with each movable plate through a driving structure and is used for synchronously pushing the plurality of movable plates to move towards one side close to or away from the test antenna, a plurality of test terminals can be tested at the same time, a worker can quickly take and place the test terminals, and the test efficiency is improved.

The present application relates to hoisting equipment technical field, specifically to a kind of wave-absorbing material hoisting system based on microwave darkroom, including hoisting drive mechanism, bottom support and the wave-absorbing wedge of being set in the top of bottom support, further including self-connection and separation mechanism, it is set on hoisting drive mechanism and bottom support, for hoisting drive mechanism and bottom support are automatically connected or separated;The self-connection and separation mechanism includes embracing component, it is set on bottom support;One-way plug-in component, it is set on hoisting drive mechanism, can reciprocate in and out along the inside of embracing component.The height position of one-way plug-in component is controlled by hoisting drive mechanism, when one-way plug-in component is inserted into embracing component and is in connecting position, the automatic connection of hoisting drive mechanism and bottom support can be realized, when one-way plug-in component is in separation position, can top pressure separation component drive embracing component to expand outward, the automatic separation of hoisting drive mechanism is realized.

The utility model discloses an aisle wave-absorbing plate for a microwave anechoic chamber. The aisle wave-absorbing plate comprises a wave-absorbing plate main body, the auxiliary connecting assembly comprises a fixing rod, an inserting rod, a mounting rod, a fixing block and a connecting frame; the fixing rods are embedded in the two sides of one end of the wave-absorbing plate body, the inserting rods are fixed to the outer side ends of the fixing rods, the mounting rods are embedded in the two sides of the other end of the wave-absorbing plate body, the fixing blocks are fixed to the two sides of the edge of one side of the top end of the wave-absorbing plate body, and the connecting frames are fixed to the two sides of the edge of the other side of the top end of the wave-absorbing plate body. According to the utility model, through the arrangement of the auxiliary connecting assembly, when the wave-absorbing plate main body is in butt joint through the conductive adhesive, the inserting rod is inserted into the mounting rod, and the wave-absorbing plate main body drives the connecting frame to move synchronously, so that the connecting frame is clamped with the fixing block, and the mounted wave-absorbing plate main body is further connected and limited through the inserting rod, the mounting rod, the fixing block and the connecting frame; the wave-absorbing plate main body is prevented from being separated from a designated position after long-term use of glue, and the wave-absorbing plate is prevented from being lost.

The utility model discloses a microwave anechoic chamber measurement supporting rotary table with a shockproof structure, which comprises a rotary table and a bottom ring which are arranged in a microwave anechoic chamber, the bottom ring is fixed on the ground of the microwave anechoic chamber through bolts, a plurality of supporting columns are arranged on one end face of the rotary table facing the bottom ring, and universal wheels are arranged at the other ends of the supporting columns. The universal wheels are sleeved with supporting cylinders, a plurality of channels allowing the universal wheels and the supporting cylinders to pass through are formed in the outer circle of the bottom ring, a top ring is installed on the end face, facing the bottom ring, of the rotary table, and the top ring is sleeved with a connecting ring. The device is simple in structure, the connecting ring can rotate downwards and is in threaded connection with the bottom ring, the extrusion part can push the supporting barrel to descend along with descending of the connecting ring until the supporting barrel abuts against the ground, the necking end of the supporting barrel abuts against the top face of a support on the universal wheel, and therefore the supporting barrel is pressed on the ground, and the supporting barrel is not prone to falling. And the rotary table can be axially positioned through the bottom ring, the connecting ring and the top ring, so that the test stability is ensured.

The utility model relates to a wave-absorbing door curtain installed in a millimeter wave radar anechoic chamber, which comprises a wallboard structure, a wave-absorbing sponge layer and wave-absorbing pyramids, the end face of the wallboard structure is provided with the wave-absorbing sponge layer, the wave-absorbing sponge layer is uniformly provided with a plurality of wave-absorbing pyramids, and the wave-absorbing pyramids are arranged in the wallboard structure. A penetrating hole penetrating through the wave-absorbing sponge layer and the wallboard structure is formed in the middle of the wave-absorbing sponge layer and the wallboard structure, a butt joint base is arranged on the upper side of the wallboard structure, the butt joint base is in butt joint with the upper end of the wallboard structure, and two sliding supporting feet are symmetrically arranged at the two ends of the upper side of the butt joint base; two longitudinally-arranged sliding rail structures are arranged on the upper side of the wallboard structure side by side, and the sliding supporting feet are installed in the sliding rail structures in a one-to-one sliding mode. The device has the characteristics of stable operation, improved measurement precision, simplified operation difficulty, saved operation time and the like.

This invention discloses a method for detecting the phase center of a Beidou navigation antenna and communication antenna feed, belonging to the field of satellite navigation and communication technology. Specifically, it includes the following steps: S1, connecting the transmitting antenna, transmitting turntable, vector network analyzer, computer, printer, antenna turntable, and antenna under test in a microwave anechoic chamber; S2, adjusting the antenna under test and the transmitting antenna using a laser beam to ensure consistent measurement standards. The microwave anechoic chamber is covered on all six sides with shielding and absorbing materials, effectively isolating external electromagnetic interference and creating a reflection-free, low-interference testing environment. This avoids distortion of phase measurement data due to external electromagnetic signal coupling, ensuring that the test results accurately reflect the antenna's inherent characteristics. Strict limits are imposed on parameters such as the quiet zone size, humidity, temperature, and atmospheric pressure of the microwave anechoic chamber to reduce the impact of slowly changing environmental factors such as temperature and humidity on the antenna's electrical performance, ensuring consistent testing conditions.

The invention discloses a hybrid wave absorber for antenna testing in a miniaturized microwave anechoic chamber and a design method thereof, the hybrid wave absorber comprises a conical wave absorber and a frequency selection surface, the conical wave absorber is a periodic array structure composed of conical wave absorber units, the frequency selection surface is a periodic array structure composed of frequency selection surface units, and the frequency selection surface is a periodic array structure composed of frequency selection surface units. The conical wave absorbing body units are in one-to-one correspondence with the frequency selection surface units; the frequency selection surface unit comprises a dielectric substrate, an air layer and a metal bottom plate which are arranged in sequence, and one surface of the dielectric substrate is printed with a centrosymmetric pattern with the center of the dielectric substrate as the symmetric center. Compared with a traditional wave-absorbing body, the mixed wave-absorbing body designed by the invention can realize the same or even better wave-absorbing performance only by using half of the thickness of the traditional wave-absorbing body. The wave-absorbing material has the advantages of smaller thickness, wider wave-absorbing frequency band and better wave-absorbing performance, and can be applied to a miniaturized microwave anechoic chamber.

The embodiment of the invention provides an anechoic chamber testing system based on a phased array radar antenna, and relates to the field of phased array radar antenna testing, and the system comprises a receiving and sending large box product end, a receiving and sending large box beacon end, a change-over switch box, a beacon horn antenna, and a phased array radar antenna. The receiving and transmitting large box product end is connected with a receiving interface and a transmitting interface of the phased array radar antenna. The receiving and sending large box beacon end is connected with the beacon horn antenna, and the beacon horn antenna is aligned with the phased array radar antenna; a receiving channel and a transmitting channel are arranged in the change-over switch box, and the change-over switch box is connected with the receiving and transmitting large box product end and the receiving and transmitting large box beacon end and used for switching the signal direction from the phased array radar antenna to the beacon horn. Compared with an existing test system, the test system has the advantages that the accuracy of test data is improved, the test preparation time and accessory preparation cost are reduced, and the test efficiency is improved.

The utility model belongs to the technical field of anechoic chambers, and particularly discloses an anechoic chamber with an adjustable assembled shielding case, which comprises a frame and two groups of sliding chutes, the top end, the bottom end, the front end and the rear end of the frame are respectively provided with two groups of sliding chutes, and a shielding plate II is fixedly inserted into the left side between the sliding chutes; a first shielding plate is assembled and fixed to the right side of the second shielding plate, and inserting grooves are formed in the right side of the second shielding plate and the right side of the first shielding plate respectively. According to the microwave anechoic chamber capable of adjusting and assembling the shielding shell, two groups of sliding grooves are formed in the top end, the bottom end, the front end and the rear end of the frame respectively, four groups of second shielding plates are inserted into the upper, lower, front and rear surfaces of the frame along the sliding grooves from the right side, then inserting grooves and inserting rods at all positions are aligned, and the other first shielding plates are installed on the right sides of the second shielding plates; the wallboard on the right side is closed, the positioning rod is inserted into the transverse groove, and the bolt is rotated to be embedded between the screw hole and the hole for reinforcement, so that the problem of inconvenience in disassembly and assembly is solved.

The invention discloses a phased-array antenna beam forming test method in a darkroom-free environment, and relates to the technical field of satellite communication terminal complete machine testing, comprising the steps of initializing test system configuration, setting test parameters, initializing an antenna state, establishing a test environment, and connecting a test antenna with a channel simulator; cross coupling of non-corresponding channels is isolated and reduced through an algorithm, a signal transmission link between a test antenna and a tested antenna is established through a wireless channel by adopting a virtual wire connection mode, non-contact test is realized, beam forming test is performed, a mobile station moves to a preset test area, impedance of the test antenna is adjusted by adopting an electronic tuning mode, and the antenna is tested. The beam former realizes independent control of an uplink and a downlink, analyzes a test result and generates a report, does not need to depend on fixed test facilities such as a microwave anechoic chamber and a calibration tower, can directly test in an actual working scene, and is particularly suitable for field test of mobile equipment such as a large vehicle-mounted phased array system.

The invention discloses an airborne direction-finding equipment darkroom calibration and attitude simulation system, which relates to the technical field of equipment calibration testing and comprises a microwave darkroom, an attitude simulation mechanism, a target simulation mechanism and an upper computer terminal. The microwave darkroom is used for providing a test environment; the attitude simulation mechanism comprises a six-degree-of-freedom mechanical arm and an airborne direction-finding equipment bearing platform, and simulates the flight working condition of the airborne direction-finding equipment on the flight platform by grasping the airborne direction-finding equipment and performing accurate movement on six degrees of freedom according to a set attitude track; the target simulation mechanism comprises a target signal source and a supporting device and is used for generating a test signal with controllable direction, polarization and waveform characteristics; and the upper computer terminal is used for configuring and issuing test and calibration tasks, and monitoring, analyzing and managing at the same time. According to the invention, scene-level test and high-precision calibration of the test link of the whole machine are completed, the dependence on a real flight test is reduced, and the problem that the degree of freedom of a ground platform is limited is solved.

The present application relates to a kind of microwave darkroom static area automatic acquisition method, microwave darkroom static area is under the static area of reflectivity level and amplitude unevenness;The static area under reflectivity level is obtained using initial seed point selection algorithm and growth algorithm;The automatic acquisition of amplitude unevenness index range is based on the reflectivity level range, by selecting amplitude unevenness standard point as initial seed point, also in the way of neighborhood growth;The calculation of amplitude unevenness growth process only needs to extract its amplitude from the previous reflectivity level calculation result, and compare with standard point amplitude;Static area is the spatial range under the superposition of two indicators.The present application realizes the static area of the required static area index three-dimensional space, realizes static area extraction automation.

The invention discloses a terahertz frequency band unmanned aerial vehicle radar cross section (RCS) dynamic measurement method, and relates to the technical field of radar detection. A terahertz radar is used for transmitting electromagnetic waves and receiving echo signals reflected by a target, measurement data including an azimuth angle, a pitch angle, a distance and an amplitude are output, and missing value filling, abnormal value removal and smoothing processing are carried out on the data by adopting multiple algorithms. A correction model is established through measurement of a metal ball with a known RCS value, and an unmanned aerial vehicle RCS calculation result is corrected. And outputting a final unmanned aerial vehicle RCS value according to a radar formula in combination with the pre-processed data and the correction result. Compared with the prior art, a microwave darkroom with high cost is not needed, the terahertz radar is adopted to measure the outdoor dynamic unmanned aerial vehicle, the RCS measurement error is + / -2.2 dBsm, and periodic RCS fluctuation caused by rotation of a propeller can be captured. Compared with a static measurement result of a conventional method, data of the method is closer to an actual flight scene, and the accuracy of unmanned aerial vehicle detection probability estimation is remarkably improved.

The application provides a simplified test method and device for batch-produced satellite receiving sensitivity. The method comprises: S1: performing classification processing on batch-produced satellites, selecting a representative satellite from each class, and performing steps S11-S16 on each representative satellite in parallel; S2: counting a target sensitivity set of all classes to obtain an overall test result of the batch-produced satellites; S1 comprises S14: measuring a corresponding second ground test signal level of a satellite in a target microwave anechoic chamber; S15: calculating the receiving sensitivity of the satellite in the target microwave anechoic chamber according to the difference between the second ground test signal level and the first ground test signal level; S16: replacing a new satellite and repeating S14-S15 until a target sensitivity set composed of the receiving sensitivities of all satellites in the target microwave anechoic chamber is obtained, thereby improving the test efficiency of the receiving sensitivity of the existing batch-produced satellites.

The application relates to the technical field of loop simulation testing, and relates to a C-V2X whole vehicle loop simulation system based on a microwave darkroom and a testing method. The method comprises the following steps: a measured whole vehicle: a whole vehicle loaded with a real C-V2X terminal, which is placed on a rotating hub platform in the microwave darkroom and is driven by a driver to simulate real road conditions; a speed sensor: collecting the speed of the measured vehicle in real time and synchronizing the speed to a virtual traffic scene; a satellite simulator simulating a satellite positioning signal and sending the satellite positioning signal to the whole vehicle; a scene simulation software used for loading a virtual simulation scene; a high-performance computing platform used for running scene simulation control software, C-V2X protocol stack software and GNSS device automatic control software; traffic participant information is sent to the measured whole vehicle through a V2X communication module, and the positioning of the measured whole vehicle is sent to the measured whole vehicle through the satellite simulator. The application can safely and repeatedly reproduce dangerous working conditions in the microwave darkroom environment, and verify the function triggering state of the networked vehicle.

The invention discloses an aviation monitoring load single machine and a whole satellite sensitivity test method. According to the method, a system is built in a microwave darkroom for stand-alone testing, and after link calibration, ADS-B signals with loads in different directions and in different formats are tested; in the whole satellite test, a satellite platform is deployed in a large darkroom, double transmitting antennas are arranged, a test signal is transmitted after link parameters are calibrated, and unpacked data are monitored. The test result shows that the load demodulation success rate is higher than 90%, and the sensitivity in the full state meets the index requirements. According to the method, coherent and accurate testing of the whole stage of load development is achieved, and a reliable method is provided for performance verification of a low-orbit satellite aviation monitoring system.

The invention belongs to the field of electromagnetic wave shielding materials, and discloses a preparation method of an electromagnetic wave shielding material, which comprises the following steps: carrying out hydrothermal reaction on a nickel source and a lanthanum source in the presence of a reducing agent to obtain a nickel-lanthanum mixed hydroxide solution; adding a carbon source into the nickel-lanthanum mixed hydroxide solution, uniformly stirring, and then carrying out high-temperature roasting to obtain a carbon-coated lanthanum-nickel mixture; and mixing the carbon-coated lanthanum-nickel mixture with PVDF powder, adding a solvent for wet mixing, and finally volatilizing the solvent to obtain the electromagnetic wave shielding material. The invention also discloses the electromagnetic wave shielding material and application thereof. Through the design of the PVDF nano wave-absorbing material film compounded by nickel and lanthanum, the material has the excellent performance that the maximum absorption strength reaches-52 dB at the frequency band of 11.3 GHz, the material can effectively absorb most electromagnetic waves, the electromagnetic interference is remarkably reduced, and the test precision is improved.

This invention discloses a simulation platform for EMI emission from pantograph-catenary arc discharge in urban rail transit metro vehicles. The platform includes a microwave anechoic chamber containing an equivalent impedance box assembly. This assembly is sequentially connected to an equivalent impedance box for power supply cables, an equivalent impedance box for the pantograph-catenary system, an equivalent impedance box for onboard line reactors, a parallel combination of equivalent impedance boxes for onboard filter capacitors and onboard converter modules, an equivalent impedance box for wheelsets, and an equivalent impedance box for return lines. One end of the equivalent impedance box assembly is connected to an EMI signal transmitting box located at the A side of the traction substation outside the microwave anechoic chamber, and the other end is connected to an EMI signal transmitting box located at the B side of the traction substation outside the microwave anechoic chamber. Using this platform, the emission environment of radiated EMI generated by arc discharge when the pantograph-catenary system is offline in a metro vehicle can be accurately simulated.

This invention discloses a method for amplitude and phase compensation of a millimeter-wave broadband radar channel, comprising the following steps: S1, performing antenna null alignment under far-field conditions in a microwave anechoic chamber; S2, extracting and calculating the reference amplitude ratio and reference phase difference of the sum and difference paths at different frequency points using the self-calibration signal within the millimeter-wave broadband radar, and storing these values; S3, extracting and calculating the average phase difference between the difference and sum paths at different frequency points using the feed signal received by the millimeter-wave broadband radar, and storing this value; S4, extracting the amplitude ratio and phase difference of the sum and difference paths from the self-calibration at different frequency points of the millimeter-wave broadband radar in real time, calculating and compensating for the changes in the amplitude ratio and phase difference of the real-time self-calibration relative to the fixedly stored reference amplitude ratio and phase difference, and compensating for the fixedly stored average phase difference between the feed differential path and the sum path. This invention utilizes broadband in-system self-calibration and feed calibration to solve the calibration compensation problem of millimeter-wave broadband radar systems.

The utility model provides a microwave anechoic chamber rotary table wave-absorbing material combined carrying device, which belongs to the technical field of microwave anechoic chambers, and comprises a driving track, a driving vehicle, a driven vehicle and a control system, and the driving track is arranged on the outer side of a microwave anechoic chamber rotary table; the driving vehicle is connected to the driving track and has the freedom degree of movement in the length direction of the driving track. The driven vehicle is positioned above a rotary table of the microwave anechoic chamber, is used for supporting a wave-absorbing material, and can be driven away from the upper end of the rotary table; the control system is connected to the side portion of the driving vehicle, electrically connected with the driving vehicle and suitable for controlling the driving vehicle to move on the driving track so as to achieve connection and separation of the driving vehicle and the driven vehicle, so that the driven vehicle is driven away from the rotary table, and the wave-absorbing materials are moved away from the rotary table. The wave-absorbing material conveying device has the technical effects that the wave-absorbing material can be automatically conveyed, the manual labor is reduced, the damage to the wave-absorbing material is reduced, and the conveying efficiency is improved.