25 results about "Microwave anechoic chamber" patented technology

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 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 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 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 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 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.

The invention relates to the technical field of radars, in particular to an amplitude-phase consistency field calibration method and system for a large low-frequency-band phased array radar, and the method comprises the steps: deploying a probe antenna in a near-field region in front of an array, and enabling the probe antenna to be located at a position which meets a single-array-element far-field condition; high-resolution time domain data are obtained through broadband frequency stepping scanning, gating processing based on direct wave arrival time is applied to time domain impulse response, multipath components such as ground reflection are filtered out in a digital domain, and a virtual microwave anechoic chamber is constructed equivalently. And then combining an accurate Fries voltage transmission model with a pre-stored antenna pattern database to invert the inherent amplitude-phase characteristics of each array element channel, and finally completing high-precision consistency calibration. The problems of multipath interference in near-field testing and insufficient time domain resolution in multipath separation are solved.

This utility model discloses a microwave anechoic chamber capable of reducing environmental interference, belonging to the field of microwave anechoic chamber technology. It includes a base plate with two sets of composite buffer mechanisms on the base plate. A microwave anechoic chamber is mounted on each of the two sets of composite buffer mechanisms. Each composite buffer mechanism includes two lower support plates fixedly connected to the base plate, and two upper support plates fixedly connected to the bottom of the microwave anechoic chamber. Piston ports are fixedly connected to the bottom of the upper support plates and the top of the lower support plates. Four rotating seats are fixedly connected to the bottom and top of the upper support plates, and pressure-bearing arms are rotatably connected to the rotating seats. This utility model, through the composite buffer mechanism, provides sufficient buffer protection for the microwave anechoic chamber through the double buffering of two buffer springs and an airtight chamber. Furthermore, two brake teeth plates inside the slider can limit the slider's movement, thereby ensuring the stability of the microwave anechoic chamber.

The invention provides a compact range-based micro-Doppler characteristic test system and method, and aims to solve the problems of difficulty in micro-Doppler characteristic extraction, remarkable dynamic attitude influence and the like of a rotorcraft in the prior art. The system comprises a microwave anechoic chamber, a compact range reflecting surface, a feed source rotary table, a feed source antenna, a multi-degree-of-freedom low-scattering rotary table, a motion synchronous controller, a broadband vector signal generator, a receiver and an upper computer, and the method comprises the following steps: installing a tested piece on the multi-degree-of-freedom low-scattering rotary table, importing a flight attitude file and simulating the attitude of an aircraft; a broadband carrier signal is transmitted and reaches a measured object through a compact range reflecting surface, an echo signal is collected and conjugate matched filtering processing is carried out, and finally micro-Doppler modulation spectrum characteristic parameters are extracted; according to the invention, environmental electromagnetic interference and machine body strong scattering can be effectively suppressed, the signal-to-noise ratio of signals is improved by more than 20dB, and high-precision micro-Doppler feature extraction is realized.

The invention provides a microwave anechoic chamber, and relates to the technical field of communication equipment testing, and the microwave anechoic chamber comprises an electromagnetic shielding chamber, a wave absorbing material, a non-metal sealing cover and a measuring antenna; wherein the wave-absorbing material is laid on the inner wall of the electromagnetic shielding chamber; the non-metal sealing cover is of a hollow and symmetrical structure and is installed on the ground of the electromagnetic shielding chamber. A measuring antenna and a to-be-tested equipment turntable are arranged in the electromagnetic shielding chamber, and to-be-tested equipment is arranged on the to-be-tested equipment turntable; the surface, facing the measuring antenna and the equipment to be measured, of the non-metal sealing cover is a spherical surface, and the center of the spherical surface is the phase center of the measuring antenna and the center of a rotary table of the equipment to be measured. The non-metal sealing cover is filled with absorptive liquid; when the anechoic chamber is filled with the absorptive liquid, a free space non-reflection test environment is simulated, and the anechoic chamber is equivalent to a full anechoic chamber; when no filling exists, the anechoic chamber is equivalent to a semi-anechoic chamber.

The invention provides a simplified test method and device for receiving sensitivity of mass production satellites. The method comprises the following steps: S1, carrying out classification processing on batch production satellites, selecting a representative satellite from each class, and executing steps S11 to S16 in parallel on each representative satellite; s2, counting the target sensitivity sets of all classes to obtain an overall test result of batch production satellites; the S1 comprises the following steps: S14, measuring a second ground detection emission signal level corresponding to a similar satellite in the target microwave anechoic chamber by taking the bit error rate index as a target; s15, according to the difference value between the second ground detection emission signal level and the first ground detection emission signal level, calculating the receiving sensitivity of a similar satellite in the target microwave anechoic chamber; and S16, a new similar satellite is replaced, and S14 to S15 are repeatedly executed until a target sensitivity set composed of the receiving sensitivity of all the similar satellites in the target microwave darkroom is obtained, so that the receiving sensitivity testing efficiency of existing mass production satellites is improved.

This invention discloses a plane wave synthesizer, testing system, and method based on a dual / multi-band co-aperture ultra-wideband Vivaldi dual-polarized array. The plane wave synthesizer includes an amplitude and phase controller, and an ultra-wideband Vivaldi three-band co-aperture antenna array or an ultra-wideband Vivaldi dual-band co-aperture antenna array. The testing system includes the plane wave synthesizer, a microwave anechoic chamber, a turntable within the anechoic chamber, and the device under test (DUT). The microwave anechoic chamber also includes an electromagnetic shield and radio frequency absorbing materials around its perimeter. During testing, the amplitude and phase controller generates multi-band radio frequency excitation signals to drive the ultra-wideband Vivaldi three-band co-aperture antenna array or the ultra-wideband Vivaldi dual-band co-aperture antenna array, forming a uniform plane wave in the near-field radiation. This invention eliminates the need for near-field and far-field transformation of electromagnetic waves, reducing the required space by three-quarters compared to systems based on compact fields, making it particularly suitable for generating large-size ultra-wideband quiet zones.

The application relates to a high-power test microwave darkroom, which comprises a shell, the outer periphery of the shell is provided with a frame, the inner side of the shell is concavely provided with a cavity, the inner wall of the cavity of the shell is provided with a wave-absorbing assembly, one side of the cavity of the shell is provided with a monitoring assembly, and the outer side of the top of the shell is provided with an illumination assembly. The shielding body selects a darkroom test environment with high shielding efficiency index, and can meet the electromagnetic environment standard limit value requirement; the high-power wave-absorbing material adopts non-woven fabric, silicon carbide, ceramic or honeycomb material, so that the wave-absorbing material can withstand the high-power test state; and the auxiliary facilities include monitoring, illumination, fire fighting and ventilation in the darkroom, so that the equipment is not disturbed and normally operates in the high-power test state.

The present application relates to a kind of microwave anechoic chamber with icing conductor measurement support, microwave anechoic chamber measuring device.The present application provides a kind of microwave anechoic chamber with icing conductor measurement support, comprising: support unit, for supporting transmission line;Refrigeration unit, for spraying refrigeration medium to the transmission line surface;Control unit is connected with the refrigeration unit, for controlling the refrigeration medium to carry out intermittent injection at preset interval;Wherein, the refrigeration unit and control unit are fixed on the support unit, the control unit is electrically connected with the refrigeration unit, the support unit is made of low electromagnetic scattering material.The present application fundamentally solves the industry problem that icing conductor cannot be stably measured due to rapid melting in normal temperature microwave anechoic chamber, and creates and maintains necessary low-temperature microenvironment for measurement target by accurate and controllable local active refrigeration, effectively prolongs effective imaging measurement time.