96 results about "Anechoic chamber" patented technology

There is provided a propagation environment reproduction device including: an anechoic chamber that blocks an electromagnetic wave from the outside; reconfigurable intelligent surfaces (RISs) that are installed in the anechoic chamber; a RIS control device that provides a control signal to the RISs; a transmission antenna that is installed in the anechoic chamber; a channel emulator that controls a characteristic of an electromagnetic wave transmitted from the transmission antenna; a reception antenna that is installed in the anechoic chamber as an evaluation target; and a control server that controls the RIS control device and the channel emulator. The RIS includes a first RIS that has a characteristic of changing transmittance of the electromagnetic wave according to the control signal and is disposed between the transmission antenna and the reception antenna.

The present application relates to a kind of boundary deformation mutual coupling reverberation chamber shielding effectiveness test device and method, it is related to electromagnetic shielding technical field of material, the test device includes flexible shielding cloth reverberation chamber, metal plate, stepper motor group, transmitting antenna, first receiving antenna, second receiving antenna, first spectrum analyzer, second spectrum analyzer and controller;Metal plate is as partition and is divided into transmitting reverberation chamber and receiving reverberation chamber by flexible shielding cloth reverberation chamber, metal plate is closely connected with flexible shielding cloth reverberation chamber around;Test window is set in the center of metal plate, for installing test material;Stepper motor group is used to control the wall deformation of transmitting reverberation chamber and receiving reverberation chamber;First spectrum analyzer is connected with first receiving antenna;Second spectrum analyzer is connected with second receiving antenna;Controller is connected with first spectrum analyzer, second spectrum analyzer and stepper motor group.The present application provides platform and method for accurately testing the shielding effectiveness of material under composite electromagnetic environment.

A measurement system for over-the-air testing of a device for non-terrestrial networks is described. The measurement system includes an anechoic chamber, at least one transmission antenna configured to transmit a source signal, a polarization rotator configured to rotate a polarization state of the source signal transmitted by the transmission antenna, and an electronic circuit configured to control the polarization rotator such that an ionospheric Faraday rotation is simulated. In addition, a user equipment (UE) is described. The UE is configured to measure a polarization direction of a received signal and to report the measured polarization direction by transmitting it as channel state information. Further, a method for emulating and determining a polarization mismatch in non-terrestrial communication systems is described. The method includes a step of establishing a connection between a system simulator and a device under test, wherein the system simulator indicates the used polarization to the device under test.

The invention discloses a vehicle cabin sound field reconstruction method based on space energy diagram constraint and deep optimization. The method comprises the following steps: 1) measuring the impulse response of a vehicle-mounted loudspeaker array in a target vehicle cabin in a listening area; (2) space scanning is conducted on the impulse response and the impulse response simulated in the ideal anechoic chamber scene through a delay and beam forming method, sound energy distribution in all preset directions is calculated, and a space energy diagram of an actual sound field and a space energy diagram of a target ideal sound field are generated; 3) calculating the space energy diagram similarity between the two space energy diagrams, and constructing a target function; 4) constructing a neural network, taking random noise as input, outputting a control filter coefficient, and iteratively optimizing the neural network by using a target function; and 5) according to the neural network after iterative optimization, outputting a control filter coefficient of each loudspeaker channel, and loading the control filter coefficient to a sound system in the target vehicle cabin to realize sound field reconstruction in the target vehicle cabin. The invention has better subjective tone quality.

This invention discloses a system and method for testing the radio frequency interference (RFI) immunity performance of train vehicle equipment. The system includes a test terminal, a mobile terminal, an adjustable bracket, an antenna, and a field strength probe. The mobile terminal houses a power supply and an immunity signal generator. The power supply powers the test terminal and the immunity signal generator, and the immunity signal generator generates and amplifies the RF modulation signal. The test terminal is located on one side of the top of the mobile terminal. This system and method for testing the RFI immunity performance of train vehicle equipment utilizes a mobile terminal connected to the test terminal, antenna, field strength probe, and immunity signal generator to perform RFI immunity testing. The immunity signal generator simulates the RF interference environment, eliminating the need for an anechoic chamber. Testing can be conducted directly within the train carriages after the train assembly is completed and all functions are properly debugged, improving the overall mobility and portability of the testing system.

This utility model discloses a support and acoustic testing system used inside an anechoic chamber. The support includes a telescopic rod, a linkage mechanism, and a tray. The telescopic rod has a fixed rod and a movable rod that are slidably engaged. One end of the fixed rod is provided with a fixing part for fixed connection with the side wall of the anechoic chamber. The linkage mechanism includes a guide rod fixedly connected to the movable rod, a swing rod hinged to the guide rod, and a push rod diagonally supported between the guide rod and the swing rod. One end of the push rod is hinged to the swing rod, and the other end is hinged to a slider slidably disposed on the guide rod. The slider is provided with a locking element for locking the slider. The tray is used to place the test object for acoustic testing, and the bottom of the tray is connected to the swing rod. The support of this utility model can easily adjust the position of the test object inside the anechoic chamber, thereby improving the efficiency of acoustic testing.

The application discloses a kind of online calibration methods of multi-antenna navigation darkroom link delay, belong to satellite navigation user equipment test field.The application includes: by metrology / testing, the receiving zero value of calibration receiver at each frequency point is obtained;Navigation signal link delay calibration environment is constructed in multi-antenna navigation darkroom;Single star multi-output navigation signal simulator transmits single star single frequency point test signal;The current channel link delay is obtained by calibration receiver;Change single star multi-output navigation signal simulator output signal frequency point and obtain other frequency point link delay;Change signal output channel and obtain the link delay of each frequency point of other channel.The application can realize the automation online calibration of multi-antenna navigation darkroom link delay, can effectively shorten system calibration time, reduce the advantages of link delay calibration complexity.

A system performs a method of verifying an anechoic chamber. A plurality of electromagnetic waves propagate from an emitter located within the anechoic chamber. Each electromagnetic wave of the plurality of electromagnetic waves is associated with one of a plurality of configurations between the transmitter and a receiver in the anechoic chamber. A plurality of reflections from a reflective element in the anechoic chamber are received at the receiver. Each of the plurality of reflections corresponds to one of a plurality of configurations. For each of the plurality of reflections, an ellipse indicative of a range of reflective elements is determined. The intersection of each ellipse is positioned to determine the position of the reflective element in the anechoic chamber. The reflectance of the reflective element is compared to a threshold to validate the anechoic chamber.

The invention relates to the technical field of electromagnetic environment effect testing, and discloses a phased array multifunctional electromagnetic environment effect testing system and a calibration method thereof.The system comprises an active array plane, a comprehensive processing extension set, a comprehensive frequency source extension set, an external feed source combination, a superheterodyne receiver and a digital acquisition extension set; wherein the active array plane is provided with a plurality of minimum sub-arrays, each minimum sub-array is composed of at least one active channel and a corresponding radiation antenna unit, and each minimum sub-array is used for receiving one excitation signal to complete power amplification and radiation synthesis; and the path number of the independent excitation signals generated by the comprehensive frequency source extension set corresponds to the number of the minimum subarrays. The calibration method comprises darkroom plane near-field calibration, external feed source combination calibration and active array plane calibration before working. The system and the method provided by the invention have the advantages of relatively strong accurate construction capability of a complex electromagnetic environment, extremely high test flexibility, multi-beam coordination and high-precision full-link calibration, and stable and reliable operation.

The utility model relates to the technical field of acoustic detection, and particularly discloses an anechoic chamber, which comprises a wall body provided with an opening; the door assembly comprises a first door plate and a second door plate which are sequentially arranged in the first direction, the first door plate and the second door plate are both located in the opening, and the second door plate is close to the ground relative to the first door plate; the ground wedge module is movably arranged on the ground of the anechoic chamber; wherein the second door plate comprises a first sub-part, a second sub-part and a third sub-part, openings of the first sub-part and the third sub-part are located on the two sides of the opening in the second direction and hinged to the wall body, and the second sub-part is movably arranged between the first sub-part and the third sub-part so as to open and close part of the opening. The ground wedge module is arranged to be movable, the indoor floor and the outdoor floor of the anechoic chamber are designed to be flush so that the ground wedge module can move conveniently, meanwhile, the door assembly is designed, the operation convenience is greatly improved while the cost is reduced, and the working efficiency is improved.

This application provides an antenna performance evaluation method and apparatus, addressing the problem in existing technologies where larger scattering objects require larger testing environments when the scattering object is significantly larger than the individual antenna. The antenna performance evaluation method includes the following steps: acquiring the radiated electric field measurement results of a single antenna; determining a hypothetical planar electromagnetic field distribution by performing spherical electromagnetic field mapping; calculating the surface electromagnetic field distribution of the single antenna using a backward inversion method based on the hypothetical planar electromagnetic field distribution; and calculating the radiation pattern of the single antenna in the presence of the scattering object based on the surface electromagnetic field distribution and the properties of the scattering object. An apparatus for implementing the above method is also provided. This application eliminates the need to place large scattering objects in an anechoic chamber, requiring only radiated electric field measurements of the individual antenna, significantly reducing the demand for testing space.

This invention discloses an electromagnetic characteristic testing method for a large-scale vacuum anechoic chamber plasma environment, belonging to the field of microwave testing technology. The method includes: setting up an antenna movement device, an antenna protective cover, and a transmitting antenna in a large anechoic chamber; evacuating the large anechoic chamber to a vacuum and providing a stable plasma environment through a plasma source inlet within the chamber; connecting the transmitting and receiving antennas to a vector network analyzer; connecting the vector network analyzer to a computer; and using the computer to control the vector network analyzer to acquire antenna data in the large-scale vacuum anechoic chamber plasma environment, calculating the gain pattern and transmittance. This invention provides a stable large-scale anechoic chamber plasma environment, ensuring the repeatability of electromagnetic characteristic testing. The antenna movement device ensures that the movement state of the receiving antenna at every angle can be obtained, enabling rapid and large-scale acquisition of stable plasma antenna data.

A kind of chassis stone knocking sound evaluation method and device in car is predicted, belong to chassis test technical field.Step S1, third microphone carries out the collection and knock the knocking sound of the knocking point on the bottom guard plate;Step S2, change the angle of bottom guard plate and ground, repeat step S1-S2;Step S3, formulate the sound transmission function ATF2 of the car to be developed;Step S4, the sound transmission function ATF2 of the car to be developed is simulated using anechoic chamber-anechoic test room set, the sound transmission function ATF3 between first anechoic chamber and second anechoic chamber is measured;Step S5, adjust the position of sound insulation part, first sound source and first microphone, the sound transmission function ATF3 between first anechoic chamber and second anechoic chamber is measured, whether the sound transmission function ATF3 and the sound transmission function ATF2 are similar, if yes, then execute step S6, if no, then execute step S5;Step S6, after playing multiple knocking sound using first sound source, it is scored;Step S7, replace bottom guard plate, repeat step S1-S7, complete the evaluation of the knocking sound of the car to be developed.

This utility model discloses a metal-faced sandwich composite integrated panel for shielded rooms, relating to the fields of electromagnetic shielding and building envelope technology. This utility model includes a new integrated panel one for external building shielding and enclosure and a new integrated panel two for internal building shielding, decoration, and sound absorption. New integrated panel one consists of an enclosure layer, a sandwich layer, and a shielding layer; new integrated panel two consists of a shielding layer, a sandwich layer, and an enclosure layer. Through the unique design of new integrated panels one and two, this utility model is suitable for a wide frequency band of 10kHz-50GHz, exhibiting excellent shielding effectiveness, meeting and exceeding the national military standard GJB5792A-2021C level standard, fully meeting the design requirements of anechoic chambers and other types of shielded rooms. New integrated panels one and two are produced and constructed using innovative models and processes, achieving true integrated shielding, resulting in higher construction efficiency, better quality, stronger safety, shorter cycle time, and higher cost-effectiveness.

This application discloses a waveguide optimization method, waveguide optimization device, and medium for audio devices, relating to the field of audio processing technology. The disclosed waveguide optimization method for audio devices includes: integrating a verified physical model of the waveguide to be optimized into a full-device simulation model of the target audio product; determining the energy ratio between reflected sound and direct sound at the receiving point when the full-device simulation model simulates sound wave propagation; and outputting the physical structure information of the waveguide if the energy ratio is greater than or equal to a preset energy ratio. This simulation optimization method ensures the compatibility of the sky or surround waveguide structure with the target audio product, improves the effectiveness and reliability of waveguide development and testing, eliminates the need for frequent reliance on costly anechoic chamber environments, and provides precise and economical technical support for optimizing the channel performance of audio devices.

The utility model provides an OTA test darkroom integrated with an environment simulation function, which comprises a darkroom body, a test mechanism for placing an object to be tested is arranged in the middle of the inner side of the darkroom body, an adjusting mechanism is arranged on the inner side of the darkroom body, the adjusting mechanism is distributed in the darkroom body in a mirror image manner, and an antenna mechanism for testing the object to be tested is arranged in the middle of the adjusting mechanism; the adjusting mechanism comprises electric guide rails, adjusting plates and mounting arc-shaped plates, the electric guide rails are arranged at the top and the bottom of the inner side of the darkroom body in a mirroring mode, the adjusting plates are arranged on the sides, away from the darkroom body, of the adjusting plates, and the adjusting plates and the electric guide rails are clamped and slide. According to the utility model, the adjusting mechanism controls the antenna mechanism to move horizontally, and cooperates with the antenna main body in the antenna mechanism to lift and rotate above the mounting arc-shaped plate, so that the antenna main body can be adjusted and tested in multiple directions when testing an object to be tested, the multipath test of the antenna main body is facilitated, and the test efficiency is improved. And complex multipath propagation simulation is realized.

The invention relates to the technical field of pipeline vibration testing, in particular to a method and device for testing the contribution of a pipeline to the NVH performance in a vehicle in the whole vehicle state, and the method comprises the steps: placing a target whole vehicle in an anechoic chamber, and arranging a plurality of vibration sensors and a plurality of noise sensors; performing noise and vibration test on the target whole vehicle according to a preset test working condition to obtain a noise total sound pressure level and a total vehicle interior and exterior vibration square and root value; according to the noise total sound pressure level and the total outside-vehicle vibration square sum root value, the peak values of all frequency bands of the inside-vehicle noise and vibration and the outside-vehicle pipeline vibration are analyzed; and according to the total outside-vehicle vibration square sum root value and the total inside-vehicle vibration square sum root value, an analysis chart of contribution of each pipeline vibration to the inside-vehicle noise and an analysis chart of contribution of each pipeline vibration to the inside-vehicle vibration are synthesized. Therefore, the problems that a related testing method cannot test or a tested transfer function is lack of accuracy, and the influence and contribution of noise and vibration of the pipeline on other parts cannot be seen in a result are solved.

The invention discloses a directional coordinate transformation method of a satellite-borne dual-offset reflector antenna, and belongs to the field of space measurement. The method comprises the following steps: firstly, calculating an installation parameter matrix representing a transformation relation between an antenna installation reference coordinate system and a satellite reference coordinate system; secondly, measuring the offset angle of the antenna in the zero attitude of the antenna, and constructing an electrical geometric parameter matrix representing the inherent structure transformation of the antenna; then, acquiring an antenna electric axis expected pointing coordinate represented by an azimuth angle and a pitch angle under a satellite coordinate system; and finally, solving a main surface axis rotation angle and an auxiliary surface axis rotation angle used for driving the antenna pointing mechanism through coordinate transformation based on the two angles. According to the invention, the problem of directional coordinate transformation caused by non-orthogonal parallelism of a dual-offset antenna rotation axis and a satellite coordinate axis is solved, high-precision in-orbit pointing of the antenna is ensured, the antenna passes darkroom test verification, and the antenna system can be expanded and applied to other antenna systems containing dual-axis rotation mechanisms.

The application relates to the technical field of air conditioners, and discloses a silencer. The silencer provided by the application comprises a silencer body, a first pipe, a second pipe and an inner connecting pipe. The first pipe comprises a first folding pipe section; the second pipe is fixed at two ends of the silencer body with the first pipe; one end of the inner connecting pipe is inserted into the first pipe and penetrates into a silencing chamber, and the other end of the inner connecting pipe is used for connecting to a refrigerant circulating system; a positioning point is arranged at the middle part of the inner connecting pipe, and the positioning point is fixedly connected with the end part of the first pipe; the first folding pipe section can be expanded or contracted, and the first folding pipe section is used for adjusting the depth of the inner connecting pipe penetrating into the silencing chamber. The length of the inner connecting pipe in the silencing cavity is variable, the length of the silencing chamber and the length of the inserted inner connecting pipe are used for judging the frequency and the sound elimination amount which need to be eliminated by the system, so that the problem that the silencer needs to be frequently replaced in the process of optimizing and improving the air conditioner noise is solved. The application further discloses an air conditioner.

This invention discloses an electrically tuned high-power telescopic antenna system and method for use in an electromagnetic reverberation chamber. The system includes a base unit with a telescopic antenna rod slidably connected to it. The telescopic antenna rod's electrical length can be adjusted by changing its extension length to accommodate resonance requirements at different test frequencies. An electrically driven mechanism is installed within the base unit, with its power output connected to the telescopic antenna rod. The telescopic antenna rod is electrically connected to an RF feed unit for feeding external RF power into the telescopic antenna rod. A position feedback sensor is installed in the base unit. A control unit is optically connected to the electrically driven mechanism and the position feedback sensor, forming a closed-loop control based on the signal from the position feedback sensor. This invention achieves good impedance matching within the 30MHz–80MHz frequency band, solving the problem of severe mismatch in this band with existing antennas. It provides precise tuning, good matching, and ensures that the VSWR meets test requirements across the entire frequency band.

The utility model provides a small darkroom applied to an EMI (Electro-Magnetic Interference) test in order to solve the problem that a designer cannot conveniently carry out the EMI test in an initial design verification process due to the fact that a darkroom of the designer is not established in the prior art. The small darkroom comprises a signal line placing room, a test room, an antenna, a wireless transceiver chip and a signal amplifier. The common surface of the signal line placing chamber and the test chamber is provided with at least one hole connected with a test probe; at least one hole is formed in at least one of the other surfaces of the signal line placing chamber except the surface which is common with the test chamber and is used for connecting an external test instrument and measuring parameters of a tested piece; connectors are used at all the holes, and a closed space is formed indoors; a wave-absorbing material is adhered to the inner wall of the testing chamber; a test probe and a tested piece are arranged in the test chamber; wireless transmission can be realized through the antenna, the wireless transceiver chip and the signal amplifier, and the test convenience is enhanced.

This invention provides a dual-platform absorbing tip transverse positioning system, installed on the floor of an anechoic chamber to simulate different radio wave environments. The system consists of two parallel hydraulic platforms with densely arranged absorbing tips on them, and a raised floor is mounted on the hydraulic platforms. The hydraulic platforms are driven by hydraulic cylinders to lift and lower scissor supports. Sprockets are located at both ends of the platforms, driven by chains, and a transverse motor is also provided. The motor drives the sprockets through gear engagement, causing the absorbing tips on the platforms to move laterally. The raised floor, originally a metal reference surface, can be adjusted to a non-reflective environment according to testing requirements. The hydraulic platforms rise, driven by the transverse motor, and the absorbing tips of the two platforms unfold laterally, providing a non-reflective test. The aforementioned actions are reversed, causing the platforms filled with absorbing tips to retract and disappear under the raised floor. This system can flexibly switch between different testing environment conditions to meet the diverse needs of the anechoic chamber.

The invention relates to the technical field of anechoic chambers, and discloses a T-shaped track system with a high-load translation trolley in an anechoic chamber, which comprises a transverse guide rail, a longitudinal guide rail, a translation trolley, a reversing turntable and a turnover reset device, the reversing turntable is arranged at the intersection of the longitudinal guide rail and the transverse guide rail, and a reversing track is arranged on the reversing turntable; the reversing rotary table rotates in a plane around a central shaft of the reversing rotary table, so that the reversing track is selectively butted with the transverse guide rail or the longitudinal guide rail; an overturning reset device is fixed to the groove, and a wave-absorbing material is installed on the top face of the overturning reset device and used for covering the opening of the groove. The problem of multi-device dynamic scheduling in an RCS darkroom is solved, safe translation of large-inertia equipment can be ensured, and meanwhile secondary scattering of a guide rail to a test can be reduced.

This invention provides a platform for fixing absorbing material for an anechoic chamber turntable and an anechoic chamber. The platform includes a platform body, the upper surface of which is covered with absorbing material. A rotating device is installed at the bottom of the platform body. The platform body is mounted on the turntable and rolls in contact with the turntable via the rotating device. The outer edge of the platform body is fixed to the ground outside the turntable by fasteners. By elevating the absorbing platform, which creates a physically isolated space between the platform and the turntable, and with the rotating structure at the bottom of the platform and the fasteners at the outer edge, the absorbing material no longer moves with the turntable when it rotates, keeping it stationary. This completely avoids the problems of edge material collision, displacement, or deformation in traditional circular cutting solutions, significantly improving the ease of absorbing material installation.

The utility model provides a microphone fixing device for testing noise in a semi-anechoic room, which comprises a device body rotationally connected with a wall. The device body comprises a telescopic mechanism, a clamping assembly is arranged at the free end, away from the wall body, of the telescopic mechanism so as to detachably fix a microphone, and the telescopic mechanism can do axial telescopic motion so as to adjust the position of the microphone relative to a tested assembly. According to the utility model, the telescoping mechanism is installed at a proper position on the semi-silencing wall body through one-time measurement so as to meet the position requirements of the microphone and the tested assembly, and the microphone is rapidly disassembled and assembled through the clamping assembly at the end part of the telescoping mechanism, so that the risk that the microphone is damaged due to falling is avoided; the position of the microphone relative to the measured assembly is adjusted through the axial telescoping of the telescoping mechanism, so that the process that the position of the microphone from the measured assembly needs to be measured again when the microphone is dismounted each time is avoided, and time and labor are saved. And during a non-noise test, the telescopic mechanism can contract to be attached to the wall body.

The invention discloses a variable reverberation acoustic laboratory structure, which comprises a laboratory body and an environment conversion mechanism, the laboratory body comprises a first body, an experiment space is formed in the first body and is used for carrying out an acoustic experiment, and the environment conversion mechanism is arranged in the experiment space and comprises a plurality of driving units and a plurality of conversion columns, at least one conversion column can be synchronously and rotatably installed on one driving unit, the peripheral side of each conversion column is provided with a sound absorption part and a reflection part arranged on the back face of the sound absorption part, each sound absorption part is made of a sound absorption material, each reflection part is made of a sound reflection material, and the conversion columns are arranged on the back face of the sound absorption part. Furthermore, when the plurality of conversion columns rotate by a preset angle through the driven unit, a semi-anechoic chamber sound field environment and a reverberation chamber sound field environment can be formed in the first body, so that the experiment requirements of different acoustic environments are met.

A nozzle box unit forming a component of an anechoic chamber fire suppression system is provided. The nozzle box unit includes a pusher assembly that is configured to dislodge a piece of acoustic material positioned in front of the nozzle box so as to permit discharge of a fire suppressing material from a nozzle mounted inside the nozzle box unit into the anechoic chamber.

1. Name of the designed product: anechoic chamber. 2. Use of the designed product: the designed product is used in a laboratory for acoustic testing. 3. Design points of the designed product: in shape. 4. Picture or photo best indicating the design points: B-B sectional view.

The embodiment of the utility model provides a kind of water-cooled muffler, relate to silencing device technical field.Water-cooled muffler includes muffler body, inlet pipe, exhaust pipe, inlet pipe and outlet pipe.Water-cooled muffler is provided with sound attenuation chamber and cooling chamber in muffler body.Inlet pipe, exhaust pipe, inlet pipe and outlet pipe are set to the outside of muffler body.Inlet pipe, exhaust pipe and sound attenuation chamber are communicated.Cooling chamber is provided with cooling element.Inlet pipe, outlet pipe are respectively communicated with cooling element.The utility model can cool muffler, reduce exhaust temperature, improve the infrared function of equipment.