19 results about "Quiet zone" patented technology

The application belongs to the technical field of test and measurement, and particularly relates to a tight-field reflecting surface realized by building cement. The tight-field reflecting surface is used for low-frequency tight-field measurement and mainly comprises a cement support, a cement parabolic reflecting surface arranged on the cement support, a surface geometry of the cement parabolic reflecting surface being a parabolic surface with periodic side teeth, and a metal plating layer formed on the surface of the cement parabolic reflecting surface and used for providing a metal boundary condition for electromagnetic reflection. The application can greatly reduce manufacturing cost and effectively form a high-quality quiet zone in a low-frequency band.

This invention discloses a concrete-based hybrid edge compaction field reflector and its design method. The reflector includes: a main body, part of a paraboloid of revolution, made of reinforced concrete with a metal-sprayed surface; and a mixed edge of rolled and sawtooth edges surrounding the main body. Measurement systems using this reflector, when placed outdoors, only need to consider ground scattering, eliminating the need to consider the influence of wall scattering on the quiet zone. The concrete reflector structure is stable, easy to form, and can create a high-quality quiet zone at low frequencies, reducing the processing cost of large low-frequency reflectors. The use of the mixed rolled and sawtooth edges effectively suppresses edge diffraction, enabling the formation of a high-quality quiet zone outdoors.

Various embodiments disclose techniques for generating one or more sound zones and a quiet zone in a listening environment. The techniques include configuring one or more filters of a filter bank, generating a respective speaker signal for each of one or more speakers by processing a respective audio zone signal for each of one or more sound zones using the filter bank, and outputting the respective speaker signals using the one or more speakers. Sound output by the one or more speakers propagates through a listening environment to generate respective sound in each of the one or more sound zones corresponding to the respective audio zone signal for that sound zone. The sound output by the one or more speakers propagates through the listening environment to generate a first quiet zone.

This invention provides a method and system for directional sound generation from a loudspeaker based on offline simulation and feedforward control, relating to the field of electroacoustic technology. The method includes: based on the feedforward compensation database, in the online implementation phase, performing frequency decomposition on the input audio signal using a digital signal processor and querying the database to obtain compensation parameters corresponding to each frequency component, thereby obtaining a real-time inverse compensation signal; using the real-time inverse compensation signal, synchronously driving the main loudspeaker and auxiliary loudspeaker, causing the compensated sound wave radiated by the auxiliary loudspeaker to destructively interfere with the sound wave behind the main loudspeaker, forming an acoustic quiet zone. This invention combines offline simulation to construct a precise database with online feedforward query for real-time compensation, ensuring accuracy and efficiency throughout the entire process from data foundation to acoustic quiet zone formation.

A testing system for testing a device under test comprises a test chamber with a test location for receiving the device under test. The testing system further comprises at least one first antenna with a corresponding reflector. The at least one first antenna is configured to transmit and / or receive an electromagnetic signal along an indirect beam path. The indirect beam path extends between said at least one first antenna and the device under test via the corresponding reflector. The testing system further comprises at least one second antenna configured to transmit and / or receive an electromagnetic signal along a direct beam path extending between said at least one second antenna and the device under test. The at least one first antenna and the corresponding reflector are arranged to provide a quiet zone at the test location. The at least one reflector can be rotated in a horizontal plane.

This invention discloses a waist-shaped double-slope sawtooth structure for a single parabolic cylindrical compact field, solving the edge diffraction problem of cylindrical waves incident from a linear array feed in a single parabolic cylindrical reflector compact field. The structure divides the sawtooth edges of the reflector surface into internal and external regions. The internal region employs a near-vertical base with a top triangular convergence structure to guide diffracted waves to the area above and below the quiet zone. The external region uses an inclined geometry to guide diffracted waves to the sides of the quiet zone. Each sawtooth unit consists of a five-point structure defined by a vertex, two waist points, and two base points. The position, width, and sawtooth inclination are parametrically controlled using an adjustable parameterized distribution function. This invention effectively suppresses edge diffraction in high aspect ratio compact fields, significantly improving quiet zone performance.

A low scattering turntable for improving quiet zone test performance and a quiet zone test method is provided, and relates to the technical field of quiet zone test. The low scattering turntable includes an L-shaped baffle, a rhombic inclined wedge supporting column, a bottom plate, a turntable base, a fixed block, a longitudinal rotating shaft and a transverse rotating shaft. In the disclosure, the rhombic inclined wedge supporting column is adopted, the sharp wedge diffraction and traveling wave scattering effects are reduced. Multi-layer side wave-absorbing materials layout are used in the rhombic inclined wedge supporting column, which can effectively reduce electromagnetic reflection and scattering in a wide frequency range. By adding sawtooth wave-absorbing material to the edge of L-shaped baffle, the reflection intensity of electromagnetic wave is reduced and the overall wave-absorbing efficiency is improved. The oval bottom plate is adopted to reduce the measurement error.

This invention provides a low-noise amorphous alloy three-dimensional transformer. The invention relates to the field of amorphous alloy transformer technology, and includes an internal noise reduction mechanism installed inside the transformer body and a second noise reduction component installed on the outside of the transformer body. The transformer body includes a housing, heat sinks, an oil tank, and a core module. The oil tank and core module are installed inside the housing, and the heat sinks are fixed to the outside of the housing. The internal noise reduction mechanism includes a buffer component, a first noise reduction component, a mounting component, and a barrier chamber. Through the coordinated use of the buffer component, the first noise reduction component, and the second noise reduction component, this solution establishes a three-level coordinated noise reduction system of "source vibration reduction, near-field isolation, and remote shielding." The vibration of the core module is directly absorbed by an air spring, and the double-layer structure of the barrier chamber and the outer protective cover achieves full-path blocking of solid-borne sound and airborne sound, ultimately meeting the most stringent quiet zone standards for noise emission.

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 compact range dead zone amplitude and phase testing method based on a reference target method, and belongs to the technical field of microwave measurement. According to the method, a mathematical relationship between a target scattering field and a target surface induction current is established, a conductor rod is used as a reference target, and one-dimensional transverse distribution of any target is represented by rotating the conductor rod around the center of the reference target. According to the compact range quiet zone amplitude and phase testing method based on the reference target method, radar cross sections RCS of a reference target under different azimuth angles are measured, compact range quiet zone amplitude and phase distribution is obtained through data processing inversion, and dependence on a complex and time-consuming probe scanning device is not needed. Wherein the reference target is a metal rod or a cylinder of which the length is greater than the range of the quiet zone, and the surface field distribution of the reference target and the RCS essentially form a Fourier transform relationship. The method effectively simplifies the test process of the quiet zone, improves the test efficiency, and is suitable for rapid and accurate evaluation of the performance of the compact range quiet zone.

An active noise cancellation (ANC) system has a mounting plate, a first face of which is configured to be disposed against an inner surface of a helmet to form, with the helmet, a chamber. When the mounting plate is mounted on the helmet, a loudspeaker provided on the first face of the mounting plate is within the chamber. The plate has an aperture for allowing transmission of sound from the loudspeaker to the spatial region. At least one reference microphone is mounted on a second face of the plate. The plate acts as a mounting plate for components of the ANC system, simplifying the process of installing an ANC system. Also, the plate serves to define a chamber that accommodates the loudspeaker of the ANC system and provides good acoustic coupling of the sound signal from the loudspeaker of the ANC system into the quiet zone of the ANC system.

The invention provides a method for quantifying the influence of amplitude-phase tapering of a quiet zone on antenna radiation characteristic parameters, and the method comprises the steps: measuring the scattering data of a standard antenna based on a preset position point of the quiet zone of a compact range, and obtaining the actual measurement statistical characteristics; constructing a function model for describing coning distribution on the basis of the actually measured statistical characteristics, wherein the function model describes the relationship between amplitude coning and phase coning of the quiet zone and the spatial position; correcting an amplitude weight and a phase weight of the antenna array unit to be measured based on the function model; calculating a corrected array factor and a total directional diagram according to the amplitude weight and the phase weight; and determining a radiation characteristic parameter difference value of the to-be-tested antenna according to the corrected array factor and the total directional diagram. According to the invention, the influence of the amplitude-phase tapering of the quiet zone on the radiation characteristic parameters of the antenna is quantified, and simulation analysis based on numerical values can be realized.

The application discloses a kind of measuring device and method of satellite load active array, belong to satellite internet and 6G non-ground network test technical field.Device includes microwave darkroom, rotary table, multiple probe scanning frame and amplitude and phase controllable synthetic array.Satellite load active array to be measured is placed on rotary table, and radiation aperture is towards upwards;Multiple probe scanning frame is located above rotary table, and multiple antenna probes simultaneously collect near-field signal, and far-field pattern is obtained by near-far field conversion;Amplitude and phase controllable synthetic array is composed of amplitude and phase independently adjustable antenna unit, can be moved into above rotary table, and the electromagnetic wave of setting wave front is synthesized in the quiet zone covering the aperture of array to be measured, or each unit received signal is weighted and synthesized, to complete receiving directional diagram, transmit-receive frequency index, dynamic scene and system level performance measurement.The application shortens measurement distance, and measurement efficiency is improved by one to two orders of magnitude compared with single probe scanning, and flat installation reduces engineering difficulty, supports active array air interface measurement of no feed interface.

The invention discloses an anechoic chamber reflection level simulation method and device, a terminal and a medium, and relates to the technical field of data processing, the method is applied to a simulation system, the simulation system comprises an anechoic chamber and a feed source antenna, and the method comprises the following steps: obtaining size data corresponding to a quiet zone in the anechoic chamber and position data corresponding to the quiet zone; based on the material parameter data of the internal wave-absorbing material of the darkroom and the wave impedance value corresponding to the air, obtaining material efficiency data of the internal wave-absorbing material of the darkroom; and calculating a target simulation result based on the size data corresponding to the quiet zone, the position data corresponding to the quiet zone, a preset simulation calculation frequency corresponding to a simulation system, antenna parameter data corresponding to a feed source antenna and the material efficiency data. The invention aims to improve the efficiency and accuracy of darkroom reflection level simulation.

Various embodiments disclose techniques for generating one or more sound zones and quiet zones in a listening environment. The techniques include: configuring one or more filters in a filter bank; processing a corresponding audio region signal for each of the one or more sound zones using the filter bank to generate a corresponding speaker signal for each of the one or more speakers; and using the one or more speakers to output the corresponding speaker signal. Sound output from the one or more speakers propagates through the listening environment to generate a corresponding sound in each of the one or more sound zones corresponding to the corresponding audio region signal for that sound zone. Sound output from the one or more speakers propagates through the listening environment to generate a first quiet zone.

The application discloses a method for improving the performance of a compact range quiet zone by adjusting the feed source deflection angle, and the method comprises the following steps: determining the focal length of a compact range reflecting surface, the deflection direction of the reflecting surface, the size of the quiet zone and the position of the quiet zone; projecting the quiet zone to the reflecting surface to determine the lowest point and the highest point projected on the deflection direction of the reflecting surface; obtaining the feed source directional diagram data through simulation or measurement; rotating the feed source from the lowest point to the highest point, and calculating the amplitude flatness of the quiet zone in the deflection direction of the reflecting surface at different deflection angles by using a geometric optics method; and finding the feed source deflection angle that makes the amplitude flatness minimum by comparison. The application can improve the performance of the compact range quiet zone without changing the compact range reflecting surface, the feed source and the darkroom structure.

The invention provides a large compact range dead zone electrical performance measuring device and a detection method thereof. The device comprises a metal flat plate, a metal support and a scanning frame system. Peripheral equipment comprises a compact range feed source and a compact range reflecting surface. The compact range feed source is located at the focus of the compact range reflecting surface, and the compact range reflecting surface is used for converting spherical electromagnetic waves radiated by the compact range feed source into planar electromagnetic waves; the section passing through the axis of the quiet zone is a section of a quiet zone to be detected, and the section of the quiet zone to be detected is circular or elliptical; the scanning frame system is located on the front side of the exterior of the quiet zone, the scanning frame system is provided with a measuring antenna, and the measuring antenna can move in the direction parallel to the axis of the quiet zone and in the vertical direction to conduct scanning detection on the electrical performance of the quiet zone; the metal flat plate is installed on the cross section of a to-be-detected dead zone through the metal support, and the metal flat plate is used for reflecting the plane electromagnetic wave emitted by the compact range reflecting surface to the measuring antenna on the front side of the to-be-detected dead zone. According to the invention, the detection of the electric performance of the large compact range quiet zone can be realized.

The application discloses a high-aperture utilization rate ultra-large quiet zone tight-field device, which comprises a tight-field reflecting surface, a feed source and a plane wave quiet zone; the feed source is an electromagnetic wave radiation source of the tight-field device; a diagonal feed layout is adopted, the vertex of the tight-field reflecting surface is arranged at a position close to the aperture diagonal line, the center of the feed source and the focal point of the reflecting surface are copointed on the virtual rotation symmetry axis of the reflecting surface; the tight-field reflecting surface is a quadric surface structure, the central entity is a rotation parabolic surface part, and is used for correcting the spherical wave radiated by the feed source into a plane wave in the quiet zone; and the plane wave quiet zone is a limited three-dimensional space region which meets the requirement of far-field test after the electromagnetic wave radiated by the feed source is corrected by the reflecting surface.

Various embodiments disclose techniques for generating one or more sound zones and a quiet zone in a listening environment. The techniques include configuring one or more filters of a filter bank, generating a respective speaker signal for each of one or more speakers by processing a respective audio zone signal for each of one or more sound zones using the filter bank, and outputting the respective speaker signals using the one or more speakers. Sound output by the one or more speakers propagates through a listening environment to generate respective sound in each of the one or more sound zones corresponding to the respective audio zone signal for that sound zone. The sound output by the one or more speakers propagates through the listening environment to generate a first quiet zone.