599 results about "Anechoic chamber" patented technology

A system and method for audio telepresence. The system includes a user station and a telepresence unit. The telepresence unit includes a directional microphone for capturing sounds at the remote location, and means for converting the captured sounds into a stream of data to be communicated to the user station. The user station includes means for receiving the stream of data and a plurality of speakers for recreating the sounds of the remote location. The user station and the speakers are located within an anechoic chamber where sound reflections are substantially absorbed by anechoic linings of the chamber walls. Because of the substantial lack of sound reflection within the anechoic chamber, a user within the anechoic chamber will be able to experience an aural ambience that closely resembles the sounds captured at the remote location. The user station may include microphones for capturing the user's voice, and the telepresence unit may include speakers for projecting the user's voice at the remote location. Feedback suppression, audio direction steering, and head-coding techniques may also be used to enhance the user's sense of remote presence.

The present invention provides a system and method for multi-path simulation that employs a shielded anechoic chamber to avoid external electromagnetic interference and other uncontrollable transmission paths during testing, and simulates a main indirect transmission path by a reflector within the chamber. An attenuating device is used to attenuate signals, thereby simulating the signal attenuation during transmission. The shielded anechoic chamber also includes a movable platform and a turntable, both controlled by a control unit, for carrying a dipole antenna and a wireless communication device to be tested respectively. The movable platform is used to shift the antenna, thereby simulating the phase shift between a direct path and a main indirect path of the system; the turntable is used to change the reception azimuth of the communication device, thereby measuring the performance of the device in various azimuth angles.

The present invention relates to testing a mobile device in a lab by providing test signals to the mobile device via a cabled connection which bypasses the actual physical antennas in the mobile device. The test signals emulate a wireless channel and incorporate representative and/or actual measured characteristics of the performance of the antennas in the mobile device. As such, the performance mobile device can be accurately measured without requiring placement in an anechoic chamber, which enables efficient testing over a large set of configurations and underlying conditions.

The present invention provides a batch testing system and method that applies a single shielded anechoic chamber to simultaneously test multiple wireless communication devices. The shielded anechoic chamber can avoid external electromagnetic interference, reduce strength of reflected signals significantly and provide stable channel environment, thereby testing signal transceiving of the wireless communication devices more precisely. The present invention also provides a design for the batch container and loading mechanism within the chamber.

The present invention provides a system and method for multi-path simulation that employs a shielded anechoic chamber to avoid external electromagnetic interference and other uncontrollable transmission paths generated in testing, and divides and adjusts a signal into multiple simulation signals to simulate the attenuations and delays generated in multi-path transmission of the signals. The shielded anechoic chamber includes a turntable, controlled by a control unit, for carrying a wireless communication device to be tested and for changing the reception azimuth of the device, thereby measuring the electric wave transceiving of the device.

The invention provides a wireless terminal antenna performance testing system which comprises an anechoic chamber, a power detector and a digital analog converter, wherein the anechoic chamber comprises a shielding box, a wave absorbing material mounted on the inner wall of the shielding box as well as measuring antennas; the power detector is connected with the measuring antennas. According to the wireless terminal antenna performance testing system provided by the embodiment of the invention, by means of the power detector and the digital analog converter, a task for converting a radio-frequency signal into direct read data, namely, a digital signal can be finished; a special measuring instrument is omitted, a comprehensive measuring instrument is not required to participate in the whole process, and the configuration cost of the testing system is reduced; meanwhile, the antenna performance is accurately tested under the shielding condition in a non-signaling mode, the waiting time for connection establishing between the measuring instrument and a to-be-measured wireless terminal is saved, outside electromagnetic interference is reduced, the testing efficiency and the accuracy are improved, and the system is particularly applicable to testing of the antennas of a wireless terminal.

A sound attenuating cover for a scroll compressor is provided. The cover has a base member configured to support the compressor, the base defines a first chamber filled with a sound attenuating material. The sound attenuating chamber further has a cover member configured to cover the compressor and couple to the base, said cover member defines another chamber. This chamber is additionally filled with a sound attenuating material.

The invention relates to a method for calibrating a high-frequency electric field probe, which comprises an anechoic chamber, an electromagnetic interference (EMI) filter, a radiofrequency signal generator, a power amplifier, a transmitting antenna, a vertical and horizontal polarization or isotropic field intensity monitoring antenna, and auxiliary equipment used for recording power level. The method comprises the following steps of: sending an electromagnetic field with specific amplitude and specific frequency through the radiofrequency signal generator in the anechoic chamber used for shielding an electromagnetic field, arranging a probe to be calibrated and the auxiliary equipment according to a certain mode, and realizing the calibration for the high-frequency electric field probe by comparing a produced field value and the reading of the electric field probe to be calibrated.

Belonging to the technical field of high polymer materials, the invention relates to a thermoplastic resin prepreg tape and preparation method thereof. The thermoplastic resin prepreg tape comprises the following components by weight: 30-80% of thermoplastic resin; 10-60% of a fiber; 0.5-3% of a compatilizer; 0.2-0.5% of an antioxidant; 0.3-2% of a lubricant; and 1-40% of a wave-absorbing material. In the invention, mainly the wave-absorbing material is added to the prepreg tape so as to make the continuous fiber reinforced thermoplastic resin prepreg tape have a wave-absorbing property. The continuous fiber reinforced thermoplastic resin prepreg tape has high strength and a wave-absorbing property at the same time, and can be applied to anechoic chambers, microwave communication, electronic equipment, medical equipment and other fields, thus enhancing product competitiveness and expanding application scope.

The invention discloses a testing method for the shielding effectiveness of a small-size shielding cavity. The testing method is characterized in that a shielding anechoic chamber and a shielding chamber are two cavities formed by separation through a metal wall plate; a wave absorbing material is arranged on the wall surface of the shielding anechoic chamber; the shielding anechoic chamber and the shielding chamber are independently grounded; a receiver is arranged in the shielding chamber; other devices are arranged in the shielding anechoic chamber; a bidirectional radio frequency connector is arranged on the wall surface of the metal wall plate; a near-field test antenna is arranged in the shielding anechoic chamber and is sequentially conducted with the bidirectional radio frequency connector and the receiver which are arranged on the wall surface of the metal wall plate through a coaxial cable; a transmitting antenna is sequentially conducted with a pre-amplifier and a signal source through a coaxial cable; the transmitting antenna, the pre-amplifier and the signal source are arranged in the shielding chamber; the center of the transmitting antenna corresponds to the center of the near-field test antenna; and the testing method is realized by three steps of measuring a direct-connection receiving value and a radio frequency leakage quantity and calculating the shielding effectiveness. The testing method is simple and accurate.

A measurement apparatus includes an anechoic chamber, a DUT board, rotation units, and a feeding arm. The anechoic chamber has inner-walls. Each inner-wall is covered with a radio wave absorber. One of the inner-wall is a first wall with an aperture and the other inner-walls are second walls. The DUT board holds a first antenna to be measured with radiation property and a probe to detect a signal from the first antenna. A part of the DUT board is inserted into the anechoic chamber through the aperture opened in the first wall. One end of the feeding arm holds a second antenna radiating a radio wave to the first antenna in the anechoic chamber. Each rotation unit provides on each second wall and is selectively attached to the other end of the feeding arm for rotating the second antenna and for feeding to the second antenna.

This disclosure claims antenna testing system, including a signal transmission simulator, a channel emulator and an anechoic chamber; more than two antennae are set in the anechoic chamber; each antenna is connected with the signal transmission simulator through the channel emulator; the more than two antennae are located on the sphere which center is the position of the device under test. This disclosure claims an antenna testing method, comprising: more than one channel model for test is set in the signal transmission simulator; a channel model is selected from the more than one channel model; wireless signals are transmitted according to the selected channel model; after emulation processed by channel emulator, emulated wireless signals are transmitted through the antennae in anechoic chamber; DUT set in the anechoic chamber receives and then processes the signals transmitted from each antenna, and outputs the processing results.

Configuring an adaptive microphone array to gather signals from a main lobe of the array, and configuring the array to reduce side interference gathered from sources that are not situated within the main lobe. A memory stores test signals gathered by the array at a plurality of predetermined angular bearings with reference to the array in an anechoic chamber. Signals gathered in real time are processed to provide a preliminary output and preliminary weights. The test signals are retrieved from memory. The preliminary weights are applied to the test signals to provide null steering weights. The null steering weights and the preliminary output are processed to reduce or minimize the amplitude response of the array at the angular orientation.

The invention discloses a multilayer sound-absorption wedge having a resonance sound absorption structure. The multilayer sound-absorption wedge comprises a wedge body and a rigid base, wherein the wedge body is in a three-layer sound absorption structure and comprises sequentially an impedance matching layer, a sound dissipation layer and a hole penetrating plate from top to bottom, a hollow cavity is formed between the hole penetrating plate and the rigid base, and the hole penetrating plate, the hollow cavity and the rigid base form the resonance sound absorption structure. The multilayer sound-absorption wedge having the resonance sound absorption structure combines two impedance gradual changing principals that the sectional area of the wedge changes from being small to being large, and the characteristic impedance of a multilayer sound absorption structure of a multilayer sound-absorption material changes from being small to being large gradually, so that the limit that the total length of the sound absorption wedge is a quarter of the cut-off frequency wedge wavelength is broken through, low cut-off frequency is guaranteed, simultaneously, length, space volume and quality of the sound absorption wedge are reduced remarkably and the cost of construction of an anechoic chamber is saved, besides, the sound-absorption wedge is provided with the resonance sound absorption structure, the low-frequency characteristic of the sound-absorption wedge is improved remarkably, the sound-absorption wedge can be designed in accordance with different sound source characteristics, and the flexibility of design is improved.

Small anechoic chambers for evaluating a wireless device under test (DUT) are characterized by a set of antennas to which a test signal is applied and for which excitation coefficients are applied such that the test signal approximates a single plane wave or a preselected superposition of plane waves in the near field of the antennas. The test-equipment antennas in the chamber may be as close as one wavelength from the boundary of a test zone in which the DUT is disposed. Hence, the test zone can be in the near field of the test-equipment antennas and the test zone can be less than a wavelength from the chamber walls. Consequently, it is possible to perform tests in a small anechoic chamber that previously required a large anechoic chamber, e.g., advanced spatial channel-model tests and antenna-pattern measurements.

A method and system for the wireless terminal receiving sensitivity performance test based on a data mode are provided. The method comprises: building a human body model, in which the upper limb of the model holds the device under test at a predefined distance in front of the head of the model; taking the antenna of the device under test as the origin to build a spherical coordinate and selecting a testing point in the spherical coordinate; placing the model under the circumstance of a full-anechoic chamber; enabling the device under test to work in a data mode, and collecting the receiving power at the testing point in the spherical placement system using the testing antenna, so as to obtain the total power receiving sensitivity of the device under test. In this way, the performance influence on the mobile terminal from the human body coupling of the human being in a data mode can be actually reflected, the reality is high and the usage is easy.

Disclosed, in general, are devices that provide a substantially sound-tight chamber over a sound source while absorbing fields of sounds from the sound source. In general, the devices feature: an anechoic chamber that is configured to receive a sound source in a substantially sound-tight manner; and an anechoic channel that is in fluid communication with the ambient atmosphere. The anechoic chamber is adapted to capture air containing sound energy generated by the sound source, and distribute the air about an internal surface area on the inside of the chamber, wherein the internal surface area is sufficiently large to dampen or otherwise absorb the sound energy. Preferably, the air is directed from the anechoic chamber through an anechoic channel extending therefrom to the ambient to further dampen or absorb the sound energy. In one configuration, the outer wall of the apparatus is configured to reflect ambient sounds.

The invention provides an EMC (Electro Magnetic Compatibility) test method of a deep space aircraft coupling. The method comprises the following steps of: turning off power of each detector consisting of the aircraft coupling, calibrating EMC test equipment, and testing the background noise of an anechoic chamber; carrying out the electromagnetic radiation and sensitivity test on each detector; analyzing test data of each detector; determining the suppression condition of mutual interference between detectors of the aircraft coupling; and carrying out the EMC test on the aircraft coupling. For the source of electromagnetic interference, by adopting a test method from the point to the surface, the EMC characteristics of the deep space aircraft couplings can be quickly, reliably and safely detected, the source of electromagnetic interference is determined, the electromagnetic interference and the failure are safely and reliably detected, and the EMC test efficiency of the deep space aircraft coupling is improved.

A testing system optimizes a cost function of a theoretical spatial cross correlation and a spatial correlation obtained with antenna elements for determining weights of the antenna elements, and forms a beam of a signal of at least one path of a simulated radio channel with at least two antenna elements of a plurality of antenna elements coupled to an emulator in an anechoic chamber. The at least two antenna elements are capable of polarizing the beam in a known manner.

The invention provides an electromagnetic compatibility immunity test system used for a key-free system. The system comprises a key signal transmitting device whose key signal transmitting antenna is arranged inside an anechoic chamber, so as to transmit a key signal to a key-free system to be tested which is arranged inside the anechoic chamber, and operation is carried out according to the key signal when the key signal received by the key-free system to be tested is a required working signal. In addition, the test system in the invention also comprises an anti-interference test system whose test signal transmitting antenna is arranged inside an anechoic chamber, so as to transmit test signals that interfere with work of the key-free system to be tested inside the anechoic chamber, and a test signal band elimination filter is arranged in the anti-interference test system and used for filtering from the test signals those within a band elimination frequency band corresponding to the frequency of a working signal, so as to eliminate influence of the test signals on the key signal, thereby enabling a test result to be relatively accurate.