27results about "Shielding efficiency measurement" patented technology

The invention relates to a spliced high-temperature superconducting magnetic shielding device and a combined device, which are used for at least solving the problem that a magnetic shielding device made of a soft magnetic material generates magnetic noise, and residual magnetism or magnetic noise can be reduced by at least 1-3 orders of magnitude after the spliced high-temperature superconducting magnetic shielding device and the combined device are combined with the spliced high-temperature superconducting magnetic shielding device. Comprising a spliced magnetic shielding barrel formed by splicing and enclosing a plurality of blocks, the blocks are superconductive blocks formed by sintering high-temperature superconductive powder, the splicing seams between the adjacent blocks are filled with the superconductive powder, the splicing seams between the adjacent blocks are adhered and sealed by superconductive tapes, and high-temperature superconduction means that the temperature of liquid nitrogen generating a superconductive phenomenon is greater than or equal to 77K.

The invention relates to the field of electron microscope chamber electromagnetic shielding, and provides a high-precision electron microscope chamber combined shielding method, which comprises the following steps: S1, simulating an electron microscope operation experiment environment to carry out initial state magnetic field measurement, and respectively testing direct current and alternating current magnetic field environment values; s2, adopting a low-carbon steel plate as a shielding shell, and calculating the thickness of the shielding shell based on the tested magnetic field environment value and the target value of the magnetic field environment of the electron microscope equipment; s3, after welding of the shielding shell and installation of the shielding door and the waveguide window are completed, shielding testing is carried out, reinforcing treatment is carried out on weak points and magnetic leakage points, the waveguide window comprises a magnetic waveguide tube and a hexagonal honeycomb vacuum brazing waveguide window, and the magnetic waveguide tube comprises a shell and a grating; and S4, setting an active shielding system, correcting an electron microscope experiment magnetic field environment deviation in an actual operation stage, simultaneously satisfying magnetic field and electromagnetic shielding, optimizing a waveguide window structure, and simultaneously satisfying low-frequency and high-frequency electromagnetic wave shielding.

Apparatus and associated methods relate to a bond-degradation device for testing EMI susceptibility and / or emission suppression of an electrical control system that includes a shielded cable assembly. The bond-degradation device includes a resistive annulus configured to be interposed between normally-connected first and second shielded connectors of the electrical control system. The resistive annulus introduces a resistance between shields of the normally-connected first and second shielded connectors, thereby compromising integrity of the shielding of conductive wires within the shielding of the shielded cable assembly by increasing loop resistance of the shielding.

Various devices and techniques help to reduce the entry of unwanted radio waves into an enclosure and reduce the reflection of radio waves inside the enclosure. Such devices and techniques enable a test environment inside the enclosure that provides high-quality functionality and performance testing.

A probe tip for an isolated probe having a triaxial cable has a conductive probe tip interface at one end of the cable, a signal conductor, the signal conductor traversing a length of the cable and electrically connected to the conductive probe tip interface, a reference conductor surrounding the signal conductor along the length of the cable, a shield conductor surrounding the reference conductor at least along the length of the cable, the shield conductor and the reference conductor electrically connected at ends of the probe tip, a first insulator between the signal conductor and the reference conductor along the length of the cable, a second insulator between the reference conductor and the shield conductor along the length of the cable, and high magnetic permeability material inside the shield conductor. A method of manufacturing a tip for an isolated probe having a triaxial cable includes accessing a shield conductor of the triaxial cable, inserting a high magnetic permeability material between the shield conductor and a reference conductor in the triaxial cable, electrically connecting the shield conductor to the reference conductor. A triaxial cable has a signal conductor, the signal conductor traversing a length of the cable, a reference conductor surrounding the signal conductor along the length of the cable, a shield conductor surrounding the reference conductor along the length of the cable, the shield conductor and the reference conductor electrically connected at ends of the cable, a first insulator between the signal conductor and the reference conductor along the length of the cable, a second insulator between the reference conductor and the shield conductor along the length of the cable, and high magnetic permeability material inside the shield conductor.

The invention relates to the technical field of building wall electromagnetic shielding, and particularly discloses an electromagnetic shielding method for a building wall, which comprises the following steps of: S1, determining an axis, and releasing a middle line and a side line of the wall by taking the axis as a datum line; insulating plates are laid on the floor, a keel frame is built according to the paying-off position, and the keel frame is fixedly installed on the wall and the ceiling through insulating parts; the keel frame is electrically isolated from the building main body through the insulating plate and the insulating part; s2, opening holes used for installing a shielding door and a shielding window are formed in the keel frame, and a shielding plate is installed on the ground insulation plate and the keel frame; conductive linings are arranged at connection gaps among the keel frame, the shielding plate, the shielding door and the shielding window, and the conductive linings enable the shielding structures to form a continuous conductive shielding surface.

The invention relates to a curtain (31) for shielding an electromagnetic field, comprising a plurality of strip elements (33), wherein a first strip element and a second strip element of the plurality of strip elements (33) have an electrically conductive layer (38), and wherein the electrically conductive layer (38) of the first strip element is electrically connected in a shielding configuration of the curtain (31) to the electrically conductive layer (38) of the second strip element and / or to an electrical connection for a reference potential, wherein the plurality of strip elements (33) are variably positionable relative to one another. The invention further relates to a shielded enclosure with a curtain (31) according to the invention and to a magnetic resonance system with a shielded enclosure according to the invention.

The invention relates to a Faraday cage comprising an inflatable frame (2) and a canvas (3) made of electrically conductive fabric supported by the inflatable frame (2), the canvas (3) comprising an opening portion (30) having an edge (300) detachable from the rest of the canvas (3) so as to allow the cage to be opened, said opening portion (30) comprising on one face an assembly element (302), the rest of the canvas (3) comprising on one face a complementary assembly element (312), the assembly element (302) and the complementary assembly element (312) being electrically conductive and configured to be assembled to each other so as to close the cage, the inflatable frame (2) and the canvas (3) made of electrically conductive fabric each being in one piece.

To provide an electromagnetic wave absorber evaluation device and an electromagnetic wave absorber evaluation method capable of precisely evaluating behavior of an electromagnetic wave absorber for millimeter wave band or submillimeter wave band electromagnetic waves.SOLUTION: In an electromagnetic wave absorber evaluation device 1, width (a), height (b), and length L of a casing 2 for housing a board 3 having microstrip lines 4, 5 for inputting and outputting signals, and an evaluation frequency ft obtained by the following formula (1) satisfies the following formula (2) in a frequency domain of 20GHz or higher, wherein α is expressed by the following formula (5).SELECTED DRAWING: Figure 1

The invention discloses a superconductive magnetic shielding structure based on a stepped splicing synergistic effect and a testing device thereof, and provides a composite configuration design of convex splicing and oblique splicing aiming at the technical bottlenecks of residual magnetism, concentrated magnetic flux at a seam, complex processing and the like in the existing direct splicing type superconductive magnetic shielding. The high-temperature superconducting blocks are spliced to form the large-size shielding plate, the magnetic flux density gradient of a vertical magnetic field at the seam can be effectively restrained through the synergistic effect of the two-dimensional special-shaped seam, the magnetic flux pinning effect is reduced, and the magnetic shielding performance is tested and characterized, so that compared with a linear splicing structure, the magnetic shielding performance of the large-size shielding plate is greatly improved. The residual magnetism shielding performance of the two-dimensional special-shaped seam structure in a geomagnetic field is improved by times.

The invention relates to the field of electromagnetic shielding in an electron microscope room and provides a high-precision combined shielding method for an electron microscope room. The method comprises the following steps: S1, simulating an electron microscope operating experimental environment to perform initial magnetic field measurement, and testing the values ​​of the direct current and alternating current magnetic field environments respectively; S2, using a low-carbon steel plate as a shielding shell, and calculating the thickness of the shielding shell based on the tested magnetic field environment value and a target value of the magnetic field environment of the electron microscope equipment; S3, after the shielding shell is welded and the shielding door and the waveguide window are installed, a shielding test is performed, and weak points and magnetic leakage points are reinforced, wherein the waveguide window comprises a magnetic waveguide tube and a hexagonal honeycomb vacuum brazing waveguide window, and the magnetic waveguide tube comprises a shell and a grid; S4, setting an active shielding system, correcting the deviation of the electron microscope experimental magnetic field environment in the actual operating stage, being able to simultaneously meet the requirements of magnetic field and electromagnetic shielding, optimizing the waveguide window structure, and simultaneously meeting the requirements of shielding for low-frequency and high-frequency electromagnetic waves.

This application discloses an RF shielding device and its design method for pod testing, belonging to the technical field of pod testing. The RF shielding device includes: a shielding shell with a pod interface on its side wall, through which the pod antenna radome enters the shielding shell; an absorbing layer disposed on the inner wall of the shielding shell for absorbing the RF signal output by the pod and interference signals from outside the shielding shell; a test antenna disposed within the shielding shell for receiving the RF signal; and an RF interface disposed on the side wall of the shielding shell, connected to the test antenna for connecting to pod testing equipment. Compared to traditional anechoic chambers, this provides a convenient and safe radiation testing environment for pods, thus reducing the difficulty of pod radiation testing.

A telematics verification system for testing vehicle telematics systems includes: a conductive ground plane adapted to be positioned under the vehicle when testing the vehicle telematics system using the telematics verification system; a conductive cover adapted to be positioned on the outer surface of the vehicle and above and around the vehicle antenna when testing the vehicle telematics system using the telematics verification system; a downlink antenna adapted to be arranged inside the conductive cover, wherein the downlink antenna is configured to wirelessly transmit downlink signals within the conductive cover, wherein the downlink signals are wirelessly receivable by the vehicle antenna; and an uplink antenna adapted to be arranged inside the conductive cover, wherein the uplink antenna is configured to wirelessly receive uplink signals within the conductive cover, wherein the uplink signals are wirelessly receivable by the vehicle antenna.

The invention discloses a shielding cable shielding effectiveness optimization method, which comprises the following steps: acquiring cable parameters, and establishing a three-dimensional geometric solid model of a high-voltage shielding cable based on the cable parameters; bending-deformation coupling modeling is carried out according to the three-dimensional geometric solid model, and deformation parameters are obtained through calculation; wherein the deformation parameter represents the microscopic geometric change of the shielding layer; evaluating the shielding effectiveness of the cable based on the deformation parameters; comparing the shielding effectiveness with a preset threshold value to determine a shielding effectiveness unqualified point; and optimizing the unqualified points of the shielding effectiveness. According to the method, the three-dimensional geometric solid model and the bending-deformation coupling model are established, the microstructure change of the shielding layer caused by deformation is obtained, and quantitative evaluation of the shielding effectiveness is realized based on electromagnetic simulation, so that unqualified points of the shielding effectiveness are optimized; the problem of shielding effectiveness attenuation caused by mechanical deformation in practical application can be effectively analyzed, and evaluation accuracy and optimization efficiency are improved.

An electromagnetic wave absorber evaluation apparatus including: a housing in which the electromagnetic wave absorber is allowed to be arranged, the housing being made of a conductive material with inner dimensions of a width a, a height b, and a length L, as b<a<L; a substrate arranged inside the housing; an input microstrip line and an output microstrip line formed on the substrate along a length direction of the housing and separated from each other in the length direction; and a signal inspecting unit capable of inputting an input signal having a frequency of 20 GHz or more into the input microstrip line and detecting an output signal output through the output microstrip line, in which an evaluation frequency ft obtained by the Formula (1) satisfies the Formula (2) in a frequency region of 20 GHz or more.

The present invention discloses a shielded insulated sliding door, comprising a door frame and multi-layer door leaves installed in the door frame in layers, wherein two adjacent layers of door leaves are spaced and insulated from each other, an insulating layer, a protective layer and a shielding layer are arranged in sequence from bottom to top under each layer of door leaves, and the shielding layers corresponding to each layer of door leaves are insulated from each other, and a driving device for driving the door leaves to move in and out of the door frame is arranged above each layer of door leaves. In order to achieve the effect of multi-layer shielding, insulation treatment is performed between the shielding layers to prevent coupling between the shielding layers from destroying the effect of electromagnetic wave reflection attenuation. By arranging multi-layer door leaves, arranging insulation between adjacent door leaves, and ensuring the insulation of the underground portion of the door frame through the insulating layer and the shielding layer, the shielding efficiency is improved, and multi-layer electromagnetic shielding in a true sense is achieved.

A shield enclosure includes a housing with a peripheral wall that defines a cavity, and a cover removably coupleable to the housing to at least partially seal the cavity. The cavity is sized to receive a printed circuit board therein. The housing shields the printed circuit board from electromagnetic interference and noise during noise figure testing of a radiofrequency component on the printed circuit board.

The invention relates to a curtain (31) for shielding an electromagnetic field, comprising a plurality of strip elements (33), wherein a first strip element and a second strip element of the plurality of strip elements (33) have an electrically conductive layer (38), and wherein the electrically conductive layer (38) of the first strip element is electrically connected in a shielding configuration of the curtain (31) to the electrically conductive layer (38) of the second strip element and / or to an electrical connection for a reference potential, wherein the plurality of strip elements (33) are variably positionable relative to one another. The invention further relates to a shielded enclosure with a curtain (31) according to the invention and to a magnetic resonance system with a shielded enclosure according to the invention.

The invention relates to a Faraday cage comprising an inflatable frame (2) and a canvas (3) made of electrically conductive fabric supported by the inflatable frame (2), the canvas (3) comprising an opening portion (30) having an edge (300) detachable from the rest of the canvas (3) so as to allow the cage to be opened, said opening portion (30) comprising on one face an assembly element (302), the rest of the canvas (3) comprising on one face a complementary assembly element (312), the assembly element (302) and the complementary assembly element (312) being electrically conductive and configured to be assembled to each other so as to close the cage, the inflatable frame (2) and the canvas (3) made of electrically conductive fabric each being a single piece. Figure for the abstract: Fig. 1.

A spliced high-temperature superconducting magnetic shielding device and a combined device, which at least solve the problem of self-generated magnetic noise that cannot be solved by a magnetic shielding device made of soft magnetic materials. After combining with the spliced superconducting magnetic shielding, the residual magnetism or magnetic noise can be reduced by at least 1-3 orders of magnitude. It is characterized in that it includes a spliced magnetic shielding barrel formed by splicing and enclosing several blocks. The blocks are superconducting blocks sintered from high-temperature superconducting powder. Superconducting powder is filled in the splicing seams between adjacent blocks, and the splicing seams between adjacent blocks are sealed with superconducting tape. High-temperature superconductivity means that the liquid nitrogen temperature at which the superconducting phenomenon occurs is ≥77K.

The invention provides a gradient magnetic field testing method and device for a magnetic shielding barrel. The gradient magnetic field testing device comprises a magnetic gradient testing unit, a supporting assembly and a connecting rod. An atom magnetometer can be nested in the magnetic gradient test unit to form a single magnetic field test unit. A plurality of magnetic gradient test units can be combined through the connecting rods to form a magnetic field gradient test array to adapt to the space in the shielding barrel. The magnetic field gradient test array can be connected with the supporting assembly, so that the magnetic field gradient test array is fixed in the shielding barrel and has mobility, and magnetic field distribution in the shielding barrel can be completely tested. According to the technical scheme, the technical problems that in the prior art, a visual large-range magnetic field imaging device is lacked, actual magnetic field gradient testing and compensation are lacked for a magnetic shielding barrel which is actually produced, processed and manufactured, and the space gradient in the magnetic shielding barrel can serve as an error term to be introduced into a magnetometer testing result are solved.

An electromagnetic wave absorbing composite sheet comprising an electromagnetic wave absorbing film (1) and an electromagnetic wave shielding film (2) laminated on the electromagnetic wave absorbing film (1); wherein the electromagnetic wave absorbing film (1) has a single- or multi-layered thin metal film (12) formed on a surface of a plastic film (11), the thin metal film (12) being provided in a large number (plurality) of substantially parallel, intermittent, linear scratches (13a, 13b) with irregular widths and intervals in multiple directions; characterized in that an area ratio of the electromagnetic wave shielding film (2) to the electromagnetic wave absorbing film (1) is 10-80%.

A shield enclosure includes a housing with a peripheral wall that defines a cavity, and a cover removably coupleable to the housing to at least partially seal the cavity. The cavity is sized to receive a printed circuit board therein. The housing shields the printed circuit board from electromagnetic interference and noise during noise figure testing of a radiofrequency component on the printed circuit board.

The invention relates to a curtain (31) for shielding an electromagnetic field, comprising a plurality of strip elements (33), wherein a first strip element and a second strip element of the plurality of strip elements (33) have an electrically conductive layer (38), and wherein the electrically conductive layer (38) of the first strip element is electrically connected in a shielding configuration of the curtain (31) to the electrically conductive layer (38) of the second strip element and / or to an electrical connection for a reference potential, wherein the plurality of strip elements (33) are variably positionable relative to one another. The invention further relates to a shielded enclosure with a curtain (31) according to the invention and to a magnetic resonance system with a shielded enclosure according to the invention.

Various devices and techniques help to reduce the entry of unwanted radio waves into an enclosure and reduce the reflection of radio waves inside the enclosure. Such devices and techniques enable a test environment inside the enclosure that provides high-quality functionality and performance testing.

The embodiment of the invention provides a wave absorbing device, application thereof and a loading capacity determination method, and belongs to the technical field of communication. The wave-absorbing device comprises a container and a wave-absorbing material accommodated in the container, the wave-absorbing material comprises water and an ionic electrolyte, and the ionic electrolyte is dissolved in the water; the container is a non-metal container. The wave-absorbing material in the form of the aqueous solution of the ionic electrolyte can convert electromagnetic energy into kinetic energy, and then the kinetic energy is converted into heat energy through friction and dissipated to the outside, so that the field intensity in the closed electromagnetic total reflection environment is reduced, the power density of the surface of the PIM source in the closed electromagnetic total reflection environment is reduced, and the power density of the PIM source is improved. Therefore, the self-excited PIM power of the closed electromagnetic total reflection environment is reduced.

The application relates to an electrostatic discharge pulse suppression device for electromagnetic compatibility detection, which comprises a shielding packaging shell, an electrostatic discharge pulse suppression circuit board in the shielding packaging shell, and an A port and a B port at two ends of the shielding packaging shell, wherein the A port and the B port each comprise a 2-wire port, an 8-wire Ethernet port and a vehicle-mounted Ethernet port which are connected with each other, an A-end overvoltage protection unit, an A-end first-stage pulse suppression unit, an A-end second-stage pulse suppression unit, an A-end filtering decoupling unit, a B-end filtering decoupling unit, a B-end second-stage pulse suppression unit, a B-end first-stage pulse suppression unit and a B-end overvoltage protection unit are sequentially connected on the electrostatic discharge pulse suppression circuit board, the A port is an input end of the A-end overvoltage protection unit, the B port is an input end of the B-end overvoltage protection unit, and the shielding packaging shell is grounded. The electrostatic discharge pulse suppression process can be realized while the communication connection is not interrupted; the port versatility is high, and the applicability of the electromagnetic compatibility test is greatly improved.