Abstract: Provided is an electromagnetic field simulation method based on a face-centered cubic and a subgrid, including setting periodic boundary conditions and a metal plate to construct an electromagnetic field simulation model based on the face-centered cubic, FDTD and the subgrid; through the electromagnetic field simulation model, setting the source point in the subgrid region, selecting the detecting point, simulating the electromagnetic field simulated, and obtaining the moment domain waveform diagram of the electric field in the simulation region.

Abstract: The present disclosure belongs to the technical field of three-dimensional packaging, and in particular relates to a bonding method for a copper-copper metal. The bonding method includes: subjecting a copper-plated surface of a clean copper-plated substrate to pretreatment with hydrazine hydrate under a protective atmosphere, to obtain a copper-plated substrate to be bonded, where the copper-plated surface is kept at 50° C. to 90° C.; and subjecting a plurality of the copper-plated substrates to be bonded to pressurized bonding at 200° ° C. to 300° ° C. under the protective atmosphere.

Abstract: A contextual visual-based synthetic-aperture radar (SAR) target detection method and apparatus, and a storage medium, belonging to the field of target detection is described. The method includes: obtaining an SAR image; and inputting the SAR image into a target detection model, and positioning and recognizing a target in the SAR image by using the target detection model, to obtain a detection result. In the present disclosure, a two-way multi-scale connection operation is enhanced through top-down and bottom-up attention, to guide learning of dynamic attention matrices and enhance feature interaction under different resolutions. The model can extract the multi-scale target feature information with higher accuracy, for bounding box regression and classification, to suppress interfering background information, thereby enhancing the visual expressiveness.

Abstract: The present disclosure belongs to the technical field of OAM antennas, and provides a frequency re-configurable OAM antenna in S band and a frequency reconfiguration method. The OAM antenna includes a lower dielectric substrate and multiple array units. Each array unit includes a metal patch, an upper dielectric substrate, an outer loop, an inner loop, a coaxial feeder, four metal probes, and four diodes. In the present disclosure, bias states of all the diodes of each array unit are controlled by applying a voltage; when all the diodes are in forward bias states, the antenna works at a high frequency; and when all the diodes are in reverse bias states, the antenna works at a low frequency. The frequency re-configurable OAM antenna in S band in the present disclosure has features of frequency reconfiguration and two OAM radiation modes, and has a stable gain over a broadband.

Abstract: The present disclosure provides a synthetic aperture radar (SAR) image target detection method. The present disclosure takes the anchor-free target detection algorithm YOLOX as the basic framework, reconstructs the backbone feature extraction network from the lightweight perspective, and replaces the depthwise separable convolution in MobilenetV2 with one ordinary convolution and one depthwise separable convolution. The number of channels in the feature map is reduced by half through the ordinary convolution, features input from the ordinary convolution are further extracted by the depthwise separable convolution, and the convolutional results from the two convolutions are spliced. The present disclosure highlights the unique strong scattering characteristic of the SAR target through the attention enhancement pyramid attention network (CSEMPAN) by integrating channels and spatial attention mechanisms.

Abstract: A method for processing anisotropic magnetized plasma medium and a system thereof are provided. The method includes obtaining the Maxwell equation and the polarization current density equation based on the electromagnetic characteristics of anisotropic magnetized plasma; processing the Maxwell equation and the polarization current density equation to obtain the electric field intensity, the magnetic field intensity, and the polarization current density after processed; based on the electric field intensity, the magnetic field intensity, and the polarization current density after processed, numerical iterative equations for electric field intensity, magnetic field intensity, and polarization current density in anisotropic magnetized plasma medium are obtained; a numerical modeling simulation electromagnetic model is used to determine the electromagnetic characteristics of the electromagnetic model.

Abstract: The present disclosure relates to a domain decomposition method and system for electromagnetic simulation. The method includes: dividing an antenna structure model into multiple subdomains, where each of the subdomains corresponds to a structure in one to-be-simulated array antenna; subdividing each of the subdomains by a tetrahedral network to obtain multiple tetrahedrons; obtaining a vector basis function of each edge of each of the tetrahedrons according to vertex positions and lengths of the edges of the tetrahedron; and calculating an electric field value and a magnetic field value of any point in a tetrahedron to which each of the edges belongs using a vector basis function corresponding to the edge and a double curl electric field wave equation of a subdomain to which the edge belongs.

Abstract: A method for diagnosing an internal loss mechanism of a solar cell is provided. The solar cell includes an anode and a cathode. An electron transport layer, an active layer and a hole transport layer are arranged in sequence from top to bottom between the cathode and the anode. The solar cell is modeled through a solar cell multi-physics simulation platform. Current density-voltage (JV) curves respectively of type A, type B, type C and type D are simulated by regulating a bulk defect and a surface defect of the active layer and a voltage scan rate. The solar cell is subjected to forward voltage scan and reverse voltage scan to obtain forward and reverse JV curves. According to the forward and reverse JV curves, whether the JV curve type of the solar cell is the type A, the type B, the type C or the type D is determined.

Abstract: A grounding spring and an electronic device. The grounding spring is applied to an electronic device. The electronic device includes a camera assembly, a camera bracket configured to mount the camera assembly, and a main board. The main board has a grounding area. The grounding spring includes a body part and a grounding part. The grounding part is located on one side of the body part and is fixedly connected to the body part. A side that is of the body part and that is away from the grounding part is bent in a direction close to the grounding part to form a first bending part, and a side that is of the first bending part and that is close to the grounding part is bent in a direction away from the grounding part to form a second bending part.

Abstract: An ultra-wideband electromagnetic band gap (EBG) structure includes multiple EBG units in an array. Each EBG unit includes a power plane, a dielectric substrate and a ground plane from top to bottom. The power plane includes a patch, a coupled complementary split ring resonator (C-CSRR) and a plurality of semi-improved Z-bridge structures. Each edge of the patch is provided with a semi-improved Z-bridge structure. The C-CSRR is provided within a ring formed by the semi-improved Z-bridge structures. The Z-bridge structure includes a first horizontal branch, a first vertical branch, a second horizontal branch and a second vertical branch connected in sequence. The second vertical branch is connected to the patch. First horizontal branches of adjacent EBG units are connected to each other. A circuit board including the aforementioned EBG structure is also provided.

Abstract: Disclosed are a broadband millimeter-wave circularly polarized antenna element, a single-mode array, and a dual-mode array, relating to the technical field of circularly polarized antennas. A microstrip feeder is arranged on a lower surface of a second dielectric substrate of the antenna element. A coupling slot is etched on a metal ground layer, two metallized vias are formed on a first dielectric substrate, and a metal strip is tiled on an upper surface of the first dielectric substrate. Two L-shaped parasitic patches are also tiled on the first dielectric substrate. The two L-shaped parasitic patches are located on both sides of the metal strip, and the two L-shaped parasitic patches are rotationally symmetric about a center point of the upper surface of the first dielectric substrate. According to the present disclosure, a 3-dB axial ratio bandwidth of the antenna element is improved by using L-shaped parasitic patches.

Abstract: Bidirectional circularly polarized antenna element and bidirectional circularly polarized array antenna are provided, and comprising a dielectric substrate, a feeder, a radiation patch, a first plane, a second plane, a first coupling assembly and a second coupling assembly which are embedded in the surface of the dielectric substrate. The first plane and the second plane of the antenna element are kept at different heights, and compared with the solution that two planes at the same height can only generate linear polarization radiation in the prior art, the circular polarization radiation can be generated, which solves the problem of linear polarization mismatch. Furthermore, two coupling assemblies are introduced into two sides of the radiation patch to enable the coupling effect with the radiation patch, such that the frequency bandwidth of the circularly polarized antenna can be greatly improved without increasing the size of the antenna.

Abstract: A silicon-on-insulator metal-oxide-semiconductor field-effect transistor (SOI MOSFET) structure is provided, including a substrate layer; a buried oxide layer which is arranged on an upper surface of the substrate layer and is made of SiO2; an active zone which is arranged on an upper surface of the buried oxide layer; a source electrode and a drain electrode which are arranged on an upper surface of the active zone; a gate dielectric layer which is arranged between the source electrode and the drain electrode; a gate electrode which is provided in the gate dielectric layer; and a heat conduction column which penetrates through the buried oxide layer, and its top wall is in contact with the active zone. The heat conduction column dissipates heat in the active zone, resulting in a lattice temperature of the active zone will not increase extremely and avoiding a decrease of a current of the drain electrode.

Abstract: A silicon-on-insulator metal-oxide-semiconductor field-effect transistor (SOI MOSFET) structure is provided, including a substrate layer; a buried oxide layer which is arranged on an upper surface of the substrate layer and is made of SiO2; an active zone which is arranged on an upper surface of the buried oxide layer; a source electrode and a drain electrode which are arranged on an upper surface of the active zone; a gate dielectric layer which is arranged between the source electrode and the drain electrode; a gate electrode which is provided in the gate dielectric layer; and a heat conduction column which penetrates through the buried oxide layer, and its top wall is in contact with the active zone. The heat conduction column dissipates heat in the active zone, resulting in a lattice temperature of the active zone will not increase extremely and avoiding a decrease of a current of the drain electrode.

Abstract: The present disclosure belongs to the technical field of three-dimensional packaging, and in particular relates to a bonding method for a copper-copper metal. The bonding method includes: subjecting a copper-plated surface of a clean copper-plated substrate to pretreatment with hydrazine hydrate under a protective atmosphere, to obtain a copper-plated substrate to be bonded, where the copper-plated surface is kept at 50° C. to 90° C.; and subjecting a plurality of the copper-plated substrates to be bonded to pressurized bonding at 200° ° C. to 300° ° C. under the protective atmosphere.

Abstract: The present disclosure relates to a domain decomposition method and system for electromagnetic simulation. The method includes: dividing an antenna structure model into multiple subdomains, where each of the subdomains corresponds to a structure in one to-be-simulated array antenna; subdividing each of the subdomains by a tetrahedral network to obtain multiple tetrahedrons; obtaining a vector basis function of each edge of each of the tetrahedrons according to vertex positions and lengths of the edges of the tetrahedron; and calculating an electric field value and a magnetic field value of any point in a tetrahedron to which each of the edges belongs using a vector basis function corresponding to the edge and a double curl electric field wave equation of a subdomain to which the edge belongs.

Abstract: The present disclosure relates to a high-speed and low-power successive approximation register analog-to-digital converter (SAR ADC) and an analog-to-digital conversion method. Binary redundancy reassembly is performed to improve a digital-to-analog converter (DAC) capacitor array included in the SAR ADC such that the total number of capacitors included in a capacitor sub-array of the DAC capacitor array is greater than the number of precision bits of the SAR ADC, and the total number of unit capacitors included in all capacitors when the total number of capacitors included in the capacitor sub-array is greater than the number of precision bits of the SAR ADC is equal to the total number of unit capacitors included in all capacitors when the total number of capacitors included in the capacitor sub-array is equal to the number of precision bits of the SAR ADC.

Abstract: The present disclosure provides a dual-mode orbital angular momentum (OAM) convergence base cell array and metasurface preparation method. The base cell array includes 2n(2n?1) anisotropic cell structures and 2n isotropic cell structures. Each of the anisotropic cell structures includes a bottom ground layer, a dielectric substrate layer and a top pattern layer which are disposed in sequence from bottom to top, where each top pattern layer has an axisymmetric H-shaped structure. Each of the isotropic cell structures includes a bottom ground layer, a dielectric substrate layer and a top pattern layer which are disposed in sequence from bottom to top, where each top pattern layer has a square structure.

Abstract: An ultra-wideband electromagnetic band gap (EBG) structure includes multiple EBG units in an array. Each EBG unit includes a power plane, a dielectric substrate and a ground plane from top to bottom. The power plane includes a patch, a coupled complementary split ring resonator (C-CSRR) and a plurality of semi-improved Z-bridge structures. Each edge of the patch is provided with a semi-improved Z-bridge structure. The C-CSRR is provided within a ring formed by the semi-improved Z-bridge structures. The Z-bridge structure includes a first horizontal branch, a first vertical branch, a second horizontal branch and a second vertical branch connected in sequence. The second vertical branch is connected to the patch. First horizontal branches of adjacent EBG units are connected to each other. A circuit board including the aforementioned EBG structure is also provided.

Abstract: A broadband fifth-generation (5G) circularly polarized filtering antenna includes a reflecting plate, a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a fourth dielectric substrate, a feed line with a phase adjustment function print on one surface of the first dielectric substrate, a ground with a chair-like groove on an other surface of the first dielectric substrate, a first rectangular radiating unit, a second rectangular radiating unit, a first metal transmission strip group and a second metal transmission strip group.