73 results about "Electromagnetic Compatibility Problem" patented technology

The invention discloses a fast electromagnetic compatibility test and diagnosis system with quantization electromagnetic interference. A receiving antenna of the system is arranged on a frequency spectrum tester, a chuck end of a current probe is clamped on a cable through which tested objects are connected, the other end of the current probe is connected on the frequency spectrum tester which is connected with a computer; and the computer is internally provided with a fast electromagnetic compatibility test and diagnosis unit. The fast electromagnetic compatibility test and diagnosis unit is used for fast testing the electromagnetic-transmitted frequency spectrum of the tested objected on site, conducting analysis and diagnosis to the electromagnetic-transmitted frequency spectrum, and judging whether the electromagnetic transmission characteristic exceeds a standard limit value or has abnormality. The fast electromagnetic compatibility test and diagnosis system has important meaning on solving the electromagnetic compatibility problem and monitoring and evaluating the electromagnetic environment.

The invention provides an electromagnetic compatibility emission test method, which adopts standard measurement bandwidth to improve measurement bandwidth before an emission test to confirm that the invention can process prior measurement when the lowest noise of an EMI receiver is not higher than a standard limit value and the invention can compare the curve lines of the measurement result and the limit value to find a corresponding electromagnetic compatibility problem. The invention adopts the standard measurement bandwidth for the frequency range exceeded the limit value, to improve the test sped of the whole electromagnetic compatibility, save test time, and accurately and quantitatively determine the test result for the emission test on a sample.

The invention provides an electromagnetic anti-interference performance test system and method for an intelligent networked automobile. The system comprises a networked system part, an intelligent system part and / or an electromagnetic disturbance part. The networked system part activates a automobile-mounted V2X module and a navigation module respectively through a communication comprehensive tester and a satellite signal generator, a data collector collects the automobile networked system data, and the intelligent system part simulates a road scene through a radar target simulator and a videoplaying device and activates an automobile-mounted millimeter wave radar and an ADAS camera separately. A test device for activating the intelligent networked system needs to simulate the same road scene and synchronize in real time. According to the invention, the electromagnetic anti-interference performance of the whole automobile is tested in an anechoic chamber in a single automobile intelligence and Internet of automobiles technology fusion scheme, and the electromagnetic compatibility problem existing in the system is discovered at the research and development stage of the intelligentnetworked automobile, so that the functional safety of the automobile is improved, and the automatic driving performance of the automobile is improved.

The invention discloses a method for solving the electromagnetic compatibility problem of an antenna of a minitype terminal mobile phone. A monopole antenna is adopted as the antenna of the minitype terminal mobile phone, a wire is printed in the clearance area of the monopole antenna of a printed circuit board (PCB), one end of the wire is connected with the ground end of the PCB in a non-clearance area, the other end of the wire extends in the clearance area and the wire can effectively disperse distribution of hearing aid compatibility (HAC) electric field and magnetic field hotspots; the rear cover of the minitype terminal mobile phone is adhered with an electric conduction cloth or is sprayed with an electric conduction paint, and then the minitype terminal mobile phone is connected with the ground end of the PCB; and the transmitting and receiving properties of the antenna can be in an ideal state due to the matching circuit of a tuned antenna. The method for solving the electromagnetic compatibility problem of the antenna of the minitype terminal mobile phone has the beneficial effect of leading the antenna volume to be smaller to meet the specific absorption rate (SAR) andHAC indexes and over the air (OTA) test specification requirements on the premise of meeting the electromagnetic compatibility.

A new bipolar output boost converter for ac input applications is revealed. The new boost converter is bridgeless, i.e., it does not require use of a line frequency diode rectifier which improves the efficiency of the converter significantly. The new bipolar boost converter does not include the common mode noise generating mechanisms of prior art ac input bridgeless boost rectifier circuits, thereby easing electromagnetic compatibility problems. Although the new converter requires two output filter capacitors, total capacitor stored energy is the same as other boost converters of the same power level so that capacitor volume and cost is not significantly adversely effected. Zero voltage switching cells which can be substituted for a switch to eliminate first order switching losses are also revealed. New three terminal bipolar input source switching networks having operating properties similar to conventional full bridge source switching networks are also revealed.

The invention provides a positioning method of an electromagnetic interference source in a vehicle based on CAN bus data, and belongs to the technical field of vehicle and electromagnetic compatibility. According to the technical scheme, the positioning method of the electromagnetic interference source in the vehicle based on the CAN bus data comprises the following steps that S1, CAN bus data acquisition equipment is used for data acquisition and analysis; S2, the electromagnetic compatibility of a node is analyzed; S3, oscilloscope measurement data is analyzed; S4, CAN faults are analyzed based on a function or logic of an error frame node; and S5, interference sources and interference paths are analyzed. The positioning method has the beneficial effects that efficiency of positioning the interference sources and interference paths to the CAN bus in the vehicle can be improved, the time of positioning and analyzing the electromagnetic compatibility problems in the vehicle is shortened, and accuracy of interference source positioning is guaranteed.

The invention discloses a packaging structure for three-dimensional integration of a radio frequency system and a design method thereof. The structure comprises a silicon-based adapter plate and at least two supporting interconnection adapter plates which are alternately and longitudinally stacked from bottom to top, wherein a cavity is formed between the at least two supporting interconnection adapter plates; each of the silicon-based adapter plate and the supporting interconnection adapter plates comprises a silicon substrate, a through silicon via (TSV), micro bumps and an RDL wiring layer.The TSV penetrates the silicon substrate; the RDL wiring layers are arranged on the upper surface and the lower surface of the silicon substrate; the micro bumps are arranged on the two RDL wiring layers; the TSV, the RDL wiring layers, and the micro bumps are connected with one another. The structure has the effects of vertical interconnection and structural support, three-dimensional vertical stacking of radio frequency chips can be achieved, and the problem of electromagnetic compatibility during three-dimensional stacking of the radio frequency chips can be solved through flexible design.

The invention discloses an electromagnetism compatibility classification method of frequency equipment for ship platform based on analytic hierarchy process. The method comprises the following steps:1) classifying the ship platform according to equipment function and use requirement; 2) according to the factors influencing the electromagnetic compatibility performance, determining the electromagnetic compatibility classification elements, and defining the grades and grade scores of each classification element; 3) determining that relative weight of each grading element accord to the grading element and the grading thereof; 4) according to the relative weights of each classification element, determining the electromagnetic compatibility performance score of the shipboard electronic equipment; 5) determininThe classification result of the electromagnetic compatibility of the frequency equipment according to the scores of the electromagnetic compatibility of the shipboard electronic equipment. The invention introduces classification factors such as electromagnetic compatibility problem attribute of equipment, technical state of equipment, importance degree, electromagnetic sensitivity degree of frequency-using equipment, whether the equipment needs to carry out platform electromagnetic compatibility management and control, and the like, so that the classification basis is comprehensive and reasonable.

The present invention relates to the field of electromagnetic shielding technology, and more particularly relates to graphene / carbon nanotube composite electromagnetic shielding paper and a preparation method thereof. Graphene and carbon nanotubes as conductive agents and thermoplastic polyurethane as a matrix are used for preparing a conductive coating, the graphene and the carbon nanotubes overlap each other to form a continuous conductive network, the electrical conductivity of the coating can be significantly improved; the conductive coating is pulled on cotton fiber paper to form a film to obtain the electromagnetic shielding paper, the thermoplastic polyurethane allows the graphene and the carbon nanotubes to be firmly attached to the surface of the cotton fiber paper, and the problems that the bonding force between the conductive agent and the paper fiber is poor and powder is easy to fall off can be solved. The graphene / carbon nanotube composite electromagnetic shielding paperhas high shielding efficiency and wide frequency bandwidth, but also has excellent characteristics such as light weight, ultra-thinness and softness, has simple preparation process, low cost and easyrealization of large-scale production, and provides a solution to solve the electromagnetic compatibility problem of portable electronic products.

The invention discloses a confirming method of same frequency multiple interference for an electromagnetic coupling weak path, and belongs to the technical field of electromagnetic compatibility. Electromagnetic coupling relations of a plurality of interference sources and a plurality of sensitive points in a system are translated into digraphs, and sides of the coupling digraphs are valued through simulation and testing; then coupling paths where interference can be most easily generated between each interference source and each sensitive body are found from an electromagnetic coupling network in the same valued coupling digraph through a shortest-path tracking method for a plurality of times; and finally the same interference coupling path is extracted form a weak path from the each interference source to the each sensitive body, key rectification is conducted aiming at the weak path of repeated coupling, and therefore maintenance and strengthening of system electromagnetic compatibility faults are efficiently and accurately achieved, and electromagnetic compatibility problems can be accurately and effectively solved with low cost.

The invention discloses a self-adaptive configuration wireless charging system for an electric vehicle parking lot and a planning method. The system comprises an entrance detection part, a charging parking space part, a scheduling platform and an electromagnetic publicity part, wherein the entrance detection part comprises a charging plan acquisition device, a vehicle-mounted coil identification device and a parking space guiding system; the electric vehicle charging parking space part comprises a coil reconstruction execution mechanism and a charging parameter collector. The scheduling platform comprises a coil reconstruction strategy selector, an electromagnetic environment model construction module and a regional collaborative parking space planning program; the electromagnetic publicity part comprises an inspection unmanned aerial vehicle, a human body electromagnetic exposure model construction module and an electromagnetic environment publicity screen. According to the invention,based on the fusion of the reconfigurable coil and the coil recognition, the regional cooperative wireless charging network is provided for various types of parking lots in combination with related detection and control technologies, and in combination with related electromagnetic evaluation means, the problems of parking charging of electric vehicles in the existing public area and large-scale electromagnetic compatibility of the parking lots are solved.

Disclosed herein is a safety stoppage device and method for safety stoppage using a brake system of an autonomous vehicle, wherein the brake system includes a brake-control unit and wheel brakes; the autonomous vehicle is provided with control networks and sensors for monitoring the autonomous vehicle surroundings and motion, and a signaling processing system for processing sensor signals enabling an autonomous drive mode thereof. It is continuously predicted where a drivable space exists, based on data from the sensors and sensor fusion, and calculated a safe trajectory to a stop within the drivable space, that is sent to the brake-control unit and stored therein; and the brake-control unit is shielded against electromagnetic compatibility problems and arranged to monitor if the control networks are operational, and if determined incapacitated, control the autonomous vehicle to follow the most recently calculated safe trajectory to a stop within the drivable space using differential braking of the wheel brakes thereof in order to effectuate steering.

A device which in an optical interface adapts XFP to a 300 pin MSA transponder socket, permitting replacement of 300 pin MSA transponders with an XFP module on an existing host circuit pack. The device performs dispersion compensation in a removable module, addressing issues of jitter, path length equalization, cross talk and electromagnetic compatibility. As deployed, the device presents at the optical interface the attributes of XFP, hence connected optical devices are “fooled” into reading a connection to XFP instead of the 300 pin MSA.

The invention discloses a braided shielding layer radius design method based on shielding effectiveness, and relates to the technical field of braided cables, provides an efficient way for electromagnetic radiation of electromechanical equipment for the cable, is one of main sources of electromagnetic compatibility of the equipment, and does not disclose an effective technology for solving the electromagnetic compatibility problem of the cable from a shielding structure design at present, and the key points of the technical scheme are as follows: establishing a kley transfer impedance model; establishing a function relation between the core wire current and the shielding layer current according to the kley transfer impedance model; establishing an electromagnetic radiation model of the shielding layer current by adopting a dipole approximation method; defining the shielding effectiveness of the cable. According to the method, the mathematical relationship between the cable shielding effectiveness and the braided shielding layer is determined, the quantitative relationship between the cable shielding effectiveness and the radius of the shielding layer is obtained through analysis, atheoretical basis is provided for evaluation of the electromagnetic compatibility of the cable and design of a shielding structure, and the compatibility problem of signal transmission in a complex electromechanical equipment system is solved.

The invention relates to the technical field of laser drive power supplies, in particular to a constant-current drive circuit and method for a laser power supply. The constant-current drive circuit for the laser power supply comprises a main control circuit, a current protection circuit, a power output circuit, a current feedback adjustment circuit, a display circuit, a key circuit, a voltage power supply circuit and an AC-to-DC circuit, wherein the main control circuit is in two-way communication connection with the current protection circuit and the current feedback adjustment circuit separately; and a signal output end of the main control circuit is connected with a signal input end of the display circuit. According to the constant-current drive circuit and method, the damage to a device can be prevented, the output stability and the service life of a semiconductor laser are not affected by abnormal factors in any working environment, an electromagnetic compatibility problem and theconversion efficiency, and the constant-current drive circuit is relatively high in stability and relatively good in reliability.

A method for storing multi-path high-speed short-blanking interval linear array CCD (charge-coupled device) image data relates to a method for storing CCD camera image data, solving the problem that high-resolution high-speed aeronautical and astronautical remote sensing camera image data are difficult to store. The method comprises the following steps of: storing various paths of image data into an SDRAM (synchronous dynamic random access memory) assay in parallel; and reading out the image data path by path and storing the image data in a hard disc of a host by an acquisition card. The conversion between an input data bit nbit and a storer bit 16bit is performed on the image data; the reading-writing clock frequency of the SDRAM can be reduced to n / 16 of an original value; the method can be applied to the situations that the effective data amounts in all rows are the same and the row frequency can be increased to 16 / n of an original value; in order to reduce power consumption of the system and reduce the problem of electromagnetic compatibility at a high frequency, the lowest working frequency of the SDRAM is set and a specific formula is given; and in order to save the inner resources of an FPGA (field programmable gate array), the smallest depth of an asynchronous FIFO (first-in, first-out) is set according to an application condition.

The invention discloses a data transfer system based on an electronic information technology. The data transfer system comprises a master station, a concentrator, a collector and a Zigbee wireless sensor module, wherein the master station is in communication connection with the concentrator by means of a GPRS wireless module, the concentrator is connected with the Zigbee wireless sensor module and a router, and the collector is connected with the other end of the router, the other end of the Zigbee wireless sensor module and a plurality of wireless transmission modules. According to the data transfer system based on the electronic information technology, a communication distance of the data transfer system can be up to 500 m in the non-routing case by using the Zigbee wireless sensor module and adopting an application-free 2.4GHz communication frequency band, a network protocol adopted by the data transfer system has functions of automatic network organization, automatic routing, network self-healing and the like, the communication problem between the concentrator and the collector can be solved, the electromagnetic compatibility problem of hardware and the anti-interference problem of the system are fully considered in design, the stability of system operation is significantly improved, and the data transfer system is suitable for popularization and application.

The invention discloses a fine simulation-based current distribution and near-field electromagnetic distribution three-dimensional visual method. The method comprises the steps of a), judging a data type, and if the data type is electromagnetic field data, executing the step b); if the data type is current field data, executing the step d); b), firstly obtaining a frequency value, an electromagnetic field name and a contained point number from the electromagnetic field data; c), performing statistics on the point number and a triangle number contained in the electromagnetic field data; d), firstly obtaining a frequency value and a contained point number from the current field data; e), performing statistics on the point number, a line number, a triangle number and a quadrangle number contained in the current field data; f), calculating amplitudes and phase angles of multiple components; g), visually displaying the amplitudes and the phase angles; and h), performing conversion from a frequency domain to a time domain. According to the visual method, the reasonability of design can be tested without processing a real object, and the electromagnetic compatibility problem of the design can be analyzed; and, the product design cost can be reduced and the product research and development cycle can be shortened.

The invention discloses a weak electromagnetic coupling path determining method and belongs to the technical field of electromagnetic compatibility. The method includes: converting a schematic diagram of equipment into an electromagnetic interference coupling network, converting the coupling network into a coupling directed diagram, simplifying the coupling directed diagram, and finding out weak links of electromagnetic coupling paths in the coupling network by the shortest path tracing algorithm, so that problems of low pertinence, time consuming and labor consuming in previous electromagnetic compatibility troubleshooting of electronic systems are solved. In consideration of that primary coupling paths and secondary coupling paths exist in the electromagnetic coupling network, the shortest path tracing algorithm is adopted to find weak paths of electromagnetic interference coupling so as to accurately know main coupling processes of interference signals, so that the electromagnetic compatibility problem is rectified more specifically and effectively.

The invention provides an LED dimming method and system based on the ambient brightness. According to the invention, ambient brightness information is collected through a brightness sensor, and an ambient brightness signal is generated and transmitted to a PWM (Pulse Width Modulation) signal generator; the PWM signal generator receives the ambient brightness signal and determines a dimming level;the PWM signal generator generates a voltage change signal corresponding to the dimming level on an LED driving line according to the diming level; an LED driver collects the voltage change signal through the driving line, determines the dimming level according to the collected voltage change signal and adjusts the output power so as to achieve the purpose of dimming. The dimming information is transmitted through the voltage change signal on the LED driving line, so that the problems of equipment cost, installation cost and electromagnetic compatibility brought about by additionally arranginga dimming signal transmission line in the prior art are solved.

The invention provides a device and a method for microwave active and passive composite detection. The device comprises an active radar and a passive radiometer. The active radar is used for transmitting a radar signal and receiving an echo signal. The passive radiometer is used for receiving a radiation signal. The working frequencies of the active radar and the passive radiometer are different.When the active radar receives an echo signal, the passive radiometer starts the integral time and receives the radiation signal. When the active radar transmits a radar signal, the passive radiometerperforms integral shielding and does not receive the radiation signal. The electromagnetic compatibility problem of microwave active and passive composite detection is solved, and the detection precision of microwave active and passive composite detection is improved.

The invention belongs to the design field of airplane system circuits, and relates to a method for solving electromagnetic compatibility of a horizontal tail rudder surface control system of an airplane. The method comprises the following steps: serially connecting a variable resistance box; determining a resistance range of the variable resistance box when a load terminal circuit can normally work; and optimizing a resistance value. Aiming at solving the problem of the electromagnetic compatibility in the prior system, the invention ensures stable operation of the system, convenient implementation, wide adaptability and low cost.

The invention discloses a deflection angle measuring method and equipment and a storage medium, and belongs to the field of communication technology. The method comprises the following steps: obtaining the wave absorbing characteristic of a wave absorbing material of a gyroscope surface; measuring the duty cycle of the wave absorbing material; calculating the deflection angle of the gyroscope according to a preset formula and the duty cycle. Compared with the prior art, the deflection angle measuring method disclosed by the invention at least has the following advantages: first, the gyroscopeis of a hollow-core structure, and dead weight of the gyroscope can be remarkably reduced; second, the electromagnetic waves leaking from various equipment can be used as a radiation source, for example, minor lobes of primary and secondary antennas; thus, the power can be saved to certain extent, and the problem of electromagnetic compatibility in a mobile phone is solved; third, the method is suitable for various working conditions and experiences little environmental influence.

The invention discloses a shielding type high-power microwave waveguide phase shift control device which comprises a control system and an optical fiber feed-through, and the control system is in communication connection with an external upper computer through the optical fiber feed-through. The problems that in the prior art, the electromagnetic compatibility problem in the high-power microwave environment cannot be effectively solved, and the electromagnetic shielding effect is poor are solved.

The invention discloses a multi-frequency-point radio frequency impedance and current testing system. The multi-frequency-point radio frequency impedance and current testing system comprises a radio frequency multi-frequency-point testing clamp and a radio frequency current probe, wherein a gap is formed between inner cores of a top cover shell, a pressure gauge is arranged on the inner core of atop cover, a base inner core is arranged in a base shell, a radio frequency signal injection end is arranged at the end of the base inner core, the radio frequency current probe and a device to be tested are placed at the boundary between the top cover shell and the base shell, and the device to be tested is located between the inner core of the top cover and the inner core of the base; a microstrip line is arranged on the top face of a T-shaped plate and connected with a vector network analyzer and the radio frequency current probe; and the T-shaped plate is provided with a coupling coil, andthe coupling coil is electrically connected with the microstrip line and the ground plane. The multi-frequency-point radio frequency impedance and current testing system overcomes the defect that thehigher harmonic signal testing capacity is insufficient in the actual testing process, the good transmission performance of the clamp to multiple frequency points is achieved, the electromagnetic compatibility problem is solved, radio frequency current information is obtained in the testing process, and the problem that devices such as foam cannot be accurately tested due to the irreversible characteristic of compression in the testing process is solved.

The invention discloses an anti-electromagnetic interference capacitive oil mass measuring method and a system thereof. The method comprises the steps of S1, covering a capacitive sensor for measuring oil mass with one or more metal shielding layers, S2, measuring the capacitance of the capacitive sensor and outputting an analogue voltage signal according to the capacitance, and S3, converting the analogue voltage signal into a digital signal for outputting. The system comprises the capacitive sensor with the metal shielding layers, an operational amplifier and an analog-digital converter. According to the anti-electromagnetic interference capacitive oil mass measuring method and the system thereof, the electromagnetic compatibility problem of the capacitive sensor is solved from the following two aspects: firstly, the capacitive sensor is completely isolated from the external electromagnetic environment by use of the metal shielding layers so as to guarantee the accuracy of the measured data; secondly, the digital signal is output instead of the analog signal, and the reliability of the signal is enhanced and the anti-interface capability of the signal is improved. The anti-electromagnetic interference capacitive oil mass measuring method and the system thereof can be widely applied to various capacitive oil mass measuring systems.

The invention relates to an intelligent railway high-speed train electromagnetic compatibility prediction system, which comprises electromagnetic compatibility between single objects, electromagnetic compatibility generated by interaction between modules formed by different or different numbers of the same object. The electromagnetic compatibility problem caused by interaction between groups formed by randomly combining the plurality of modules according to constraint conditions such as environmental factors and equipment placement can be solved; and the electromagnetic compatibility of the whole train system is finally determined. Through the system, the electromagnetic compatibility problem of the train can be flexibly and reliably analyzed, the complexity is reduced, the calculation time is shortened, and the prediction precision is improved.

The invention discloses a device for realizing rapid visualization of an internal circuit of a teaching experiment module. The device comprises a shielding case body, a shielding cover body and a shielding assembly, wherein the shielding case body comprises a cavity for accommodating a circuit board; the opening surface of the shielding case body is provided with an opening; the shielding cover body is hinged to the opening surface of the shielding case body; and the shielding assembly is mounted on the contact surface between the shielding cover body and the opening surface of the shielding case body. On the basis of solving the possible problems of power short circuit danger and dust accumulation due to falling of metal objects such as screws and the like, and the electromagnetic compatibility problem, in a teaching process, a student can conveniently open an upper cover by directly using a hand without aid of any tool such as a screwdriver, a spanner or the like, and then intuitively observe the specific structure of the internal circuit board, so that the perceptual understanding of the student on the circuit is enhanced, and the interactivity and the teaching effect of a teaching experiment process are enhanced. The upper cover can be conveniently closed and fastened by directly using the hand after being observed, and the shielding protection of the circuit is restored.