76results about How to "Solve electromagnetic compatibility" patented technology

The invention provides an overall control method of a large-angle maneuvering high-resolution microwave remote sensing satellite, comprising the following steps: S1, systematically identifying the difference between a large-angle maneuvering high-resolution microwave remote sensing satellite and other existing satellites at the technical level, and determining key problems to be solved; S2, determining a scheme of maneuvering around the rolling shaft of the satellite according to the specific requirements of large-angle maneuvering; and S3, in view of the fact that the detection range of sensors fixedly connected to the satellite changes with maneuvering of the satellite due to large-angle maneuvering, inventing a sensor field analysis method based on a space digital ball method to determine the layout of the sensors on the satellite. The high-resolution microwave remote sensing satellite has the ability to revisit a to-earth observation target. The technical difficulty in large-angle quick maneuvering of the attitude of the satellite is solved. The problem on multi-system integrated control is solved. The use efficiency of the satellite is improved. The problem of electromagnetic compatibility and the problem of wireless high-power transmission during whole-satellite vacuum thermal test are solved.

The invention relates to a network communication architecture applied to a networking information transmission system and a communication method. The network communication architecture is composed of multiple nodes, such as a master control node, a relay transmitting node and a plurality of task executing nodes. The network communication architecture can reasonably restrain the space distribution of the nodes according to the different functions of the nodes. A combined communication mode of various communication systems of CDMA (code division multiple access), FDMA (frequency division multiple access) and TDMA (time division multiple access) is adopted, the relay transmitting node is utilized to realize the BVR (Beyond Visual Range) bidirectional information transmitting capacity of the master control node and the task executing nodes, and the problem of multi-node cooperative work of the networking information transmission system is solved.

The invention discloses a specific harmonic cancellation multi-level radio frequency pulse width modulation method in which K odd number of specific harmonic waves are selected, and M-level RF-PWM signals are processed to be equivalent to N 3-level RF-PWM signals with pulse width separately controlled by corresponding comparison thresholds and stacked in a weighted manner, wherein K, M and N are all integers more than 0, N is more than K, and M is equal to 2N+1; N comparison thresholds and corresponding weighting coefficients are controlled in real time according to a normalized envelope signal SA, so that the K specific harmonic wave components of the N 3-level RF-PWM signals has stacked in a weighted manner are mutually counteracted, a base wave component is in direct proportion to the SA, and thus the K specific harmonic waves and integer multiples of odd harmonic waves of the M-level RF-PWM signals are eliminated. Based on the method, the invention also provides a specific harmoniccancellation multi-level radio frequency pulse width modulator. Compared with the prior art, the modulation method and the modulator have the beneficial effects that on the basis that the basic modulation performance is equivalent to the RF-PWM of the same level in the prior art, the suppression requirement on the filter is effectively reduced, the cost and size of the filter are reduced, and thus the comprehensive performance of the wide frequency band DTX is improved.

The invention relates to a switching device for power supply or power distribution, and discloses a surge suppressor of a switch for power supply and distribution of low-power equipment. The surge suppressor is characterized in that resistors R1 and R3 are connected in parallel; one end of the resistors is connected with the grid of an MOS (metal-oxide-semiconductor) field-effect transistor Q1, and the other end of the resistors is connected with the source of the Q1 and the positive end of a direct-current power supply; resistors R2 and R4 are connected in parallel and are connected between the grid of the Q1 and the negative end of the direct-current power supply in series; capacitors C1 and C2 are connected between the grid and source of the Q1 in series; and the drain of the Q1 is connected with power supply filtering or loading equipment by a fuse. The invention also discloses a surge suppressor of a switch for power supply and distribution of high-power equipment. The surge suppressors solve the problem of electromagnetic compatibility of on/off power equipment of complex systems and achieve the beneficial effects of simple circuit, convenience in debugging, obvious surge suppression, low cost, high reliability and the like.

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 water-pollution microwave active-passive compound detection method and device. The method includes the following steps: (10) system initialization, (20) active scanning, (30)passive scanning, (40) determination of target characteristics, (50) target distribution determination and (60) real-time monitoring. The device includes an antenna system (1), an X-band radar transmitter (2), a circulator (3), an X-band radar receiver (4), an active/passive switch (5), a Ka-band radiometer receiver (6), and a modulator (7) and an information generation and collection system (8).The antenna system (1) is connected to the X-band radar transmitter (2) and the X-band radar receiver (4) through the circulator (3), and the Ka-band radiometer receiver (6) is directly connected with the antenna system (1). The water-pollution microwave active-passive compound detection method and device have good electromagnetic compatibility, small mutual interference, and can work together atthe same time by sharing a platform.

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 relates to a method for determining weak electromagnetic coupling paths between multi-frequency interference pairs and belongs to the technical field of electromagnetic compatibility. The method includes: converting electromagnetic coupling relation between interference sources and sensitive bodies in the system into digraphs, evaluating edges coupled with the digraphs at different frequency points by means of simulation and test, searching for weak coupling paths of each pair of interference sources and sensitive bodies at corresponding frequency points from a plurality of electromagnetic interference coupling digraphs through a shortest-path tracking method, sequencing peaks of all the weak paths according to times of the peaks appearing on weak links, and rectifying coupling channels on interference links according to the sequence. Therefore, repair and reinforcing of system electromagnetic compatibility faults are realized efficiently and accurately, the problem about electromagnetic compatibility can be solved accurately and effectively by low cost, and the method has great guidance significance in reinforcement and rectifying of the system electromagnetic compatibility.

The invention discloses a centering type locking mechanism based on piezoelectric motor drive and relates to the technical field of automatic clamping mechanism equipment of machine tools or machining centers. The centering type locking mechanism aims at solving the problems that an existing electromagnetic motor drive type locking mechanism is complex in structure, and electromagnetic interference exists. According to the centering type locking mechanism, a clamp and clamping claws are hinged through bolts, limiting plates are connected with the top ends of side walls of the clamp, a wedge head driving shaft penetrates through two output shaft sleeves, one output shaft sleeve is connected with the center of the bottom surface of the clamp to be fixed, the other output shaft sleeve is connected with a motor fixing plate, a wedge head of the wedge head driving shaft is connected with the bottom ends of the four clamping claws, two driving feet of a piezoelectric motor are connected with the output shaft sleeves, forward voltage and backward voltage are applied to all piezoelectric ceramic pieces on the piezoelectric motor, reciprocating motion of the wedge head driving shaft is controlled by controlling the timing sequence of applying the voltage to the piezoelectric ceramic pieces, and thus the locking and unlocking functions of the locking mechanism are achieved. The centering type locking mechanism can be applied to manufacturing of automatic locking mechanism equipment of numerical control machine tools or machining centers.

The invention provides a motor axial conducted emission test system and method for an electric drive system of an electric vehicle. The system comprises an electromagnetic environment simulator, a test platform, a signal receiving and processing device and a monitoring device; the electromagnetic environment simulator comprises a high-tension battery pack, a vehicular battery, a motor controller and a motor under test; the test platform is connected with the motor under test; the signal receiving and processing device comprises a receiver and a voltage probe; the monitoring device comprises amonitoring computer and a photoelectric conversion module; the monitoring computer is connected with the motor controller and the high-tension battery pack through the photoelectric conversion module.The system provided herein allows motor axial conducted emission to be measured under loading condition; loaded speed and torque can be precisely controlled; vehicle actual condition and complex electromagnetic environment are simulated, and axial conducted disturbing signals under loading under nearly actual condition are also simulated; reliable data are provided to solve the electromagnetic compatibility issue caused by axial conducted emission of the electric drive system.

The filter network and module of filter network are setup between power input end and rectification circuit. The filter network includes seven capacitors; internal connecting ends of capacitors are connected to each other, and external connecting ends of capacitors constitute passive linear network in seven ends. An external connecting end of one capacitor is connected to ground of power source. Other six capacitors are paired to three groups, and parameters in each capacitor group are identical. External connecting ends of first group as input ends are connected to two input ends of power source. External connecting ends of second group as middle ends are connected to two input ends of rectification circuit. External connecting ends of third group as output ends are connected to two output ends of rectification circuit. The module is encapsulated as thick film IC with nine pins. Features are simple, compact, stable for solving electromagnetic interference.

The invention discloses a space deployment mechanism driven based on a multi-piezoelectric vibrator step crawling mode, which relates to the field of space deployment mechanisms and aims at solving the problems of complicated structure, serious electromagnetic interference and complicated self locking existing in the current electromagnetic motor driving-type space deployment mechanism. The space deployment mechanism driven based on the multi-piezoelectric vibrator step crawling mode comprises a base, two shaft extension sleeves, two deployment mechanisms, four piezoelectric vibrators, two driving shafts and a mounting seat, wherein two opposite side walls of the base are provided with through holes, and the through holes in the two side walls are coaxial; the two shaft extension sleeves are fixed in the two through holes; the two deployment mechanisms are fixed on the two opposite side walls of the base respectively; the four piezoelectric vibrators are fixed inside the base via the mounting seat; and one ends of the two driving shafts are tightly connected with two piezoelectric vibrators via a pretightening force, and the other ends pass through the shaft extension sleeves to be connected with the two deployment mechanisms respectively. Thus, relaxation and contraction of the space deployment mechanism can be realized.

The invention relates to a cable connection with shielding continuity, which comprises a cable, a cable connector, a shielding layer ground wire, a connector tail clip, a copper cloth, a heat shrinkable film, a copper foil adhesive tape, a polyimide adhesive tape and a box. Shielding between a shielding uncovering part and a connector is realized by using a metal cover such as a copper cloth, so that 360 degree sealed overlapping connection between the shielding layer and the electrical connector is realized; The shielding integrity of the whole signal transmission path is realized by coveringthe gap between the connector and the chassis and between the chassis and the chassis with a plastic and sticky metal cover such as copper foil adhesive tape. The cable connection according to the invention can remarkably reduce the electromagnetic leakage between the cable and the connector and between the connector and the box, thereby realizing comprehensive and continuous electromagnetic shielding of the entire signal transmission path, and solving the problem that the traditional shielding by means of a shielding card or the tail cover needs extra weight and mounting space.

The invention discloses a switching circuit capable of reducing electromagnetic interference. The switching circuit comprises a first terminal and a second terminal which are respectively connected to an alternating current power supply and a load, a control loop which is connected between the first terminal and the second terminal, a dynamic voltage-stabilized source and a static voltage-stabilized source which are connected between the two terminals in series and are used for supplying the power to the control loop, and a controlled silicon or a CMOS (Complementary Metal Oxide Semiconductor) tube which is connected between the two terminals in series and is controlled by the control loop, wherein a current main loop of the switching circuit is formed by the first terminal, the second terminal, the control loop, the dynamic voltage-stabilized source, the static voltage-stabilized source and the controlled silicon or the CMOS tube. The switching circuit further comprises a linked switching circuit merging into the current main loop, and the linked switching circuit comprises a filter network used for reducing the electromagnetic interference and a linked reaction circuit used for controlling synchronous linkage of the filter network and the switching circuit. The switching circuit is designed for the electromagnetic interference problem caused by adopting the controlled silicon or the CMOS tube as a main loop, and provides a scheme, which is easily controlled and low in cost, and is capable of better solving the problem of electromagnetic compatibility, and the linked switching circuit is guaranteed to have no standby power consumption.

The invention discloses a radio frequency optical transceiver case having an electromagnetic shielding function. The radio frequency optical transceiver case comprises a box body, wherein the box body is made by all-aluminum milling, at least one interface is arranged outside the box body, at least one baffle plate is arranged in the box body and integratedly formed with the box body, an inner cavity of the box body is divided into a first cavity body, a second cavity body and a third cavity by the baffle plate, the first cavity body is provided with a power supply module, an optical isolation module susceptible to interference is arranged in the second cavity body, a pre-distortion correction and electro-optical conversion module which is difficult to generate an interference signal, a low-noise amplification unit and an impedance matching module are arranged in the third cavity body, and the first cavity body, the second cavity body and the third cavity body are electrically connected through a feed-through filter. With the adoption of a cavity division mode, components susceptible to interference are arranged in respectively closed spaces, components insusceptible to interference are arranged in the same divided cavity, and thus, the problem of electromagnetic compatibility of the radio frequency optical transceiver is solved better.

The invention relates to the technical field of electromagnetic compatibility and specifically relates to an electromagnetic compatibility passive control type adjustable load circuit and a box applying the circuit. The electromagnetic compatibility passive control type adjustable load circuit comprises a circuit master switch S1, a direct current ammeter A, a direct current voltmeter V, a current adjusting circuit, a control circuit and a load resistor RL, the current adjusting circuit and the control circuit are connected with the direct current ammeter A, and the circuit master switch S1 is connected with a positive pole of a tested power supply product, the direct current ammeter A and the direct current voltmeter V; the current adjusting circuit is connected with the control circuit; and one end of the load resistor RL is connected with the control circuit and the current adjusting circuit, and the other end of the load resistor RL is connected with a negative pole of the tested power supply product. According to the electromagnetic compatibility passive control type adjustable load circuit and the box applying the circuit, the circuit can work without additional power supplies, no electromagnetic radiation can be generated, the cost is low, the performance is reliable, the using is convenient and rapid, and the effect is obvious.

The invention relates to the technical field of communication, and discloses an antenna module and terminal equipment. The antenna module comprises a first antenna and a second antenna. The first antenna comprises a first coil, the second antenna comprises a second coil, the first coil is parallel to the second coil, and the central axis of the first coil coincides with that of the second coil; the first coil and the second coil are both of a symmetrical structure. The first coil and the second coil are arranged into the symmetrical structures, meanwhile, the first coil is parallel to the second coil, and the central axis of the first coil coincides with that of the second coil to avoid interference by the second coil to the first coil and also avoid interference by the first coil to the second coil, so that it is ensured that the first coil and the second coil can work normally, it is effectively avoided that the terminal equipment cannot work normally due to mutual signal interference between antennas of two different sizes and different frequency bands, and normal use of the terminal equipment is guaranteed.

The invention discloses a multifunction vehicle bus interface device which comprises a case, a back plate, a control drive circuit, an interface circuit and two data interfaces connected with the interface circuit. The control drive circuit is arranged on a control circuit board, the control circuit board is inserted in a control slot of the back plate, the interface circuit is arranged on the back plate and is connected with the control drive circuit through a wire arranged on the back plate, the distance between the interface circuit and the control drive circuit is smaller than a distance threshold, the two data interfaces and the interface circuit are arranged on the back plate in a back-to-back mode, and both the two data interfaces are located on the outside of the case. The interface circuit and the two data interfaces are arranged on the back plate on the outside of the case in the back-to-back mode, the interface circuit is electrically connected with the data interfaces through wires printed on the back plate, connecting wire harnesses are saved, fixation of the data interfaces is strengthened, and electromagnetic compatibility is achieved; the interface circuit is directly arranged on the back plate, one slot in the back plate is omitted, and extension of functions of the back plate is facilitated.

The invention relates to the technical field of electromagnetic compatibility, in particular to an electromagnetic compatibility pre-amplifier and a control method thereof. The electromagnetic compatibility pre-amplifier comprises a power supply circuit, a power supply filter circuit, an amplifying tube, an input coupling circuit and an output coupling circuit, wherein the power supply filter circuit is connected with the power supply circuit; the amplifying tube is connected with the power supply filter circuit; the input coupling circuit and the output coupling circuit are both connected with the amplifying tube; the input coupling circuit is connected with a signal input end; the output coupling circuit is connected with a signal output end. The utility model provides the electromagnetic compatibility pre-amplifier which is low in cost, low in noise, high in stability, and wide in frequency band. The electromagnetic compatibility pre-amplifier is applicable to the design, the analysis and the rectification of the electromagnetic compatibility circuit, and can analyze the source of the electromagnetic noise visually and accurately, be positioned quickly, and solve the problem of electromagnetic compatibility of the product. Through the application of the electromagnetic compatibility pre-amplifier and the control method, the high cost for purchasing the pre-amplifier is saved, and the measurement and analysis and the rectification of electromagnetic noise lower than ambient noise level are realized in natural space environments without professional facilities such as a shielded room or an anechoic chamber.

The invention relates to a cable connecting an airplane electric brake controller and an electromechanical actuator. A cable core is arranged in the center and composed of three sets of wires which are three force sensor wire cores, five Hall sensor wire cores and three motor three-phase wire cores respectively, wherein the force sensor wire cores are composed of the supply wire, the ground wire and the signal wire, the Hall sensor wire cores are composed of the supply wire, the ground wire and the three Hall signal wires, and the motor three-phase wire cores are composed of the motor three-phase voltage wires. According to the cable connecting the airplane electric brake controller and the electromechanical actuator, the problem of electromagnetism compatibility of the cable in an airplane electric brake system is solved, the disturbance-resistant capacity of the system is improved, the disturbance variable overlaid on a force sensor feedback signal is greatly reduced through a test, and the control accuracy of an airplane electric brake is improved.