303 results about "Magnetic dipole" patented technology

The present disclosure discloses a circularly polarized satellite antenna based on a magnetoelectric dipole. A floor is slotted, and an equivalent magnetoelectric dipole is excited using a grounded right-angle folded dipole, while two square parasitic patches are loaded to enhance a radiation performance, thus exciting a broadband high-gain circularly polarized radiation beam. The present disclosure utilizes the L-shaped right-angle folded dipole to simultaneously realize an ingenious combination of an electric dipole and a magnetic dipole, realizing a good circularly polarized radiation performance. At the same time, the present disclosure realizes circularly polarized radiation using a form of the magnetic dipole, which results in a stable pattern and a high gain.

The invention discloses a high-strength and high-toughness aluminum nitride ceramic and a preparation method thereof, and relates to the technical field of ceramics, a sol-gel method is adopted to coat the surface of aluminum nitride with a stable shell layer to form a core-shell structure, meanwhile, the low lattice mismatch rate of a core-shell interface is utilized to reduce thermal resistance, and toughness and thermal conductivity are both considered; according to the external magnetic field tape casting method, the magnetic dipole moment orientation principle is utilized, an external magnetic field is applied in the tape casting stage, the in-plane mechanical property is improved, and the fracture toughness is improved through the magnetism of aluminum nitride whiskers; a reinforcement is introduced to improve the mechanical property and corrosion resistance of the aluminum nitride ceramic material, multi-granularity powder is compounded, large-particle aluminum nitride powder is used as a sintering and heat-conducting framework material, and high activity provided by submicron particles is utilized to promote sintering, so that the sintering temperature of aluminum nitride can be remarkably reduced, and the performance is greatly improved; and the aluminum nitride substrate expands more application fields on a future packaging circuit.

The invention provides a magnetic target state estimation system and device, and relates to the technical field of magnetic target state estimation, and the system mainly comprises a data collection module, a magnetic field model construction module, a deep learning module and a result output module. The data acquisition module comprises a field measurement unit and a data set unit; the magnetic field model building module is used for enabling a magnetic target to be equivalent to a physical model; the physical model is a mixed model of an ellipsoid and a magnetic dipole array; the deep learning module comprises a neural network, the physical model and an optimizer; and the result output module is used for sending out the state prediction result of the magnetic target after the neural network training is completed. According to the scheme, the complex magnetic field data is efficiently fitted through the neural network, and the physical constraint is introduced into the loss function, so that the robustness is improved, and the overfitting problem in simple data fitting is avoided; the calculation time and resources can be greatly reduced; and the solution quality and stability can be improved.

The invention relates to the technical field of magnetic detection, in particular to a target positioning method based on geomagnetic anomaly and an axis frequency magnetic field. Comprising the following steps: S1, preparing before entering water; s2, approaching a target; s3, target detection: when no target appears, an observation signal is composed of an environment magnetic field, and the energy value of the part is very small; once the target appears, the energy of the observation signal can be continuously and obviously increased, when the energy value is greater than a preset judgment threshold, the target point is judged as a suspected target point, and if the suspected point is continuously detected for a specified time, the existence of the target is confirmed; s4, combined positioning: under a Kalman filtering framework, enabling the target to be equivalent to a magnetic dipole and an electric dipole, and correcting a position predicted by a target state equation by combining measurement equations of the two models, thereby realizing combined positioning of the target and obtaining more accurate target position information; and S5, verifying and outputting a positioning result. The method has the advantages of improving the positioning precision, enhancing the anti-interference capability and the like.

The invention discloses a magnetic source positioning method based on a spin-exchange relaxation-free atom magnetometer, and aims to provide a high-precision brand-new solution for magnetic source positioning in a near-zero magnetic environment by performing physical modeling and least square estimation on space magnetic field distribution of a target magnetic source. The magnetometer is enabled to be simultaneously sensitive to a three-axis magnetic field, a light absorption detection method is utilized to ensure that complete three-axis magnetic field information is obtained, and the sensitivity of the three axes reaches fT / Hz1 / 2 (1fT = 10 <-15 > T) magnitude. In the positioning process, the target magnetic source is abstracted into a physical model of the magnetic dipole, and the space magnetic field information generated by the target magnetic source is obtained through the atom magnetometer, so that the long-term stability of the magnetic source positioning process and the high precision of the positioning result can be ensured in the zero magnetic environment; therefore, a high-precision magnetic positioning technical means with great potential is provided for various application scenes such as paleomagnetic sample testing and magnetic source positioning in medical research, and technical progress and application expansion in related fields are expected to be promoted.

An antenna element, an antenna module, an antenna array and an electronic device. The antenna element (4) comprises electric dipoles (41), magnetic dipoles (42) and a feed unit (43). The current of the feed unit (43) is coupled to the magnetic dipoles (42), and is then directly transmitted to the electric dipoles (41) by the magnetic dipoles (42). Each pair of electric dipoles (41) comprises two first patches (411), each first patch (411) is of a closed loop structure, and the coupled current is transmitted along the contour of the first patch (411), thereby facilitating the lengthening of a transmission path of the coupled current. For the same transmission path length, the electric dipoles (41) of this structure have a smaller volume, which can reduce the volume of the antenna element (4). Each first patch (411) of the closed loop structure reduces the radiation area of an antenna to a certain extent, and reduces the coupling between antenna elements (4), so that the radiation gain of the antenna module (100) can be improved. Therefore, the antenna element (4) can improve the radiation gain of the antenna module (100) while making the antenna module (100) smaller. (FIG. 1)

The invention discloses a stomach tube tail end three-dimensional positioning method based on a high-precision permanent magnet mark and a flexible TMR array. The method comprises the following steps: disinfecting a stomach tube and a permanent magnet marker; the miniaturized permanent magnet marker is firmly installed at the front end of the stomach tube; reserving a mounting position at the front end of the stomach tube, and inserting the stomach tube into the esophagus of a patient through a nasal cavity or an oral cavity until the stomach tube reaches a preset position; flexible TMR sensor arrays in double-sided distribution are arranged in the chest area and the back area of the patient; according to magnetic field data detected by a TMR sensor array, coordinates of a permanent magnet marker in a sensor coordinate system are solved through magnetic dipole modeling and nonlinear optimization, a thoracic coordinate system transformation matrix is established, and three-dimensional position coordinates of the permanent magnet marker in a world coordinate system are determined; a magnetic dipole reverse solution positioning method is adopted, and meanwhile, the zero radiation exposure risk is ensured; spatial registration with an ultrasonic image is supported, and the positioning precision and the anti-interference capability are improved.

The invention discloses a cilia type magnetic tactile perception method for distributed force load. The size and direction of the distributed force load are calculated based on magnetic field distribution around magnetic cilia by using a force-magnetic coupling model; the magnetic cilia is composed of a flexible non-magnetic material segment and a flexible magnetic material segment, the flexible non-magnetic material end is fixed to the substrate, and the flexible magnetic material end is a free end; discretizing the magnetic cilia into a plurality of sections, wherein each section is regarded as a combined fragment of a plurality of magnetic dipoles; for any combined segment, superposing the magnetic fields of all the magnetic dipoles in the combined segment to obtain the magnetic field of the combined segment based on the superposing property of the magnetic fields; and the overall space magnetic field distribution of the magnetic cilia is obtained by superposing the magnetic fields of all the combined fragments based on the superposing property of the magnetic fields. The method has the advantages of high sensitivity, simple structure, strong anti-interference capability and the like, and is suitable for the fields of robot touch, medical micro-force detection, industrial precision measurement and the like.

The invention discloses a BiLSTM-based while-drilling electromagnetic wave logging data rapid inversion method and system, and the method achieves the efficient processing of logging data through constructing a deep network structure composed of four BiLSTM layers and a full-connection layer. According to the method, ideal magnetic dipole response is adopted as training data, and the problem that local minimum is likely to occur in traditional data interpretation is solved. And the recurrent dropout technology is utilized to reduce overfitting, so that the generalization ability of the model is improved. The technology not only can accurately classify the stratum model, but also can predict various stratum parameters, so that the accuracy and processing speed of data interpretation are remarkably improved, and powerful technical support is provided for geological exploration and stratum evaluation.

The invention discloses a cilia type magnetic tactile perception method for concentrated force load. The size and direction of the concentrated force load are calculated based on magnetic field distribution around magnetic cilia by using a force-magnetic coupling model; the magnetic cilia is composed of a flexible non-magnetic material segment and a flexible magnetic material segment, the flexible non-magnetic material end is fixed to the substrate, and the flexible magnetic material end is a free end; discretizing the magnetic cilia into a plurality of sections, wherein each section is regarded as a magnetic dipole fragment; the overall space magnetic field distribution of the magnetic cilia is obtained by superposing the magnetic fields of all the magnetic dipole segments based on the superposing performance of the magnetic fields. The method has the advantages of high sensitivity, simple structure, strong anti-interference capability and the like, and is suitable for the fields of robot touch, medical micro-force detection, industrial precision measurement and the like.

The invention provides a wear coefficient correction method for a shield cutter, and relates to the technical field of wear monitoring, and the method comprises the steps: collecting a time sequence magnetic field signal obtained by a magnetic sensor array disposed on a non-rotating part of a shield tunneling machine, and synchronously obtaining a cutter angle coding signal; performing time-frequency conversion and filtering on the magnetic field signal to obtain a noise reduction time sequence signal; determining a geometric position sequence of each shield cutter in combination with the angle coding signals; based on the magnetic sensor pose, the tool position and the magnetic dipole model, theoretical magnetic field mapping between the tool and the sensor is constructed, and a system response matrix is generated; reconstructing an independent magnetic feature vector of each cutter to obtain an optimal feature set; generating a vector difference through comparison with a reference vector, inputting the vector difference into an abrasion identification model, obtaining the abrasion loss and type identification of each cutter, and correcting an abrasion coefficient; the method improves the wear recognition precision and reliability, and is suitable for tunnel construction under complex geological conditions.

The invention provides a multi-magnetic accurate positioning method based on APSO-LM fusion, and solves the technical contradictions that global search and local convergence are unbalanced and the resolving efficiency is low in the existing multi-magnetic accurate positioning technology. The method comprises the following steps: constructing a magnetic moment calibration module, selecting a sensor array calibration point, collecting magnetic field data, and calculating a precise magnetic moment amplitude based on a magnetic dipole model; an NSS-VMGT initial positioning result is input through a parameter initialization module, APSO and LM algorithm parameters are configured, and particle vectors are normalized; generating a particle swarm by using an APSO global search module, and iteratively screening a global optimal parameter as an LM initial value; calculating a residual error and a Jacobian matrix by means of an LM local refining module, and iteratively optimizing and outputting a magnetic source position and a magnetic moment; and the dynamic compensation module is used for calibrating clock skew and inhibiting environment interference. The device is realized based on STM32H743, and comprises a 7 * 7 lis2mdltr sensor array, a dual-chip data acquisition link, an APSO-LM algorithm hardware acceleration module and an upper computer interaction unit.

The invention belongs to the technical field related to nanometer material testing, and discloses a magnetic nanoparticle relaxation time detection method and an environmental parameter detection method, and the method comprises the following steps: applying an excitation magnetic field around a to-be-detected target mixed with magnetic nanoparticles; obtaining magnetization response generated by the magnetic nanoparticles in any direction of the magnetic field plane, and obtaining phase lag corresponding to any order harmonic term of the magnetization response; according to the function relationship between the phase lag corresponding to any harmonic term and the Brown relaxation time of the magnetic nanoparticles, solving and obtaining the Brown relaxation time of the magnetic nanoparticles; wherein the function relationship comprises a correction term introduced by magnetic dipole interaction of the magnetic nanoparticles. The magnetic dipole interaction among the magnetic nanoparticles is introduced, relaxation time detection of particle space distribution under an external magnetic field is corrected, the interference of the magnetic dipole interaction on the magnetic nanoparticle Brown relaxation time detection process can be effectively reduced, and accurate estimation of the magnetic nanoparticle Brown relaxation time is realized.

The invention discloses a broadband circularly polarized magnetoelectric dipole antenna with superposed Ka-band radiation modes, and belongs to the field of radio frequency front-end devices. The antenna is composed of an electric dipole patch composed of a rectangular patch and a stepped patch, a magnetic dipole radiator composed of four metal columns, an H-shaped slotted coupling floor, a feeder line, coaxial feed metal columns, an SIW structure, a metal ground backboard, an upper dielectric substrate, a lower dielectric substrate and a pp bonding layer, an antenna unit is subjected to 4 * 4 arraying, and the circularly polarized radiation performance of the antenna unit is verified. According to the invention, the circularly polarized wave beam range is wide, and the axial ratio bandwidth is 3GHz to cover the complete working frequency band. After the array is formed, the active S parameters of the array elements are well matched, and the excellent axial ratio performance is still achieved during beam scanning.

The invention relates to a radio frequency coil design method for transmitting array space coding imaging, and belongs to the technical field of magnetic resonance imaging. Aiming at the problems of low single-dimensional coding efficiency, strong coupling interference among coils and nonlinear phase gradient in the traditional TRASE technology, axial and radial coding coils are designed based on a target field method and a magnetic dipole method, two-dimensional radio frequency phase coding is realized through reverse current solenoid decoupling combination, and excitation and signal receiving are realized in combination with a saddle-shaped coil. According to the technical scheme, by optimizing the coil structure and the decoupling design, multi-dimensional efficient coding, high-precision phase gradient, strong anti-interference and light system weight are achieved, and the method is suitable for portable and dynamic monitoring scenes of low-field magnetic resonance.

The invention provides an indoor local magnetic field modeling method and device based on a magnetic source equivalence principle, and belongs to the technical field of indoor localization, and the method comprises the steps: collecting the data of a three-axis magnetometer in a space range through an array type magnetic sensor, and obtaining the original measurement information of an indoor magnetic field; based on a magnetic source equivalence principle, an indoor magnetic field is modeled into an equivalent magnetic dipole model consisting of a plurality of equivalent magnetic dipoles, and a magnetic field generated by the model is consistent with a real magnetic field in an observation area by setting magnetic moment and position parameters of the magnetic dipoles; according to the measured value of the array type magnetic sensor, an observation model is established in combination with an equivalent magnetic dipole model and used for describing the relation between the measured value and model parameters; through a nonlinear least square optimization method, parameters of the equivalent magnetic dipole model are solved according to the observation model, the equivalent magnetic dipole model of the indoor magnetic field is obtained, and the parameters comprise the magnetic moment and the position of the magnetic dipole. The precision and the reliability of the model are remarkably improved.

A magnetic alignment assembly can be incorporated into an electronic device to facilitate alignment with another device. The magnetic alignment assembly can include a main magnet (e.g., a square or rectangular magnet) having a magnetic dipole in an axial direction and a ring magnet coaxial with the main magnet. The ring magnet can be smaller than the main magnet. The ring magnet can be positioned between the main magnet and an interface surface.

The invention discloses a magnetic field calculation method and device for a magnetic dipole and a storage medium, and relates to the technical field of magnetic field calculation, and the method comprises the steps: calculating a model of first magnetic induction intensity at the center of the magnetic dipole, a model of target magnetic induction intensity at a target point, and a model of second magnetic induction intensity at the center of the magnetic dipole; polynomial fitting is carried out on the change relation between the target point and the first position vector of the target point relative to the center of the magnetic dipole to obtain a first relation function; determining a model of the target magnetic induction intensity at the target point according to the first relation function; polynomial fitting is carried out on the change relation between a second position vector corresponding to the second magnetic induction intensity and the vector direction of the second position vector, and a second relation function is obtained; determining the target direction of the vector of the magnetic induction intensity of the target point according to the second relation function; and determining the target magnetic induction intensity of the target point according to the model of the target magnetic induction intensity and the target direction. According to the invention, the magnetic induction intensity of the magnetic dipole can be accurately calculated.

The invention discloses a dual-polarization filtering integrated antenna and a manufacturing method, and relates to the technical field of communication, the dual-polarization filtering integrated antenna comprises an antenna assembly and a filtering assembly, the antenna assembly comprises a substrate, a grounding plate and two groups of radiation units, the grounding plate is arranged at the first end of the substrate, and the filtering assembly is arranged at the second end of the substrate; each radiation unit comprises an electric dipole, a magnetic dipole and a feed part, the magnetic dipole comprises two single walls, each single wall comprises a plurality of metal columns, the feed part is arranged at the second end of the substrate, the electric dipole is arranged in the horizontal direction and located between the first end and the second end, and the metal columns are arranged at intervals and form an electromagnetic shielding cavity; the filtering assembly is arranged between the electric dipole and the first end and is positioned in the electromagnetic shielding cavity; the filtering assembly comprises a filter, a vertical transmission line and an improved structure; the filter comprises a plurality of capacitors and inductors; according to the technical scheme provided by the invention, the limitation of contradiction between the structural integration level and the electromagnetic performance in the conventional filtering antenna design can be broken through.

A single-layer broadband vertically polarized endfire magnetoelectric dipole (ME-dipole) antenna and an antenna array. The main radiator of this antenna is a substrate-integrated closed loop, which consists of two horizontal metallic strips printed on the upper and lower surfaces of substrate and a pair of vertical metallic vias. Excited by a double-sided parallel-strip line at the center of the loop, the metallic vias function as electric dipoles while the entire loop aperture works as magnetic dipole. To facilitate integration, this magnetoelectric dipole loop antenna is fed by an open-ended substrate integrated waveguide (SIW), which also works as a backed cavity to enhance the front-to-back ratio. Moreover, rectangular slots are etched at the edges of the SIW aperture to further improve the front-to-back ratio and also the cross-polarization performance. Thus, a vertically polarized endfire ME-dipole loop antenna with a low-profile structure, broad bandwidth, and stable radiation performance is achieved.

The invention discloses a two-dimensional motion trail tracking device based on permanent magnet positioning. The two-dimensional motion trail tracking device comprises an induction positioning plate, a signal acquisition module, a data transmission interface, a position calculation module and a display device, a three-axis magnetic sensor array is arranged on an induction positioning plate, magnetic field changes during movement of a permanent magnet are collected in real time, the three-dimensional position of the permanent magnet is inversed in combination with a magnetic dipole model, and the positioning precision is improved through an adaptive weighted fusion algorithm for multi-point position estimation. The signals are transmitted to display equipment after being processed, so that real-time drawing and physical quantity analysis of a motion track are realized; the permanent magnet serves as a passive projectile, power supply is not needed, and trajectory tracking of various motion modes such as horizontal projectile, free falling and simple pendulum can be achieved by matching with an optional auxiliary module. Through the synergistic effect of the passive permanent magnet and the magnetic sensor array, maintenance-free and high-precision real-time tracking and visual analysis of a two-dimensional motion track in a middle school physical experiment are realized.

The embodiments of the present application provide an antenna assembly and an electronic device, which are intended to avoid reducing the influence of the metal plate on the radiation pattern and efficiency of the antenna structure, and to generate horizontally polarized radiation by equivalent magnetic dipole. In the antenna assembly provided in the embodiments of the present application, the metal plate and the antenna structure are arranged on the same side of the circuit board, and the metal plate and the antenna structure are an integrated structure. The metal plate is used to achieve heat dissipation of the antenna assembly. The metal plate and the antenna structure are arranged adjacent to each other in a direction parallel to the circuit board. The antenna structure is located inside the circuit board. While the metal plate can achieve heat dissipation of the antenna structure, the antenna structure can also be exposed, reducing the influence of the metal plate on the radiation pattern and efficiency of the antenna structure, thereby improving the radiation pattern and efficiency of the antenna structure and the metal plate. The electronic device provided in the embodiments of the present application can realize two-way communication between the user equipment and the communication system, thereby realizing fiber to the room (Fiber To The Room, referred to as FTTR).

The invention relates to an autonomous docking wireless charging method for an underwater robot, and the method comprises the steps: enabling the underwater robot to monitor the state of a battery in real time through a battery management module, and triggering a charging mode when the electric quantity is detected to be lower than a preset low electric quantity threshold value; when the underwater robot moves to a preset to-be-charged area near the charging base station, magnetic field gradient data and motion state data of the underwater robot are collected, and three-dimensional coordinates and attitude angles of the underwater robot relative to the magnetic dipole beacons of the charging base station are calculated; calculating a position deviation between a charging coil of the underwater robot and a charging base station coil according to the three-dimensional coordinate and the attitude angle; after the position of the underwater robot is adjusted, the underwater robot is driven to be in charging butt joint with the charging base station, and a charging program is started; and monitoring the charging process in real time until the electric quantity of the underwater robot reaches the preset charging electric quantity. According to the invention, charging is autonomously triggered through electric quantity monitoring, accurate docking in a complex environment is realized through magnetic field gradient positioning, and efficient charging is ensured.

The invention provides a positioning system and method for a permanent magnet target in a gastrointestinal tract. The positioning system comprises a magnetic source, a magnetic sensor array and a processing module, the magnetic source is used for generating a magnetic field; the magnetic sensor array is used for measuring the magnetic field intensity in the space; and the processing module acquires magnetic field intensity data, and further performs spatial position and orientation calculation of the target by using the magnetic moment and magnetic field intensity data of the magnetic source based on a magnetic dipole model and a magnetic moment theory. By means of the innovative magnetic field induction technology and the magnetic dipole model, the problems that in the prior art, positioning of an electronic capsule in the gastrointestinal tract is insufficient in precision, large in external interference, difficult in posture information obtaining, incapable of meeting the requirement for precise diagnosis and treatment in modern medical treatment and the like are solved, and permanent magnet target positioning in the gastrointestinal tract can be achieved.

The invention discloses a low-profile bidirectional end-fire circularly polarized antenna array and an adjusting method thereof, the antenna array comprises eight sub-arrays, a single-layer F4B dielectric substrate and a one-to-sixteen radio frequency circuit, the eight sub-arrays are divided into four left sub-arrays and four right sub-arrays, and the four left sub-arrays and the four right sub-arrays are arranged on the single-layer F4B dielectric substrate in a central symmetry mode; each sub-array comprises a feed metal column, a short-circuit metal column, a magnetic dipole and an electric dipole, and the adjustment method comprises the steps of introducing polarization constraint conditions, constructing a model, constraining an electric field component in a bidirectional end-fire direction, forming a circularly polarized wave, and accurately adjusting the excitation of each antenna array element according to optimal excitation distribution. The problem of polarization mismatch when a receiving terminal moves among circularly polarized waves in different rotation directions is solved, bidirectional left-hand circularly polarized radiation is flexibly realized, the defect of low end-fire circularly polarized gain of a traditional single electromagnetic dipole is overcome, and bidirectional end-fire gain exceeds 11.5 dBic.

The invention relates to a planar end-fire dual-frequency circularly polarized antenna with a small frequency ratio, which comprises a first magnetic dipole unit used for providing a vertical polarization component, and the first magnetic dipole unit comprises a medium, a first patch assembly, a first short circuit assembly and a feed end, the first patch assembly and the first short circuit assembly form a first cavity; the feed end is arranged on the first patch assembly; the second electric dipole unit comprises a first folding structure and a second folding structure, the second folding structure is a reverse folding structure of the first folding structure, and the second folding structure and the first folding structure form a complementary structure at the tail end. According to the invention, the structure is simple, the requirements of circular polarization phases of two frequency bands can be met at the same time, and the design complexity and the processing and manufacturing cost are greatly reduced; the complementary structure of the folded electric dipole tail end structure and the reverse extension branch knot can realize a small frequency ratio of about 1.3, and has the advantages of high gain and wide impedance bandwidth at high frequency.

An antenna includes a grounding plate; a first electric dipole; a first feeding unit, where the first feeding unit includes a first coupling structure coupled to the first electric dipole, and the first feeding unit performs coupled feeding on the first electric dipole through the first coupling structure; a second electric dipole, where the second electric dipole is disposed between the first electric dipole and the grounding plate; a second feeding unit, where the second feeding unit includes a second coupling structure coupled to the second electric dipole, and the second feeding unit performs coupled feeding on the second electric dipole through the second coupling structure; and a magnetic dipole, where the magnetic dipole is electrically connected to the grounding plate, the first electric dipole, and the second electric dipole.

The invention discloses a millimeter wave broadband dual-polarization magnetoelectric dipole antenna. The antenna comprises a first dielectric plate, a first bonding layer, a second dielectric plate, a second bonding layer, a third dielectric plate and a metal floor which are sequentially arranged from top to bottom, the upper surface of the first dielectric plate is provided with a group of electric dipoles used for radiating electromagnetic waves, a feed structure and a metal patch, and magnetic dipoles are arranged between two adjacent layers of the first dielectric plate, the first bonding layer, the second dielectric plate, the second bonding layer and the third dielectric plate. A first metal column unit used for moving out of a matching abnormal resonance point in a working frequency band is arranged between the first dielectric plate and the first bonding layer. According to the invention, millimeter wave frequency band, wide bandwidth performance, compact structure and multi-polarization characteristic can be integrated in one antenna, so that the requirements of wireless communication on high speed, low cost, large coverage, good anti-interference capability and the like can be met.

The embodiment of the invention provides a spacecraft multi-layer near field method magnetic moment calculation method and device, and the method comprises the steps: determining the characteristics of a spacecraft, and determining the experiment arrangement of a magnetometer based on the characteristics of the spacecraft; wherein the magnetometer experiment arrangement comprises at least two layers; determining a magnetic moment conversion matrix based on magnetometer experimental arrangement; determining a magnetic moment result through a multi-layer near field method based on magnetometer experimental arrangement; a magnetic moment measurement is determined based on the magnetic moment conversion matrix and the magnetic moment result. Based on the multilayer near-field method and the magnetic dipole magnetic field model, optimization of the spacecraft multilayer near-field method magnetic moment calculation method can be realized, so that the magnetic characteristics of the spacecraft can be evaluated.

A circularly polarized antenna includes a finite, conducting base plate defining a base plane, and an S-shaped top part defining a top plane parallel to the base plane, wherein the top plane has a non-zero distance from the base plane, and wherein both ends of the S-shaped top part have an end contact coupled either to the base plate or to an antenna feed. The antenna is configured to be fed single-ended or differentially to produce at least one pair of co-aligned electric and magnetic dipoles.