529 results about "Electromagnetic wave equation" patented technology

The invention discloses a full-carbon coaxial line and a manufacturing method of the full-carbon coaxial line, and belongs to the technical field of integrated circuits. Graphene serves as a monatomic layer thickness, is coiled into a cylinder and form an inner conductor of the coaxial line with a small radius (can be as small as the nm level), and the inner conductor of the coaxial line transfers currents. Meanwhile, a signal layer or multiple layers of graphene serve(s) as an outer conductor of the coaxial line to form a boundary of electromagnetic waves in a space, and graphite oxide serves as medium materials between the inner conductor and the outer conductor to limit and guide oriented transmission of electromagnetic wave energy. The coaxial line is quite small in size and applicable to radio-frequency and microwave integrated circuits.

A method for acquiring an image or spectrum of a subject or object residing within the magnetic field of a magnetic resonance apparatus, comprises the steps of:

• • executing a predetermined pulse sequence for applying gradient magnetic fields and for coupling in electromagnetic excitation pulses to induce nuclear magnetic resonance within the subject or object;
  • detecting an electromagnetic signal resulting from said magnetic resonance; and
  • constructing at least one image or magnetic resonance spectrum of said subject or object from said detected electromagnetic signal.

According to the invention, said coupling in of the electromagnetic excitation pulse and/or said detecting of the electromagnetic signal are carried out substantially by means of travelling electromagnetic waves.

The invention discloses a measuring method for electrical resistivity of electromagnetic waves while drilling, comprising the following steps: generating an electromagnetic wave power signal with specific frequency; emitting the electromagnetic wave power signal into a ground layer through an emitting antenna coil; receiving two electromagnetic wave power signals including measured ground layer information through two receiving antenna coils so as to generate two paths of electromagnetic wave power signals including the measured ground layer information; carrying out band-pass filtering to the two paths of the electromagnetic wave power signals including the measured ground layer information, and carrying out AD sampling to the two paths of the electromagnetic wave power signals including the measured ground information which is subjected to the band-pass filtering so as to generate two paths of electromagnetic sampling digital signals; carrying out frequency mixing transformation and low-pass filtering to the electromagnetic wave sampling digital signals so as to generate amplitude value information and phase information; generating amplitude value ratio and phase difference according to the amplitude value information and the phase information; and generating an electrical resistivity drawing board of the electromagnetic wave power sinals in a chart inversion method according to the amplitude value ratio and the phase difference. An embodiment of the invention also discloses a measuring device for the electrical resistivity of the electromagnetic waves while drilling.

The invention relates to a wave beam regulating and controlling device which comprises a metal layer and a medium layer. The wave beam regulating and controlling device is characterized in that the thickness of the metal layer is smaller than one third of an operating wavelength, the thickness of the medium layer is smaller than a half of the operating wavelength, the total thickness of the metal layer and the medium layer which are alternately stacked is not more than two wavelengths, and the metal layer is provided with super cells which comprise a plurality of metal resonant units. The metal resonant units are utilized to regulate and control phases, consequentially, regulation and controlling of wave beams are achieved, and therefore the wave beam regulating and controlling device is ultra-thin in thickness. Phase control which is wide in frequency band and high in efficiency is generated by using a locally resonant mode of a multilayer metal structure through near-field coupling, and consequentially efficient regulation and controlling over the wave beams is achieved. The electromagnetic wave beams are regulated and controlled by using a plane structure, preparation is simple, price is low, and therefore high economic benefits are possessed.

A target object detection apparatus periodically executes a transmit/receive operation to transmit radar waves and obtain received signals from resultant incident reflected waves from respective target objects. An individual correlation matrix of received signal values is derived for each one of a fixed plurality of successive transmit/receive operations, with the transmission frequency being changed at successive operations. Individual correlation matrices derived from respective transmit/receive operations are time-averaged to obtain an average correlation matrix for use in obtaining target object information such as direction or velocity, with effects of correlation between respective incident waves being suppressed.

A method for detecting an object, comprising the steps of defining expected characteristics of scattered electromagnetic radiation to be received at a receiver; attenuating at least a portion of electromagnetic radiation received at the receiver by a presence of an object within a path of electromagnetic information; and detecting the attenuation to indicate a presence of the object. The object may be a low radar profile object, such as a stealth aircraft. The electromagnetic radiation is preferably microwave, but may also be radio frequency or infrared. By using triangulation and other geometric techniques, distance and position of the object may be computed.

A radar level gauging system for determining at least one process variable related to a distance to a surface of a product in a tank comprising transceiver circuitry, processing circuitry, a wave guiding structure arranged guide measurement signals towards the surface, and a radiator connected to the transceiver circuitry and arranged to emit the measurement signal into the wave guiding structure. The system further comprises a mode generator adapted to convert electromagnetic waves emitted from the radiator from a first propagation mode to a second propagation mode, wherein the mode generator includes a lens in the form of a body transparent to electromagnetic waves in the operating frequency range.

With this design, electromagnetic waves having the first propagation mode emitted by the radiator into the lens will be reflected at least twice within the lens (first in the bottom surface and then in the upper surface). At the second reflection (in the upper surface of the lens), the propagation mode will be changed, and the electromagnetic waves exiting the lens will have the second propagation mode.

The invention belongs to the technical field of electromagnetic wave polarization detection, and particularly discloses an efficient microwave polarization detection device based on a photonic spin Hall effect. For the detection device, electromagnetic wave to be detected is decomposed into left-hand circularly polarized beam and right-hand circularly polarized beam through the efficient photonic spin Hall effect, the module values and phases of the left-hand circularly polarized beam and right-hand circularly polarized beam are respectively measured, and backstepping is carried out to obtain the polarization of the electromagnetic wave to be detected. The photonic spin Hall effect is realized through linear geometry Berry phase gradient of total-reflection type meta-surface with a spin structure. Compared with the traditional polarization detection manner (linear polarization loudspeakers opposite to each other are used for directly measuring x component and y component of electromagnetic wave), the efficient microwave polarization detection device has the advantages that higher convenience and quickness are achieved, the errors are few, and the stability is better. The operating frequency of the device is 10-14GHz, and the structure constants of meta-atoms are scaled in equal proportion or redesigned, so that the operating frequency can be applied to other operating frequency ranges.

The invention relates to a metamaterial polarization transformer which comprises a base material and a plurality of artificial micro structures being arranged on the base material and having anisotropic electromagnetic characteristics, wherein the artificial micro structures are uniformly arranged on one or more planes vertical to an entering direction of electromagnetic waves, refractive indexesinside the metamaterial polarization transformer are uniformly distributed, an electric field vector of the entering electromagnetic waves is decomposed into two non-zero quadrature components on oneor more planes, the two quadrature components are respectively parallel or vertical to an optical axis of positions where the micro structures are in, and after the electromagnetic waves penetrate through the metamaterial polarization transformer, the two quadrature components have a phase difference delta theta different from a phase before entering. The metamaterial polarization transformer hasa simple structure, and can easily realize polarization transformation of the electromagnetic waves.

The invention provides a reflective array antenna. The reflective array antenna comprises a reflective array face, and the reflective array face comprises a function board which is used for beam modulating of incidence electromagnetic wave and a reflecting layer which is arranged on one side of the function board and is used for reflecting the electromagnetic wave. The function board comprises two or more function board units. The reflecting layer comprises reflecting units, wherein, the number of the reflecting units corresponds to the number of the function board units. A phase shift unit which is used for shifting phase is formed by each function board unit and each corresponding reflecting unit. The reflective array face has a focusing ability for the incidence electromagnetic wave in a scheduled angle range with a normal direction of the reflective array face. According to the fact that the reflective array antenna has the focusing ability of the incidence electromagnetic wave in the preset angle range, the reflective array antenna is capable of having a plurality of focal points so as to be used for different environment or areas.

The present invention relates to a structure having a characteristic of conducting or absorbing electromagnetic waves, which comprises a substrate; a powder material convex structure section having a characteristic of conducting or absorbing electromagnetic waves disposed on a surface of the substrate, the powder material convex structure section containing a powder material having a characteristic of conducting or absorbing electromagnetic waves and being formed so as to have a convex structure; and a holding part disposed on a surface of the substrate, the holding part holding the convex structure of the powder material convex structure section having a characteristic of conducting or absorbing electromagnetic waves. The structure of the invention has the characteristic of conducting or absorbing electromagnetic waves at an excellent level and can be produced easily and inexpensively.

The invention discloses a transformer substation local discharging signal online monitoring and positioning method. Different from the traditional local discharging monitoring method which only can be used for monitoring one power equipment, the method provided by the invention is used for carrying out online monitoring and positioning on the local discharging signals of all the power equipment in a transformer substation. The method comprises the following steps of: (1) arranging an antenna array close to a central position in a space region of the transformer substation, and receiving an electromagnetic signal in the transformer substation by adopting the antenna array; (2) acquiring electromagnetic wave signals received by all antennae; (3) filtering the acquired electromagnetic wave signals, comparing the filtered electromagnetic wave signals with a standard local discharging signal; if the filtered electromagnetic wave signals are similar to or same with the standard local discharging signal, judging that a local discharging source exists in the substation; and (4) positioning the local discharging source by utilizing time difference of the local discharging signals received by two different antennae.

The invention relates to an on-line power switch cabinet monitoring system and a monitoring method thereof. The system comprises a switch cabinet, wireless sensor nodes which is installed at the parts heating easily in the switch cabinet, and a wireless energy transmission device which is installed in an instrument room of the switch cabinet or outside the switch cabinet, wherein the wireless energy transmission device conducts data interaction with a monitoring center through GPRS (General Packet Radio Service) or optical fibers. The method comprises the following steps that: the power-on wireless energy transmission device sends RF (radio frequency) energy to the wireless sensor nodes in the switch cabinet and waits restoration answering signals; the wireless sensor nodes convert electromagnetic wave energy into electric energy by utilizing RF energy collecting modules; the power-on wireless sensor nodes send the restoration answering signals to the wireless energy transmission device and provide ID numbers of the nodes; the wireless energy transmission device after receiving data sent by the wireless sensor nodes conducts local display and uploads the data to the monitoring center. According to the invention, power is supplied to sensors through an electromagnetic radiation mode, so that the characteristics of free maintenance, safety and reliability, convenience in installation and the like can be achieved.

The invention discloses a compact range antenna measuring system which comprises a feed source which is arranged in a microwave anechoic chamber and a planar wave generation unit formed by a plurality of meta-material layers which are overlapped with one another, wherein each meta-material layer comprises a substrate and a plurality of artificial hole micro-structures on the substrate; and electromagnetic waves generated by the feed source are converted into planar electromagnetic waves after passing through the planar wave generation unit. A reflecting surface in the prior art is replaced by the planar wave generation unit made from meta-materials, and the refraction characteristics of the planar wave generation unit are simulated by a computer according to test requirements, so that an antenna testing turntable is provided with a quasi-plane-wave testing area with excellent performance after the electromagnetic waves generated by the feed source are refracted by the planar wave generation unit. Thereby, the manufacturing of a high-precision reflecting surface and a high-difficulty processing technique are omitted, and thus the manufacturing cost of the compact range antenna measuring system is greatly reduced.

The invention provides an energy pickup device for a robotic fish, which is characterized by comprising a non-contact charging induction coil arranged in the robotic fish and an active coil array arranged on the bottom of a fish tank, wherein the active coil array is communicated with an external power source through a power control board and a plug; the active coil array is used for generating electromagnetic waves; and the non-contact charging induction coil can be coupled with an active coil, output of the non-contact charging induction coil is connected with a rechargeable battery through a rectifier voltage stabilizing circuit module which can convert alternating current into a stabilized voltage direct current, and the non-contact charging induction coil is used for converting the electromagnetic wave energy sensed from the active coil into direct current to provide power source energy for the robotic fish. The robotic fish can be charged in a non-contact mode through the energy pickup device very conveniently and effectively without changing the battery, thus the trouble of changing the battery for the robotic fish frequently by an operator is solved, and the maintenance cost of the robotic fish at ordinary times is reduced, and no pollution is caused.

A touch sensor of an electromagnetic resonance type includes a plurality of touch electrodes configured to generate an electromagnetic wave according to an input signal or to transmit an output signal according to a response electromagnetic wave from an approached object, wherein corresponding ones of the plurality of touch electrodes are at a same layer.

In driving of the vehicle, when an object unexpected by a driver suddenly appears at a close range in a traveling direction of the vehicle, a collision is liable to occur. A vehicle risk prediction apparatus includes: a first imaging unit that detects an electromagnetic wave of a wavelength ranging from a millimeter wave to a submillimeter wave to output a first image; a first detection unit that processes the first image output from the first imaging unit to detect a given object; and a risk prediction unit that outputs a detection result of the given object detected by the first detection unit. The first imaging unit includes: a transmit antenna unit that radiates the electromagnetic wave of the wavelength ranging from the millimeter wave to the submillimeter wave; a receive antenna array unit that has a plurality of receive antenna units arranged two-dimensionally, and receives a reflected wave of the electromagnetic wave radiated by the transmit antenna unit from the given object; and a signal processing unit that measures a time from radiation of the electromagnetic wave by the transmit antenna unit to reception of the reflected wave by the receive antenna array unit according to the number of read frames by the receive antenna array, and calculates both or any one of a distance from the subject vehicle to the given object, and a relative speed between the subject vehicle and the given object.