106 results about "X-wave" patented technology

The invention discloses a microwave optical fiber link device for long-distance transmission of radar reference frequency signals and relates to the technology of radar detection. The microwave optical fiber link device consists of an optical emitter, an optical receiver, a Faraday rotating mirror, an optical circulator, a polarization maintaining optical fiber, a radio-frequency power amplifier and the like. By subjecting microwaves to electric-optical and optical-electric conversion and utilizing the advantages of low insertion loss and high-temperature phase stability of the optical fiber, the microwaves are transmitted in low phase fluctuation and loss in the long distance. The microwave optical fiber link device can be used for transmission of rate-aided signals of spatial long-base line interference synthetic aperture radar (SAR) and transmission of reference frequency signals of radar systems such as phased array radars and multi-base radar monitoring net. Besides, phase changes caused by environmental factors such as temperature and irradiation can be accurately compensated during long-distance transmission of X-wave band microwave signals, and meanwhile, the microwave optical fiber link device has ultrawide radio-frequency (RF) working band and can be developed for transmission of radar reference frequency signals ranging from 50MHz to18GHz.

The invention discloses an electromagnetic shielding silicon rubber/graphene/carbon nanotube nano composite material and a preparation method thereof. The composite material comprises the following components in parts by mass: 100 parts of silicon rubber, 0.05-1 part of graphene and 0.01-0.5 part of carbon nanotubes. The composite material has the structural characteristics that a three-dimensional continuous conductive network framework formed by graphene/carbon nanotubes is filled with the silicon rubber of the composite material, and the conductive framework is a three-dimensional continuous porous material formed by the graphene and the carbon nanotubes in a mutual interweaving manner. The preparation method of the composite material comprises the following steps: firstly, establishingthe three-dimensional continuous graphene/carbon nanotube conductive network framework, backfilling the silicon rubber, and performing vulcanization molding. By adopting the composite material, properties of high conductivity and outstanding electromagnetic shielding are achieved with a low packing amount (less than or equal to 1.5wt%), the conductivity can be up to 100S/m or greater, and the electromagnetic shielding property of the composite material at an X-wave band (8.2-12.4GHz) can be up to 35dB or greater.

The invention discloses a coal mine area surface deformation monitoring method based on a lifting rail time sequence InSAR. The coal mine area surface deformation monitoring method is characterized bycomprising the steps of acquiring a plurality of scene SAR images of C and X wave bands, generating a short baseline set, differentiating an interference pattern, acquiring a high coherence point, constructing an equation, acquiring surface deformation information and the like. Compared with the prior art, the coal mine area surface deformation monitoring method has the advantages of breaking through the limitation that a single SAR satellite platform InSAR technology can only obtain deformation information in a radar sight line direction, effectively weakens the influences of space-time incoherence, phase unwrapping errors, atmospheric delay errors and the like, improves the precision and reliability of the InSAR technology for monitoring surface deformation information, and promotes thewide application of the InSAR technology in the field of deformation monitoring.

The invention discloses an electromagnetic shielding silicon rubber/graphene/silver nanowire nano composite material and a preparation method thereof. The composite material comprises the following components in parts by mass: 100 parts of silicon rubber, 0.05-1 part of graphene and 0.01-0.5 part of silver nanowires. The composite material has the structural characteristics that a three-dimensional continuous conductive network framework formed by graphene/silver nanowires is filled with the silicon rubber of the composite material, and the conductive framework is a three-dimensional continuous porous material formed by the graphene and the silver nanowires in a mutual interweaving manner. The preparation method of the composite material comprises the following steps: firstly, establishingthe three-dimensional continuous graphene/silver nanowire conductive network framework, backfilling the silicon rubber, and performing vulcanization molding. By adopting the composite material, properties of high conductivity and outstanding electromagnetic shielding are achieved with a low packing amount (less than or equal to 1.5wt%), the conductivity can be up to a magnitude order of 104S/m, and the electromagnetic shielding property of the composite material at an X-wave band (8.2-12.4GHz) can be up to 40dB or greater.

The invention belongs to the field of wave remote sensing technology, and particularly relates to a method for conducting X wave band navigation radar wave parameter inversion through a band-pass filter based on a novel wave dispersion relation, wherein sea clutter images are obtained through navigation radar so that wave parameter inversion can be conducted. The method comprises the steps that radar image data are collected; radar images are preprocessed; Fourier transform is conducted on an image sequence under a Cartesian coordinate system, so that a three-dimensional wave number frequency image spectrum of the radar images is obtained; wave spectrum information is extracted; wave information inversion is achieved. Influence on the dispersion relation by the ship speed is kept by the filter, the problem that the band pass of a traditional broadband-pass filter is increased along with increase of the movement speed is effectively solved, and therefore filtering can be conducted under the condition that a radar platform is moved along with movement of a ship. In band pass boundary derivation of the novel filter, an approximate value of any quantity is avoided, calculation errors are reduced, influence on the band pass boundary is avoided, band width calculation is more accurate, and wave inversion accuracy is improved.

The invention provides a filtering power divider of an X wave band substrate-based integrated waveguide coaxial cavity. An input and output structure and a substrate integrated waveguide coaxial filtering unit are designed on one side of a dielectric substrate, and a floor is arranged on the outer side of the dielectric substrate; the input and output structure comprise an input end and two output ends; the input end adopts a secondary T-shaped step impedance matching network switched coplanar waveguide feed structure; the substrate integrated waveguide coaxial filtering unit is formed by cascading two substrate integrated waveguide coaxial resonant cavities, and energy is coupled through an opening between the resonant cavities; the two output ends are coplanar waveguide switched micro-strip structures respectively, and a 100-Ohm resistor is connected between the two output ends. The filtering power divider has higher unloaded quality factor, the filtering power divider has remarkable effects for improving the insertion loss of the device and reducing the size of the device, particularly the narrow-band application and performance indexes under relatively high frequency are obviously improved respectively, and the filtering power divider has obvious effects for miniaturization and cost control of modern radar systems.

The invention discloses a Ku wave band fully-coherent radar target simulator. The Ku wave band fully-coherent radar target simulator comprises a control device, a Ku wave band microwave signal source, an X wave band microwave signal source, an S wave band microwave signal source and an intermediate frequency signal source. The Ku wave band fully-coherent radar target simulator can simulate and generate radar target echo signals, two-way local oscillator signals and intermediate frequency signals and completes detection of performance of radar equipment; utilizes a DDS (Direct Digital Synthesis) technology as theoretical basis and successfully achieves the generation of intermediate frequency Doppler signals of the radar target simulator; utilizes the DDS spread spectrum technology to expand a DDS operation bandwidth to a microwave frequency band needed by people, and completes the generation of echo simulation signals of a radio frequency target; utilizes a PLL (Phase Locking Loop) technology to achieve the generation of the local oscillator signals, meanwhile utilizes the same crystal oscillator as clock reference, achieves full-coherence of all the signals, and provides basis for completion of performance tests of Ku wave band radar equipment.

The invention provides a wideband wide beam circular polarization medium resonator antenna suitable to X wave band, and belongs to the field of antennas. The antenna includes a medium substrate of which the right side is covered with a layer of metal surface mount device, a rectangular medium resonator which is arranged on the metal surface mount device, and an L-shaped feed microstrip antenna which is arranged on the back side of the medium substrate. The 4 corners of the bottom part of the rectangular medium resonator are dug out 4 same dimension rectangular medium blocks, and cross-slot-coupled the L-shaped microstrip antenna feed are adopted, so that the features of the wideband of the antenna area realized. The antenna is advantaged by wide frequency band, low profile, easiness to process, high stability of directional diagram within the working frequency band and wide wave beam width.

The invention belongs to a five-bit X wave band phase shifter matched with an X wave band communication device for use. The five-bit X wave band phase shifter comprises a CPW (circular polarized wave) signal line rotatably arranged on a base plate and chamfering at exterior angles of corners, an insulating layer and CPW (coplanar waveguide) ground wires, an MEMS (micro-electromechanical systems) switch beam, a support plate, an upper polar plate and a lower polar plate of an MAM capacitor as well as an MEMS switch group consisting of components inside a supporting piece thereof. A connecting bridge, a bias electrode and an insulating layer are arranged between the CPW ground wires at the front and rear ends of the corners cross the CPW signal line. The positive electrode and the negative electrode of the bias electrode are connected with a lead. The base plate with the insulating layer is arranged on the upper surface. Compared with a conventional five-bit X wave band phase shifter, the five-bit X wave band phase shifter has the advantages that the area of the five-bit X wave band phase shifter provided by the invention is reduced by nearly 1/3, meanwhile the performance and the stability of the phase shift are improved. Therefore, the five-bit X wave band phase shifter is compact in structure, small in volume, high in strength and stability, low in insertion loss, large in Q value and high in phase shifting precision, and can be processed with high precision and large scale. Meanwhile, the packaging difficulty and the production cost in the production process are reduced and the like.

The invention provides an X-wave band high-power microwave integration radiation field measuring system. After being received by an antenna, a high-power microwave radiation field signal is processed by power attenuation by a waveguide attenuator and is successively transmitted to a programmable attenuator and a coaxial attenuator by a waveguide coaxial transducer to carry out power attenuation; a detector detects an envelop waveform of the signal and a digital converter carries out acquisition; the signal is transmitted to a single-board computer; and a monitoring computer uses a fiber optical transceiver to carry out monitoring on the digital converter and a temperature sensor; and the digital converter and the programmable attenuator are controlled. According to the invention, the system is integrated with functions of electromagnetic protection, attenuation adjustment, signal detection, data acquisition and process, remote controlling, and optical fiber data transmission and the like. The system with the compact structure is simple and can be carried conveniently; and rapid development of the external field measurement can be realized conveniently. The electromagnetic protection capability of the whole system is improved; the dynamic range of measurement is increased; and the system well adapts to measurement of radiation fields with different power levels.

The invention discloses a dual-polarized X-wave band radar ocean wave parameter measurement system, comprising a radar, wherein the radar consists of a radar host and a dual-polarized antenna which isconnected with the radar host in a communicated manner; the radar host is connected with a data acquisition module of a computer; the data acquisition module converts video signal output by the radarinto digital signal and stores the digital signal in a memory unit of the computer; the computer is connected with a polarized switching control module by an I/O interface and is connected with the dual-polarized antenna by the polarized switching control module in a control manner; one end of the dual-polarized antenna is connected with the radar host in a communicated manner, and the other endthereof is connected with the polarized switching control module. The system can provide off-shore area ocean wave parameter information for all day in real time accurately, with the characteristics of security and non-easy lost, low maintenance cost, stable and reliable work, simple and easy operation, and can observe for a long term, therefore, the invention has good application value and marketprospects.

The present invention provides an SSPPs type microwave band-pass filter, and relates to the microwave filter technology field. The filter adopts a three-segment type structure, the first segment is a coplanar waveguide segment, the second segment is a transition segment transformed from the coplanar waveguide segment to an SSPPs segment, and the third segment is the SSPPs segment, wherein the SSPPs segment adopts a novel child-mother composite groove structure characterized by arranging the child groove structures which are periodic, are in mirror symmetry and are arranged parallelly in the mother grooves. By the number and the geometric sizes of the child grooves, the sub-wavelength bound effect of a microwave electric field can be improved further, and the band-notched characteristic of the SSPPs filter is more excellent. The filter can be widely used in the microwave communication systems, such as the micro-strip circuits of L-wave band to X-wave band, a microwave base station, etc.

The invention discloses a high-performance magnetic carbon-based composite nanofiber microwave absorbent and a preparation method thereof. Composite nanofibers are prepared by electrostatic spinning and a post heat treatment one-step method; the mean diameters of the composite nanofibers are 150-500 nm; generated Fe nanoparticles are relatively uniformly distributed in or on the surfaces of the carbon nanofibers, and are wrapped by a graphitized carbon layer; and the absorbent has better oxidation resistance and corrosion resistance. The density of a wave absorption coating prepared by compositing with silica gel is only 0.8-1.0g/cm<3>; when the thickness of the coating is 1.2-2.0mm, the minimum reflection loss of the absorbent reaches -35dB to -75dB; the effective absorption band width with the reflection loss less than -10dB at 2-18GHz reaches 10.2GHz; a whole Ku wave band and an X wave band are covered; and the absorbent has the advantages of light mass, broadband, strong absorption, convenient adjustment of electromagnetic parameters, and the like.

The invention relates to a microwave absorbing compounding material that uses silicon carbide as basal material, and the manufacture method. The technology is that: adopting silicon carbide powder that has the diameter of 0.1-10um, graphite C power that has the diameter of 0.1-10um. After molding, the compounding material is sintered at 1700-2250 degree centigrade. The feature is that the density range is 1.6-3.2cm³, resistivity range is 10⁰-10⁴.cm, the real part of dielectric constant is 1-200. The material is machined to sectional area of 22.86*10.16mm², and the thickness at 4, 8, 12mm, the microwave maximum of attenuation value of the X wave section at 8-12.4GHz is -40db, and the attenuation values in the whole X section are all above -20db.

The invention discloses a navigation X-wave-band radar wave group detection method based on a wave theory. The navigation X-wave-band radar wave group detection method based on a wave theory includes the steps: performing empirical orthogonal function decomposition on a navigation X-wave-band radar image sequence, selecting a main modal to reconstruct a wave field, and obtaining the wave surface displacement of different positions in an observed sea area through scaling of the wave field; for the wave surface of one radial direction, utilizing change of the displacement gradient to detect the extreme value of the wave surface, and according to the difference between adjacent two maximum values and minimum values, obtaining the wave height at different positions; utilizing the sum of two sine functions to fit the wave surface between the adjacent minimum wave heights, and identifying the area as a wave group when the fitting parameter accords with the wave theory; and combining with observations at different times, obtaining the parameters of the wave group, such as amplitude, length and group speed. The navigation X-wave-band radar wave group detection method based on a wave theory utilizes the buoy to perform scaling on the main modal of the wave field so as to obtain the wave height information of a large area in the observed sea area, and then utilizes the two sine functions which are approximate in frequency based on the wave theory to determine the wave group without requirements for selecting a threshold according to the experience, and has the advantages of being simple and easy to do, and being wide in the application range.

The invention relates to a left hand material micro-strip antenna, in particular to an X-wave range branch-shaped structure left hand material micro-strip antenna. Being different from the existing micro-strip antenna, the branch-shaped structure left hand material is loaded on the micro-strip antenna; a circuit board etching technique is adopted so as to etch the branch-shaped structure left hand material onto the micro-strip antenna substrate. The peculiar electromagnetic behavior of the branch-shaped structure left hand material is used for improving the performance of the antenna, reinforcing the forward radiation of the antenna, concentrating the directionality more and improving the gain of the antenna. The preparation method used for the branch-shaped structure left hand material of the micro-strip antenna of the invention is identical to that of the antenna, adopts the circuit board etching technique, is integrally formed with the micro-strip antenna, and has simple preparation and low cost.

The invention discloses a transparent broadband random surface, comprising multiple unit structures. The unit structure comprises the upper transparent conductive film layer, transparent substrate and lower transparent conductive film layer. The upper transparent conductive film layer is located at the upper surface of transparent substrate and the lower transparent conductive film layer is fully covered at the lower surface of transparent substrate; the upper transparent conductive film layer is the double resonance unit structure with random sizes; and the double resonance unit structure is the symmetrical structure, comprising the ring located at the center of unit structure and stub ring located at the periphery of ring. The transparent broadband random surface can realize the light transmittance >=85% within the scope of visible light, effectively shorten the RCS of target object in the X wave band with simple technology, uniform structure and transparent visible light, has excellent electromagnetic scattering properties and play an important role in such fields as invisibility of aircraft cockpit.

This invention relates to a single-board RF system used in microwaves and millimeter waves, especially to an X band chip integrated waveguide single-board RF system including a medium chip set with an antenna, a duplexer, a RF receive noise amplifier, a RF receive filter, a lower converter, a local power splitter, an upper converter, a RF emission filter, an emission power amplifier, an IF emission circuit, a RF local phase lock loop and an IF receiving circuit.

The invention discloses a high-performance Fe-Ni alloy/C composite nanofiber microwave absorbent and a preparation method thereof. The absorbent is prepared by electrostatic spinning and a post heat treatment one-step method; a synthetic technology is simple; the mean diameters of obtained fibers are 200-400nm; generated Fe-Ni alloy nanoparticles are relatively uniformly distributed in or on the surfaces of the carbon nanofibers, and are wrapped by a graphitized carbon layer; and the absorbent has better oxidation resistance and corrosion resistance. The density of a wave absorption coating prepared by compositing with silica gel is only 0.8-1.0g/cm<3> when the content of the absorbent is 3-10wt%; when the thickness of the coating is 1.2-2.0mm, the minimum reflection loss of the absorbent reaches -40dB to -95dB; the effective absorption band width with the reflection loss less than -10dB at 2-18GHz reaches 10.2GHz;a whole Ku wave band and an X wave band are covered; and the absorbent has the advantages of light mass, broadband, strong absorption, convenient adjustment of electromagnetic parameters, and the like.

The invention discloses an ultra-thin electromagnetic wave absorber based on electrolyte-regulated graphene, and belongs to the technical field of microwave devices. The ultra-thin electromagnetic wave absorber comprises four layers of structures overlapped together, specifically including an electrolyte graphene layer, a high-resistance surface layer, a dielectric layer and a metal base plate, wherein the dielectric layer is arranged on the metal base plate, the high-resistance surface layer is arranged on the dielectric layer, and the electrolyte graphene layer is arranged on the high-resistance surface layer. According to the ultra-thin electromagnetic wave absorber based on electrolyte-regulated graphene provided by the invention, the electrolyte-regulated graphene technique is combined with the high-resistance surface layer to design a super wave absorbing device, the device is simple in structure, small in size and convenient to integrate, covers the broadband absorbing of X wave band, has the high absorptivity of more than 90%, is insensitive to incident angles and polarization angles of electromagnetic waves, is applicable to the fields of communication, household consumer electronics and military stealth technologies, and is very high in practicability.

The invention discloses a high-performance magnetic carbon-based composite nanofiber microwave absorbent and a preparation method thereof. Composite nanofibers are prepared by electrostatic spinning and a post heat treatment one-step method; a synthetic technology is simple; the mean diameters of the obtained fibers are 100-300nm; generated Ni nanoparticles are relatively uniformly distributed in or on the surfaces of the carbon nanofibers, and are wrapped by a graphitized carbon layer; and the absorbent has better oxidation resistance and corrosion resistance. The density of a wave absorption coating prepared by compositing with silica gel is only 0.8-1.0g/cm<3> when the content of the absorbent is 3-10wt%; when the thickness of the coating is 1.2-2.0mm, the minimum reflection loss of the absorbent reaches -36dB to -71dB; the effective absorption band width with the reflection loss less than -10dB at 2-18GHz reaches 9.7GHz; a whole Ku wave band and 5% of X wave band are covered; and the absorbent has the advantages of light mass, broadband, strong absorption, convenient adjustment of electromagnetic parameters, and the like.

The invention belongs to the technical field of a material and an antenna cover, in particular relates to an ultrathin frequency-selective metamaterial capable of wave absorption from two sides, an antenna cover and an antenna system. The ultrathin frequency-selective metamaterial capable of wave absorption from the two sides is virtually divided into a plurality of square unit structures arranged periodically, wherein each square unit structure comprises a dielectric substrate, a square annular resistance thin film and a comb-shaped frequency selective surface periodic structure, the square annular resistance thin film is attached onto the upper surface of the dielectric substrate, and the comb-shaped frequency selective surface periodic structure is attached onto the lower surface of the dielectric substrate. The antenna cover disclosed by the invention is used for covering the antenna system and comprises the above ultrathin frequency-selective metamaterial capable of wave absorption from the two sides. The antenna system comprises an antenna and the above antenna cover. With the metamaterial disclosed by the invention, favorable radiation characteristic of the antenna in a Ku wave band can be maintained, and the antenna can freely transmit and receive communication; and meanwhile, in an X wave band and a K wave band on the two sides of the Ku wave band, the metamaterial disclosed by the invention is provided with the resistance thin film with wave absorption characteristic taking a square metal patch layer as a grounding surface, and the wave incident to the antenna cover is absorbed.

The invention discloses a terahertz security imaging system based on a vector network analyzer, which includes a signal generation and acquisition device, an analog front end, a scanning drive device, a signal and data processing device; the vector network analyzer is used as the signal generation and acquisition device, Through the analog front-end, the step frequency signal of the X-band is up-converted to the terahertz band to radiate to the space to be inspected, and then the target echo signal of the terahertz-band is down-converted to the X-band through the analog front-end for signal processing; the main control computer is used for signal processing. The scanning drive device, signal and data processing device are controlled, and the user can adjust the corresponding scanning parameters according to the actual situation to achieve optimal detection, which improves the efficiency of the security inspection system; Such substances have good penetrability, and can effectively detect hidden items in packages and human clothing, with high resolution and accuracy.

The invention relates to metal powder and preparation and application thereof. Specifically, the metal powder has the components as shown in formula I, wherein M, R, a, b and c are defined according to the specification; and, the particle size of the metal powder is smaller than or equal to 8 microns. The invention further discloses the preparation and the application of the metal powder. The metal powder is especially suitable for preparing a wave-absorbing material, and the obtained wave-absorbing material can achieve complete covering of X wave bands under -10 dB. Thus, the waver-absorbing material can fully meet the application requirements of military use and civil use X wave band wave-absorbing materials for communication, radar detection and the like, and has wide market application prospect. FeMaRbNc is the formula I.

The invention discloses an adjustable narrowband wave-absorbing device based on a plasma meta-material. The adjustable narrowband wave-absorbing device comprises a bottom metal reflecting plate, a dielectric substrate and solid-state plasma resonator units, the dielectric substrate and the solid-state plasma resonator units are arranged on the metal reflecting plate, solid-state plasma is implemented by an array composed of PIN units, the PIN units are isolated from one another through isolation layers, and the PIN unit array is controlled and excited through a programmable logic array loadedon two ends of the PIN unit array to obtain the solid-state plasma. Each solid-state plasma resonator unit has two kinds of working states including the excited state and the unexcited state. the wave-absorbing device has a good absorption effect on TE polarized waves, the excitation region of each resonator unit formed by the solid-state plasma is controlled in a programming mode, excitation of different resonator units can be achieved, and therefore the aim of maintaining the high absorption rate of the wave-absorbing device in a high frequency band and dynamically controlling progressive optimization of the absorption rate in a low frequency band is achieved, and the working frequency of the wave-absorbing device can efficiently cover the whole X wave band when the excitation region isselected appropriately.

The invention discloses honeycomb core material, compound wave-absorbing material and honeycomb enhanced metamaterial. The honeycomb core material comprises a plurality of honeycomb periodic structure units and is characterized in that artificial metal microstructures are attached to honeycomb walls of at least part of the honeycomb periodic structural units. Both the compound wave-absorbing material and the honeycomb enhanced metamaterial comprise the honeycomb core material. Compared with the traditional pure-honeycomb structure of the prior art, the honeycomb core material has the advantages that the metal microstructures are attached to the honeycomb walls, leading to dielectric parameter and permeability greatly improved within the X wave band, besides, within the frequency band, the permeability generates magnetic resonance so as to enhance loss; In this way, remarkable advantages are imparted on production of the narrow-band wave-absorbing material and high-loss shielding material.

The invention discloses a C interlayer broadband radome structure with the band-pass performance in C and X wave bands. The C interlayer broadband radome structure comprises a frequency selective surface (FSS) core layer, a skin and an air interlayer, the FSS core layer comprises a dielectric substrate and the periodic FSS arrays etched on the upper layer and the lower layer of the substrate, andthe interlayer fixation and isolation between the skin and the FSS core layer are realized through a plurality of medium screws and gaskets, so that an air interlayer with a certain thickness is formed. According to the invention, under an oblique incidence condition, the broadband radome bandwidth stability problem is solved, the radome structure design realizing the broadband, high wave transmission rate and steep drop out-of-band rejection functions and insensitive to the influence of the incident angles and polarization changes is provided, and on the premise of guaranteeing the normal radiation of an antenna, the anti-interference capacity and the stealth performance of an antenna system are effectively improved.