93 results about "Electromagnetic wave polarization" patented technology

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 the field of communication and measurement control and especially relates to a dual polarization transmit-receive waveguide array antenna. The polarization transmit-receive waveguide array antenna includes N broadband dual polarization antenna sub arrays and a polarization adjusting device. Each broadband dual polarization antenna sub array includes a dual polarization opening waveguide array radiation layer and a network feed layer, wherein the dual polarization opening waveguide array radiation layer is arranged above the network feed layer and the polarization adjusting device is arranged below the network feed layer. By adopting the waveguide grid structure for feeding a plate satellite antenna, the working bandwidth of the plate satellite antenna is enlarged,share of transmit-receive of antenna opening and face is realized, radiation grating lobe is reduced and an interface is provided for automatic adjustment of electromagnetic wave polarization direction.

The invention discloses a multifunctional device based on a VO2 and graphene mixed metamaterial, and relates to the technical field of photoelectricity. The device comprises a plurality of unit structures, wherein each unit structure comprises a vanadium dioxide layer, a graphene layer, a dielectric layer and a metal reflection layer, wherein the dielectric layer is arranged at the upper end of the metal reflection layer; the graphene layer is arranged at the upper end of the dielectric layer; a groove is arranged in the graphene layer; the groove extends into the dielectric layer; the vanadium dioxide layer is arranged at the upper end of the bottom of the groove; a dielectric layer region is reserved between the vanadium dioxide layer and the graphene layer; electromagnetic wave polarization conversion is carried out by adjusting the Fermi level of the graphene layer in order to realize functional shift of the multifunctional device between a perfect absorber and a polarization converter; the multifunctional device can work in a high-temperature environment, the absorption effect of the absorber on the electromagnetic wave cannot be weakened along with the increase of the temperature, and instead the absorption effect can be enhanced; and the polarization converter has the advantages of being ultra-thin, wide in frequency band, high in efficiency and the like.

The invention discloses a sub-wavelength layered three-dimensional broadband absorbing structure based on a loss type frequency selective surface. The sub-wavelength layered three-dimensional broadband absorbing structure is a periodic array structure formed by a plurality of structural units. Each structural unit consists of four annular frequency selective surfaces a dielectric layer serving asa supporting layer, a ferrite layer arranged at the lower surface of the dielectric layer, and a metal backing plate arranged at the lower surface of the ferrite layer; and the four annular frequencyselective surfaces are uniformly distributed in the dielectric layer in the vertical direction. The ferrite layer uses ferrite with a working frequency lower than 2 GHz; and the annular frequency selective surfaces are made of conductive materials with the electric conductivity of 100-200 S/m. According to the invention, with the sub-wavelength layered three-dimensional broadband absorbing structure, the wide-band absorption of spatial electromagnetic waves is realized. The sub-wavelength layered three-dimensional broadband absorbing structure has advantages of being insensitive to electromagnetic wave polarization, having the light weight, having a simple structure, being easy to process, having the low cost, having the wide working frequency band and having the relative thin thickness.

The invention belongs to the technical field of electromagnetic wave polarization regulation and control and particularly relates to a broadband THz wave plate composed of a specific electromagnetic surface. The whole wave plate is manufactured on a silicon wafer substrate and composed of a bottom back scattering metal layer, a medium layer and a surface anisotropy specific medium layer. The broadband THz wave plate is a reflection-type ultra wideband THz wave plate manufactured on the basis of specific media and the specific electromagnetic surface, and the working frequency of the broadband THz wave plate ranges from 0.45 THz to 1.15 THz. With regard to plane linearly-polarized electromagnetic waves which are emitted into the broadband THz wave plate at a specific polarization angle phi within the frequency range, the reflected waves of the plane linearly-polarized electromagnetic waves can generate 90-degree polarization deflection with the efficiency exceeding 95%, and the overall energy loss is small (lower than 10%); in addition, with regard to the plane linearly-polarized electromagnetic waves which are obliquely incident at different angles theta (below 50 degrees), the effect of the broadband THz wave plate is lowered slightly, and ultrahigh polarization deflection efficiency can still be achieved within a wide frequency band range. A user can manufacture the wave plate of a corresponding structure according to the needs. Besides, the working frequency of the wave plate can be changed by zooming in or zooming out the structure dimensions in equal proportion.

The invention relates to the technical field of electromagnetic wave polarization regulation and control, in particular to a nano structure capable of improving asymmetric transmission and a preparation method thereof. The nano structure is formed by connecting multiple nano structure units with the same structure in a rectangular periodical array manner. Each nano structure unit comprises a metalthin film. An oblique rectangular hole is arranged in each metal thin film. An included angle alpha is formed between the long edge of each rectangular hole and the x direction of the corresponding nano structure unit. Each rectangular hole comprises a connection strip. Two ends of each connection strip are connected to two long edges of a corresponding rectangular hole and are perpendicular to the long edges of the rectangular hole. The metal thin films and the connection strips are made of the same precious metal materials. According to the invention, the preparation method is simple; repeated whirl coating is not required; the nano structure can be formed only through film coating at a time; and compared with the traditional single-layer artificial nano structure, the asymmetric transmission can be improved by about 50%.

A polarization converter made of metamaterial, including a base material and a number of artificial microstructures disposed on the base material. The artificial microstructures can influence the electric field vector of plane electromagnetic wave propagating in it. The electric field vector of the electromagnetic wave can be decomposed into two non-zero orthogonal components on one or more planes perpendicular to the incident direction of the electromagnetic wave, the orthogonal components can be parallel and perpendicular to the optical axis at the position where the artificial microstructure located. After the electromagnetic wave passing through the polarization converter made of metamaterial, the two orthogonal components have a phase difference Δθ different from before incidence, thereby achieving mutual conversion between the above electromagnetic wave polarization methods. The polarization converter made of metamaterial of the present invention is simple in structure, and can easily realize polarization conversion of electromagnetic waves.

The invention relates to a polarization calibration method based on platform attitude time variation compensation. The method comprises steps that: S1, two-dimensional echo data is acquired; S2, scattering matrix observation values of a calibrator at one same irradiation time are extracted; S3, an incidence angle and an oblique angle of the calibrator irradiated by electromagnetic waves are acquired; S4, when the calibrator receives polarization calibration angles of the electromagnetic waves, deflection amount at each irradiation time is acquired; S5, full polarization echo data after attitude error compensation correction is acquired; S6, azimuth compression of the full polarization echo data after the attitude error compensation correction is carried out to acquire an image; and S7, scattering matrixes after calibrator deflection amount correction are extracted in each polarization channel of the image, an unbalance degree which is left over in the scattering matrixes after calibrator deflection amount correction and is led in by a transceiver module of a full polarization synthetic aperture radar system, and crosstalk in each channel are evaluated, error correction of the full polarization synthetic aperture radar system is realized, and the full polarization synthetic aperture radar image is acquired.

The invention belongs to the technical field of telecommunication and specifically relates to a P-band dual circularly polarized helical antenna. The antenna comprises, from upper to lower part, the first, second, third and fourth layer of metal radiation ring (including radio-frequency control circuit) and metal reflection layer; each layer of metal is engraved on the medium of epoxy glass cloth playing the role of supporting; each layer of metal radiation ring comprises two semicircular rings. The right semi-circular rings of metal of the first and the third layer are connected with the left semicircular rings of metal of the second and the fourth layer through a metal microstrip to form the right-hand circularly polarized helical antenna. The radio-frequency control circuit is located on the upper surface of the fourth layer of medium. The input end of the control circuit is connected with the SMA joint. The two output ends are respective connected with the left-hand circularly polarized helical antenna and the right-hand circularly polarized helical antenna. Signals are input from the SMA joint and the polarization mode of electromagnetic wave radiated by the antenna is selected by the radio-frequency control circuit.

The invention belongs to the technical field of antennas, in particular to a single-layer reflective and transmissive bidirectional radiation beam scanning antenna based on a reconfigurable electromagnetic surface technology, comprising a feed source and an array composed of a plurality of bidirectional phased radiation units; A feed for transmitting or receiving electromagnetic waves; A bi-directional phased radiation element is used to modulate the phase of the reflected and transmitted waves. The bidirectional phased radiation unit comprises a metal layer, a dielectric plate and a DC bias circuit layer from top to bottom, wherein the metal layer is provided with a digital control device, and the DC bias circuit layer is used for supplying an operating voltage to the digital control device and controlling an operating state of the digital control device. The reflection and transmission polarization directions of the bidirectional phased radiation unit are the same and orthogonal to the polarization direction of the feed source. In the transmission propagation direction of the front surface, the transmission electromagnetic wave of the antenna and the polarization direction of theelectromagnetic wave incident on the front surface of the feed source are orthogonally isolated, and the cross polarization is adopted to realize the phase control function.

The invention discloses a circularly polarized microstrip duplex antenna. The circularly polarized microstrip duplex antenna comprises a microstrip patch antenna, two feed probes, a duplex power distribution network, a transmitting port and a receiving port; the two feed probes are both connected with the duplex power distribution network; the duplex power distribution network comprises a power distribution microstrip line, a transmitting microstrip band elimination filter, a transmitting impedance conversion microstrip line, a receiving microstrip band elimination filter and a receiving impedance conversion microstrip line; each feed probe comprises a horizontal microstrip and a vertical metal probe; one end of the vertical metal probe is connected with the center of the horizontal microstrip while the other end of the vertical metal probe is connected with the power distribution microstrip line. The microstrip circularly polarized antenna with a duplexing function is designed in the invention; transmitting and receiving of the antenna adopt the same electromagnetic wave polarization mode which refers to left-hand circular polarization electromagnetic wave; and meanwhile, by virtue of the setting of the transmitting and receiving microstrip band elimination filters, high isolation degree between transmitting and receiving ports can be realized.

The invention relates to a half-wave plate in the terahertz band based on the Mylar, and belongs to the technical field of the electromagnetic wave polarization regulation. The half-wave plate is composed of a plurality of structural units in turn, wherein each structural unit adopts an electromagnetic meta-material surface, and the specific structural composition from bottom to top is: a reflective metal layer, a dielectric layer, an elongated metal structure layer. The layers are directly stacked between the layers. The resonant frequency and quality factor of the half-wave plate are respectively regulated by the length and the width of the elongated metal structure layer. Regarding the plane line polarized electromagnetic waves that are vertically incident in a frequency range, the reflected waves produce the 90-degree polarization deflection with an efficiency of more than 90%, and the overall energy loss is small, thereby achieving an ultra-high polarization deflection efficiencyin a wide frequency band range. Moreover, the half-wave plate has a simple process and a low price, and is more suitable for popularization and use. A user can make a corresponding structural wave plate as desired. In addition, the operating frequency of the wave plate can be changed by equally scaling the size of a scaled structure.

The present invention relates to the technical field of microwave antennas and discloses a circular polarizer with switchable polarization. The circular polarizer comprises an upper structure and a lower structure. According to the lower structure, metal grids are formed by arranging a plurality of metal lines with gaps, the metal grids are printed on dielectric plates, and the dielectric plates are bonded to foam layers. According to the upper structure, metal meander line structures are formed by arranging multiple metal meander lines with gaps, the metal meander line structures are printedon three layers of dielectric plates, and the three dielectric plates and two foam layers are bonded to each other. Both the upper structure and the lower structure are coaxial disk structures, and the upper structure can rotate around an axis relative to the lower structure. By rotating the structure of the polarizer, the arbitrary conversion of a linearly polarized wave to left and right circularly polarized waves is achieved, or the polarization form of an original electromagnetic wave is not changed. In addition, according to the design of the two-layer structure, the interaction between the antenna structure and meander line circular polarizer is eliminated, the shaft ratio performance of an antenna is improved, and the polarization conversion efficiency is improved.

A terahertz transmitting-receiving common dual-polarized quasi optical circulator comprising: a transmitting component for transmitting a circularly polarized signal; a first transmitting-receiving common branch for dividing the transmitted circularly polarized signal into a horizontal polarization signal and a vertical polarization signal, and transmitting the vertical polarization signal and receiving the horizontal polarization signal by using electromagnetic polarization characteristics; a second transmitting-receiving common branch for transmitting the horizontal polarization signal and receiving the vertical polarization signal by using the electromagnetic polarization characteristics; a transmitting-receiving component for combining the vertical polarization signal transmitted by the first transmitting-receiving common branch and the horizontal polarization signal transmitted by the second transmitting-receiving common branch into a circularly polarized signal to be transmitted as a radar signal, dividing a received radar echo circularly polarized signal into a horizontal polarization signal and a vertical polarization signal, enabling the horizontal polarization signal to enter the first transmitting-receiving common branch and the vertical polarization signal to enter the second transmitting-receiving common branch. The terahertz transmitting-receiving common dual-polarized quasi optical circulator has isolated transmitting and receiving channels and a function of receiving dual polarization information at the same time.

The invention relates to the field of electromagnetic wave polarization beam splitting, and discloses a polarization beam splitting element and device. The polarization beam splitting element comprises dielectric films and metal films, wherein the dielectric films and the metal films are periodically alternately stacked. A dielectric film and a metal film constitute a periodic repeating unit, andthe average dielectric constant of the periodic repeating unit is zero. When light is incident at an interface parallel to the polarization beam splitting element, transverse electric waves and transverse magnetic waves in the light can be separated due to the dispersion relationship in the polarization beam splitting element. According to the difference in the thickness ratio of the dielectric films and the metal films in the periodic repeating units, the polarization beam splitting element has two working modes which can be flexibly selected under different requirements. The polarization beam splitting element in the structure has the advantages of simple structure, easy preparation and wide material selection, is much smaller than the existing polarizing beam splitter, is easy to integrate, and has a wide application prospect in optical communications and integrated optical paths.

The invention discloses a motion attitude sensing method based on electromagnetic wave polarization three-dimensional electric/magnetic signal stationary characteristics. The method comprises the steps of receiving electromagnetic wave signals through a sensor at a motion platform reference attitude, obtaining a signal cross correlation matrix, computing a CRB (Cramer-Rao bound) value estimated through attitude parameters, and judging whether the electromagnetic wave signals can be used for motion platform attitude measurement in the environment; computing the signal cross correlation matrix at the motion platform reference attitude, and judging whether the electromagnetic wave signals are stationary at the environment or not according to characteristic values of the reference attitude and a real-time attitude cross correlation matrix; converting the motion platform attitude under a real-time attitude coordinate system to be at a geographic coordinate system, and accomplishing motion platform attitude sensing. The method has the advantages that attitude/course sensing can be realized only by one receiving point on the motion platform, the system can be miniaturized, the measurement accuracy is high, the system can be miniaturized, signals are not interfered by multipath effect, the method can not only be used for actively transmitting electromagnetic wave signals, can also passively receive space distributed broadcast electromagnetic wave signals to measure attitude, and improves the system invisibility. The method is applied to aerospace vehicles.

The invention belongs to the technical field of stealth materials and particularly relates to a wave-absorbing material with a regular honeycomb 10-degree structure. The material comprises a wave-transmitting layer, a wave-absorbing layer, and a reflecting layer which are stacked in sequence from top to bottom, the wave-transmitting layer is made of a composite fiber material and has a first preset size, the wave absorbing layer is made of a magnetic micron wire material, is of a regular honeycomb 10-degree structure and has a second preset size; and the reflecting layer is made of metal and has a third preset size. The invention discloses the wave-absorbing material with the regular honeycomb 10-degree structure, a regular honeycomb-shaped wave-absorbing structure of an unconventional structure of a novel wave-absorbing medium is adopted; impedance matching is achieved by adding the wave-transparent layer, electromagnetic energy reflection is reduced, incident electromagnetic wave polarization and magnetization are caused by fully utilizing the structure, a good absorption effect on 2GHz-18GHz electromagnetic waves is achieved through the wave-absorbing medium loss effect, and theelectromagnetic compatibility shielding or stealth effect is achieved.

The invention relates to a metamaterial, comprising at least one fold line structural layer; the fold line structural layer comprises a substrate and at least one fold line structure arranged on the substrate; the fold line structure comprises a first fold line portion and a second fold line portion; the first end of the first fold portion is in connection with the first end of the second fold line portion; a length difference exists between the first fold line portion and the second fold line portion; and the first fold line portion and the second fold line portion form an angle of 90 DEG. The metamaterial sets the fold line structure on the fold line structural layer to realize electromagnetic wave polarization conversion through the fold line structure. In addition, the length difference between the first fold line portion and the second fold line portion can be determined according to the wave length of original polarized wave, and electromagnetic wave conversion results can be controlled through the relation between the length difference and the wave length.

The invention discloses a novel waveguide polarization mode transition diaphragm structure applied in terahertz band. The whole diaphragm is in a disc structure. Eight symmetrical circular holes are arranged around the center in the disc, wherein four large circular holes and four small circular holes are arranged with spacing. The specific center of location is equal to a standard flange UG387. The center can be provided with a coupling cavity according to needs. The novel waveguide polarization mode transition diaphragm structure provided by the invention has the advantages of simple processing and low processing cost. Missile-borne, satellite-borne and other microwave millimeter-wave systems have the device requirements of small size and light weight. The thickness of the monopole polarization twist waveguide provided by the invention is slightly greater than quarter wavelength. Due to small size, light weight and small standing wave and insertion loss, the working bandwidth can reach the whole band of waveguide. The diaphragm structure fully meets the function of electromagnetic wave polarization direction conversion in a small space structure, meets engineering needs, and has a high application value in bomb, spaceborne and other narrow band systems with harsh requirements on size and weight.

The invention discloses an electromagnetic-wave polarized reconfigurable radome formed by a plurality of unit structures arranged regularly along an orthogonal direction. Each unit structure is formedby successive lamination of a front metal layer, a first dielectric plate, an intermediate metal layer, and a second dielectric plate and a back metal layer; the front metal layer having a square shape is arranged at the front side of the unit structure and an L-shaped slot and a metalized through hole are formed in the front metal layer; a cross metal strip is arranged at one edge of the first dielectric plate; one end point of the front metal layer is connected with the cross metal strip at the edge of the first dielectric plate by a metal strip with a crack; an inductor is arranged in thecrack of the metal strip; the back metal layer is arranged at the back of the unit structure and the back structure of the unit structure and the front structure of the previous unit structure are arranged symmetrically; and the metalized through hole formed in the front metal layer and a metalized through hole formed in the back metal layer are connected by a metal wire. Therefore, transformationamong linear polarization, left-right circular polarization, andlinear polarization is realized conveniently.

The present invention discloses a space-time-polarization combination anti-interference method based on a polarization sensitive array. The method receives electric field components of two orthogonal directions while employing a quadrature linear polarization unit to obtain electromagnetic wave polarization domain information, the spatial distribution of array elements is employed to obtain signal spatial domain information and obtain time domain information through adoption of time domain tapping of each channel so as to realize space-time-polarization multi-domain combination interference resistance. On the basis of the LCMV criterion, according to the distribution characteristics and polarization characteristics of satellite signals, normal right-handed circular polarization constraint is added. Compared to a traditional array, the breakthrough of N-1 degree of freedom of N array elements is realized, 2N-1 broadband interference can be inhibited, and the gain of satellite signals is ensured while effectively inhibiting the interference.

The invention discloses an angle-insensitive conformal broadband reflective linear polarization converter and belongs to the field of electromagnetic wave polarization conversion. The polarization converter is formed by seamlessly stacking a metamaterial structural layer, two dielectric layers and a bottom metal backing plate. The metamaterial structural layer is composed of a long metal ring resonator, a circular metal patch and a short metal ring. The long metal ring resonator provides the anisotropy and the main resonance of the metamaterial, and the coupling of the circular metal patch andthe short metal ring adjusts the intensity and resonance frequency of magnetic resonance and electrical resonance, thereby realizing the broadband linear polarization conversion and good angle insensitivity. Furthermore, by using a flexible electromagnetic metamaterial as the dielectric layer, the designed polarization converter can be conformed to an object having a developable curved surface.

The invention relates to a linear polarized wave transmitting-receiving device. The linear polarized wave transmitting-receiving device comprises an electromagnetic wave linear polarized unit, a transmission assembly and a drive module, wherein the electromagnetic wave linear polarized unit comprises at least one meta-material layer; the meta-material layer comprises a base material and a plurality of manmade micro structures with anisotropic electromagnetic properties arranged on the base material, wherein the plurality of manmade micro structures are arranged on a plane vertical to the incidence direction of the electromagnetic wave; the transmission assembly is driven based on a drive module to rotate the electromagnetic wave linear polarized unit, so that the direction from which the electromagnetic wave linear polarized unit receives the linear polarized wave is the same as the incident electromagnetic wave polarized direction. By rotating the electromagnetic wave linear polarized unit, the direction from which the electromagnetic wave linear polarized unit receives the polarized wave is the same as the polarized direction of the incident electromagnetic wave, thereby timely adjusting the polarized direction from which a ground base station antenna or a wireless mobile communication device receives the polarized wave to improve the electromagnetic wave communication efficiency.

The invention relates to a structure capable of being used for Ku and Ka dual-band wave transmission. The structure comprises skin layers and an FSS layer; the FSS layer is bonded between the two skinlayers; the structure has the advantages that the Ku and Ka dual-band wave-transmitting function can be achieved, electromagnetic wave polarization insensitivity is achieved, the stable wave-transmitting characteristic is achieved when the incident angle of electromagnetic waves in the wave-transmitting band ranges from 0 degree to 60 degrees, the low-band electromagnetic wave reflecting functionis achieved, and the stealth performance of a radar is improved.