22 results about "Electromagnetic wave polarization" patented technology

The present invention discloses a polarization-insensitive electromagnetic rectifying surface, which solves the problems that the efficiency of the rectifying surface is easily affected by the polarization direction of the incident electromagnetic wave, the matching and DC synthesis circuits are complex, and the energy loss is relatively large. The upper surface of the dielectric substrate (2) of the rectifying surface includes m rows and n columns of rectifying surface units (1) with the same size and shape, where m and n are positive integers greater than or equal to 2, and an output filter circuit (4). The lower surface of the dielectric substrate (2) is covered by a metal ground (3), and the lower surface includes pads (14) with metallized vias (13) and Schottky diodes (15); each rectifying surface unit (1) includes 1 energy receiving unit (11), 4 microstrip lines (12), 4 metallized vias (13), 4 pads (14) located on the lower surface, and 4 Schottky diodes (15). The present invention has the advantages of being insensitive to the polarization direction of the incident wave, having a simple structure, and high rectifying efficiency.

The invention provides a hybrid superstructure applied to low-frequency ultra-wideband electromagnetic isolation. Comprising a low-frequency antenna metal mounting plate, an air and / or medium complementary substrate integrated cascade structure, a sub-wavelength low-frequency electromagnetic wave high-resistance surface cascade structure, a sub-wavelength low-frequency electromagnetic wave polarization converter cascade structure, a low-frequency ultra-wideband metamaterial wave absorber and a low-frequency ultra-wideband transceiving antenna. Through hybrid design of complementary substrate integration, high-resistance surface cascading, polarization converter cascading and a wave absorbing structure, excellent electromagnetic isolation performance is realized in a wide frequency band; the isolation degree between the low-frequency ultra-wideband receiving and transmitting antennas is remarkably improved, and the direction finding precision of the system is improved; the adverse effect of the antenna mounting plate on the radiation characteristic of the antenna is effectively reduced, and the working performance of the antenna is improved; the structure is flexible and adjustable, structural parameters can be optimized according to specific application scenes, and different engineering requirements are met.

The electromagnetic wave polarization parameter estimation method based on a single antenna is implemented as follows: (1) establish a three-dimensional rectangular coordinate system, and the real signal of the electromagnetic wave incident from any direction in space is represented as E(n); (2) use two adjacent snapshot electric field vectors p1 and p2 to calculate the vector m(n) parallel to the propagation direction of the electromagnetic wave, and take its average value #imgabs0#; (3) estimate the pitch angle θ and azimuth angle φ of the incoming wave based on the components of the vector #imgabs1#; (4) use coordinate transformation to obtain the pitch component E of the electric field θ (n) and the azimuth component E φ (n); (5) Obtain the analytical signals #imgabs2# and #imgabs3# of each component through Hilbert transform (6) Calculate the amplitude E of each component θm (n) and E φm (n), calculate the polarization parameter γ(n); (7) calculate the phase difference Δ(n) between the elevation component and the azimuth component, and estimate the polarization parameter η(n); (8) average the above polarization parameters to obtain the phase descriptor #imgabs4#. The present invention has the advantage of estimating the polarization parameters of electromagnetic waves based on a single antenna, with low cost and small size. The present invention can be applied to fields requiring polarization parameter estimation, such as communications and radar.

The application discloses a method for estimating the elevation angle of a slant ionospheric sounding incoming wave based on polarization response, which comprises the following steps: obtaining the polarization response information of the incoming wave through an orthogonal receiving antenna, so as to determine the limit polarization of the incoming wave signal from the ionosphere into free space, and determining the direction of the incoming wave through the relationship between the limit polarization and the elevation angle of the incoming wave and the geomagnetic field. The method for estimating the elevation angle of the slant ionospheric sounding incoming wave based on polarization response can be applied to the acquisition of the elevation angle information of the incoming wave through the processing and estimation of the polarization information of the electromagnetic wave, and can also be used as an auxiliary means of the traditional short-wave direction finding method.

The invention discloses a metasurface antenna for realizing complete polarization and all-phase modulation, which belongs to the technical field of electromagnetics, and comprises at least one metasurface unit, the metasurface unit comprises a metasurface layer, a dielectric substrate, a metal grounding layer and a metal via hole, the metasurface layer comprises a circular metal patch and a pair of arc-shaped openings which are symmetrical about the center of the patch, a metal via hole penetrates through the dielectric substrate and serves as a rotating center shaft of the metasurface layer, and continuous regulation and control of electromagnetic wave polarization components are achieved by rotating azimuth angles of the arc-shaped openings; and the whole metasurface layer is rotated around the metal through holes, so that global regulation and control of the radiation electromagnetic wave phase are realized. Full-polarization continuous regulation and control and all-phase global coverage are achieved, the system integration degree is greatly improved through ultra-low profile integration, and the large-scale application potential is achieved.

This invention discloses a Ku-band wave-to-wave conversion structure, relating to the fields of millimeter-wave communication and radar technology. The Ku-band wave-to-wave conversion structure comprises a three-layer planar structure based on PCB / LTCC technology. The top layer is a graded dielectric substrate, the dielectric constant of which is gradually varied by a doping concentration gradient. The middle layer is a metal microstrip line array, with the linewidth and spacing continuously varying along the propagation direction. The bottom layer is a copper foil grounding layer. The Ku-band wave-to-wave conversion structure provided by this invention is used to achieve efficient conversion of electromagnetic wave polarization modes over a wide frequency band.

The present invention relates to a reconfigurable reflective polarization converter, and more particularly, to a temperature-voltage-controlled reconfigurable reflective polarization converter. The converter comprises a bottom metal reflector, an intermediate dielectric layer, and a top resonant unit layer, arranged sequentially from bottom to top. The top resonant unit layer comprises a plurality of square metal sheets, which are periodically arranged in an M×N pattern on the intermediate dielectric layer to form a periodic array. A phase-change material is coated between adjacent square metal sheets; the phase-change material is VO2 nanopowder dispersed in a PVP matrix. The present invention enables temperature and voltage control of the converter's operating state, is insensitive to the polarization and angle of incidence of the incident electromagnetic wave, exhibits strong adjustability and frequency flexibility, and has the potential to be easily expanded to the terahertz and even optical bands. The converter also features a simple manufacturing process and has significant application value in fields such as antenna radiation and radar cross-section reduction for dynamic electromagnetic wave control.

The present invention discloses an ultra-thin broadband reconfigurable transmission unit and its array, comprising a first metal layer, a second metal layer, and a dielectric layer, with the dielectric layer disposed between the first and second metal layers. The first metal layer includes a radiating patch etched with a π-shaped slot, and a radio frequency switch disposed on the π-shaped slot. The radio frequency switch is reversed to change the state of electromagnetic waves radiated by the radiating patch. The second metal layer includes a receiving patch etched with an L-shaped slot. The first metal layer is connected to the second metal layer via a metal column. The first and second metal layers form a polarization rotation structure such that the polarization of the electromagnetic waves radiated by the first metal layer is perpendicular to the polarization of the electromagnetic waves received by the second metal layer. The reconfigurable transmission unit can be formed by using these two metal layers, the first and second metal layers. The structure is simple and easy to process, which helps to simplify design and reduce costs. The unit can be widely used in the field of antenna technology.

The present invention provides a carrier for circular polarization testing of a dihedral angle structure, which is applied to the technical field of electromagnetic wave polarization testing. The carrier is an integrally formed structure. The carrier has a support surface, and a fixing part for supporting the dihedral angle structure is arranged on the support surface. The included angle between the dihedral angle structure located on the support surface and the horizontal plane is 45°. The carrier for circular polarization testing of the dihedral angle structure provided by the present invention can improve the support stability of the dihedral angle structure and ensure the accuracy of the RCS characteristic measurement of the dihedral angle structure.