30results about How to "Improved Angular Stability" patented technology

The invention discloses an aperture multi-layer structure-based high-out-of-band rejection frequency selective material design method. The method includes the following steps that: (1) a frequency selective material is designed based on an aperture multi-layer structure, wherein the aperture multi-layer structure includes three layers of structures, namely, a top-layer patch, a bottom-layer patch and a middle coupled aperture layer; (2) an out-of-band transmission null characteristic is realized through constructing a design method of patch displacement of the top-layer patch and the bottom-layer patch, and the side band cut-off characteristic of the aperture multi-layer structure-based frequency selective material can be further improved; and (3) a unit interdigital technology is adopted to carry out miniaturization processing on the surface of the frequency selective material, so that the unit size of the surface of the frequency selective material can be decreased. With the method of the invention adopted, a high-order coupling characteristic is realized, and the side band cut-off performance of the frequency selective material can be improved; and the unit interdigital method is adopted, so that the unit size of the surface of the frequency selective material can be decreased, and angle stability under the incoming of electromagnetic waves can be improved; and the out-of-band rejection ability of the frequency selective material is stronger, and the pass-band edge rise performance and sharp drop performance of the frequency selective material are better.

The invention belongs to the technical field of antenna RCS (radar cross section) reduction, and particularly relates to a wide-angle RCS reduction metasurface based on a radar wave absorbing and scattering cancellation technology. The metasurface is characterized by comprising an upper dielectric substrate (2), a metal floor (1) and a lower dielectric substrate (3), radiation metal patches (11) are distributed on the upper surface of the upper dielectric substrate (2). microstrip feeder networks (10) are distributed on the lower surface of the lower dielectric substrate (3), and the upper dielectric substrate (2), the metal floor (1) and the lower dielectric substrate (3) are combined from top to bottom to form the wide-angle RCS reduction metasurface antenna array (4). Different from the conception of the prior art, the metasurface design is carried out in a mode of combining radar wave absorption and scattering cancellation technologies, and a good reduction effect can be realized in a wide-angle electromagnetic wave incidence range.

The invention provides a 2.5D braided structure-based high-angular stability frequency selective surface and aims at improving the angular stability of the frequency selective surface. The 2.5D braided structure-based high-angular stability frequency selective surface comprises M*N passive resonance units, wherein each passive resonance unit comprises a dielectric slab, a first metal patch printedon the upper surface of the dielectric slab, a second metal patch printed on the lower surface of the dielectric slab, and metallized through holes; each first metal patch comprises six rotational symmetric first strip groups; each second metal patch comprises six rotational symmetric second strip groups; various strips in the second strip groups are located in gaps, in corresponding positions onthe lower surface, of various corresponding strips in the first strip groups; and the strips in the first metal patches and the second metal patches are connected through the corresponding metallizedthrough holes which penetrate through the dielectric slabs to form a 2.5D braided structure. According to the 2.5D braided structure-based high-angular stability frequency selective surface, good angular stability is achieved on the basis of miniaturization, and the 2.5D braided structure-based high-angular stability frequency selective surface can be applied to the aspects of communications andradars.

Disclosed is a white light top emission type OLED and a preparation method thereof. A substrate, a reflective anode, a hole injection layer, a hole transport layer, a double blue light luminous layer, a red light luminous layer, an electron transfer layer, an electron injection layer, a semitransparent cathode and an optical coupling output layer are sequentially evaporated from bottom to top. The preparation process comprises firstly cleaning the substrate, then performing evaporation in vacuum and cooling after the evaporation is finished. The preparation method of white light top emission type OLED effectively restrains multi-beam interference by means of the semitransparent cathode and the optical coupling output layer, thereby enhancing output of white light on the whole; enhances wide-angle interference of a blue light blue light waveband through a structural feature that the double blue light luminous layer is adjacent to the anode; utilizes the double blue light luminous layer of a heterojunction structure to control an exciton recombination region for increasing intensity of blue light as well as improving stability of chroma of a device; effectively improves the chroma and the stability of the white light top emission type OLED, thereby having potential application values.

The invention discloses a dual polarization broadband external inhibition three-dimensional frequency selective surface. The frequency selective surface is of a three-dimensional periodic structure processed by a dielectric substrate, and comprises a square coaxial line waveguide and a parallel slab waveguide. The surface of the dielectric substrate is provided with metal patches, rectangular grooves are formed in two ends of each metal patch in the propagation direction of electromagnetic waves, and metal via holes in the dielectric substrate are connected to the metal patches on two sides. Adual mode resonator is formed by the parallel slab waveguide, a passband containing two transmission poles is generated, and due to the interaction between the two waveguides, a wide stop band containing two transmission zero points is generated near the passband. The frequency selective surface has low polarization sensitivity in a dual polarization operating mode, the frequency ranges of the passband and the stop band can be controlled by changing relevant physical parameters, dual polarization application is realized, and the frequency selective surface has high incident angle stability.

The invention discloses an atlantoaxial dislocation anterior anatomy template with an automatic reduction function. The atlantoaxial dislocation anterior anatomy template comprises an atlas part, an axis part and a connecting part. The atlas part is in an arc shape, and symmetrical screw holes are designed in the two sides of the atlas part. The axis part is located below the back of the atlas part and matched with the front structure of the body of the axis, five screw holes are designed in the axis part, four screw holes are symmetrically located in the two sides, and the other screw hole is located in the middle and is an oblong sliding screw hole. The atlas part and the axis part are connected through the connecting part. A screw slides in the sliding screw hole, so that the atlantoaxial dislocation reduction effect is achieved; through screw fixing, the atlantoaxial reduction purpose is achieved, the form of the template is completely matched with the anatomic form of the atlas and the axis, a higher degree of fit is achieved, and the template is attractive in appearance and good in reduction effect.

The invention discloses a low-profile dual-band wave-absorbing surface applied to a vehicle-mounted radar test environment. The low-profile dual-band wave-absorbing surface comprises a dielectric substrate, an array printed on the front surface of the dielectric substrate and formed by periodically arranging resistive frequency selection units, and a metal floor printed on the back surface of the dielectric substrate, and the resistive frequency selection unit is composed of a resistive square ring and a resistive square patch, and the square patch is embedded in a hollow area of the square ring. According to the invention, effective absorption of electromagnetic waves can be realized in two vehicle-mounted radar frequency bands of 24GHz and 77GHz for omnidirectional angles, pitch angles within 30 degrees, TE polarized incident waves and TM polarized incident waves. Compared with the prior art, the low-profile dual-band wave-absorbing surface has the advantages of extremely low profile, light weight and simplicity and convenience in processing and mounting, can effectively eliminate the interference of stray electromagnetic waves when being applied to a vehicle-mounted radar test environment, can greatly reduce the occupied space of a test system, and has a very good engineering application prospect.

The invention relates to a power angle stability improving method and system for an alternating current and direct current interconnected power system. The method comprises the steps of: collecting the power angle difference of a generator in the alternating current and direct current interconnected power system; determining a charging/discharging power reference value of the energy storage systemaccording to the power angle difference; determining the charging/discharging power of the energy storage system according to the charging/discharging power reference value; and controlling the energy storage system to perform charging/discharging based on the charging/discharging power of the energy storage system. The technical scheme provided by the invention aims at the power angle stabilitycharacteristic of the AC/DC interconnected power system, the feasibility that the energy storage technology rapidly consumes the unbalanced power of the AC-DC interconnected power system and improvesthe power angle stability of the AC-DC interconnected power system is analyzed, an energy storage controller capable of improving the power angle stability is designed, and finally the power angle stability of the AC-DC interconnected power system is improved based on the energy storage technology.

The invention belongs to the field of electromagnetic metamaterials, and relates to a low-RCS metasurface, in particular to an ultra-wideband RCS reduction metasurface based on mutual superposition of polarization conversion bandwidths, which is characterized by comprising an upper dielectric substrate (4), a lower dielectric substrate (5) and a metal reflecting plate (3) which are distributed at intervals from top to bottom, a low-frequency metasurface structure (1) of a lumped resistor is loaded on the upper surface of the upper-layer dielectric substrate (4), and a high-frequency metasurface structure (2) is arranged on the upper surface of the lower-layer dielectric substrate (5); and a low-frequency polarization conversion unit (111) in the low-frequency metasurface structure (1) and a high-frequency polarization conversion module (211) at the corresponding position in the high-frequency metasurface structure (2) form an overall polarization conversion unit (6), and coupling parameters are changed by adjusting the interval, shape and layout of low-frequency units and high-frequency units, so that the overall polarization conversion unit (6) obtains broadband polarization conversion. According to the invention, the bandwidth of RCS reduction is broadened, the angle stability of the metasurface is improved, and stable RCS reduction of more than 10dB in an ultra-wide frequency band can be realized under large-angle incidence of electromagnetic waves.

The invention relates to a meter-wave radar low-elevation height measurement method based on robust principal component analysis noise reduction, and the method comprises the steps: carrying out the modeling of an array receiving signal of a meter-wave radar into a two-dimensional receiving signal matrix, and obtaining an array receiving signal model; establishing a convex optimization model of a low-rank signal matrix and a sparse noise matrix by adopting a noise reduction method based on robust principal component analysis; solving the convex optimization model by using an improved non-precise augmented Lagrangian multiplier method to obtain an optimal low-rank signal matrix without noise pollution; establishing a covariance matrix by using the optimal low-rank signal matrix, and constructing the maximum likelihood estimation of the direct wave elevation direction of arrival in combination with the covariance matrix and the synthetic steering vector to obtain a target elevation estimation value; and calculating the target height by using the target elevation angle estimated value. According to the method, the problems that in the prior art, under the conditions of non-uniform noise, low signal-to-noise ratio and few snapshots, the angle measurement performance is reduced, and the angle resolution is insufficient are solved, and the method has high angle measurement stability and good angle resolution.