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

The invention provides a polarization converter based on a multi-layer frequency selective surface, which is used to solve the problems of complex structure and high loss of the electrically adjustable polarization converter; on the upper surface of the first dielectric plate (2), the second dielectric The lower surface of the board (4) and the lower surface of the fourth dielectric board (6) are respectively printed with a patch array (1) composed of M×N corner-cutting square patches (11), and the first dielectric board ( 2) The lower surface and the lower surface of the third dielectric board (5) are printed with a grid array (3) consisting of M×N metal square rings (33); the four-layer dielectric board (2, 4, 5, 6) A stacked structure is sequentially formed from top to bottom. In the present invention, the angle between the polarization converter and the polarization direction of the incident ray polarized wave can be adjusted by rotation, so that the incident wave can be converted into left-handed circular polarization, right-handed circular polarization, or linear polarization. Wave characteristics. The invention can be applied to fields such as wireless communication and satellite communication.

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 concerns a bone plate system comprising: a bone fastening element comprising a shaft with a first thread, the fastening element further comprising a head with a second thread on its outer surface, the outer surface having a first hardness; and a bone plate having a second hardness which is smaller than the first hardness, the bone plate comprising a through hole for receiving the bone fastening element. The head is oxygen diffusion hardened.

The invention belongs to the technical field of stealth and provides a high-performance frequency selection radar cover used for stealth of flight weapons in order to overcome the shortages of single-screen FSS (frequency selective surface) structural design in the prior art, and difficulty in achieving FSS engineering by bilateral dielectric load FSS and double-screen FSS due to complex structure and high processing difficulty. The radar cover comprises an original radar cover, a first splice dielectric layer, an ultralow dielectric constant dielectric layer, a second splice dielectric layer and a soft FSS film layer. The first splice dielectric layer, the ultralow dielectric constant dielectric layer, the second splice dielectric layer and the soft FSS film layer are molded and combined into an FSS lining from an outer layer to an inner layer, and an FSS lining layer is attached on an inner surface of the original radar cover. Due to the fact that selected cellular and foam media both belong to ultralight materials, weight of the frequency selection radar cover is not increased. The high-performance frequency selection radar cover is relatively simple in structure, process tolerance is large since design margin is large, and difficulty, cycle and cost of process are lowered.

Disclosed is a fixation device for fixing the broken ends of bones in fractures, the device having at least two tensioning elements (2a, 2b), each tensioning element having a body that is hollow and corrugated when viewed from above , with a continuous wall (4) and two receiving sections (6a, 6b) facing each other at the end faces. The device also has at least one clamping sleeve and at least two fastening means that can be placed in the end face receiving section. The at least two tensioning elements (2a, 2b) are placed relative to each other such that a receiving section (6a, 6b) of each tensioning element (2a, 2b) is aligned with a corresponding receiving section of the other tensioning element, And the clamping sleeve penetrates both sections, connecting the two tensioning elements (2a, 2b) to each other. According to the invention, the clamping sleeve is moreover an angled clamping sleeve (15) connected to at least two tensioning elements (2a, 2b) such that the latter are positioned at a predetermined angle relative to each other.

The invention discloses a branch-loaded three-band composite microwave absorbing structure based on a frequency selective surface, belonging to the field of electromagnetic field and microwave communication. An upper dielectric layer, a frequency selection surface and a lower dielectric layer sequentially are arranged from top to bottom; a passive resonance unit of the frequency selective surfacecomprises a three-band absorbing structure and a square ring patch for absorbing a specific wave, the square ring patch being arranged on the three-band absorbing structure, the three-band absorbing structure comprises an arm-removed rectangular Jerusalem cross-shaped patch and a branch perpendicular to each other, the square ring patch and the Jerusalem cross-shaped patch are arranged in a centercoinciding manner, and the arm-removed rectangular portion of the Jerusalem cross-shaped patch is connected with four end points of the branch. The invention solves the problems that the angular stability and the microwave absorption performance of the cross-shaped structure in the existing frequency selective surface are poor, and the square ring structure can only absorb single frequency bands,and achieves the effects of improving the angular stability and absorbing waves in three frequency bands.

The invention discloses a bionic artificial atlanto-odontoid joint which comprises an atlas component, an axis component and a screw, wherein the atlas component comprises a middle cup-and-ball part and side wings; the cup-and-ball part comprises a ball cup part and a circular truncated cone part arranged at the lower end of the ball cup; two sides of the side wings are respectively provided with symmetric lock screw holes; the axis component is divided into an upper part and a lower part; the upper part comprises a top polyethylene ball head and a cylinder below the ball head; a multi-toothed structure is designed at the contact part of the bottom surface of the cylinder and a bone surface; the lower part is matched with the front structure of an axis body; three locking screw holes formed in a Chinese character 'pin' shape are formed in the lower part; hydroxyapatite coatings are designed at the contact parts of the joints and the bone surface. On the premise of keeping the rotation function of the atlas and axis, the limited lateral bending and flexion and extension functions of the atlas and axis are realized, the design depth of the cup-and-ball joint is large, and the dislocation risk is reduced, so that the atlanto-odontoid joint is closer to the physiological status of a human body.

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.

The invention discloses a dual-polarization broadband external suppression three-dimensional frequency selective surface. The frequency selective surface is a three-dimensional periodic structure processed by a dielectric substrate, which includes a square coaxial waveguide and a parallel plate waveguide. The surface of the dielectric substrate has a metal patch, and the two ends of the metal patch in the electromagnetic wave propagation direction are provided with rectangular grooves, and the metal via holes in the dielectric substrate are connected to the metal patches on both sides. The parallel slab waveguides form a dual-mode resonator, producing a passband containing two transmission poles, and due to the interaction between the two waveguides, a wide stopband containing two transmission zeros near the passband. The invention has low polarization sensitivity in the dual-polarization working mode, can control the frequency range of the passband and the stopband by changing its related physical parameters, realizes dual-polarization application and has good incident angle stability.