6results about How to "Reduce RCS" patented technology

The invention discloses a broadband low RCS array antenna loaded with FSR. A wave absorbing layer is printed on the upper surface of a first dielectric plate, a wave transparent layer is printed on the upper, middle and lower surfaces of a second dielectric plate, a radiation layer is printed on the upper surface of a third dielectric plate, and a metal bottom plate is printed on the lower surface of the third dielectric plate; the second dielectric plate comprises two layers of dielectric plates which are stacked together; the wave absorbing layer comprises a metal square ring with four branches and lumped resistors loaded on the four sides of the metal square ring, and each branch is a metal rectangular ring which is connected to the vertex of the metal square ring and is provided with a bent metal strip; the wave-transparent layer comprises a pair of metal rings and a perforated metal plate, the pair of metal rings are placed on the upper surface and the lower surface of the second dielectric plate respectively, and the perforated metal plate is placed in the middle of the second dielectric plate; the radiation layer comprises a microstrip antenna array loaded on the upper surface of the third dielectric plate, a feed network of the microstrip antenna array, and a metal bottom plate on the lower surface of the third dielectric plate; and the radiation layer adopts coaxial line feed.

The invention discloses an electromagnetic shielding air-inlet grille with variable reflectivity and a control method thereof. The electromagnetic shielding air-inlet grille comprises a double-layer grille body, the double-layer grille is arranged at an air inlet of an engine air inlet channel, the double-layer grille comprises a fixed grille body and a rotating grille body, the overall appearance of the fixed grille body and the overall appearance of the rotating grille body are circular, the fixed grille body is composed of an outer fixed ring and an inner fixed grille body, parallel grille bodies are arranged in the inner fixed grille body, and an annular rotating groove is formed in the outer fixed ring in the circumferential direction; parallel grilles are arranged in the rotating grilles, and the rotating grilles are embedded and mounted in the annular rotating groove of the outer fixing ring through the annular rotating groove of the outer fixing ring; and the grating included angle between the rotating grating and the fixed grating is changed through the circumferential rotation of the rotating grating along the annular rotating groove, so that the air inlet area of the air inlet and the radar wave reflectivity are changed. According to the technical scheme, the problem that radar wave reflectivity and engine air inlet efficiency are difficult to consider in addition of the air inlet grille due to the fact that a stealth mode that the grille net is additionally arranged at the air inlet is adopted in the stealth design of the helicopter air inlet channel is solved.

The invention relates to a dual-polarization high-selectivity frequency selective surface based on a three-dimensional slot line structure, which comprises a plurality of printed circuit boards which are transversely and longitudinally staggered to form a grid shape, each printed circuit board is formed by a plurality of basic unit arrays, and each basic unit comprises a patch unit, a dielectric substrate and a metal micro-unit which are sequentially stacked; the patch unit comprises two interactive patches, each interactive patch comprises a fixed strip and at least one interactive strip arranged at the end part of the fixed strip, and the interactive strips of different interactive patches are arranged in a staggered manner; each metal micro unit comprises a metal foil, a main groove line and a side groove line which are parallel to each other are etched on the metal foil, each main groove line is composed of two opposite T-shaped groove lines, each T-shaped groove line comprises a long groove strip and a short groove strip, the two short groove strips of each T-shaped groove line are oppositely arranged, and a rectangular groove with the width larger than that of each side groove line is formed in the middle section of each side groove line; the method is better in selectivity and angle stability.

The application discloses a high-cut transmissive and reflective integrated reconfigurable skin, which comprises a plurality of same and periodically arranged reconfigurable metasurface units, each of which comprises, from top to bottom, a glass steel, a first reconfigurable layer, a first foam layer, a second metal mesh layer, a second foam layer and a third metal layer; the first reconfigurable layer is composed of a multilayer structure, comprising a first annular metal patch, a first dielectric substrate, a second staggered cross-shaped aperture type metal patch, a second dielectric substrate and a third oblique rectangular metal bias line which are stacked in sequence, and two metallized holes, four PIN diodes and two inductors; when the application is in a wave-transmissive state, electromagnetic waves can pass through the skin with low insertion loss when being incident, without affecting the receiving / transmitting performance of a radio frequency front-end antenna; when the application is in a shielding state, the skin can protect the antenna from being affected when high-power attack electromagnetic waves are incident.

The utility model discloses a low scattering and pneumatic integrated telescopic hexagonal groove countersunk head screw, it includes screw cap, countersunk head round platform thread and stem. Screw cap includes six prismatic marbles spring and six prismatic inner groove, when not considering the tolerance gap between six prismatic marbles and six prismatic inner groove, the stem is the cylinder that is connected with the bottom surface of screw cap, and the thread is the ordinary thread that is equidistantly surrounded in the stem, that is, the triangular tooth shape. The low scattering pneumatic telescopic hexagonal groove countersunk head screw provided by the utility model provides the design principle of low scattering pneumatic screw radar stealth and pneumatic shape, which is a design method for the comprehensive mechanical properties of the low detectability of the screw pneumatic, and the design idea is unique and ingenious, the pneumatic low detectability effect is remarkable, the mechanical properties are good, and the design part has high universality. It can be operated and used by using the general hexagonal screwdriver, and it is convenient to couple all the screws with the whole in the gap direction.

The present invention provides an airborne conformal low RCS radome, in which a conformal wave-transmitting medium substrate coated with an absorbing material is covered on a conformal aluminum alloy frame, epoxy glue is applied on the low table of the conformal aluminum alloy frame, and the conformal wave-transmitting medium substrate and the conformal aluminum alloy frame are bonded together, and the edge chamfer of the conformal wave-transmitting medium substrate and the step chamfer of the conformal aluminum alloy frame form a V-shaped groove, and the V-shaped groove is filled with tear-resistant silicone rubber, thereby forming a conformal low RCS radome. The present invention allows the scattered waves generated at the discontinuity to be absorbed by the absorbing material to achieve the purpose of low RCS. The surface of the present invention has no protrusions, steps, or depressions except for the mounting holes, thereby avoiding scattered waves generated by structural discontinuities. The use of tear-resistant silicone rubber to fill the gaps can improve the fatigue resistance of the surface coating and enhance the crack resistance of the radome surface.