142results about How to "Small reflection coefficient" patented technology

The invention provides a multilayer type electromagnetic wave absorber which comprises (a) two surface layers and (b) an intermediate layer, wherein the two surface layers mainly comprise a glass-coated yarn wave absorbent and a polymer substrate; the intermediate layer is positioned between the surface layers, and the intermediate layer mainly comprises a flat type amorphous alloy powder wave absorbent and a polymer substrate. The invention also provides a method for preparing the multilayer type electromagnetic wave absorber.

The invention relates to a high gain broadband dielectric lens Vivaldi antenna. The array antenna comprises a substrate, a radiation slot, a dielectric lens and a Chebychev tapered strip line feeder. According to the high gain broadband dielectric lens Vivaldi antenna, through changing the structural size of the dielectric lens, the fluctuation of antenna radiation impedance can be effectively improved so as to obtain better impedance matching, the transmission speed of an electromagnetic wave in the slot can be reduced according to the high dielectric constant of the lens, the current distribution on an antenna aperture is improved, thus a spherical wave is a nearly a plane wave, the antenna radiation efficiency is raised, and a higher antenna gain is obtained. According to a Chebychev tapered strip line, the impedance matching of the antenna can be improved further, and the working band is broadened. The array antenna in the invention has the characteristics of high gain and broad band and is suitable for a radiation unit of wideband array antennas of the field of mobile communication and a military radar.

The invention discloses a quick-blind-mating floating-type-mounted RF coaxial connector and a connecting method thereof. The RF coaxial connector comprises a socket and a plug. The socket comprises an inner conductor jack, an insulator, a socket outer conductor, a floating sleeve, a spring and a mounting panel. The plug comprises a plug outer conductor, an inner conductor inserting pin, an elastic collar and a mounting board. The elastic collar is connected with an engaging trough in an adapted engaging manner. The inner hole linear section of the socket is in insertion fit with the outer cycle linear segment of the plug. According to the RF coaxial connector, on the condition that the plug is inserted into the socket, two reference surfaces are superposed, thereby forming a theoretical zero clearance and ensuring continuity of capacitance. Furthermore a specific engagement structure is utilized, thereby eliminating radial clearance and preventing axial endplay clearance in a stationary state in insertion. Furthermore the quick-blind-mating floating-type-mounted RF coaxial connector and the connecting method have advantages of small size, compact structure, low reflection coefficient, low voltage standing wave, full-band linear voltage standing-wave ratio, excellent shielding efficiency, etc.

The invention discloses a graphene/silicon pillar array Schottky junction photovoltaic cell and a manufacturing method thereof. The method comprises the following steps of: performing thermal oxidation on a monocrystalline semiconductor substrate to form silicon oxide (SiO2) which is used as an isolating layer, eroding the SiO2 isolating layer to form an opening and preparing a silicon pillar array in the opening by photoetching and dry-etching methods, performing evaporation coating on the back of the substrate to form a metal back electrode, preparing a metal front electrode on the isolating layer, and finally transferring or spin-coating graphene onto the silicon pillar array and connecting with the front electrode. The solar cell has a simple structure and is easy to manufacture. Not only can the reflection of incident light be effectively reduced but also the contact area of Schottky junction is increased, as a result, the purpose of increasing conversion efficiency of the solar cell is achieved.

The invention relates to a semiconductor heterojunction solar cell based on a bionic moth eye and a manufacturing method thereof. The manufacturing method comprises the following steps: depositing silicon oxide (SiO2) or silicon nitride (Si3N4) on a single crystal semiconductor substrate to obtain an isolating layer; preparing a bionic moth eye array on the surface of the single crystal semiconductor substrate; evaporating metal on the back side of the substrate, thereby forming a back electrode; preparing a metal front electrode on the surface of the isolating layer; and filling a semiconductor material in the array to form the heterojunction. The manufactured semiconductor heterojunction solar cell has the advantages that the structure is simple, the manufacturing process is easy, the reflection of incident light is efficiently reduced and the contact area of the heterojunction is increased, thereby achieving the purpose of promoting the energy conversion efficiency of the solar cell.

The invention relates to a coaxial connector type fixed attenuator which comprises a basal body, an attenuator which is manufactured on the basal body by three discrete resistors, and the input end, the output end and the common earthed end of the attenuator; the attenuator manufactured on the basal body is positioned in the coaxial connector; and a coaxial signal of the inside of the coaxial connector runs through the input end and the output end of the attenuator and are connected with an external signal end respectively. The basal body of the attenuator is fixed inside a hollow metal column; the inside of the metal column is also provided with two grooves for fixing the basal body of the attenuator; two metal washers are arranged between the basal body of the attenuator and the grooves; through the washers, the common earthed end of the basal body of the attenuator is contacted with the hollow metal column; and the hollow metal column is contacted with a shell of the coaxial connector. The coaxial connector type fixed attenuator is suitable for various high-frequency and microwave circuits and systems and has the characteristics of wide frequency band, small size, easy manufacture and low cost.

The invention discloses a slot printing monopole ultra-wideband antenna, and relates to an ultra-wideband antenna. The invention provides the slot printing monopole ultra-wideband antenna with small size, large bandwidth, lower return loss, simple structure and omnidirectional radiation property. The slot printing monopole ultra-wideband antenna is provided with a dielectric substrate, a rectangular and trapezoidal structural array body is printed on the dielectric substrate, the lower bottom of the trapezoid is placed on the rectangle in the middle, the array body is provided with a slot, the array body is reversely placed at the top end of the dielectric substrate, the lower edge of the array body is connected with a microstrip line, the microstrip line is connected with a radiating element, and the microstrip line extends to the edge of the dielectric substrate; and the lower end of the back of the dielectric substrate is provided with a grounding plane, and a clearance is formed between the grounding plane and the array body on the facade of the dielectric substrate.

The invention relates to an antenna radiator structure and a patch antenna thereof. The structure comprises a radiator with a pair of diagonal structures, and the radiator is connected with a feed part. The diagonal structures are respectively provided with a first gap for clutter inhibition, and one side of the radiator is provided with a second gap for clutter inhibition. The other side, opposite to the second gap, of the radiator is connected with the feed part. According to the invention, the antenna is enabled to inhibit clutters in a high-order mode through the first gaps at the opposite corners of a patch and the second gap at the side. The second gap at the side of the patch enables a current path to be prolonged, and the size of the patch is reduced.

The invention relates to a solar heat collecting and storing aluminum foil and a manufacturing method thereof. The solar heat collecting and storing aluminum foil comprises the following chemical components in percentage by mass: 0.01-0.07% of Si, 0.01-0.12% of Fe, 0.08-0.12% of Cu, smaller than or equal to 0.005% of Mn, smaller than or equal to 0.005% of Zn, smaller than or equal to 0.005% of Mg, 0.01-0.03% of Ti and the balance of Al and inevitable impurities. The aluminum foil has a thickness ranging from 0.043 to 0.045mm, the tensile strength of 250-280MPa, the yield strength of 235-265MPa, the elongation greater than or equal to 1%, and the thermal conductivity greater than or equal to 225W / (m.K) at 25 DEG C. Through reasonable setting of contents of copper and other alloy elements in the aluminum foil, a black copper oxide film layer with a strong surface colorizing capability is formed during surface chemical etching of the aluminum foil, so that the aluminum foil increases the solar energy absorbing rate and decreases the reflection coefficient.

The invention discloses a K-waveband coaxial relativistic backward wave oscillator. The oscillator comprises positive electrode, a negative electrode, an electron beam guide grid mesh and a coaxial inner conductor, wherein the positive electrode is a cylindrical waveguide cavity containing a slow-wave structure; the negative electrode is arranged in the cylindrical waveguide cavity and connected with one end plane of the positive electrode through an insulator; the electron beam guide grid mesh is arranged in the cylindrical waveguide cavity and positioned in the downstream of the electron transmitting end of the negative electrode; the coaxial inner conductor adopts a cylindrical structure; one end of the coaxial inner conductor is arranged in the cylindrical waveguide cavity while the other end of the coaxial inner conductor is connected with the other end plane of the positive electrode through a metal bracket; and a coaxial structure is formed by the coaxial inner conductor, the negative electrode and the cylindrical waveguide cavity. According to the K-waveband coaxial relativistic backward wave oscillator, the electron beam guide grid mesh with the electron beam transmittance of greater than 90% is adopted for guiding electron beams to enter a beam interaction region, so that the required external magnetic field intensity is lowered, the guide magnetic field required by a device is reduced to 0.5T, the huge size of the guide magnetic field system on the exterior of the device is reduced, and requirement on the energy source supply is reduced.

The invention discloses a wave type carbon felt electromagnetic shielding structural body and a preparation method thereof. The structural body is combined by adopting multi-layer wave type carbon felts according to certain angles. The multi-layer wave type carbon felts are adhesively connected by adopting adhesives, the wave type carbon felts adopt resin as base bodies, and carbon fiber felts arefunctional bodies. The electromagnetic shielding structural body has the large internal surface area, after electromagnetic waves transmit the surface layer carbon felts, the hook faces of the innerlayer carbon felts can perform repeated reflection, by mans of the multiple electromagnetic wave scattering effect of carbon fiber inside the carbon felts, and therefore the electromagnetic wave consumption and absorption of the carbon felt structural body are remarkably enhanced, the electromagnetic shielding effect is improved, the surface layer wave type carbon felt can remarkably lower the reflecting effect for emission electromagnetic waves, the influence of electromagnetic waves for peripherals and workers is lowered, and the invisibility effect can be achieved in some application fields.

The invention relates to an asymmetric broadband Doherty power amplifier suitable for a full frequency band of a 5G low frequency band, and belongs to the technical field of wireless communication. The amplifier is composed of a power divider, a main power amplification branch, an auxiliary power amplification branch and a power synthesis network, wherein the main power amplification branch and the auxiliary power amplification branch respectively comprise an input and output offset line, a gate and drain bias network, and an input and an output matching network; the working bandwidth of the Doherty power amplifier is expanded by reducing an impedance transformation ratio of a quarter-wave impedance adjustment line and an impedance transformation line in the power synthesis network; and arequired broadband matching network is designed by a broadband impedance transformation network of a low-pass filter prototype, and the influence on an input matching network is reduced by using gatebias networks of antedisplacement primary and secondary power amplifiers. By adoption of the asymmetric broadband Doherty power amplifier provided by the invention, the working bandwidth of the Doherty power amplifier can be expanded.

The invention discloses an inclined multi-path synthetic gyrotron traveling wave tube TE02 mode input coupler, and belongs to the technical field of microwave and millimeter wave devices. The input coupler comprises a power distribution part, an inclined multi-path synthesis part and a cut-off circular waveguide. According to the invention, a high-purity TE02 mode is coupled in a main circular waveguide by adopting an inclined multi-path synthesis structure, and by changing the number and position distribution of the branches of rectangular waveguides on the side wall of the main circular waveguide and the included angle between the branches of the rectangular waveguide on the side wall and the circular waveguide, the field distribution of the main competitive modes (TE01 and TE41) of a TE02 mode in the main circular waveguide is destroyed to improve impedance matching, so that the beneficial effects of effectively suppressing a parasitic mode, reducing a reflection coefficient, improving conversion efficiency and increasing bandwidth are achieved.

The invention discloses an array antenna, and particularly relates to a seam-variable large-bandwidth traveling wave seam array antenna with a radiation-type load. The seam-variable large-bandwidth traveling wave seam array antenna with the radiation-type load solves the problem that an existing dielectric integrated waveguide seam array antenna is small in impedance bandwidth. The seam-variable large-bandwidth traveling wave seam array antenna comprises a radiation metal layer, a first dielectric slab, a feed metal layer, a ridge metal layer, a second dielectric slab, a bottom metal layer, a trapezoid metal layer, a strip-shaped metal layer, a first metal wafer and a second metal wafer. Both the first dielectric slab and the second dielectric slab are rectangular slabs, the feed metal layer is a strip-shaped metal sheet, the ridge metal layer is a rectangular metal sheet, and the radiation metal layer, the first dielectric slab, the feed metal layer, the ridge metal layer, the second dielectric slab and the bottom metal layer are sequentially arranged from top to bottom in an overlapping mode. The seam-variable large-bandwidth traveling wave seam array antenna with the radiation-type load is applied to the radio field.

The invention relates to a microwave spraying vacuum drier for drying sticky materials, in particular for chemicals, Chinese traditional medicines and food, and the like, with strong thermal sensitivity as desiccant. The invention comprises a drying container, a feed inlet, a microwave feed-in device and a material atomization device arranged on the top part of the drying container, a container for drying finished products arranged on the lower part of the drying container, a metal screen arranged between the drying container and the container for drying finished products, a vacuum pump joint arranged on the lateral wall of the drying container, a material preheating components connected between the feed inlet and the material atomization device below the microwave feed-in port of the microwave feed-in device and a vibrating mechanism for delivering materials and preventing materials from being sticky to the wall surface. The vacuum drier of the invention has the advantages of simple production, wide application range, as well as comparatively high drying uniformity and efficiency.

The invention discloses a metamaterial antenna housing, which comprises a substrate and a plurality of artificial metal microstructures, wherein the substrate is provided with two opposite side surfaces, and the plurality of artificial metal microstructures are periodically arranged on the two opposite side surfaces. The substrate is virtually divided into a plurality of metamaterial units, and two opposite side surfaces of the metamaterial unit are both attached with one artificial metal microstructure. The artificial metal microstructure comprises an opening metal ring branch provided with an opening, and three straight line metal branches which are arranged inside the opening metal ring and share an endpoint, and an angle formed between two adjacent straight line metal branches is 120 degrees. The reflection coefficient S21 of the metamaterial antenna housing is 20-40dB higher than the transmission coefficient of an ABS material antenna housing, thereby greatly improving the electromagnetic performance of the antenna housing, and being capable of not damaging the mechanical performance of the antenna housing.

The invention discloses a full-bandwidth rectangular waveguide coaxial conversion device. The device comprises a rectangular waveguide body. An opening is arranged in the front end of the rectangularwaveguide body, and the back is a cut-off wall. The device is provided with a coaxial connector. The metal inner shaft of the coaxial connector is connected with a metal probe in the rectangular waveguide body from the outer side of the bottom of the rectangular waveguide body. The outer side of the probe is coated with a non-metal dielectric layer. The non-metal dielectric layer is made of polytetrafluoroethylene. A metal body perpendicularly connected with the bottom wall of an inner cavity is arranged in the cavity of the rectangular waveguide body. The metal body is located on the front side of the probe. According to the invention, the reflection coefficient of the full waveguide bandwidth is greatly reduced; the insertion loss is effectively reduced; the conversion efficiency is improved; the effect is stable; and due to simple structure and easy processing and molding, the device can be widely used in a rectangular waveguide wave tube technology in the field of microwave communication in a standardized way and in a full-bandwidth spectral range.

The invention relates to a dual-frequency rotary joint used for S single frequency and X single frequency transmission, including an X frequency band joint and an S frequency band joint. The X frequency band joint mainly includes a circular waveguide, a rectangular waveguide and a short-circuit cylinder. The two ends of the circular waveguide are connected to each other, the rectangular waveguide is arranged on the side circular surface of the two ends of the circular waveguide, and the rectangular waveguide and the circular waveguide are connected to each other through the coupling hole; the S-band joint mainly includes a coaxial waveguide, two work points device, magic T and waveguide elbow, the coaxial waveguide and the circular waveguide are coaxially arranged, and are located outside the circular waveguide, forming a transmission channel between the coaxial waveguide and the circular waveguide, and the two power dividers are respectively located on the coaxial Both ends of the waveguide are connected to the transmission channel between the coaxial waveguide and the circular waveguide, and the two horizontal signal ports of the magic T are connected to the two signal ports of the two-power splitter through the waveguide elbow. The invention is a rotary joint capable of simultaneously transmitting high-power radio frequency signals of S and X frequency bands, so as to solve the requirement of dynamic transmission of uplink high-power signals of S+X dual-frequency co-constructed antennas.