6results about How to "Reduce Impedance Mismatch" patented technology

The invention relates to the technical field of electric connectors, in particular to a feed-through connector which comprises a feed-through insertion piece, a coaxial cable, a coaxial connector with the characteristic impedance of 50 ohms, an epoxy resin sealing layer and a connecting plug. The feed-through insertion piece is made of an insulating high-molecular polymer material and comprises an installation body, the installation body is provided with a first side and a second side which are oppositely arranged in the axial direction, an installation channel penetrating in the axial direction is formed in the installation body, and a plurality of bolt holes are formed in the installation body; the mounting channel comprises a first hole section and a second hole section which are sequentially communicated in the axial direction, the hole diameter of the first hole section is larger than that of the second hole section, and the connecting plug is fixedly arranged on the first side of the mounting body and coaxially and correspondingly arranged with the mounting channel; and stable coaxial transmission and sealing insulation effects can be realized while the mechanical connection reliability is maintained.

The application relates to the technical field of ultrasonic nondestructive testing, and provides a superhigh-temperature piezoelectric sheet dry-coupling ultrasonic detection device and a detection method, which comprises a conductive base, a top pressing assembly which is arranged above the conductive base in a liftable mode, and a multilayer detection unit which is arranged between the top pressing assembly and a workpiece to be detected; the multilayer detection unit is sequentially stacked from top to bottom as follows: a high-temperature-resistant insulating layer, a conductive pressing sheet, an upper dry-coupling sheet, a piezoelectric sheet and a lower dry-coupling sheet; the conductive pressing sheet is electrically connected with a first signal lead-out wire, the conductive base is electrically connected with a second signal lead-out wire, and the first signal lead-out wire and the second signal lead-out wire are both used for connecting an external information processing unit. Through the technical scheme, the technical problem that there is no technical scheme capable of realizing continuous and stable ultrasonic detection through stable coupling and reliable structural design in an overall superhigh-temperature environment is solved.

The utility model discloses a K waveband wave same conversion structure relates to microwave communication and radar technical field. The K waveband wave same conversion structure includes integrated metal - dielectric composite cavity, and the cavity has the top cover plate, the intermediate layer and the bottom plate, the top cover plate inlay ceramic sheet array of dielectric constant gradient, the intermediate layer includes the metal grid of suspension gradient, and the grid density is increasing along the propagation direction, and the bottom plate is provided as the metal reflection plate of the bellowed convex projection. The K waveband wave same conversion structure provided by the utility model is used for solving the narrow bandwidth, high loss and volume limit problem in the prior art.

A preparation method of a glass fiber / graphene oxide / metal electromagnetic shielding composite material, comprising the following steps: S1: repeatedly centrifuging and washing an oxide graphene diluent liquid prepared by a Hummers method to obtain neutral layered oxide graphene; S2: impregnating the neutral layered oxide graphene on a glass fiber fabric, drying to obtain a GF@GO composite material; S3: sequentially performing silver-ammonia solution coordination activation, formaldehyde reduction treatment and chemical copper plating treatment on the GF@GO composite material to obtain a GF@GO-Cu composite material; and S4: performing ultrasonic induction nickel-phosphorus nucleation and adsorption treatment on the GF@GO-Cu composite material through an ultrasonic activation solution, and then performing chemical nickel plating treatment to obtain a GF@GO-Cu / Ni composite material. The method has the characteristics of simple process, low cost, good mechanical strength and shielding performance.

The embodiment of the present application relates to the technical field of communication, and discloses a waveguide cavity antenna and a radar device.The waveguide cavity antenna comprises a metal base body provided with a radiation surface, a main transmission cavity, an auxiliary matching cavity, a radiation hole and a feed structure arranged on the metal base body;the first end of the auxiliary matching cavity is communicated with the main transmission cavity, the second end is communicated with the radiation hole, the radiation hole penetrates to the radiation surface, and the signal fed by the feed structure is transmitted to the auxiliary matching cavity through the main transmission cavity and radiated outward through the radiation hole.Through arranging the auxiliary matching cavity between the main transmission cavity and the radiation hole to match the impedance of the signal, the embodiment of the present application can reduce the impedance mismatch during electromagnetic wave propagation and radiation, reduce the reflection loss inside the cavity during high-frequency signal transmission, and improve the signal transmission efficiency of the antenna.