7 results about "Tm waves" patented technology

The novel low-pass notch filter comprises a dielectric substrate, a CPW part, a transition part and an SSPP transmission line part which are sequentially cascaded are arranged on the front face of the dielectric substrate, and six interdigital coupling structures are loaded on the back face of the dielectric substrate in an up-down symmetrical mode; the CPW part is connected with the microwave system; the transition part is used for converting the TEM wave of the CPW structure into the TM wave of the SSPP structure; the SSPP transmission line part comprises six novel SSPP transmission line units; according to the novel SSPP transmission line unit, two sides of a central transmission line are respectively provided with a group of symmetrical linear groove structures which are etched on a CPW grounding plate, a folding groove structure is loaded between each group of symmetrical linear groove structures, and the top end of each folding groove structure is aligned with the top end of each linear groove structure; the interdigital coupling structure is used for generating resonance at a specific frequency and generating a transmission zero point. By loading an interdigital coupling structure on the back surface of the filter, a communication signal at a specific frequency is radiated to a free space, and suppression of the signal at the specific frequency is realized.

This invention discloses a fully polarized omnidirectional matched retroreflector based on optical void materials. It mainly consists of a metal shell, which is a concave block. The two convex ends of the metal shell face the incident direction of external electromagnetic waves and serve as the input and output ends of the fully polarized omnidirectional matched retroreflector, respectively. Hollow TM wave air tunnels and TE wave air tunnels are respectively formed inside the metal shell. Both the TM wave and TE wave air tunnels are concave blocks with the same shape as the metal shell. The TM wave and TE wave air tunnels connect from the input end to the output end of the fully polarized omnidirectional matched retroreflector. This invention has a simple structure and can be implemented using only metal. It can work for fully polarized incident waves at all angles and can be widely used in radar target modeling and sensing fields.

The invention discloses a Janus antenna array device and method for realizing one-way near-field coupling of a coupling surface. More flexible near-field directional excitation of light is realized. The device of the Janus antenna array for realizing the unidirectional near-field coupling of the coupling surface comprises a feed network structure and an outer coupler, the outer coupler comprises two dielectric waveguides which are parallel to each other, and the two dielectric waveguides are arranged at an interval to form an assembly space; the feed network structure comprises a feed network and a plurality of Janus antennas based on Janus dipoles, the Janus antennas are connected to the feed network, the Janus antennas are arranged in the assembly space in an array mode, each Janus antenna is provided with an electric dipole and a magnetic dipole, and the electric dipoles and the magnetic dipoles are perpendicular to each other and have phase differences. The magnetic dipoles correspond to the width direction of the assembly space, and the electric dipoles correspond to the length direction of the assembly space so as to excite quasi-TM waves in the dielectric waveguide.

The application provides a kind of wideband wide-angle wave absorber based on three-dimensional frequency selective surface, comprising a plurality of three-dimensional frequency selective surface units with same structure and continuous arrangement, each three-dimensional frequency selective surface unit is a hollow cuboid, and each three-dimensional frequency selective surface unit comprises horizontal structure, vertical structure and metal bottom plate arranged in sequence from top to bottom; the wave absorber provided by the application can significantly improve the angle stability of the wave absorber by combining the horizontal structure with the vertical structure, and for 0-60° oblique incidence of TE and TM waves, more than 90% absorption can be achieved within 2.1 times the frequency bandwidth; meanwhile, the wave absorber in the application has the advantages of low profile, small thickness and period size, is easy to integrate with other devices, and is high in convenience; in addition, a center-symmetric pattern design is used in each layer structure of the frequency selective surface unit in the application, which reduces the polarization direction sensitivity of the wave absorber to incident electromagnetic waves.

The invention discloses a frequency-band-switchable artificial surface plasmon full-angle scanning antenna, and the antenna comprises a first dielectric plate which is provided with a feed structure, a transition unit, and a tunable artificial surface plasmon unit on the outer surface; the feed structure is used for giving a direct current signal and is connected with the tunable artificial surface plasmon unit through the transition unit; the transition units are arranged at the two ends of the tunable artificial surface plasmon unit, the widths of the transition units are gradually increased from the feed structure to the tunable artificial surface plasmon unit, and the transition units are used for converting the fed quasi TEM waves into TM waves; the tunable artificial surface plasmon unit performs dispersion regulation and control through direct current bias voltage to change cut-off frequency; a DC bias circuit and an isolation inductor which are connected with the tunable artificial surface plasmon unit are arranged on the outer surface of the dielectric plate II; and the radiation patch is connected between the dielectric plate I and the dielectric plate II. According to the invention, 360-degree omnibearing scanning of beams can be realized on the premise of keeping the working frequency constant.

The invention discloses a cased well ground signal two-way wireless electromagnetic transmission device and method, and belongs to the technical field of oil and gas field development logging, the cased well ground signal two-way wireless electromagnetic transmission device comprises an underground terminal system, a metal loop transmission channel and a ground terminal system, the metal loop transmission channel is a closed metal loop constructed with an oil pipe and a casing as carriers, and the metal loop transmission channel is a closed metal loop. The underground terminal system is sequentially and electrically connected with a first centralizer, an ascending transmission short section, a packer, a descending transmission short section, a sensor integration short section and a second centralizer from top to bottom along the axis of a casing pipe, and the first centralizer and the second centralizer are made of conductive rubber materials. The oil pipe and the sleeve are electrically conducted to construct the closed metal loop, the oil pipe and the sleeve serve as carriers to construct a closed metal loop transmission channel, transmission media do not need to be additionally laid, the metal loop provides a low-loss transmission path for TM waves, signal attenuation is effectively reduced, and the transmission efficiency is improved. The problem of serious signal attenuation in a deep well in traditional wireless electromagnetic transmission is solved.

The application provides a silicon-based five-channel absorber, which comprises a full-metal reflection layer and a dielectric layer arranged on the full-metal reflection layer in a periodic arrangement; a ring-shaped cavity is etched on the surface of the dielectric layer, and the absorption performance of the absorber is regulated by changing the depth, inner diameter or outer diameter of the ring-shaped cavity. The silicon-based five-channel absorber provided by the application is provided with a ring-shaped cavity, the same absorption curve can be obtained for TE waves and TM waves, and the polarization insensitivity of the absorber is ensured; meanwhile, the periodic ring-shaped cavity can excite different resonance modes inside and outside the ring, the adjustable double-frequency absorption can be realized in the near-infrared wave, the absorption effect of up to five channels can be realized, and the absorption rate can all reach more than 90%; the dielectric silicon is adopted instead of the traditional metal, the problem of excessive ohmic loss of the traditional metal layer can be avoided, the absorption rate is improved, and the absorption is achieved.