10 results about "Dipole mode" patented technology

Apparatuses and methods for accelerating charged particles include an accelerator. The accelerator includes a cavity comprising a chamber and conductive walls enclosing the chamber, and having one or more inlets and one or more outlets, an electro-magnet substantially surrounding at least a portion of the cavity; two or more rods disposed predominantly longitudinally within the chamber; and one or more RF couplers. The RF couplers are configured to generate a rotating or non-rotating dipole radio frequency field within the cavity by exciting the RF couplers in phase to accelerate the charged particles entering the cavity through the one or more inlets. The radio frequency field operates predominantly in transverse electromagnetic mode.

The invention discloses a light broadband wave-absorbing material which is of a three-dimensional structure and comprises a reflecting layer and a peripheral square ring wave-absorbing unit, the peripheral square ring wave-absorbing unit is vertically arranged on the reflecting layer and forms a cavity structure with the reflecting layer, an inner square ring wave-absorbing unit which forms a self-similar structure with the peripheral square ring wave-absorbing unit is arranged in the cavity structure, and an outer square ring wave-absorbing unit which forms a self-similar structure with the inner square ring wave-absorbing unit is arranged in the cavity structure. Gaps among the reflecting layer, the peripheral square ring wave-absorbing unit and the inner square ring wave-absorbing unit are filled with flexible wave-absorbing foam. According to the light broadband wave-absorbing material provided by the invention, the square ring wave-absorbing units with self-similar structures form resistance rings arranged in an array, and the resistance rings can be coupled to generate response of an electric dipole mode, so that electromagnetic waves can enter the material as much as possible to be consumed and converted into heat energy, the wave-absorbing efficiency is improved, and the wave-absorbing effect within the frequency band range of 1-75GHz can reach-10dB; and meanwhile, the self-similar square ring unit structures are all cavity structures, so that the density of the material is effectively reduced.

The invention discloses a terahertz pure silicon equiphase low-loss waveguide based on a bound state in a continuous spectrum, and belongs to the technical field of terahertz on-chip communication. The waveguide comprises a conical gradual change input structure, a first straight waveguide, an equiphase waveguide, a second straight waveguide and a conical gradual change output structure which are sequentially connected along a transmission direction, the equiphase waveguide is of a one-dimensional photonic crystal structure formed by arranging a plurality of periodic unit structures, each unit is a cuboid made of a high-resistance silicon material, and symmetrical elliptic cylindrical grooves are formed in the upper surface and the lower surface of each unit. Energy band degeneracy of monopole and dipole modes is realized through points in a Brillouin region, a Dirac cone is formed, a near-zero effective refractive index is obtained at a central working frequency, and equiphase transmission is realized; and meanwhile, a bound state mechanism in a continuous spectrum is utilized to greatly improve quality factors and suppress radiation loss. The waveguide supports flexible adjustment of the working frequency through geometric dimension equal-proportion scaling, covers the frequency band of 0.1-10 THz, and can be designed to be of a bent structure. According to the invention, an all-silicon process is adopted, the structure is compact, the loss is low, and the device is suitable for high-fidelity signal transmission and processing in a terahertz integrated system.

The invention discloses a double-frequency directional PCB (printed circuit board) antenna, and relates to the technical field of wireless communication, in particular to a double-frequency directional PCB antenna, which is characterized in that a pair of planar inverted-F antennas are symmetrically arranged on a printed circuit board with the size of 50mm * 35mm, and the planar inverted-F antennas work in a dipole mode and share a second grounding metal layer to realize directional radiation. Each antenna unit comprises a main radiation arm with the length of 22.5 mm and used for generating 2.4 GHz resonance; the tail end of the branch radiation arm is connected with the branch radiation arm which is 5.7 mm long and is used for generating 5GHz resonance; a short-circuit column with double through holes connected in parallel is connected with the grounding layer; electromagnetic coupling of the 50-ohm microstrip feeder line is realized through a coupling gap with the length of 15mm and the width of 0.25 mm on the grounding layer. The standing-wave ratios of the antenna in 2.4 GHz and 5GHz frequency bands are not greater than 2, the gains respectively reach 2-3dBi and 5-7dBi, and the antenna is suitable for an MIMO wireless communication system with the IEEE 802.11 b / g / n / ac / ax standard.

The invention provides a high-efficiency unbiased photoconductive terahertz source and a terahertz emitter, and the terahertz source comprises a substrate, and a first semiconductor layer, a second semiconductor layer and a conductive layer which are sequentially disposed on the substrate from bottom to top. Wherein the material of the first semiconductor layer is p-type doped InAlAs, and the material of the second semiconductor layer is InAlAs, or the material of the first semiconductor layer is p-type doped InGaAs, and the material of the second semiconductor layer is InGaAs; the second semiconductor layer is configured as a dielectric metasurface with periodic patterns; according to the invention, the dielectric metasurface is introduced, and degeneracy of an electric dipole mode and a magnetic dipole mode is realized, so that the device obtains uniform light field distribution and high absorption efficiency; secondly, the p-type doped semiconductor layer is introduced to optimize the energy band structure, a uniform strong built-in electric field highly matched with the light field space is formed in the whole active region, and efficient collection of photon-generated carriers can be realized without additional bias.

According to the metal frame antenna system capable of integrating the low frequency band, the closed metal ring of the electronic equipment and the metal chain connected to the closed metal ring are utilized, and the low-frequency excitation source loaded between the mainboard and the closed metal ring is combined, so that the electrical length of antenna radiation is effectively increased, and the antenna performance is improved. A low-frequency special-shaped dipole mode is excited, low-frequency-band transmitting and receiving in a metal frame antenna system can be achieved, and the frequency band and the frequency width of the low frequency can be adjusted by adjusting the position relation between connection points of the low-frequency excitation source and the metal chain and / or the length of the metal chain. The metal frame antenna system is widened to a low frequency band while the attractiveness is ensured, and integration of low frequency and high frequency is realized; in addition, besides the low-frequency excitation source, other high-frequency excitation sources can be loaded between the mainboard and the closed metal ring according to needs, and the integration level of the antenna is further improved.

The invention provides a wearable electronic device. The wearable electronic equipment comprises an antenna assembly, and the antenna assembly comprises a radiator and a feed source. The radiator comprises a first sub-radiator and a second sub-radiator; the first sub-radiator is provided with a first free end, a feeding point and a second free end which are arranged in sequence, and the first free end and the second free end form a first opening; the second sub-radiator and the first sub-radiator are arranged at intervals in the first direction and are electrically connected, the second sub-radiator is provided with a third free end and a fourth free end, and the third free end and the fourth free end form a second opening; the feed source is electrically connected to the feed point so as to excite a first resonant mode of the first sub-radiator to support a first target frequency band and excite a second resonant mode of the second sub-radiator to support a second target frequency band, the first resonant mode is a half-wavelength dipole mode, the second resonant mode is a half-wavelength dipole mode, and the second target frequency band is a half-wavelength dipole mode. The frequency of the second target frequency band is greater than that of the first target frequency band.

This invention discloses a self-decoupling antenna array and device based on a magnetoelectric dipole. The antenna array includes: a first dielectric substrate with two stepped microstrip lines on a first surface; two radiating elements, each composed of two identical magnetoelectric dipole antennas. Each magnetoelectric dipole antenna consists of two rectangular metal patches, three pairs of second metal-plated vias, and a Γ-shaped probe. The Γ-shaped probe includes two third metal-plated vias and a second metal patch. The antenna array is fed into the Γ-shaped probe through the stepped microstrip lines to excite the antenna. This invention achieves excellent decoupling functionality through the characteristics of higher-order electric dipole modes without introducing additional decoupling circuits or components. Simultaneously, the array structure is simple, easy to implement and expand, and has potential application prospects in millimeter-wave multiple-input multiple-output wireless communication systems. This invention can be widely applied in the field of mobile communication antennas.

A topological bulk laser includes a topological photonic crystal (32) having an energy band inversion between dipole mode and quadrupole mode near the center of Brillouin zone and a trivial photonic crystal (31) not having band inversion for splicing to each other. The reflection and confinement of an optical field occurs at the interface; and the interface encloses to form a closed contour, thereby forming a laser cavity with an effective cavity feedback for lasing at the interior of the interface. This band-inversion-induced reflection mechanism induces single-mode lasing with directional vertical emission. At room temperature, the topological bulk laser can achieve low threshold, narrow linewidth, and a high side-mode suppression ratio, reduce the fabrication difficulty and costs, and improve heat dissipation and electrical injection efficiency, hence improving lifetime and stability of devices.

The application discloses an anti-metal wide-bandwidth RFID tag antenna and belongs to the technical field of radio frequency identification antennas. The antenna comprises a dielectric substrate, a radiation structure arranged on the surface of the dielectric substrate and a feed structure electrically connected with the radiation structure; the radiation structure comprises a perpendicular magnetic ring structure and dipole radiation arms arranged on both sides of the feed structure, wherein the middle part of the feed structure is used for connecting an RFID chip, and the two ends of the feed structure form a vertically closed loop with a metal mounting surface through a short-circuit structure. The perpendicular magnetic ring structure is used for generating a radiation field type mainly in a magnetic dipole mode, so as to reduce the influence of a metal surface on the radiation performance of the antenna; the dipole radiation arms introduce an electric resonance mode through electromagnetic coupling with the feed structure, and form a double-resonance working mechanism with the magnetic ring structure. By adjusting the structural parameters of the dipole radiation arms, the adjustment of the working frequency and impedance characteristics of the antenna can be realized. The antenna has simple structure and small size, is suitable for the application of an ultra-high frequency RFID tag in a metal environment, and can be used for passive Internet of Things application scenarios.