摘要:
An arrayed-waveguide grating type optical multi-demultiplexer includes input waveguides, a first slab waveguide, a channel waveguide array, a second slab waveguide, and output waveguides. A pair of different refractive index regions, each having a refractive index different from that of the second slab waveguide, are formed on the second slab waveguide near a boundary between the second slab waveguide and channel waveguide array. The different refractive index regions project in peninsular shapes from both side portions of the slab waveguide. Light traveling from each waveguide of the channel waveguide array toward the output waveguides passes through the different refractive index regions. An optical distribution with a flattened field-distribution peak is created at a boundary between the second slab waveguide and output waveguides.
摘要:
An optical multi-demultiplexer of the present invention comprises an input waveguide to which wavelength division multiple signals are applied, a plurality of output waveguides for demultiplexing and outputting the wavelength division multiple signals, an arrayed waveguide including a plurality of channel waveguides having different waveguide lengths, an input slab waveguide, and an output slab waveguide. The input slab waveguide is provided between the input waveguide and the arrayed waveguide. The output slab waveguide is provided between the arrayed waveguide and the output waveguides. The input slab waveguide is formed with tapered island regions having a refractive index lower than that of the core layer of the slab waveguide. The island regions are situated in positions opposite the channel waveguides of the arrayed waveguide.
摘要:
An antenna device includes a plurality of loop elements. The loop elements are made of conductive material, and constitute a planar antenna element having N-fold rotationally symmetric shape with respect to a center portion of the planar antenna element, the N being an integer of three or more. Each of the loop elements includes at least two first elements extending in a first direction parallel to a radial direction of the planar antenna element and at least one second element extending in a circumferential direction of the planar antenna element. A ground plate is made of conductive material and opposes the planar antenna element. A power feeding line extends from the ground plate to the planar antenna element, and is electrically connected to the planar antenna element at the center portion.
摘要:
A thin plane antenna that copes with the horizontally polarized waves and the vertically polarized waves, or the levo-rotary polarized waves and the dextro-rotary polarized waves, and in which a loop-shaped plane antenna element (12) is arranged in parallel with a ground plane (15), and a first feeder conductor (13) and a second feeder conductor (14) having feeding points displayed by 90 degrees are arranged between the plane antenna element and the ground plane. Central conductors (18a) and (19a) of the coaxial lines are connected to the first and second feeder conductors, and external conductors (18b) and (19b) thereof are connected to the ground plane to feed electric power to the antenna element through the electromagnetic coupling. When the electric power is fed from the first feeder conductor (13), the horizontally polarized waves are radiated and when the electric power is fed from the second feeder conductor (14), the vertically polarized waves are radiated. Upon changing over the first and second feeder conductors, the horizontally polarized waves and the vertically polarized waves can be transmitted and received. By providing the horizontal antenna element with slide elements, further, the levo-rotary polarized waves and the dextro-rotary polarized waves can be transmitted and received.
摘要:
To provide a thin wideband antenna unit capable of shrinking the size of a radiation element in a case where a dielectric is not used.In a wideband antenna unit 10 having a ground plate 12 and a flat shaped radiation element 14 disposed on a plane (x, y) flush with a plane where the ground plate extends, the radiation element 14 has an elliptically shape. The radiation element 14 and the ground plate 12 are apart from each other by a predetermined feeding distance ΔFD. A ratio between an outside diameter 2aout in an ellipse's x-direction and an outside diameter 2bout in an ellipse's y-direction is 8:5. The elliptically shaped radiation element 14 has an elliptically shaped opening 14a which is concentric O with the elliptically shape. An inside diameter 2bin in the ellipse's y-direction is half of an outside diameter 2bout in the ellipse's y-direction. It is desirable that an inside diameter 2ain of the elliptically shaped opening 14a in the ellipse's x-direction is not more than half of the outside diameter 2aout in the ellipse's x-direction.
摘要:
An antenna unit consists of an EBG reflector, a single curl antenna supported at a central portion of the EBG reflector, and a periodic structure upper plate disposed apart from a principal surface of the EBG reflector by a predetermined distance. The EBG reflector includes a substrate having the principal surface and (Nx×Ny) square patches which are printed on the principle surface of the substrate and which are arranged in a matrix fashion (lattice structure). The periodic structure upper plate consists of a film and (Nx×Ny) square patch-like conductors printed on the film. The (Nx×Ny) square patch-like conductors are disposed so as to oppose to the (Nx×Ny) square patches, respectively.
摘要:
To provide a compact and light broad range antenna apparatus transmitting and receiving an electric wave in GHz frequency band (wavelength: λ), a flat shaped antenna element (10), where a length b′ in an X-axis direction is less than λ/4 and a length a′ in a Y-axis direction is less than λ/4, is arranged at a distance j less than λ/4 from a ground plate (2) in the Y-axis direction and connected to a high-frequency power source (9), and an enlarged flat shaped parasitic element (15) is structured by connecting a base portion (13) having approximately the same shape and dimension as those of the antenna element (10) with an extension portion (14) extending from the base portion (13) in the X-axis direction so as to face to the antenna element (10) with a distance, and connected conductively with the ground plate (2) by a ground line (5).
摘要:
An antenna unit consists of an EBG reflector, a single curl antenna supported at a central portion of the EBG reflector, and a periodic structure upper plate disposed apart from a principal surface of the EBG reflector by a predetermined distance. The EBG reflector includes a substrate having the principal surface and (Nx×Ny) square patches which are printed on the principle surface of the substrate and which are arranged in a matrix fashion (lattice structure). The periodic structure upper plate consists of a film and (Nx×Ny) square patch-like conductors printed on the film. The (Nx×Ny) square patch-like conductors are disposed so as to oppose to the (Nx×Ny) square patches, respectively.
摘要:
In a broadband antenna unit having a ground plate and an elliptically shaped radiation element disposed at an upper portion of the ground plate in a plane where the ground plate extends, the ground plate has a semi-elliptically shaped upper edge and a lower portion where both side corner portions are deleted with a central portion left. The ground plate and the radiation element are formed on a substrate.
摘要:
An indicator includes a case mountable in a gas filling passage of a pressure container; a valve element which is urged toward one side of the case connectable to the pressure container, the valve element being movable in the case to a position balanced with gas pressure in the pressure container; a seal member for ensuring gas tightness between the valve element and the case; and an indicating member slidable relative to the case between a position protruding outside the case and a position not protruding. The spring force and a gas pressure force may be equally balanced at first and second balanced positions of the valve element.