Abstract: A reflection-type bandpass filter for ultra-wideband wireless data communication is provided. The filter comprises two conductors extending in a first direction on the surface of a dielectric substrate at a first distance from each other, the surface of the dielectric substrate between the conductors defining a non-conducting portion, wherein the width of the two conductors or the first distance, or both, varies in a length direction of the two conductors. Furthermore, a reflection-type bandpass filter comprising a dielectric substrate; a first conductor provided on the surface of the dielectric substrate; and a side conductor provided next to the first conductor at a first distance from the first conductor, with a non-conducting portion intervening a portion between the first and side conductors, wherein the first conductor width or the distance between the first and side conductors, or both, varies along the length direction of the first conductor, is provided.

Abstract: A reflection-type bandpass filter for ultra-wideband (UWB) radio data communications is provided. The reflection-type bandpass filter includes a substrate formed by laminating a conducting layer and a dielectric layer, and a microstrip line made of a conductor of a non-uniform width and provided on the dielectric layer. The width distribution of the microstrip line in the lengthwise direction is set such that the absolute value of the difference in reflectivity at the frequency f in the regions f<3.1 GHz and f>10.6 GHz and the reflectivity in the region 3.7 GHz?f?10.0 GHz is not less than 10 dB, and the variation of the group delay in the region 3.7 GHz?f?10.0 GHz is between ?0.2 and 0.2 ns.

Abstract: The optical waveguide-type wavelength dispersion compensation device of the present invention has an optical waveguide as a reflection-type wavelength dispersion compensation device. The equivalent refractive index of a core changes unevenly along a light propagation direction by changing physical dimensions of the core that is embedded in a cladding.

Abstract: This invention provides a reflection-type bandpass filter for ultra-wideband wireless data communication, in which are provided, on the surface of a dielectric substrate, a center conductor and side conductors, provided on both sides of the center conductor, securing a prescribed distance between conductors with non-conducting portions intervening therebetween. The center conductor width or the distances between conductors, or both, are distributed non-uniformly in a length direction of the center conductor.

Abstract: Provided is a reflection-type bandpass filter for ultra-wideband wireless data communication. The filter includes a substrate including a dielectric layer and a conducting layer layered on the top and bottom surfaces thereof, and a center conductor provided within the dielectric layer and serving as a strip line. A width distribution of the center conductor is non-uniform in a length direction of the center conductor.

Abstract: The present invention is to provide an antenna that is small in size, has such input characteristics as to secure consistency in each band, and is capable of maintaining omnidirectionality, and a wireless communication device that has the antenna mounted thereon. An antenna 101 according to the present invention includes a grounded conductor 11, a shorting pin 13 that is formed with a conductor, and a radiation conductor 12 that has one end 21 connected to the grounded conductor 11 via the shorting pin 13, has the other end 22 left open, and receives power supplied from a feeding point 23 located at the one end. The radiation conductor 12 is folded at a portion between the one end 21 and the other end 22, and forms a lower arm 24 closer to the grounded conductor 11 and a folded upper arm 25, with at least part of the lower arm 24 and the upper arm 25 having a meandered portion 26.

Abstract: An extended triangular lattice type photonic bandgap fiber, includes a cladding and a capillary core, the cladding having a plurality of holes disposed within a silica glass portion in a longitudinal direction of the fiber and arranged in an extended triangular lattice shape, the capillary core having a plurality of holes arranged in a triangular lattice shape, wherein the cross-sectional area of the respective holes in the capillary core is smaller than that of the respective holes in the cladding.

Abstract: A method for measuring a multimode optical fiber includes: monitoring a temperature change within a measurement time in a DMD measurement of the multimode optical fiber, where the DMD measurement is carried out in an environment in which a magnitude of temperature change is controlled.

Abstract: An optical waveguide comprising a cladding and a core embedded in the cladding. An equivalent refractive index of the core changes unevenly along a light propagation direction by changing physical dimensions of the core.

Abstract: The present invention provides an antenna that is small in size and has band frequencies corresponding to multibands, and a wireless communication apparatus including the antenna. The antenna according to the present invention has two radiation elements 12a and 12b connected to a ground plate 11 via a shorting pin. The two radiation elements 12a and 12b each have a lower arm and an upper arm that are formed through bending. The lower arm is connected to the shorting pin and is located closer to the ground plate 11 than the upper arm is. At least one of the lower arm and the upper arm has a meandered structure.

Abstract: This invention provides a reflection-type bandpass filter for ultra-wideband wireless data communication, in which are provided, on the surface of a dielectric substrate, a center conductor and side conductors, provided on both sides of the center conductor, securing a prescribed distance between conductors with non-conducting portions intervening therebetween. The center conductor width or the distances between conductors, or both, are distributed non-uniformly in a length direction of the center conductor.

Abstract: An antenna 1 includes: a plate-like base 3 made of an insulating material; and a conductor 5 in a predetermined shape, which has multiple cut-out portions 10, 13, 15 and which is provided at a predetermined position of the base 3 to obtain predetermined antenna characteristics. The antenna 1 is configured so that the antenna characteristics can be mostly maintained even when the base 3 is deformed into a predetermined curved-surface shape.

Abstract: A photonic band gap fiber is provided having multiple air holes in a silica portion extending in the longitudinal direction of the fiber. The fiber includes a cladding containing an air hole periodic structure in an extended triangular lattice configuration, wherein first rows each having a number of air holes at a first pitch are arranged alternately in the cross section of the fiber with multiple second rows of air holes each with multiple air holes at a second pitch which is twice the first pitch. The fiber further includes an air hole core.

Abstract: An extended triangular lattice type photonic bandgap fiber, includes a cladding and a capillary core, the cladding having a plurality of holes disposed within a silica glass portion in a longitudinal direction of the fiber and arranged in an extended triangular lattice shape, the capillary core having a plurality of holes arranged in a triangular lattice shape, wherein the cross-sectional area of the respective holes in the capillary core is smaller than that of the respective holes in the cladding.

Abstract: An extended triangular lattice type photonic bandgap fiber, includes a cladding and a capillary core, the cladding having a plurality of holes disposed within a silica glass portion in a longitudinal direction of the fiber and arranged in an extended triangular lattice shape, the capillary core having a plurality of holes arranged in a triangular lattice shape, wherein the cross-sectional area of the respective holes in the capillary core is smaller than that of the respective holes in the cladding.

Abstract: This invention provides a reflection-type bandpass filter for ultra-wideband wireless data communication, in which are provided, on the surface of a dielectric substrate, a center conductor and side conductors, provided on both sides of the center conductor, securing a prescribed distance between conductors with non-conducting portions intervening therebetween. The center conductor width or the distances between conductors, or both, are distributed non-uniformly in a length direction of the center conductor.

Abstract: A photonic band gap fiber is provided having multiple air holes in a silica portion extending in the longitudinal direction of the fiber. The fiber includes a cladding containing an air hole periodic structure in an extended triangular lattice configuration, wherein first rows each having a number of air holes at a first pitch are arranged alternately in the cross section of the fiber with multiple second rows of air holes each with multiple air holes at a second pitch which is twice the first pitch. The fiber further includes an air hole core.

Abstract: A reflection-type bandpass filter for ultra-wideband wireless data communication is provided. The filter comprises two conductors extending in a first direction on the surface of a dielectric substrate at a first distance from each other, the surface of the dielectric substrate between the conductors defining a non-conducting portion, wherein the width of the two conductors or the first distance, or both, varies in a length direction of the two conductors. Furthermore, a reflection-type bandpass filter comprising a dielectric substrate; a first conductor provided on the surface of the dielectric substrate; and a side conductor provided next to the first conductor at a first distance from the first conductor, with a non-conducting portion intervening a portion between the first and side conductors, wherein the first conductor width or the distance between the first and side conductors, or both, varies along the length direction of the first conductor, is provided.

Abstract: A higher order mode dispersion compensating fiber includes an optical fiber and a first loss layer which is provided within the fiber and which attenuates a lower order mode propagating through the optical fiber while not attenuating a higher order mode which is higher than the lower order mode. A dispersion compensating fiber mode converter for a higher order fiber includes a single mode fiber; a higher order mode dispersion compensating fiber; and a fused and extended portion which has been formed by fusing and extending the single mode fiber and the higher order mode fiber. The fused and extended portion converts between the LP01 mode of the single mode fiber and the LP02 mode of the higher order mode dispersion compensating fiber.

Abstract: A graded-index multimode fiber includes a core made of silica glass, the core having a central region and an outer peripheral region, and a cladding which is provided at an outer periphery of the core. The central region contains one of germanium and phosphorus, and the outer peripheral region contains fluorine.