Abstract: A UWB antenna has an upper dielectric, a lower dielectric, and a conductive pattern sandwiched therebetween. The conductive pattern has a feeding point at a substantially center portion of a front surface. The conductive pattern has a reversed triangular portion having a right-hand taper part and a left-side taper part which widen from the feeding point at a predetermined angle toward a right-hand side surface and a left-hand side surface, respectively, and a rectangular portion having a base side being in contact with an upper side of the reversed triangular portion. The rectangular portion may preferable have at least one slit formed therein.

Abstract: 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.

Abstract: A printed circuit board has an inverted-L-shaped antenna pattern, which is provided with a conductor pattern connected to a ground pattern, so formed thereon as to be in close proximity to the outside of an inverted-F-shaped antenna pattern which is provided with a conductor pattern connected to a feeding point and with a conductor pattern connected to a ground pattern. By making resonance frequency of each of the inverted-F-shaped antenna pattern and the inverted-L-shaped antenna pattern different, it is possible to compose a frequency antenna using different frequency bands.

Abstract: A UWB antenna has an upper dielectric, a lower dielectric, and a conductive pattern sandwiched therebetween. The conductive pattern has a vertex apart from a feeding point with a predetermined gap. The conductive pattern has a reversed triangular portion having a right-hand taper part and a left-side taper part which widen from the feeding point at a predetermined angle toward a right-hand side surface and a left-hand side surface, respectively, and a semicircular portion having a base side being in contact with an upper side of the reversed triangular portion. The UWB antenna further has a feeding pattern connected to the feeding point, whereby carrying out feed from the feeding pattern to the conductive pattern by electromagnetic coupling.

Abstract: An antenna apparatus includes a dielectric substrate, a radiation element buried in the dielectric substrate, and a feeding lead connected to the radiation element and extending outward from the dielectric substrate. The dielectric substrate is covered with a conductor cover except at an exposed portion left on an upper surface thereof. The conductor cover comprises a side wall portion extending in a thickness direction of the radiation element and covering all side surfaces of the dielectric substrate, and a hood portion extending from an upper edge of the side wall portion and covering a part of the upper surface of the dielectric substrate. The hood portion has a trapezoidal or a rectangular shape.

Abstract: In a UWB antenna having an upper dielectric member, a lower dielectric member, and a conductor pattern interposed therebetween, the conductor pattern has a feeding point at a generally center portion of a front surface of the antenna. The conductor pattern further has an inverted triangular portion including a right tapered portion and a left tapered portion extending from the feeding point towards right and left side surfaces of the antenna, respectively. A main expanding portion expands from an upper side of the inverted triangular portion. A right expanding portion and a left expanding portion expand from the right and the left tapered portions of the inverted triangular portion, respectively.

Abstract: At least one of the following requirements is satisfied. A position of a curvature center of an arcuate portion in at least one of waveguide plates is selected between a connecting member and a feeder, in accordance with a desired horizontal beam radiation characteristic. A curvature radius of the arcuate portion in at least one of the waveguide plates is selected in accordance with a desired vertical beam radiation characteristic. A slanted angle of a peripheral face of the arcuate portion, which connects a top face and a bottom face of each waveguide plate, in at least one of the waveguide plates is selected in accordance with a desired vertical beam radiation characteristic.

Abstract: A circular polarized wave reception antenna has a monopole antenna having a pole portion and an ground plate for grounding one terminal of the pole portion and a polarization converting arrangement disposed around the monopole antenna. The polarization converting arrangement has a plurality of helical leads extending in a helical fashion along the pole portion with apart from the pole portion by a predetermined distance. Each of the helical leads has an end grounded in said ground plate. The helical leads are disposed at equal angular spaces around the pole portion. When a resonance wavelength ? is equal to 128.3 mm, the predetermined space is equal to 20 mm. Each helical lead has a length of ?/4. A pitch angle included between the ground plate and each helical lead is equal to 40 degrees.

Abstract: 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.

Abstract: A UWB antenna has an upper dielectric, a lower dielectric, and a conductive pattern sandwiched therebetween. The conductive pattern has a vertex apart from a feeding point with a predetermined gap. The conductive pattern has a reversed triangular portion having a right-hand taper part and a left-side taper part which widen from the feeding point at a predetermined angle toward a right-hand side surface and a left-hand side surface, respectively, and a semicircular portion having a base side being in contact with an upper side of the reversed triangular portion. The UWB antenna further has a feeding pattern connected to the feeding point, whereby carrying out feed from the feeding pattern to the conductive pattern by electromagnetic coupling.

Abstract: A UWB antenna has an upper dielectric, a lower dielectric, and a conductive pattern sandwiched therebetween. The conductive pattern has a feeding point at a substantially center portion of a front surface. The conductive pattern has a reversed triangular portion having a right-hand taper part and a left-side taper part which widen from the feeding point at a predetermined angle toward a right-hand side surface and a left-hand side surface, respectively, and a rectangular portion having a base side being in contact with an upper side of the reversed triangular portion. The rectangular portion may preferable have at least one slit formed therein.

Abstract: An antenna apparatus comprises a dielectric substrate (42), a radiation element (31) buried in the dielectric substrate, and a feeding lead (43) connected to the radiation element and extracted outward from the dielectric substrate. The dielectric substrate is covered with a conductor cover (44) except an exposed portion left on a front surface thereof. The conductor cover comprises a side wall portion extending in a thickness direction of the radiation element and covering all side surfaces of the dielectric substrate, and a hood portion (44W) extending from an upper edge of the side wall portion and covers a part of the front surface of the dielectric substrate. The hood portion (44W) has a trapezoidal or a rectangular shape.

Abstract: 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.

Abstract: A ground pattern 8 has a portion thereof removed in an area 13 where an inverted-F plate antenna 1 is mounted. This gives the inverted-F plate antenna 1 almost non-directional directivity patterns as distinct from those obtained with an ordinary inverted-F antenna, and helps achieve a higher degree of gain isotropy.

Abstract: A printed circuit board has an inverted-L-shaped antenna pattern, which is provided with a conductor pattern connected to a ground pattern, so formed thereon as to be in close proximity to the outside of an inverted-F-shaped antenna pattern which is provided with a conductor pattern connected to a feeding point and with a conductor pattern connected to a ground pattern. By making resonance frequency of each of the inverted-F-shaped antenna pattern and the inverted-L-shaped antenna pattern different, it is possible to compose a frequency antenna using different frequency bands.

Abstract: A circular polarized wave reception antenna has a monopole antenna having a pole portion and an ground plate for grounding one terminal of the pole portion and a polarization converting arrangement disposed around the monopole antenna. The polarization converting arrangement has a plurality of helical leads extending in a helical fashion along the pole portion with apart from the pole portion by a predetermined distance. Each of the helical leads has an end grounded in said ground plate. The helical leads are disposed at equal angular spaces around the pole portion. When a resonance wavelength &lgr; is equal to 128.3 mm, the predetermined space is equal to 20 mm. Each helical lead has a length of &lgr;/4. A pitch angle included between the ground plate and each helical lead is equal to 40 degrees.

Abstract: At least one of the following requirements is satisfied. A position of a curvature center of an arcuate portion in at least one of waveguide plates is selected between a connecting member and a power feeder, in accordance with a desired horizontal beam radiation characteristic. A curvature radius of the arcuate portion in at least one of the waveguide plates is selected in accordance with a desired vertical beam radiation characteristic. A slanted angle of a peripheral face of the arcuate portion, which connects a top face and a bottom face of each waveguide plate, in at least one of the waveguide plates is selected in accordance with a desired vertical beam radiation characteristic.

Abstract: An electromagnetic coupling type four-point feeding loop antenna (10) comprises a cylindrical body (11) formed by rounding a flexible insulator film member (20) around a central axis (O) in a cylindrical fashion and a loop portion (12) made of conductor that is formed on the cylindrical body along a peripheral surface thereof around the central axis in a loop fashion. In order to feed to the loop portion at four points, four feeders (13) are formed on the peripheral surface of the cylindrical body. Between the loop portion and each of the four feeders, a gap (&dgr;1) is provided, whereby carrying out feed to the loop portion by electromagnetic coupling.

Abstract: An electromagnetic coupling type four-point feeding loop antenna (10) comprises a cylindrical body (11) formed by rounding a flexible insulator film member (20) around a central axis (O) in a cylindrical fashion and a loop portion (12) made of conductor that is formed on the cylindrical body along a peripheral surface thereof around the central axis in a loop fashion. In order to feed to the loop portion at four points, four feeders (13) are formed on the peripheral surface of the cylindrical body. Between the loop portion and each of the four feeders, a gap (&dgr;1) is provided, whereby carrying out feed to the loop portion by electromagnetic coupling.

Abstract: A ground pattern 8 has a portion thereof removed in an area 13 where an inverted-F plate antenna 1 is mounted. This gives the inverted-F plate antenna 1 almost non-directional directive patterns as distinct from those obtained with an ordinary inverted-F antenna, and helps achieve a higher degree of gain isotropy.