Abstract: A variable-directivity antenna comprises an omnidirectional antenna element, a transmission line connected to the antenna element, and an electric field adjusting structure provided in a boundary region between the antenna element and the transmission line. The electric field adjusting structure is configured to change electric field distribution of the transmission line to a desired direction.

Abstract: A coplanar stripline is provided, including a dielectric substrate, and first and second strip conductors, which are each formed on the dielectric substrate, parallel to each other and separated by a predetermined distance. The corrugated structure is formed at least on one side of the strip conductors, including a plurality of slits. The slits are formed periodically on the side of each of the strip conductors, which is located in the outside portion thereof and not facing the other confronting strip conductor, so that the length direction of the slit is substantially perpendicular to the direction of the electromagnetic wave transmitted through the coplanar stripline.

Abstract: A surface-emission laser diode includes a distributed Bragg reflector tuned to wavelength of 1.1 &mgr;m or longer, wherein the distributed Bragg reflector includes an alternate repetition of a low-refractive index layer and a high-refractive index layer, with a heterospike buffer layer having an intermediate refractive index interposed therebetween with a thickness in the range of 5-50 nm.

Abstract: An optical module has a first light source which emits a first light beam from a first light emission point in a predetermined direction, a second light source which emits a second light beam from a second light emission point in the predetermined direction, and an optical element. The optical element includes a plurality of reflection surfaces for reflecting the first and second light beams, and finally outputting the first and second light beams in the predetermined direction with a separation between the first and second light beams smaller than a distance between the first and second light emission points.

Abstract: In a power divider/combiner, two quarter wavelength lines are connected to a first I/O terminal. A first transmission line is connected between the other end of one of the quarter wavelength lines and one of the second I/O terminals, a second transmission line is connected between the other end of the remaining quarter wavelength line and the remaining second I/O terminal, a third transmission line is connected between an absorption resistor and the one of the second I/O terminals, and a forth transmission line is connected between the absorption resistor and the remaining second I/O terminal. Assuming that the characteristic impedance at the I/O terminals is Z0, the characteristic impedance of each of the four transmission lines is set to {square root over (2)}·Z0.

Abstract: In a power distribution/synthesis apparatus, two quarter wavelength lines are connected to a first I/O terminal. A first transmission line is connected between the other end of one of the quarter wavelength lines and one of the second I/O terminals, a second transmission line is connected between the other end of the remaining quarter wavelength line and the remaining second I/O terminal, a third transmission line is connected between an absorption resistor and the one of the second I/O terminals, and a forth transmission line is connected between the absorption resistor and the remaining second I/O terminal. Assuming that the characteristic impedance at the I/O terminals is Z0, the characteristic impedance of each of the four transmission lines is set to {square root}2·Z0.

Abstract: An integrated type optical pickup module apparently approximates a plurality of light-emitting points of semiconductor lasers. An optical element is interposed between first and second semiconductor lasers. The optical element has first and second reflecting surfaces perpendicular to each other. The first and second reflecting surfaces reflect laser beams projected from the first and second semiconductor lasers, respectively. The optical element further has a mounting surface perpendicular to both the first and second reflecting surfaces. The optical element is mounted, via the mounting surface of the optical element, to a submount having a top surface on which the first and second semiconductor lasers are mounted. Heterojunction surfaces of the first and second semiconductor lasers may be substantially perpendicular to the first and second reflecting surfaces, respectively.

Abstract: A tapered slot antenna is provided including a substrate and a metal layer which is disposed on the substrate and removed in a region to form a tapered slot portion having a closed narrow end and extending outward toward a relatively wider end that is open. The tapered slot antenna is further provided with a corrugated structure including a plurality of slits formed periodically positioned in opposing outer edge portions of the metal layer parallel to the direction of the radiation by removing rectangular portions of the metal layer, having a sit depth ranging from 0.04 wavelengths to 0.12 wavelengths. With the structure, an electric field component can adequately be generated to thereby reduce the cross-polarized D-plane component and the electric field intensity at the substrate edge portions as well.

Abstract: A tapered slot antenna includes a dielectric sheet, a conductor layer laminated on said dielectric sheet, in which conductor layer a tapered slot pattern is formed as a result of a slot width of a slotline being widened gradually, and corrugated structures provided at two sides of said conductor layer, parallel to a direction in which an electromagnetic wave is radiated from said antenna. The shape of said antenna is axially asymmetrical.

Abstract: A tapered slot plane antenna apparatus for a millimeter wave radio communication system which provides a tapered pattern composed by utilizing a Fermi-Diac distribution function so as to consider an impedance matching and a directivity of the antenna apparatus. Supporting layers and protection layers may be utilized to provide sufficient strength for implementation in a compact millimeter wave radio communication system. The plane antenna may further prevent a directivity from deteriorating even if distances between end portions of an antenna aperture portion and ends of an antenna are decreased. A slot width of a slot line may be widened in tapering for radiating an electromagnetic wave in a progressive direction of the slot line by a conductor portion having a slot line and a corrugated structure portion at respective end portions located parallel to a radiating direction of the electromagnetic wave.

Abstract: A light emitting diode array has light emitting dots arranged in a line and is characterized in that a semiconductor substrate of a chip constituting the light emitting diode array has a Dovetail grooved mesa shape on a chip end face opposed to an adjacent chip and arranged in a direction perpendicular to an arranging direction of light emitting diodes. A light emitting portion can be protected from chipping even when a length from the light emitting portion of the light emitting diode array to a chip end portion is shorter than the size of a chipping portion.