Abstract: A low-cost, compact circular waveguide array antenna which improves an antenna reflection loss characteristic and enables an improvement in radiation characteristics, particularly radiation gain. The circular waveguide array antenna includes feeding portions which feed electromagnetic waves to one ends of circular waveguides and radiation apertures which radiate the electromagnetic waves at the opposite ends. Each circular waveguide includes a conical horn, with a diameter of a feeding side aperture at the feeding portion end being a, a diameter of the radiation aperture being d, which is larger than the diameter a of the feeding side aperture, and an opening angle being 2?. If a wavelength of a central frequency of an employed frequency band is ?, then a value of ?, which is half of the opening angle 2?, is set between 0.8×Arcsin(0.1349114/(d/?)) and 1.2×Arcsin(0.1349114/(d/?)).

Abstract: A low-cost, compact circular waveguide array antenna which improves an antenna reflection loss characteristic and enables an improvement in radiation characteristics, particularly radiation gain. The circular waveguide array antenna includes feeding portions which feed electromagnetic waves to one ends of circular waveguides and radiation apertures which radiate the electromagnetic waves at the opposite ends. Each circular waveguide includes a conical horn, with a diameter of a feeding side aperture at the feeding portion end being a, a diameter of the radiation aperture being d, which is larger than the diameter a of the feeding side aperture, and an opening angle being 2?. If a wavelength of a central frequency of an employed frequency band is ?, then a value of ?, which is half of the opening angle 2?, is set between 0.8×Arcsin(0.1349114/(d/?)) and 1.2×Arcsin(0.1349114/(d/?)).

Abstract: A flat antenna includes a 2×2 array of circular waveguide antenna elements that receive power from a splitting circuit including first to fourth striplines. The second stripline extends in two directions from one end of the first stripline. The third stripline extends in two directions from one end of the second stripline. The fourth stripline extends in two directions from the other end of the second stripline. Four feeder electrodes extend in mutually identical directions from the ends of the third and fourth striplines into the waveguides. The third and fourth striplines are bowed in way that shifts the second stripline closer to the center of the array. This arrangement permits a compact spacing of the waveguide antenna elements.

Abstract: A flat antenna includes a 2×2 array of circular waveguide antenna elements that receive power from a splitting circuit including first to fourth striplines. The second stripline extends in two directions from one end of the first stripline. The third stripline extends in two directions from one end of the second stripline. The fourth stripline extends in two directions from the other end of the second stripline. Four feeder electrodes extend in mutually identical directions from the ends of the third and fourth striplines into the waveguides. The third and fourth striplines are bowed in way that shifts the second stripline closer to the center of the array. This arrangement permits a compact spacing of the waveguide antenna elements.

Abstract: A method for the injection foaming molding of a light alloy wherein a melt(2) of a light alloy containing a thickener and a blowing agent decomposing at a high temperature to generate a gaseous component in respectively specified percentages is held at a temperature lower than the decomposition temperature of the blowing agent and then is agitated to allow the thickener and the blowing agent to disperse, a predetermined amount of the melt is measured for the injection into a mold (24) and then is injected into the mold (24) to produce a foaming molded article of the light alloy, characterized in that the temperature of the melt (2) is adjusted to a temperature higher than the decomposition temperature of the blowing agent and also the foaming of the melt is inhibited by pressuring at least immediately before the injection; and an apparatus for practicing the method.

Abstract: The sputtering target is manufactured by adjusting the ratio of the gas flow volume (Nm3)/molten liquid flow mass (kg) to 5 Nm3/kg or more in the gas atomizing step of the spray forming method using an Al or Al alloy sputtering target material in which the maximum length of all the inclusions is 20 &mgr;m or less.

Abstract: An Al alloy film containing one kind or two or more kinds of alloy components selected from a group of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and Mn in a total amount of 0.1 to 10 at %, and a melting Al alloy sputtering target for depositing the Al alloy film, wherein the above-mentioned film is used as a reflection film for an optical recording medium, a shading film for a liquid crystal display panel or for a solid image pickup device, and an Al alloy thin film line or electrode material for a semiconductor device.

Abstract: A metal-semiconductor field effect transistor includes an AlGaAs buffer layer made of Al.sub.x Ga.sub.1-x As, wherein 0<x<0.4, and a channel layer made of an n-type doped In.sub.y Ga.sub.1-y As, wherein 0<y<0.4, having a thickness equal to or less than a critical thickness for lattice-matching with GaAs. Further, a doped AlGaAs layer is interposed between the AlGaAs buffer layer and the channel layer. The doped AlGaAs layer is made of Al.sub.x Ga.sub.1-x As, wherein 0<x<0.4, is doped with Si of a concentration of 5*10.sup.17 cm.sup.-3 or more, and has a thickness which is sufficient to provide a barrier against holes caused by a donor depletion region.

Abstract: An Al alloy film containing one kind or two or more kinds of alloy components selected from a group of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and Mn in a total amount of 0.1 to 10 at %, and a melting Al alloy sputtering target for depositing the Al alloy film, wherein the above-mentioned film is used as a reflection film for an optical recording medium, a shading film for a liquid crystal display panel or for a solid image pickup device, and an Al alloy thin film line or electrode material for a semiconductor device.

Abstract: A semiconductor device for a microwave circuit includes a semiconductor substrate with an active element formed in the top surface, surface wirings on the top surface of the semiconductor substrate which are connected to terminals of the active element, and rear electrodes on the rear surface of the semiconductor substrate which are connected to the surface wirings by via holes. A structure includes the microwave semiconductor device, and a dielectric substrate which has surface wirings on a top surface. The semiconductor device is fixed with the dielectric substrate such that the rear electrodes of the semiconductor device are connected with the wirings on the top surface of the dielectric substrate.

Abstract: An Al alloy film containing one kind or two or more kinds of alloy components selected from a group of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and Mn in a total amount of 0.1 to 10 at %, and a melting Al alloy sputtering target for depositing the Al alloy film, wherein the above-mentioned film is used as a reflection film for an optical recording medium, a shading film for a liquid crystal display panel or for a solid image pickup device, and an Al alloy thin film line or electrode material for a semiconductor device.

Abstract: Disclosed is a method of lowering the permeability of a difficult-to-work Co alloy by introducing high working strain. It includes the steps of: making a Co alloy by melting, the Co alloy containing 0.1 to 40 atomic % of Ni and/or 0.1 to 40 atomic % of Pt, and 0.5 to 10 atomic % of one or more kinds of elements selected from a group consisting of Ta, Mo, W, V, Nb, Hf, Zr, Ti and B (the upper limit of B: 5 atomic %), the balance being 50 atomic % or more of Co and inevitable impurities; preparing a sheet like ingot having a thickness of 30 mm or less using the Co alloy; and covering the surface of the ingot with a metal capsule or coating it with a glass lubricant, and hot-rolling the treated ingot in such a manner that the reduction is performed in two stages accompanied by re-heating and the whole reduction is 30% or more.