Abstract: An information acquisition device is provided within a virtual plane including a coil axis of a coil-shaped antenna and having a perpendicular line orthogonal to an axis of rotation of a tire, such that the angle formed by the coil axis of the antenna relative to the tire rotational axis is within a range of 0° to 40°. The amount of attenuation of radio waves emitted from the antenna to the exterior of the tire is thereby reduced.

Abstract: An information acquisition device is provided within a virtual plane including a coil axis of a coil-shaped antenna and having a perpendicular line orthogonal to an axis of rotation of a tire, such that the angle formed by the coil axis of the antenna relative to the tire rotational axis is within a range of 0° to 40°. The amount of attenuation of radio waves emitted from the antenna to the exterior of the tire is thereby reduced.

Abstract: A normal mode helical antenna comprises a coil made by winding a first conductor helically, and a second conductor shorter than the first conductor having a feeding point at the middle thereof. The second conductor is disposed outside of the coil at a center part in a longitudinal direction thereof along the first conductor. Both ends of the second conductor are connected to the first conductor of the coil.

Abstract: A disk brake pad for controlling rotation of a rotating disk by being pressed against the disk, is provided with a first friction member that is disposed at a leading side portion that is an inward-rotating side of the disk; a second friction member, which has a friction coefficient and a Young's modulus that are large as compared to those of the first friction member and which is easily worn, that is disposed at a trailing side portion that is an outward-rotating side of the disk. Further, on a surface that contacts with the disk, the first friction member protrudes further than the second friction member. In addition, a slit is provided between the first friction member and the second friction member; both of the friction members and are partitioned by the slit so as to be spaced apart from each other.

Abstract: Two beams with equiangular spacing are formed at a single antenna face, and multiple beams are generated by combining a plurality of such faces. This makes it possible to reduce the size of an antenna device and to decrease the wind load sustained by an antenna, whereby it becomes possible to mount many antennas on a single supporting structure and to achieve substantial weight reduction of a supporting structure.

Abstract: An aperture antenna having the improved phase performance of radiated co- and cross-polarization has been found. The present antenna has, at least, a horn for radiating an electro-magnetic wave, and means for focusing the electromagnetic wave. The focusing means is actually implemented by a reflector or a dielectric lens, and is designed so that the phase distribution of an electric field on an aperture plane of the focusing means has the period of .pi./2 and the maximum phase at (2m-1) .pi./8 from the reference plane of one polarized wave in the polar coordinates system on the aperture plane, where m is an integer.