Abstract: An inner-feed-type planar antenna of single-layered structure excited by an axially symmetric mode for propagating radio waves from the center toward the outer periphery within a propagation layer having an antenna surface. If the planar antenna is used for transmission, it is provided with a plurality of coupling slots formed and arrayed in one surface of an axially symmetric mode waveguide member in such a manner that the coupling factor of the external radiation is high at the outer periphery and becomes successively lower as the center is approached. A spiral or ring-shaped terminating slot is provided in the antenna surface at the outer portion of the axially symmetric mode waveguide member. A region not coupled with the outer portion is provided at the center of the antenna surface.

Abstract: This invention provides a flat circular waveguide device which permits uniform radiation or power through a plurality of power-radiating openings in order to increase the antenna gain in the technical field of electric communications, especially, broadcasting antennas. To achieve such uniform radiation of power, the device is equipped with means for feeding power from a peripheral wall of a wave-guiding space, which is surrounded by metallic walls, toward a central part of the wave-guiding space.

Abstract: A slotted waveguide antenna comprises a plurality of radiating waveguide having at least one radiating slot, a feed waveguide for feeding to the radiating waveguides, and coupling apertures arranged between the feed waveguide and the radiating waveguide at a distance of an integral multiple of the guide wavelength of the feed waveguide. The plurality of radiating waveguides are disposed in parallel to form an array in a manner that the radiating slots in the respective radiating waveguides are directed in the same direction. The feed waveguide is in the same plane as the array formed by the radiating waveguides. The transverse width of each radiating waveguide is one half of the distance between the adjacent coupling apertures. The coupling apertures provided on the feed waveguide supply electromagnetic waves having the same amplitude and the same phase to each radiating waveguide.

Abstract: The present invention relates to telecommunication technology and broadcasting antenna technology. The power-feeding portion and the wave-guiding space, and the power-feeding wave-guiding space and the power-radiating wave-guiding space are matched for the effective radiation of the fed power. A conical matching body is disposed within the wave-guiding space with the apex thereof directed toward a power-feeding opening; the junction of the power-feeding wave-guiding space and the power-radiating wave-guiding space is formed in a sectional shape of a semicircle, a hemihedral polygon or a desired curvilinear shape; the power-feeding wave-guiding space the power-radiating wave-guiding space are matched in impedance; or a matching body is provided at the junction of the power-feeding wave-guiding space and the power-radiating wave-guiding space.

Abstract: In a portable radio communication apparatus comprising a handset (20) having a side surface (23) and a recessed surface (24), first and second antennae (51 and 52) of different resonance frequencies are fixed to the recessed surface by first and second conductive plates (55 and 56), respectively. First and second conductive lines (61 and 62) connect a common conductive line (63) to the first and the second antennae, respectively. The common conductive line is connected to an electro-audio and audio-electro converting device (30) to feed a transmitting electric signal to the first and the second antennae and to receive the received electric signal from the first and second antennae. The first and the second antennae have first and second antenna widths (W.sub.1 and W.sub.2), respectively. The first and the second conductive plates have first and second plate widths, respectively, and first and second axes centrally of the first and the second plate widths, respectively.