Abstract: A wide-band antenna includes radiation devices and an electric supply line. The radiation devices include a first radiation device and a second radiation device. The electric supply line includes a coaxial cable. The first and the second radiation devices are conductor members placed opposite to each other across an electric supply point. The conductor members are line-symmetrical with respect to a straight line passing through the electric supply line. The first radiation device is connected to an inner core of the electric supply line. The second radiation device is connected to an outer conductor of the electric supply line. A conductor member including two electrode portions is connected to the second radiation device. The two electrode portions are placed such that a longitudinal axis thereof is parallel to the electric supply line and is line-symmetrical with respect to the straight line passing through the electric supply line.

Abstract: In order to provide a radio device which enables reducing its size regardless of the shape of a radio device antenna, a radio device includes a radio device antenna having a transmission/reception face A for transmitting and/or receiving signals, and a signal processing circuit for conducting predetermined processing on signals received at the radio device antenna and/or converting signals to be transmitted into signals adaptable to outputting from the radio device antenna. Further, in the radio device, a straight line (II)-(I) starting from a predetermined point (I) on the radio circuit board and extending from the predetermined point (I) in the direction opposite from the direction from the predetermined point (I) to a predetermined point (II) on the radio device antenna passes through a predetermined point (III) on the radio device antenna.

Abstract: A mono-conical antenna serving as a dielectric-loaded antenna includes: (i) a electricity supply electrode, which has a conical surface; (ii) an earth electrode, which has a flat surface that is so positioned as to face an apex of the conical surface; and (iii) a dielectric member, which is provided between the conical surface and the flat surface. The dielectric member has an outer circumferential surface which has such a slope that extends from a side of the conical surface to a side of the flat surface. This allows the dielectric-loaded antenna to have a small size, and to handle a wider frequency band in which the maximum value of the VSWR is restrained to be small.