Abstract: An antenna device, a radio communication terminal, an external antenna, and a hand strap can be provided, which are capable of ensuring satisfactory communication performance without being affected by the surrounding environment even in an area where the electric field is weak, and having the antenna performance improved by slightly modifying the body of an existing radio communication device. The antenna device according to the present invention includes an internal antenna (2) electrically connected to and incorporated into a circuit for radio communication within a case (1) and an external antenna (3) externally attached to the case.

Abstract: An antenna device, a radio communication terminal, an external antenna, and a hand strap can be provided, which are capable of ensuring satisfactory communication performance without being affected by the surrounding environment even in an area where the electric field is weak, and having the antenna performance improved by slightly modifying the body of an existing radio communication device. The antenna device according to the present invention includes an internal antenna (2) electrically connected to and incorporated into a circuit for radio communication within a case (1) and an external antenna (3) externally attached to the case.

Abstract: The antenna device includes a linear antenna (2, 11, 15), a fixing member (7), and a power feed member (10, 12, 14). The fixing member (7) is formed from a dielectric, and holds a portion (11) of the antenna. The power feed member (12, 10) contacts the antenna (11, 15). The fixing member (7) holds the antenna (2, 11, 15) in a movable manner.

Abstract: An antenna device includes: a conductive board (3) having one end portion and the other end portion opposite the one end portion; a flat plate antenna(4, 18a, 18b, 19) mounted on the board (3) with a dielectric interposing therebetween wherein when feeding a current thereto to excite, a current also flows in said board (3); a first current direction change means (5a, 6, 6a, 6c, 7, 7a, 7c, 14a, 17a, 17c, 21a, 22a, 22b, 24a) changing a direction of the current flowing in the board (3) to a first direction when exciting the antenna (4, 18a, 18b, 19) and located on said one end portion of the board (3); and a second current direction change means (5b, 6, 6b, 6d, 7, 7b, 7d, 14b, 17b, 17d, 21b, 22c, 22d, 24b) changing a direction of the current flowing in the board (3) to a second direction different from the first direction when exciting said antenna (4, 18a, 18b, 19) and located on the other end portion of the board (3).

Abstract: A portable telephone including a main unit case and an antenna element. The antenna element includes a meander line antenna as the first antenna unit arranged within the main unit case and formed to extend in one direction, and a second antenna unit extending substantially orthogonal to the extending direction of the meander line antenna, and arranged projectable from the main unit case, having an electrical length of approximately (&lgr;/2)×A (A is an integer), and coupled to the meander line antenna.

Abstract: An antenna device (3a) includes a substrate (11) and an antenna (21) provided on the substrate (11) and having an electrical length of (&lgr;/2)×A (A is an integer). The antenna (21) includes a plate antenna (21b) positioned at a portion where an electrical length from an end portion (21d) is approximately &lgr;/4+(&lgr;/2)×B (B is an integer), and a meander line antenna (21a, 21c) connected to the plate antenna (21b).

Abstract: An antenna element includes a plate antenna which is substantially equivalent to a series resonant circuit, and a monopole antenna which is connected to the plate antenna and is substantially equivalent to a parallel resonant circuit.

Abstract: A portable telephone includes a metal substrate, a shield box, a monopole antenna and a feed unit. The surface of the metal substrate includes a conductive metal layer. The shield box covers a radio transmitter-receiver unit provided on the metal substrate to electromagnetically shield the radio transmitter-receiver unit, and has conductivity. The monopole antenna extends in a predetermined direction, and has an electrical length of (&lgr;/2)×N (N is an integer). The feed unit is provided at the metal substrate so as to be apart from the shield box in the extending direction of the monopole antenna. The feed unit includes a matching circuit.

Abstract: A slide lever (6) is provided to a cabinet (2) of portable radio equipment, and an antenna (3) formed by nickel elastic alloy is held by a holding member (5). A lower portion of the antenna engages with an engaging portion (61) of slide lever (6), and by sliding slide lever (6), the lower portion of antenna (3) is bent at engaging portion (61) such that the entire antenna is inclined in a vertical direction by a desired angle, thereby reducing loss due to nonconformity of polarization with respect to an antenna of a base station.

Abstract: An antenna device (3a) includes a substrate (11) and an antenna (21) provided on the substrate (11) and having an electrical length of (&lgr;/2)×A (A is an integer). The antenna (21) includes a plate antenna (21b) positioned at a portion where an electrical length from an end portion (21d) is approximately &lgr;/4+(&lgr;/2)×B (B is an integer), and a meander line antenna (21a, 21c) connected to the plate antenna (21b).

Abstract: In a foldable portable telephone, a shield box provided within an upper casing is connected via a flexible cable to an output terminal of a transmitting circuit provided within a lower casing, and the shield box is used as an antenna. Thus, compared to the conventional case where a rod antenna is provided at an upper end of the lower casing, variation in gain dependent on a state of the user's hand holding the portable telephone is lessened.

Abstract: When the portable wireless device of the present invention is used, the second housing 3 with the antenna unit 4 telescopically received therein is turned about the hinge 2 to a spread position where the antenna unit 4 is spread out a sufficient distance away from the housing 1 and is extended from the second housing 3. Hence, during communication the antenna unit 4 is kept sufficiently far apart from the user's head 100 to provide improved transmission and/or reception characteristics.

Abstract: An object of the present invention is to provide an antenna feeding circuit, which requires no balance-unbalance converter and has a simplified structure. The object is attained, by an antenna feeding circuit, according to the present invention, in which micro-strips lines are constituted from one or more pair(s) of band conductors (5a, 5b) disposed on the outer surface of the cylindrical body (1) and an inner conductor (6) disposed on the whole of the inner surface of the cylindrical body (1). A 180 degree distributor (2) supplies electric power to the band conductors (5a, 5b) so that the phase difference between the currents in the band conductors (5a, 5b) is 180 degrees. Inutile current induced in the inner surface of the inner conductor can be cancelled out, because the inner conductor 6 is disposed on the whole of the inner surface of the cylindrical body (1).

Abstract: A non-driven first linear element is disposed in the vicinity of an inverted-F second linear antenna element. The driven second linear element is disposed over a conductive plate having a flat shape, in such a manner as to be substantially parallel to the inverted-F antenna. The non-driven element has a short-circuited end of the inverted-F antenna, and has substantially the same resonant frequency as that of the inverted-F antenna.

Abstract: A slot antenna includes a plate-like conductor provided vertically on the upper surface of the metallic cabinet and having a recess, whose length is equal to the half wavelength relative to a using frequency and whose depth is sufficiently smaller than the wavelength. Such a slot antenna is supplied with power to excite a half-wavelength conductor provided in the neighborhood thereof in a non-contact state through a electrostatic capacitive coupling.