Kabushiki Kaisha Toshiba

Bushiki Kaisha Toshiba

Noriaki Odachi

Syuichi Sekine

Shuichi Sekine

Hiroshi Watanabe

Motoji Noda

Hiroyuki Kayano

Kazuhiro Inoue

Hiroki Shoki

Keiichi Yamaguchi

Akihiro Tsujimura

Yasushi Murakami

Naoko Ono

Toshiki Miyasaka

Yuji Iseki

Syuuichi Sekine

Shu-ichi Sekine

Takayoshi Itoh

A portable radio terminal comprises a housing, a radio circuit included in the housing, a matching circuit mounted on the top of the housing at a position which is offset from the longitudinal center line of the housing, a load connected to the tip of the matching circuit, and a linear antenna connected to the load. This portable radio terminal further comprises load changing means for changing the value of the load. The matching circuit may comprise a meander matching element, a zigzag-shaped matching element, a helical matching element, a conical matching element, a rectangular helical matching element or a pyramid helical matching element which are formed so as to a predetermined shape, such as a meander shape, a zigzag shape, a helical shape, a conical shape, a rectangular helical shape or pyramid helical shape. Thus, even if the terminal is held in a user's left or right hand, it is possible to increase the quantity of radiation of vertically polarized waves, so that it is possible to provide the optimum antenna construction to carry out good radio communication.

Portable radio terminal capable of obtaining good polarization efficiency regardless of position and direction of antenna

An antenna apparatus coupled to a feeding point arranged on a cavity is disclosed. The apparatus includes a linear element extending from the feeding point and having a physical length that is shorter than a one-quarter wavelength. A half-wave antenna element is connected to an end of the linear element. The apparatus also includes a metal conductor piece including a connecting point between the linear element and the half-wave antenna element and located close to one surface of the cavity. The linear element includes a first portion extending in a first direction opposite to that of the half-wave element from the feeding point and in parallel with one surface of the cavity and a second portion extending in a second direction, which is equal to a direction in which the half-wave antenna element extends, and in parallel with one surface of the cavity.

Antenna apparatus

In a radio equipment of portable type, the impedance of an antenna is optimized by adjusting a matching circuit which has the adjustment function and is connected to an antenna, based on a reflection phase sent back from the antenna, outputted from a reflection phase detector, and a current supplied to a transmitter-receiver which generates a transmitting signal.

Portable type radio equipment

A method for estimating an arrival direction of an electromagnetic wave by the BS-MUSIC, by inputting into one receiver arrival wave reception signals received by a plurality of antenna elements constituting an array antenna. At first, a wide range is scanned in a plurality of directions with a wide antenna beam and a first estimation of arrival direction is carried out. Next, a plurality of directions are scanned with a narrow antenna beam to cover only the directions obtained as a result of the first estimation of arrival direction. Thus, a second estimation of arrival direction is carried out. With this arrangement, it is possible to provide a method of estimating an arrival direction by using a small number of receivers in a small apparatus at low cost. Further, based on this method, it is also possible to estimate an arrival direction in a small calculation volume even under the unknown environment of waves.

Wave arrival direction estimating method and antenna apparatus having wave arrival direction estimating function

Antenna apparatus is comprised of dipole antenna arranged proximate to a surface of metal housing including radio device circuit and having two quarter wavelength elements having opposite end portions being feed points, short-circuit element short-circuiting the quarter wavelength elements, and coaxial feed line having outer conductor and central conductor having one ends connected to the feed points, respectively, and connecting the feed points to radio device circuit. The coaxial feed line is arranged along part of the quarter wavelength element and part of the short-circuit element and branched from central portion of the short-circuit element. The outer conductor is electrically connected to part of the quarter wavelength element and part of the short-circuit element. Currents leaked onto the feed line and flowing through the two quarter wavelength elements are also divided to the short-circuit element. The currents are mixed at a position at which the coaxial feed line is branched and flow into the outer conductor of the coaxial feed line as a leak current from the dipole antenna. The currents branched from the two quarter wavelength elements to the short-circuit element are almost opposite in phase to each other. Thus, the currents cancel each other and the leak current becomes zero.

Antenna apparatus and radio device using antenna apparatus

A case with a shape of a thin rectangular parallelepiped which incorporates a radio signal processing circuit is provided with a data input/output section disposed on its surface and a microphone and a speaker disposed on either longitudinal end of the surface. Disposed inside of the case is a linear antenna, which longitudinally extends and goes out of the case from its side, and is placed adjacent to the surface of the case. Thus, the antenna characteristics are protected from deterioration even when the device is used on the desk. Further, the speaker is disposed in one of the sections divided by the longitudinal center line on the case surface and the linear antenna is disposed in the other section. Thus, the antenna gain fluctuation caused by the human body can be prevented so that the stable antenna characteristics can be maintained without being affected by the environment of utilization.

Portable radio terminal device

Growing community of inventors

Yokohama, Japan

Noriaki Odachi