Murata Manufacturing Co., Ltd.

Kabushiki Kaisha Toshiba

Osamu Shibata

Yuichi Takamine

Ichiro Seto

Yoichi Sawada

Hidehiro Matsuoka

Yasushi Murakami

Takanori Uejima

Kengo Onaka

Yuichi Kushihi

Masaru Yata

Hiroki Watanabe

Koichi Ichige

A time of arrival t and a carrier wave phase &#x3d5; of a positioning pulse that is transmitted from a mobile station in each posteriori period and that is received by each of at least three fixed stations are input. Then, by using an error reduction algorithm, a time of arrival tof the positioning pulse in the following posteriori period is predicted by using a carrier wave phase difference &#x394;&#x3d5; of the positioning pulse. Then, by using the predicted time of arrival t of the positioning pulse, the location of the mobile station is calculated. A time interval dt of a posteriori period is set to a time interval with which a difference &#x394;&#x3d5;between the carrier wave phase differences, which is changed by the movement of the mobile station at an assumable maximum movement speed, is no greater than 180&#xb0;.

Location system and computer program

An antenna unit and a radio communication device are provided. An antenna unit has a monopole antenna section and a loop antenna section. The monopole antenna section includes a linear radiating electrode that resonates at a first frequency and has an electrical length of one-quarter of the wave length corresponding to the first frequency. The loop antenna section includes a radiating electrode that resonates at a second frequency, is vertically erected on a non-ground region, and connected to a feed line. A proximal end of the radiating electrode of the loop antenna section is connected to an intermediate portion of the feed line, and a distal end thereof is connected to a ground region. The electrical length of the radiating electrode of the loop antenna section is one-half of the wave length of the second frequency.

Antenna unit and radio communication device

A high-frequency switch module includes a first switching element and a second switching element. A common terminal of the first switching element is connected to an antenna. A common input terminal of the second switching element is connected to a multi-band power amplifier. A second individual output terminal of the second switching element is connected to a fourth individual terminal of the first switching element via a first low-pass filter, and is connected to a third individual terminal of the first switching element via a series circuit including a second low-pass filter and a high-pass filter. A first individual output terminal of the second switching element is connected to a first individual terminal of the first switching element via a phase-shift circuit and a first SAW duplexer, and is connected to a second individual terminal of the first switching element via the phase-shift circuit and a second SAW duplexer.

High-frequency switch module

A patch antenna device and an antenna device that are miniaturized while avoiding degradation of radiation characteristics, such as gain and efficiency. A first electrode is formed on a front surface of a rectangular parallelepiped-shaped dielectric substrate. A second electrode is formed on a rear surface of the dielectric substrate. The first electrode is connected through a coaxial cable to a power supply unit. The width W of each of the first and second electrodes is smaller than or equal to a quarter of the length L thereof, and the thickness T of the dielectric substrate is larger than or equal to the above width W. Advantageously, the second electrode is set so as to be longer than the first electrode, and both end portions of the second electrode are bent and arranged on both end surfaces of the dielectric substrate.

Patch antenna device and antenna device

There is disclosed a radio communication system in which a constitution of a base station and further a control station can be simplified. A radio communication system according to the present invention converts a received signal received by a plurality of antenna elements in a base station to a signal of different frequency band, and then conflates the converted signal in order to generate sub-carrier wave multiplex signal. The signal is converted to an optical signal, and then the optical signal is transmitted to a control station via an optical fiber. Or the control station performs weighting to phase of the transmitted signal transmitted from a plurality of antennas of a base station, and then performs frequency conversion to different frequency band, and then conflates the converted signal in order to generate the sub-carrier wave multiplex signal. The signal is converted to an optical signal, and then an optical signal is transmitted to the base station side via the optical fiber. The control station and the base station divides the received sub-carrier wave multiplex signal by each frequency band, and then the frequency of the divided signals are converted to the same frequency band in order to generate the transmitted/received signal of each antenna element. By such a constitution, it is possible to reduce constituent of the optical transmission components to the minimum and to simplify the constitution of the base station. Furthermore, it is possible to maintain the relative phase difference and the relative intensity of the transmitted/received signal of each antenna element. Because of this, it is possible to estimate an arrival direction of the received signal and to control radiation beam pattern of the transmitted signal.

Radio communication system

A surface acoustic wave device includes a piezoelectric substrate that does not restore the pyroelectric effect, and a method for manufacturing the same. A surface acoustic wave element housed in a package includes a piezoelectric substrate having a specific resistance in the range of about 1.0&#xd7;10&#x3a9;&#xb7;cm to about 1.0&#xd7;10&#x3a9;&#xb7;cm. Pads are electrically connected to an external electrode with a solder. The space between the package and a cap of the package is sealed with a sealing material. At least one of the solder and the sealing material has a melting point of about 300&#xb0; C. or less.

Surface acoustic wave device and method that prevents restoration of a pyroelectric effect

An antenna apparatus including a feed element excited by first and second wireless frequency signals, first non-feed elements for controlling directivity with respect to the first wireless frequency signal, second non-feed elements for controlling directivity with respect to the second wireless frequency signal, second variable-reactance circuits disposed between the second non-feed elements and ground, filters for passing the first frequency band and cutting off the second frequency band, which are connected to the first non-feed elements, and first variable-reactance circuits disposed between the filters and the ground.

Antenna apparatus

A surface acoustic wave device includes at least four surface acoustic wave elements that are arranged to have an unbalanced-to-balanced conversion function. In a surface acoustic wave element on the balanced side, the phase between the input and output terminals is 180 degrees shifted so that the phase difference between the outputs on the balanced side becomes substantially 180 degrees.

Surface acoustic wave device and communication device

A surface acoustic wave apparatus includes three longitudinally-coupled-resonator-type interdigital transducers (IDTs) having a balanced-to-unbalanced conversion function, which are provided on a piezoelectric substrate in a direction in which a surface acoustic wave (SAW) propagates. Weighting is applied to at least one of the IDTs. For example, among the electrode fingers of the IDT located on the left side, an apodization-weighted electrode finger is provided for one of the electrode fingers positioned adjacent to the central IDT.

Surface acoustic wave apparatus and communication unit

A surface acoustic wave device having an unbalanced-to-balanced conversion function, which is capable of improving balanced characteristics, includes a first resonator filter and a second resonator filter, having a plurality of interdigital transducers disposed along the propagation direction of a surface acoustic wave. The surface acoustic wave device has an unbalanced-to-balanced conversion function as a result of the phase of the second resonator filter being reversed by 180&deg; with respect to that of the first resonator filter. The surface acoustic wave device further includes a first resonator connected in series to an unbalanced signal terminal side of the first resonator filter, and a second resonator connected in series to an unbalanced signal terminal side of the second resonator filter. The first resonator and the second resonator have different design parameters.

Growing community of inventors

Kawasaki, Japan

Osamu Shibata