Fujitsu Corporation

Shin Watanabe

Hiroyuki Abe

Katsumi Kanasaki

Masatomo Ohta

Masahiro Haga

Ryosuke Kobayashi

Shigeki Yamaji

Akira Sawada

Shinichiro Mori

Yoshiaki Nakano

Masaru Kanazawa

Hidehiko Hizuka

Katsuki Matsunaga

Hitoshi Yamasaki

Hideki Ikuta

Haruki Nishida

Tominaga Watanabe

Manabu Matsumoto

Takayuki Sakuma

A radio communication device includes a transmission unit that performs a radio transmission process on a baseband signal in which transmission data is included and that transmits a signal in which the baseband signal is superimposed on a carrier wave; a feedback unit that feeds back the signal transmitted by the transmission unit; a detecting unit that detects a carrier wave component by removing a component corresponding to the baseband signal from a feedback signal that is fed back by the feedback unit; a counting unit that counts the pulses of the carrier wave component detected by the detecting unit; and a calculating unit that calculates a frequency error of the carrier wave by using a count value obtained by the counting unit.

Radio communication device and frequency error measurement method

A distortion compensation unit compensates distortion in the amplifier by using a distortion compensation coefficient that is in accordance with a power value of a signal before amplification in the amplifier. An updating unit updates, on the basis of the signal before amplification in the amplifier and a signal after amplification in the amplifier, the distortion compensation coefficient. An extracting unit extracts, at a predetermined number of measurement periods, when the power value of the signal before amplification in the amplifier is equal to or greater than a threshold, the distortion compensation coefficient that is in accordance with the power value. A first calculating unit calculates, by using an average value of the extracted distortion compensation coefficients, an amount of variation in the distortion compensation coefficient. A determination unit determines, on the basis of the calculated amount of variation in the distortion compensation coefficient, whether the amplifier is degraded.

Wireless device

The distortion compensation apparatus includes: a branching unit to branch a part of the output signal of an amplifier to a signal path to a distortion compensating unit; a switch to pass the output signal of the amplifier to the interference or branching unit; and a controlling unit to control an amount of the compensation of the distortion under a pass-permitted state in which the switch passes the output signal in response to a result of measurement of a signal transmitted through the signal path under a state where the switch is in an interruption state.

Distortion compensation apparatus and method

The present invention relates to an antenna apparatus corresponding to a plurality of multi-bands, etc. and makes a plurality of radio communication frequencies easily changed or set. The present invention includes a passive element composed of a plurality of element units (elements) linked with a switching element (PIN diode) between the element units, and since the operating frequency of the passive element is switched by opening and closing the switching element and the passive element acts as a waveguide element, a radiation pattern can be acquired by the passive element and the effect of a human body is reduced on the radiant efficiency.

Antenna apparatus and radio communication apparatus

The present invention relates to an antenna device and enables the directivity of an antenna element to be changed without affecting the resonance frequency of the antenna element. The antenna device comprises a first grounded conductor, an antenna element mounted on the first grounded conductor via an insulator, a second grounded conductor disposed separate from the first grounded conductor, and a changing unit for changing directivity of the antenna element by adding the second grounded conductor to the first grounded conductor or canceling the addition thereof.

Antenna device, method and program for controlling directivity of the antenna device, and communications apparatus

A plane antenna of the present invention gives the realization of a surface mounting construction on a circuit base board, the enlargement of a mounting area for components, and the improvement of an SN ratio by avoiding the influence of a noise from a back face side of the mounting base board. The plane antenna mounted on the circuit base board has a dielectric substrate and a junction conductor, and realizes the surface mounting construction. The dielectric substrate is provided on the circuit base board, and an antenna pattern part is mounted on the dielectric substrate. To a feeding point of the antenna pattern part one end portion of the junction conductor is connected, and its the other end portion is connected to a feeding conductor of the circuit base board at a side of a mounting face of the antenna element of the circuit base board. According to a construction like this, the surface mounting construction on the circuit base board is realized.

Antenna, method and construction of mounting thereof, and electronic device having antenna

The extra length accommodation structure for the optical fiber includes a base and first and second winding drums pivotably supported to the base. Each of the first and second winding drums is pivotable between a position where it is positioned over the base and another position where it is partially projected from the base. The first winding drum is pivotably supported through a first support member to the base, and the second winding drum is pivotably supported through a second support member to the base.

Extra length accommodation structure for optical fiber

A variable attenuator includes a resistance region, a signal line to which the resistance region is connected, a very high frequency signal being propagated through the signal line, and a voltage applying part which applies a dc voltage across the ends of the resistance region, the dc voltage controlling a magnitude of attenuation to the very high frequency signal.

Variable attenuator

A high-performance low-cost functional module package handles microwaves or millimeter waves. The package has multilayered dielectric substrates, signal through holes (25, 28) connected to signal conductors that are formed on one of the dielectric substrates, and ground through holes (24, 26, 27, 29) connected to ground conductors that are formed on another of the dielectric substrates. The through holes are formed on side faces of the dielectric substrates and serve as terminals. Each pair of the ground through holes (24 and 26, or 27 and 29) is arranged on opposite sides of a corresponding one (25 or 28) of the signal through holes. The terminals are positioned between parts of the package to be connected to an external circuit board and the signal and ground conductors.

Microwave/millimeter-wave functional module package

A device for preventing laser beam leakage, which excludes a danger that a laser beam emitted from a laser source directly attacks eyes of an operator when an external connector is connected to or disconnected from an internal connector, aiming at being inexpensive and excellent in operability, and having a high safety. When the external connector has been removed from the optical transmission apparatus, a pair of movable shield plates are constantly urged in respective directions for closing a receiving opening of the apparatus to bring joining portions of the movable shield plates into close contact with each other, thereby preventing dust from entering the inside of the apparatus and the laser beam from being leaked. Further, a limit switch is provided, which stops delivering an ON signal to an E/O laser module when the external connector is pulled out of the optical transmission apparatus, whereby the E/O laser beam stops supply of the laser beam, thereby bringing into effect a perfect measure for protection of the eyes of the operation from the laser beam.

Device for preventing laser beam leakage

An input signal specified by an input frequency is divided by an out-of-phase type input hybrid coupler, into two divided signals with regard to the power of the input signal, where the divided signals have different phases. The input frequency of each of the divided signals is multiplied by a frequency multiplier connected with the input hybrid coupler, producing frequency multiplied signals each specified by the multiplied frequency. The frequency multiplied signals are composed by an out-of-phase type output hybrid coupler with regard to power, producing an output signal specified by the multiplied frequency. A phase shifter is provided between the input and the output hybrid coupler for varying the phase difference between the frequency multiplied signals, so that the frequency multiplied signals are composed in in-phase.

Growing community of inventors

Kawasaki, Japan

Shin Watanabe