Fujitsu Corporation

Setsuya Nagaya

Hideo Sugawara

Youji Nakata

Tominaga Watanabe

Mutsuhito Ota

Shinichi Kawai

Kenji Iwai

Yusuke Yamamori

Mikio Hayashihara

Masaaki Saitou

Atsushi Kudo

Shinji Kakizaki

Kosei Nishimura

Akio Sasaki

Narito Matsuno

Youji Najata

A wireless communication apparatus includes an amplifying unit that amplifies an input signal that includes signals with different frequencies of a first frequency and the second frequency; a measuring unit that measures a level of inter modulation distortion generated in a signal obtained by the input signal being amplified by the amplifying unit; a determining unit that determines whether the level of the inter modulation distortion measured by the measuring unit is equal to or greater than a regulation value that is previously stored; and a control unit that decreases, when a result of the determination obtained by the determining unit indicates that the level of the inter modulation distortion is equal to or greater than the regulation value, a level of a signal input to the amplifying unit.

Wireless communication apparatus, communication control method, and computer-readable recording medium

A radio communication circuit includes a transmitter that includes a modulator modulates a signal with a first modulation scheme and a power amplifier amplifies the signal modulated with the first modulation scheme and output the amplified signal and transmits the amplified signal, a receiver that includes a demodulator demodulates the signal output from the transmitter with a second modulation scheme that is different from the first modulation scheme, a pre-distortion compensator compensates occurred upon the amplification of the signal, of the signal input to the transmitter, based on the demodulated signal and a power controller controls supply of power to the receiver and the pre-distortion compensator and stop the supply of the power based on an average power level of the signal output from the transmitter and a peak-to-average power ratio that is a ratio of an instantaneous peak power level to the average power level.

Radio communication circuit and radio communication device

In a wireless communication device, in a correction value calculating mode, a control unit flips switches to the 'a' sides, a modulation processing unit generates a CW signal as an I channel signal, a DAC converts the digital CW signal into an analog CW signal, an LPF eliminates the high-frequency component from the CW signal, a mixer functions as an up-converter for up-converting the CW signal, a PA amplifies the RF power of the CW signal, a mixer functions as a down-converter for down-converting the CW signal, an ADC converts the analog CW signal into a digital CW signal, a level detecting unit detects the voltage level of the CW signal, a correction value calculating unit calculates a correction value based on the detected voltage level, and a correction value storing unit stores the calculated correction value.

Wireless communication device for calculating level correction value for transmission signal

An amplifier circuit includes an amplifier, a detecting unit which detects a power output from the amplifier, a control unit which controls a saturation point of the amplifier with respect to a Peak-to-Average Power Ratio (PAPR) obtained by a detection output of the detecting unit.

Amplifier circuit, control method for supplying power to amplifier circuit, and transmission device

An amplifying circuit is suitable for an integrated circuit that has a characteristic of low-noise, high-gain, and low-consumptive current. In the circuit, transistors or FETs are used as amplifying elements. A basic amplifying circuit employing transistors, that forms a differential pair of first and second transistors, first and second resistors connected to each collector of the first and second transistors, and a constant current source connected to a common emitter of the first and second transistors, comprises a third transistor, of which emitter is connected to a connecting point of the first and second resistors, a condenser connected between a connecting point of the first transistor and the first resistor, or a connecting point of the second transistor and the second resistor, and a base of the third transistor, and a voltage source connected to a collector of the third transistor, wherein outputs are obtained from an emitter of the third transistor.

FET amplifying circuit which can improve low-consumptive current

Amplifying circuit for an integrated circuit with low-noise

Growing community of inventors

Sapporo, Japan

Setsuya Nagaya