Fujitsu Corporation

Yasuaki Takeuchi

Yasuhiro Murakami

Takashi Tanii

Yusuke Yamamori

Mikio Hayashihara

Seiji Miyoshi

Masato Takeyabu

Nobuhide Hachiya

Manabu Murakami

Masahiko Hirao

Yuji Kobayashi

Masahisa Yoshimi

A power adjustment method includes: measuring output power that is obtained when input power to be amplified in a linear region is input to a power amplifier configured to amplify input power linearly in the linear region and amplify input power nonlinearly in a nonlinear region; deriving a straight line connecting a measurement point corresponding to the measured output power and a boundary point between the linear region and the nonlinear region in a coordinate plane representing input/output characteristics; acquiring information on an approximate equation that is stored in advance in correspondence with the measured output power, the approximate equation representing a relation between input power and output power in the nonlinear region; and storing information on the derived straight line and the acquired information on the approximate equation in a semiconductor integrated circuit provided at a preceding stage of the power amplifier.

Power adjustment method, computer-readable recording medium and power adjustment apparatus

A radio communication circuit includes a power amplifier configured to amplify a signal and output the amplified signal, an envelope detector configured to extract an envelope of an input signal inputted to the power amplifier, an offset generator configured to generate an offset value for a power supply voltage to be applied to the power amplifier, based on a distortion amount in an output signal from the power amplifier, and a power supply voltage modulator configured to control the power supply voltage to be applied to the power amplifier based on the envelope extracted and the offset value generated.

Radio communication circuit and radio communication apparatus

When a transmission-line driver circuit that transmits a signal to a transmission line is supplied with a power-supply voltage from a power-supply circuit, the value of the power-supply voltage is controlled based upon the amplitude of a signal output from the transmission-line driver circuit. For example, the maximum value of a signal input to the transmission-line driver circuit in time units delimited at fixed time periods is detected, the target value of power-supply voltage supplied to the transmission-line driver circuit is decided based upon the maximum value, and the power-supply circuit is controlled in such a manner that the target value of power-supply voltage and actual value of power-supply voltage will agree.

Signal transmitting apparatus

Growing community of inventors

Sapporo, Japan

Yasuaki Takeuchi