Hitachi-Kokusai Electric Inc.

Yasuo Sera

Yoichi Okubo

Kiyoshi Funada

Toshio Nojima

Manabu Nakamura

Naoki Hongo

Tetsuhiko Miyatani

Toshio Takada

Masaki Suto

Takashi Uchida

Taizo Ito

Junya Dosaka

Kazuyoshi Sato

Masato Horaguchi

Junichiro Yamakawa

Terufumi Nagano

Masahiro Himono

Fumitake Kawanabe

A high frequency power amplifier includes an amplifying device for amplifying an input high frequency signal, a harmonic reflection circuit for reflecting a harmonic outputted from the amplifying device, and a harmonic generating circuit provided at an input terminal of the amplifying device, the harmonic generating circuit including a divider for dividing an input signal of a fundamental wave into two parts, a harmonic generator for generating a second harmonic from one part of the fundamental wave signal, and a combiner for combining the second harmonic generated from the harmonic generator with the other part of the fundamental wave signal to offer a combined signal to the amplifying device, wherein the harmonic reflection circuit reflects the second harmonic.

High frequency power amplifier

A distortion compensator that compensates for distortion arising in a main amplifierthat amplifies a signal effectively compensates for third order distortion which is unbalanced between the higher frequency band and lower frequency band. An amplitude detectordetects the level of a signal subject to amplification and a signal level change direction detection meansdetects the direction of change in the level of the signal. A signal level change control meansstores the correspondence between the signal level and the mode of changing the signal in order to compensate for distortion for when the direction of change in the signal level is positive and when it is negative, and controls a signal change meansso that the amplitude and phase of the signal is changed in a mode of changing the signal corresponding to the detected direction of change in the signal level and the detected signal level. A signal change control content updating meansupdates the content of this correspondence so that the distortion contained in the signal after amplification is reduced.

Distortion compensator

According to the present invention, there is provided a strain (error) compensation amplifier which realizes miniaturization, loss reduction, and cost reduction. In the strain (error) compensation amplifier, by unifying at least two or more of a power distributor, a first delay unit, a first power synthesizer, a second delay unit, a second power synthesizer, a directional coupler, an isolator and a terminating resistor, the miniaturization, loss reduction, and cost reduction are realized.

Strain error compensation amplifier

Excellent compensation of the distortion is realized with a distortion-compensated amplifier device that compensates a distortion that is generated in a main amplifier, through the respective operations of a circuit comprised of a distortion-detecting loop and a distortion-compensating loop and a pre-distortor. In a distortion-detecting loop, the signal is distributed. With respect to one distribution signal, a vector adjuster ( ) performs vector adjustment of it and the pre-distortor ( ) generates a distortion. A main amplifier ( ) amplifies this signal. The resulting amplification signal and the other distribution are composed, whereby a distortion component is detected. In a distortion-compensating loop, that amplification signal and this distortion component are composed to thereby eliminate the distortion component from the amplification signal. In a control part, a distortion component level detecting means ( ) detects the levels of the distortion component that is detected. Vector adjusting/controlling means ( ) and ( ) controls the vector adjusting means ( ) to thereby make the average value of those levels small. On the other hand, pre-distortor controlling means ( ) and ( ) controls the pre-distortor ( ) to thereby make the peak values of those levels.

Distortion-compensated amplifier device

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Tokyo, Japan

Yasuo Sera