Matsushita Electric Industrial Co., Ltd.

Toshimitsu Matsuyoshi

Kaoru Ishida

Seiji Fujiwara

Koichi Ogawa

Masayuki Miyaji

Atsushi Yamamoto

Hisashi Adachi

Kenichi Takahashi

Hiroyuki Nakamura

Hiroshi Iwai

Toshio Ishizaki

Yoshio Koyanagi

Toru Matsuura

Makoto Sakakura

Toshiaki Nakamura

Yuji Saito

Tomoki Uwano

Minoru Tachibana

Naoki Takachi

Kenji Monma

Junichi Yoshizumi

A power amplifier comprises an amplifier amplifying a high-frequency signal modulated by an input signal. An inverted envelope generates circuit generating an inverted envelope signal by using the input signal or the high-frequency signal The inverted envelope signal having an inverted envelope. A variable gain amplifier adjusts the amplitude of the inverted envelope signal, and a variable delay circuit adjusts a phase of the inverted envelope signal. A control circuit outputs a control signal to the variable gain amplifier and the variable delay circuit based on information about distortion or a signal level of the amplified high-frequency signal. The inverted envelope signal having been adjusted in amplitude or phase is injected to the high-frequency signal or the amplified high-frequency signal. The control circuit controls the variable gain amplifier or the variable delay circuit so that distortion or a signal level of the amplified high-frequency signal is minimum.

Power amplifying method, power amplifier, and communication apparatus

A predistortion linearizer has signal dividing circuit dividing an input signal into two signals; signal adjusting circuit using one of the divided signals to execute predetermined adjustment and outputting a signal based on the adjustment; distortion signal generating circuit generating a distortion signal using the signal output from the signal adjusting circuit; signal synthesizing circuit synthesizing the other of the divided signals with the generated distortion signal; and signal amplifying circuit amplifying the synthesized signal and outputting an output signal, and wherein the signal adjusting circuit executes the predetermined adjustment such that there is a predetermined relationship between the level of a difference between the signal amplitudes of predetermined frequency components contained in a distortion signal and the level of a difference between the signal amplitudes of the predetermined frequency components contained in a distortion signal.

Predistortion linearizer and predistortion distortion compensation method, program, and medium

A wireless communication base station system of the present invention includes a wireless key base station, an optical forward base station, and an optical transmitter which connects the wireless key base station and the optical forward base station to each other. An optical signal modulated by a signal component and that modulated by a distortion component are transmitted from the wireless key base station to the optical forward base station. In the optical forward base station, these optical signals are converted to high-frequency electrical signals, and the high-frequency signal consisting of the signal component is amplified. Thereafter, the amplified signal is combined with the high-frequency signal consisting of the distortion component with their phases opposite to each other, so that the distortion component include in the amplified signal is removed.

Radio communication base state system including optical advanced base station

A power amplifier capable of compensating for distortion by pre-distortion and achieving a large distortion suppressing effect even if IM3L components and IM3U components occurring at the power amplifier have a large level difference. A power amplifying circuitamplifies an original signal. An envelope detectorgenerates an envelope signal having components identical to envelope components included in the original signal. Based on the original signal a distortion signal generating circuitgenerates a distortion signal for canceling distortion components occurring while the original signal is amplified by the power amplifying circuit. In a power combiner, the envelope signal is injected to the original signal, thereby eliminating the asymmetric characteristic of the distortion components. In the power amplifying circuit, the distortion signal is injected to the original signal, thereby suppressing the distortion components.

Power amplifier

The conventional feedforward amplifier is unable to suppress distortion components efficiently. The present invention provides a feedforward amplifier wherein the vector adjustor is adjusted so that (1) suppression is performed on only the distortion component generated within a predetermined frequency range out of the range of frequencies to be suppressed in which distortion components to be suppressed occur or (2) the suppression of the distortion component generated within the predetermined frequency range is greater than the suppression of the distortion component generated within the frequency range other than the predetermined frequency range out of the range of frequencies to be suppressed, and the pre-distortion circuit is adjusted so that at least the distortion component generated within the frequency range other than the predetermined frequency range is suppressed.

Feedforward amplifier, communication apparatus, feedforward amplification method, program and medium

It is difficult that the impedance of the circuit part on the output side of an amplifying element at the frequency of a modulating wave is lower, and consequently, it is difficult to more effectively use the linearity of the amplifying element. The phase of a signal of the frequency of the modulating wave included in an amplified signal output from a FET is inverted by a difference frequency inverting circuit. The inverted signal of the frequency of the modulating wave and a signal of the frequency of a modulated wave included in an amplified signal output from a FET cancel each other out at the drain of the FET. At the drain end of the FET, the signal of the frequency of the modulating wave included in the amplified signal of the FET and a signal of the frequency of the modulating wave output from the FET cancel each other out.

Power amplifier, power amplifying method and radio communication apparatus

A power amplifier capable of compensating for distortion by pre-distortion and achieving a large distortion suppressing effect even if IM3L components and IM3U components occurring at the power amplifier have a large level difference. A power amplifying circuit amplifies an original signal. An envelope detector generates an envelope signal having components identical to envelope components included in the original signal. Based on the original signal a distortion signal generating circuit generates a distortion signal for canceling distortion components occurring while the original signal is amplified by the power amplifying circuit . In a power combiner , the envelope signal is injected to the original signal, thereby eliminating the asymmetric characteristic of the distortion components. In the power amplifying circuit , the distortion signal is injected to the original signal, thereby suppressing the distortion components.

Control method and circuit for feedforward distortion compensation amplifier

Provided is a distortion-compensated amplifying circuit capable of suppressing distortion without attenuating a level of carrier components, and further obtaining a larger amount of suppression of distortion, which has not been achievable by conventional distortion-compensated amplifying circuit using a pre-distortion technique. A balanced type amplifying circuit is structured such that amplifiers and placed in parallel are sandwiched by 90-degree hybrid circuits and . The 90-degree hybrid circuit is supplied with an original signal including carrier components and a distortion signal including distortion equal in amplitude and opposite in phase (having a phase difference of 180 degrees) to distortion that occurs when the original signal is amplified by the amplifiers and . The 90-degree hybrid circuit performs a process of differential amplification with a phase difference of 180 degrees between the original signal and the distortion signal. Then, the amplified original signal and distortion signal outputted from the 90-degree hybrid circuit are combined by a directional coupler , thereby canceling distortion components included in both signals with each other.

Distortion-compensated amplifying circuit

A feedforward amplifier includes a first power splitter for dividing an input signal into two paths. The first path, in sequence, includes a first vector adjuster, a main amplifier, a second power splitter and a delay circuit. The second path, in sequence, includes a delay circuit, a distortion detecting power combiner, a second vector adjuster and an error amplifier. The distortion detecting power combiner combines a portion of a signal from the first path with a signal in the second path. Each vector adjuster adjusts amplitude and phase of a signal in each path. A distortion suppression power combiner synthesizes a signal in the first path with a signal in the second path. Control is included for stopping operation of the error amplifier or main amplifier based on a predetermined condition.

Feedforward amplifier

An antenna for mobile wireless communications in which two built-in antennas having a bisymmetric shape arranged in an axi-symmetric location of a ground plate and, by feeding both of the antennas by using a balanced-to-unbalanced conversion circuit at the same amplitude and the phase difference of 180 degrees, balanced operations are performed.

Antenna for mobile wireless communications and portable-type wireless apparatus using the same

A power amplifier that reduces intermodulation distortion generated by the amplifier while reducing the number of parts is provided. A power amplifier comprises a first balun, to which a combined signal combining two signals of different frequencies is inputted, and which outputs, based on the combined signal, the first and the second signal whose phase are opposite; a first amplifier that outputs the first amplified signal containing the differential frequency component comprising the difference of the frequencies of two signals from the first signal; a second amplifier that outputs the second amplified signal containing the component comprising the difference of the frequencies of two signals from the second signal; and a second balun that outputs the combined signal of the first and the second amplified signals. The component contained in the first and the second amplified signal are inputted via the second and the first amplifier, respectively, to reduce the component.

Power amplifier with coupler for cross-coupling amplifiers for reduction of differential frequency component

A delay circuit in which amplitude characteristic and delay time characteristic of the output signals do not have any ripple relative to the length of the transmission line is provided. The delay circuit includes a circuit that makes a part of signals distributed into two parts by the power divider ( ) to be identical in amplitude and inverse in phase relative to the component of signals outputted from the terminal-a directly to the terminal-c of the circulator ( ). By composing with the power combiner ( ) both signals are offset each other at the output terminal. As a result, only the signals that are inputted from the input terminal ( ) and transmitted through the circulator ( ) and the open-ended transmission line ( ) are outputted to the output terminal ( ).

Delay circuit and feedforward amplifier

The ground conductor, the side conductor, and the ceiling conductor surround the antenna element, which is connected to the coaxial power supply part arranged on the surface of the ground conductor. The ceiling conductor is arranged to face the ground conductor with the antenna element therebetween. The ceiling conductor is provided with an opening whose size, shape, and position are changed to vary the directivity of radio waves.

Monopole antenna

A patch antenna apparatus with a simple structure can obtain an improved desired projection area in accordance with a projection space. The patch has a dielectric substrate with a grounding conductor on its bottom surface. On the dielectric substrate is formed at least one conductor patch having a first feeding point for producing resonance in parallel to the X-axis at a predetermined resonance frequency and a second feeding point for producing resonance in parallel to the Y-axis at the resonance frequency. A controller for a power distributing and combining circuit controls each of radio signals of the resonance frequency fed to the first and second feeding points so as to change at least one of the amplitude and phase thereof. When the radio signals of the resonance frequency are fed to the first and second feeding points, the patch antenna apparatus projects radio waves including two linear polarizations which are parallel to the X and Y axes and which cross each other to be perpendicular to each other in a projection directional pattern corresponding to the control for the radio signals by the controller of the power distributing and combining circuit.

Growing community of inventors

Osaka, Japan

Toshimitsu Matsuyoshi