Abstract: A predistorter for correcting distortion caused by a memory effect in amplifying a signal by an amplifier is provided. In the memory PD 2 provided to the predistorter, the level detection means 21 detects the level of the signal, the coefficient output means 22 outputs the coefficient corresponding to the detected level, the delay means 23 delays the output coefficient, the difference detection means 24 detects the difference between the output coefficient and the delayed coefficient, the multiplication means 25 multiplies the detected difference with the signal, and the combination means 26 combines the result of the multiplication and the signal. Thus, the result of the combination is output to the amplifier.

Abstract: A predistorter for correcting distortion caused by a memory effect in amplifying a signal by an amplifier is provided. In the memory PD 2 provided to the predistorter, the level detection means 21 detects the level of the signal, the coefficient output means 22 outputs the coefficient corresponding to the detected level, the delay means 23 delays the output coefficient, the difference detection means 24 detects the difference between the output coefficient and the delayed coefficient, the multiplication means 25 multiplies the detected difference with the signal, and the combination means 26 combines the result of the multiplication and the signal. Thus, the result of the combination is output to the amplifier.

Abstract: An amplifying apparatus includes a splitting unit for splitting an input signal into a first split signal and a second split signal; phase-shifting unit for phase-shifting the first split signal and the second split signal, respectively; a first amplifying unit for amplifying a first phase-shifted signal and outputting the signal as a first output signal; a second amplifying unit for amplifying, in a substantially identical manner to the first amplifying unit, a second phase-shifted signal and outputting the signal as a second output signal; and a matching unit for matching the first output signal and the second output signal to a first transmission unit and a second transmission unit, respectively. The first transmission unit is for transmitting the first output signal from the matching unit to a load resistor, and the second transmission unit is for transmitting the second output signal from the matching unit to the load resistor.

Abstract: A predistorter for correcting distortion caused by a memory effect in amplifying a signal by an amplifier is provided. In the memory PD 2 provided to the predistorter, the level detection means 21 detects the level of the signal, the coefficient output means 22 outputs the coefficient corresponding to the detected level, the delay means 23 delays the output coefficient, the difference detection means 24 detects the difference between the output coefficient and the delayed coefficient, the multiplication means 25 multiplies the detected difference with the signal, and the combination means 26 combines the result of the multiplication and the signal. Thus, the result of the combination is output to the amplifier.

Abstract: A predistorter for correcting distortion caused by a memory effect in amplifying a signal by an amplifier is provided. In the memory PD 2 provided to the predistorter, the level detection means 21 detects the level of the signal, the coefficient output means 22 outputs the coefficient corresponding to the detected level, the delay means 23 delays the output coefficient, the difference detection means 24 detects the difference between the output coefficient and the delayed coefficient, the multiplication means 25 multiplies the detected difference with the signal, and the combination means 26 combines the result of the multiplication and the signal. Thus, the result of the combination is output to the amplifier.

Abstract: The invention aims to converge predistortion coefficients efficiently in a predistorter adapted to compensate for distortion generated in an amplifier. Level detection means (11) detects the level of a signal input to an amplifier (4). Signal acquisition means (5-7) acquire a signal output from the amplifier as a feedback signal. Correspondence acquisition means (14) updates a predistortion coefficient expressed using a set of orthogonal polynomials so that a distortion component contained in the acquired feedback signal is reduced and acquires a correspondence between the level of the signal input to the amplifier and a control coefficient for predistortion (contents of a distortion compensation table (12)). Predistortion executing means (13) applies distortion for predistortion with respect to the signal input to the amplifier in accordance with the control coefficient for predistortion that corresponds to the detected level based on the acquired correspondence.

Abstract: An amplifier apparatus for providing a pre-distortion to perform a distortion compensation, wherein even if the frequency of occurrence of levels around the input signal peak is small, a distortion compensation table is efficiently updated so as to improve the performance of the distortion compensation. The compensation values of a distortion compensation table (2) are divided into a first group of compensation values corresponding to large input levels that lead to large output distortions and a second group of compensation values corresponding to the other small input levels. If a level detected by a level detecting part (1) exceeds a threshold value, a control part (5) updates the first group of compensation values. Otherwise, the control part (5) updates the second group of compensation values.

Abstract: A predistorter for correcting distortion caused by a memory effect in amplifying a signal by an amplifier is provided. In the memory PD 2 provided to the predistorter, the level detection means 21 detects the level of the signal, the coefficient output means 22 outputs the coefficient corresponding to the detected level, the delay means 23 delays the output coefficient, the difference detection means 24 detects the difference between the output coefficient and the delayed coefficient, the multiplication means 25 multiplies the detected difference with the signal, and the combination means 26 combines the result of the multiplication and the signal. Thus, the result of the combination is output to the amplifier.

Abstract: A first control unit controls a bias applied to the peak amplifier to (a) make a peak amplifier operate as class C when the level of the input signal is lower than a first threshold value, to (b) make the peak amplifier operate as class AB with a second conduction angle substantially equal to a first conduction angle, when the level of the input signal is higher than a second threshold value higher than the first threshold value, and to (c) make the peak amplifier operate as class AB with a third conduction angle smaller than the first conduction angle, when the level of the input signal is not less than the first threshold value and not more than the second threshold value.

Abstract: In an amplifying apparatus performing distortion compensation by imparting pre-distortion, a table for distortion compensation is efficiently updated for improving the accuracy of distortion compensation even when the frequency of occurrences of levels near a peak of an input signal is low. Compensation values in a distortion compensation table 2 are divided into a first group of compensation values associated with great input levels resulting in great distortion of output and a second group of compensation values associated with other small input levels. A control unit 5 updates the first group of compensation values when a level detected by a level detecting unit 1 is equal to or greater than a threshold and updates the second group of compensation values when the level is equal to or smaller than the threshold.

Abstract: A conventional power amplifying device has a problem that when a signal band is widened, sampling frequency for distortion detection is increased and an FFT calculation amount of a distortion compensation unit is increased, which increase a circuit size and power consumption. The present invention provides a non-linear distortion detection method and a distortion compensation amplifying device capable of suppressing increase of the circuit size and the power consumption even if the signal band is widened. A signal obtained by feeding back an output of a power amplifier is sampled by an A/D converter. An equalizer of a distortion detection unit uses an input signal d(n) of a predistorter as a reference symbol to detect an equalization error e(n) of the orthogonal demodulation signal u(n). An absolute value averaging unit outputs an absolute value of the equalization error e(n) which has been temporally averaged to E(n) as a distortion value to a control unit.

Abstract: The invention provides a spectrum analyzing method, a distortion detector and a distortion compensation amplifying device for performing time/frequency conversion processing at high speed, and reducing a convergent time of a compensation coefficient. The distortion detector for detecting distortion in a frequency area with respect to an input signal includes a time window processing section for multiplying the input signal by a time window; an averaging processing section for averaging an output of the time window processing section; an FFT processing section 52 for converting an output of the averaging processing section from a time area to a frequency area; and a distortion extracting section 53 for extracting a distortion component from an output of the FFT processing section 52.

Abstract: A predistorter for correcting distortion caused by a memory effect in amplifying a signal by an amplifier is provided. In the memory PD 2 provided to the predistorter, the level detection means 21 detects the level of the signal, the coefficient output means 22 outputs the coefficient corresponding to the detected level, the delay means 23 delays the output coefficient, the difference detection means 24 detects the difference between the output coefficient and the delayed coefficient, the multiplication means 25 multiplies the detected difference with the signal, and the combination means 26 combines the result of the multiplication and the signal. Thus, the result of the combination is output to the amplifier.

Abstract: A distortion compensator compensates for distortion arising in an amplifier that amplifies a signal with improved efficiency. The distortion compensator includes a signal level detector which detects the level of a signal to be amplified by an amplifier, a distortion compensation execution unit which executes distortion compensation on the signal to be amplified according to a mode of distortion compensation corresponding to the signal level detected by the signal level and a correspondence between signal levels and distortion compensation control values as pairs, a distortion compensation control value correspondence updater which updates the correspondence between the signal levels and the distortion compensation control values used in the execution of distortion compensation, and a distortion compensation control value number controller which controls the values of stipulated parameters.

Abstract: A predistortion distortion signal generating unit uses a signal to be amplified to generate a predistortion distortion signal including odd-order signal components of the signal. A delay time difference adjusting unit adjusts a delay time difference between a signal to be amplified and a distortion signal for predistortion such that an influence by the memory effect occurring in the amplifier can be reduced. A predistortion distortion signal giving unit gives a predistortion distortion signal to a signal to be amplified in a form that the delay time difference is adjusted.

Abstract: To provide a predistorter compensating for distortion generated at an amplifier by inputting a signal to be inputted to the amplifier constituting an object of compensating for the distortion and previously providing the distortion to the input signal. Amplifier replica means is provided with an input/output characteristic the same as an input/output characteristic of an amplifier or an input/output characteristic approximated thereto and inputs a signal to output. Difference detecting means detects a difference between an input signal to a predistorter and an output signal from the amplifier replica means. Amplifier replica input signal changing means changes a signal inputted to the amplifier replica means such that the difference detected by the difference detecting means is reduced. Change signal outputting means outputs a signal changed by the amplifier replica input signal changing means to the amplifier.

Abstract: A distortion compensator for compensating for distortion produced in an amplifier that amplifies a signal includes a signal level detector for detecting a level of a signal to be amplified and a distortion compensator for conducting distortion compensation based on the detection result separately for each frequency band signal of multiple frequency band signals contained in the signal to be amplified. The distortion compensator improves distortion compensation performance by reducing the effect of frequency characteristics that restrict the distortion compensation performance limit.

Abstract: A memory effect distortion component compensating unit compensates for a distortion component caused by a memory effect of an amplifier by using a time difference of results from raising an input signal to even power.

Abstract: To provide a predistorter compensating for distortion generated at an amplifier by inputting a signal to be inputted to the amplifier constituting an object of compensating for the distortion and previously providing the distortion to the input signal. Amplifier replica means is provided with an input/output characteristic the same as an input/output characteristic of an amplifier or an input/output characteristic approximated thereto and inputs a signal to output. Difference detecting means detects a difference between an input signal to a predistorter and an output signal from the amplifier replica means. Amplifier replica input signal changing means changes a signal inputted to the amplifier replica means such that the difference detected by the difference detecting means is reduced. Change signal outputting means outputs a signal changed by the amplifier replica input signal changing means to the amplifier.

Abstract: To provide an amplifying device which is reduced in size, weight and cost and which can improve the distortion compensation performance. In the amplifying device, input signals are each subjected to digital orthogonal modulation using an IF and further to offset rotation processing in digital orthogonal modulators, then bifurcated into a main signal system and a control system, and detection of a power value is performed at an IF band in a power detecting section of the control system. Therefore, offset rotation processing of the input signals in the power detection is not required, so that a structure for matching phases of a multi-carrier signal and a power value signal is not required, resulting in improving the distortion compensation performance without using an analog delay line.