34results about How to "Component distortion" patented technology

A transmitting method and a transmitter apparatus, which need no manual adjustment, are disclosed. A delay amount of a delay means is automatically adjusted such that an out-of-band distortion component of a transmission signal is minimized, and a correct timing is produced by the method and the apparatus. In this transmitter apparatus, a first delay means adjusts a control timing over a voltage that controls a power amplifying means, and a distributor distributes an output from the power amplifying means in order to feedback parts of the output. A distortion adjusting means calculates a distortion component of the transmission signal by using the signal fed back by the distributor, and adjusts automatically a delay amount of the first delay means so as to minimize the distortion component. This structure allows eliminating manual adjustment, and obtaining high power-efficiency with fewer distortions.

A memory effect distortion component compensating unit compensates for a distortion component caused by the memory effect of the amplifier by using a time difference of results from raising an input signal to even power. For example, the amplifier may include a memory effect distortion component compensating unit having an even power raising means for raising an input signal to even power, an even power raising result delaying unit for delaying a signal of a result of even power raising, an even power raising result time difference detecting unit for detecting a difference between a signal of an even power raising result and a delayed signal, an input signal multiplying unit for multiplying a signal of a detection result by an input signal, a distortion compensation coefficient multiplying unit for multiplying a signal of a multiplication result by a distortion compensation coefficient, and a distortion compensation coefficient multiplication result adding unit for adding an input signal and a signal of a multiplication result.

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. For example, the amplifier may include a memory effect distortion component compensating unit having an even power raising unit for raising an input signal to even power, an even power raising result delaying unit for delaying a signal of a result of even power raising, an even power raising result time difference detecting unit for detecting a difference between a signal of an even power raising result and a delayed signal, an input signal multiplying unit for multiplying a signal of a detection result by an input signal, a distortion compensation coefficient multiplying unit for multiplying a signal of a multiplication result by a distortion compensation coefficient, and a distortion compensation coefficient multiplication result adding unit for adding an input signal and a signal of a multiplication result.

There are provided, as a low noise amplifier (70) a low noise amplifier (71) with a low gain and a low noise amplifier (72) with a high gain, selectively operable under control of a bias current, and an output from the low noise amplifier (72) and a quadrature demodulator (80) are connected with a serial capacitance (73) and also an output from the low noise amplifier (71) and the quadrature demodulator (80) are serially connected. A control section (66) controls a reception circuit so that the low noise amplifier (71) operates when a reception signal level is high and the low noise amplifier (72) operates when the reception signal level is low. When the low noise amplifier (72) operates, a DC bias current thereof is made flow separately from a DC bias current of the quadrature demodulator (80), and, when the low noise amplifier (71) operates, a DC bias current thereof is shared with the quadrature demodulator.

One divided signal divided into two by a dividing circuit is inputted to a gate of a source grounded FET through a first matching circuit. In a drain of the FET, a second harmonic having a phase and an amplitude in accordance with an impedance of the first matching circuit is generated and extracted in a band pass filter and then the amplitude is adjusted in an attenuation circuit to input to an addition circuit through a second matching circuit. In the addition circuit, the output of the second matching circuit is added to another divided signal of the dividing circuit and inputted to a power amplifier. The impedance in the first matching circuit affecting the phase of the second harmonic generated from the FET is set so that a distortion component generated in the power amplifier is compensated for by the second harmonic inputted in the addition circuit.

In a cable television converter terminal, NICAM signal passthrough is achieved using an alignment-free passthrough circuit including a NICAM SAW filter. The alignment-free passthrough circuit directly taps the output of the converter terminal's tuner to obtain the NICAM signal. As a result, the NICAM signal is not distorted by the components involved in obtaining the other signal components of the cable television signal. Consequently, sound quality is improved and rendered less vulnerable to degradation due to component aging, temperature fluctuations, and human error. The passthrough circuit can be implemented as a removable circuit module.

A wireless communication unit includes a transmitter for processing a baseband transmit signal to produce a first radio frequency signal. A receiver is arranged to convert a second radio frequency signal to a baseband receive signal, where the receiver has a summation module arranged to add a cancellation signal to the baseband receive signal. A selectivity element is arranged to couple the transmitter and the receiver to an antenna, where a reduced portion of the first radio frequency signal is introduced into the second radio frequency signal thereby creating a second order inter-modulation distortion component in the baseband receive signal. An adaptive estimator module has a filter for filtering the baseband receive signal to remove dc offsets associated with the second order inter-modulation distortion component and generate the cancellation signal based on the baseband transmit signal and the filtered baseband receive signal for inputting to the summation module.

The image processing method processes an image generated by image pickup using an optical system (100). The method includes a step of acquiring the image, an image restoration step (S2-S7) of performing image restoration processing to reduce a blur component of the image using an image restoration filter, and a distortion correction step (S8) of performing geometric transformation processing to reduce a distortion component of the image on which the image restoration processing has been performed.

A wireless communication unit includes a transmitter for processing a baseband transmit signal to produce a first radio frequency signal. A receiver is arranged to convert a second radio frequency signal to a baseband receive signal, where the receiver has a summation module arranged to add a cancellation signal to the baseband receive signal. A selectivity element is arranged to couple the transmitter and the receiver to an antenna, where a reduced portion of the first radio frequency signal is introduced into the second radio frequency signal thereby creating a second order inter-modulation distortion component in the baseband receive signal. An adaptive estimator module has a filter for filtering the baseband receive signal to remove dc offsets associated with the second order inter-modulation distortion component and generate the cancellation signal based on the baseband transmit signal and the filtered baseband receive signal for inputting to the summation module.

A linear friction welding head apparatus for dual axis forging, the apparatus including three sets of orthogonal actuators for providing X-, Y-, and Z-planes of apparatus movement for providing Y-axis oscillation, a first forge load along a first forge axis, and a second forge load along a second forge axis. A method for dual axis forging for welding including providing a welding head for applying first and second forge loads along X- and Z-forge axes to weld at more than one interface. The forge loads may be applied at right angles to each other and have magnitudes corresponding to weld interface length.

A wireless communication unit includes a transmitter, a receiver, a selectivity element and a baseband processing module. The receiver has at least one summation module arranged to add a cancellation signal to the quadrature baseband receive signal. a baseband processing module arranged to: receive the quadrature baseband transmit signal and quadrature baseband receive signal; apply independent gain and phase adjustments to quadrature portions of the quadrature baseband transmit signal, based on at least one signal component of the quadrature baseband receive signal, to form independent cancellation signals; and apply the independent cancellation signals to the at least one summation module.

The image processing method processes an image generated by image pickup using an optical system (100). The method includes a step of acquiring the image, an image restoration step (S2-S7) of performing image restoration processing to reduce a blur component of the image using an image restoration filter, and a distortion correction step (S8) of performing geometric transformation processing to reduce a distortion component of the image on which the image restoration processing has been performed.

One divided signal divided into two by a dividing circuit is inputted to a gate of a source grounded FET through a first matching circuit. In a drain of the FET, a second harmonic having a phase and an amplitude in accordance with an impedance of the first matching circuit is generated and extracted in a band pass filter and then the amplitude is adjusted in an attenuation circuit to input to an addition circuit through a second matching circuit. In the addition circuit, the output of the second matching circuit is added to another divided signal of the dividing circuit and inputted to a power amplifier. The impedance in the first matching circuit affecting the phase of the second harmonic generated from the FET is set so that a distortion component generated in the power amplifier is compensated for by the second harmonic inputted in the addition circuit.

A distortion cancellation amplifier is described having a main amplifier and an error amplifier. The main amplifier, in response to an input signal, generates an output signal having an amplified signal component and a distortion signal component. The error amplifier is sized and biased to generate, in response to the same input signal, a distortion signal component that has substantially the same magnitude as the distortion signal component of the main amplifier. The distortion signal component from the error amplifier is subtracted from the output signal of the main amplifier.

The present invention provides an amplifying apparatus including, two amplifiers for receiving input signals in common and for outputting their respective amplified signals, a combiner for combining the output signals of the two amplifiers and for outputting a combined signal, the amplifying apparatus which inhibit the distortion component in the output of amplifiers in the transition state. This amplifying apparatus comprises, a predistortion unit for determining a distortion compensation component based on the output of the combiner and for predistorting the input based on the determined distortion compensation component, and a gain control unit for attenuating the inputs to set lower than in the steady state by reducing the gain in the transition from two amplifier operation to one amplifier operation, or in the transition from one amplifier operation to two amplifier operation, or at the time of removal or attachment the amplifiers.

A liquid crystal display device and method for driving the same is described for reducing a compensating deviation of a common voltage. The liquid crystal display device includes a liquid crystal display panel; a data driver for driving data lines of the liquid crystal display panel; a gate driver for driving gate lines of the liquid crystal display panel; and a common voltage compensating unit for generating a plurality of compensating signals for compensating respective distortions of common voltages at a plurality of common regions of a common electrode of the liquid crystal display panel by using common voltages fed back from the common regions, and supplying compensating signals corresponding to each of the plurality of common regions.

A distortion compensating circuit for a power amplifier attains raised compensating accuracy with shorter convergence time by accurately and quickly generating a distortion compensation signal for predistortion. An error signal representing the difference between the input and output signals of the power amplifier is generated. From the error signal and the input signal, the coefficients of the third-order intermodulation distortion, fifth-order intermodulation distortion and seventh-order intermodulation distortion are calculated. According to these coefficients, a distortion compensating signal which is characteristically opposite in phase and gain to the intermodulation distortions is generated.

A wireless communication apparatus includes an RF front-end unit constituting reception and transmission systems, a digital baseband signal processor, and a bias current circuit. The digital baseband signal processor performs a process of a digital baseband receive signal received from a reception system and performs a process of a digital baseband transmit signal supplied to a transmission system. The bias current circuit supplies a reference current to at least a part of a circuit constituting the reception system within the RF front-end unit. The bias current circuit switches the reference current supplied to at least the part of the circuit constituting the reception system within the RF front-end unit, in response to a transmission-operation control signal outputted by the digital baseband signal processor to the transmission system within the RF front-end unit.

A linear friction welding head apparatus for dual axis forging, the apparatus including three sets of orthogonal actuators for providing X-, Y-, and Z-planes of apparatus movement for providing Y-axis oscillation, a first forge load along a first forge axis, and a second forge load along a second forge axis. A method for dual axis forging for welding including providing a welding head for applying first and second forge loads along X- and Z-forge axes to weld at more than one interface. The forge loads may be applied at right angles to each other and have magnitudes corresponding to weld interface length.

An optical transmitter for generating a modulated optical signal for transmission over a fiber optic link to a remote receiver including a laser; an input coupled to the laser for directly amplitude modulating the laser with an analog RF signal to produce an output optical signal including an amplitude modulated information-containing component; and a phase modulator coupled to the output of the laser for reducing the distortion present in the received optical signal at the remote receiver.

A power series predistorter of the present invention includes a delay path for delaying a signal, a distortion generation path having an N-th order distortion generator and a vector adjuster, a divider for dividing an input signal between the delay path and the distortion generation path, a combiner for combining the output signal of the delay path and the output signal of the distortion generation path, and a controller for controlling the vector adjuster. The controller includes a setting unit, a distortion component measurement unit, a minimum condition calculation unit, and a recording unit. The setting unit specifies the phase or amplitude value of the vector adjuster. The distortion component measurement unit measures the distortion component of a power amplifier. The minimum condition calculation unit obtains a phase or amplitude value that minimizes the distortion component by function approximation, using the magnitude of the distortion components corresponding to three or more phase or amplitude values specified for sampling by the setting unit.

A linearity corrector is provided that reduces distortion in a signal processing system, such as an ADC. The linearity corrector provides a first order signal path having distortion components connected to an adder, and a filter product circuit that is also connected to the adder. A method is provided for reducing distortion by calculating a filter product and adding the filter product to a first order signal having a relative delay such that the filter product reduces, or eliminates, the order of distortions corresponding to the order of the filter product.

There are provided, as a low noise amplifier (70) a low noise amplifier (71) with a low gain and a low noise amplifier (72) with a high gain, selectively operable under control of a bias current, and an output from the low noise amplifier (72) and a quadrature demodulator (80) are connected with a serial capacitance (73) and also an output from the low noise amplifier (71) and the quadrature demodulator (80) are serially connected. A control section (66) controls a reception circuit so that the low noise amplifier (71) operates when a reception signal level is high and the low noise amplifier (72) operates when the reception signal level is low. When the low noise amplifier (72) operates, a DC bias current thereof is made flow separately from a DC bias current of the quadrature demodulator (80), and, when the low noise amplifier (71) operates, a DC bias current thereof is shared with the quadrature demodulator.

An optical transmitter for generating a modulated optical signal for transmission over a fiber optic link to a remote receiver including a laser; an input coupled to the laser for directly amplitude modulating the laser with an analog RF signal to produce an output optical signal including an amplitude modulated information-containing component; and a phase modulator coupled to the output of the laser for reducing the distortion present in the received optical signal at the remote receiver.

Fundamentals and IM waves comprising distortion signals are detected by vector measurement from an amplified baseband signal. Detected IM waves are related to power and frequency and plotted on the frequency axis. IM waves related to power and frequency are subjected to IFFT processing, and thereby converted so as to be related to time and power. Amplitude and phase components of IM waves subjected to IFFT processing are found. Compensation signal generation information is generated by relating a distortion compensation signal that has amplitude components of inverse amplitude to the amplitude components of IM waves and phase components of inverse phase to the phase components of IM waves to power, and creating a table by storing the generated compensation signal generation information in a compensation table. By this means, the circuit configuration can be made small and simple, processing can be simplified and speeded up, and distortion components can be suppressed with high precision.

Disclosed is a polar modulation transmission circuit wherein distortion components resulting from variations between individual amplifiers are compensated for with few man-hours, and deterioration in signal quality is effectively suppressed. A frequency converter (180) converts the frequency of an output signal of a high frequency power amplifier (170) and outputs a frequency domain signal, and a phase compensation unit (150) measures the power level, for each delay amount, at a low frequency band and high frequency band wherein the detuning frequency from the frequency domain signal is the same, calculates the “unlevel amount” (relative level difference) between the power level of the low frequency band and power level of the high frequency band for each delay amount, and determines the compensation characteristics on the basis of the relationship of the unlevel amount (relative level difference) to the delay amount. Then, the phase compensation unit (150) compensates for the phase signal by adding to the phase signal the phase compensation amount, in the determined compensation characteristics, that corresponds to the amplitude signal.

In a transmission device including an RF power amplifier with less number of terminals for monitoring an input / output signal of the RF power amplifier, there are provided with an input signal detector detecting the input signal; an output signal detector detecting the output signal; a first power amplifier switch switching ON or OFF the power amplifier; a monitor terminal; and an RF switch selecting an input signal or output signal of the power amplifier to be transmitted to the monitor terminal, in association with the first power amplifier switch being switched ON or OFF.

A voltage controlled current source outputs oscillator drive current and oscillator equivalent current. A signal oscillator outputs first source oscillation signal and second source oscillation signal. A differential amplifier outputs first amplification oscillation signal and second amplification oscillation signal. First switch circuit and second switch circuit output first current oscillation signal and second current oscillation signal, respectively. A first current value converter-amplifier circuit converts a value of the first current oscillation signal whereas a second current value converter-amplifier circuit converts a value of the second current oscillation signal, so that the thus converted values become output current finally. An adder outputs to the differential amplifier a differential amplifier drive current in which equivalent current for use with conversion is added up with the oscillator equivalent current outputted from the voltage controlled current source.