306 results about "Amplitude correction" patented technology

An amplitude error compensating device comprises an amplitude correcting section for performing amplitude correction with respect to an in-phase component and a quadrature component of a complex signal obtained by quadrature demodulation, based on amplitude error information, and outputting a resultant amplitude-corrected complex signal, and an amplitude error detecting section for obtaining the amplitude error information, depending on amplitudes of an in-phase component and a quadrature component of the amplitude-corrected complex signal. The amplitude error detecting section comprises a power difference calculating section for obtaining as a power error a difference in power between the in-phase component and the quadrature component of the amplitude-corrected complex signal, a rotation detecting section for detecting a rotation of a signal point of the amplitude-corrected complex signal, an error information control section for outputting the power error when a rotation of the signal point has been detected, and 0 when a rotation of the signal point has not been detected, and a smoothing section for smoothing an output of the error information control section, and outputting the result as the amplitude error information.

A power amplifier controller controls a power amplifier and is coupled to a polar modulator. The polar modulator generates an amplitude component and a phase-modulated component of the desired RF modulated signal, and outputs to the power amplifier controller. The power amplifier controller regenerates a combined phase and amplitude modulated RF signal to generate an input signal to a power amplifier by adjusting the gain of a VGA based on the amplitude component of the desired RF modulated signal. Concurrently, the power amplifier controller both controls an adjusted supply voltage to the PA and adjusts the gain of the VGA based upon an amplitude correction signal or amplitude error signal.

An RF power amplifier system comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The phase control loop adjusts the phase of the input signal based upon a phase error signal indicating a phase difference between phases of the input signal and the output signal. The phase control loop may comprise one or more variable phase delays introducing a relative phase delay to allow the phase differences between the input and output signals of the PA circuit to be within a range compatible with a phase comparator generating the phase error signal, and a low frequency blocking module that removes the larger extent, lower frequency components of the phase error signal.

A circuit for use with a power amplifier that amplifies an input signal. The circuit may comprise an amplitude correction circuit and an open-loop switching regulator. The amplitude correction circuit may be configured to generate a corrected envelope signal from an input envelope signal that represents an envelope of the input signal. The open-loop switching regulator may be connected to the amplitude correction circuit and may be for powering the power amplifier based on the corrected envelope signal. According to various embodiments, the corrected envelope signal generated by the amplitude correction circuit is a function of the input envelope signal and an error voltage of the open-loop switching regulator.

A power amplifier controller controls a power amplifier and is coupled to a polar modulator. The polar modulator generates an amplitude component and a phase-modulated component of the desired RF modulated signal, and outputs to the power amplifier controller. The power amplifier controller regenerates a combined phase and amplitude modulated RF signal to generate an input signal to a power amplifier by adjusting the gain of a VGA based on the amplitude component of the desired RF modulated signal. Concurrently, the power amplifier controller both controls an adjusted supply voltage to the PA and adjusts the gain of the VGA based upon an amplitude correction signal or amplitude error signal.

A multi-path equalization system for orthogonal frequency division multiplexing communication (OFDM) system includes a first estimator for estimating the channel characteristic using pilot signal. A divider is coupled to the estimator for dividing each sub-carrier with the channel characteristic to get the equalization to the data signal. A de-mapper uses the phase and amplitude correction of the channel estimate to recover the data signals. An improved channel estimation is provided by a repeat channel estimation feedback loop that includes the de-mapper a multiplier, an inverse fast Fourier transform (IFFT), a low pass filter and a fast Fourier transform (FFT). The improved channel estimation is obtained by multiplying at the multiplier the conjugate of the de-mapped data to the input sub-carriers and applying inverse FFT, low pass filtering and FFT to get the new channel estimate. Each sub-carrier is divided with new channel characteristic to get new equalization to the data signal. The channel estimation is repeated until there is convergence. The output is provided after the de-mapper. In the case of channel decoding to improve performance a Viterbi decoder and convolutional encoder is coupled in loop between the de-mapper and the multiplier.

A multi-path equalization system for orthogonal frequency division multiplexing communication (OFDM) system includes a first estimator for estimating the channel characteristic using pilot signal. A divider is coupled to the estimator for dividing each sub-carrier with the channel characteristic to get the equalization to the data signal. A de-mapper uses the phase and amplitude correction of the channel estimate to recover the data signals. An improved channel estimation is provided by a repeat channel estimation feedback loop that includes the de-mapper a multiplier, an inverse fast Fourier transform (IFFT), a low pass filter and a fast Fourier transform (FFT). The improved channel estimation is obtained by multiplying at the multiplier the conjugate of the de-mapped data to the input sub-carriers and applying inverse FFT, low pass filtering and FFT to get the new channel estimate. Each sub-carrier is divided with new channel characteristic to get new equalization to the data signal. The channel estimation is repeated until there is convergence. The output is provided after the de-mapper. In the case of channel decoding to improve performance a Viterbi decoder and convolutional encoder is coupled in loop between the de-mapper and the multiplier.

A power amplifier controller circuit controls a power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The power amplifier controller circuit comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal. The amplitude loop may include a variable gain amplifier adjusting the amplitude of the input signal. The amplitude loop can include a compression control block which may be configured either to adjust the gain in the variable gain amplifier or the voltage from the power supply based upon the operating level of the other, in addition to being based upon the amplitude correction signal, thus providing a way of maintaining the depth beyond the PA's compression point and allowing a control of the efficiency of the RF power amplifier.

A power amplifier controller circuit controls a power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The power amplifier controller circuit comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal. The amplitude correction signal may also be split into two or more signals with different frequency ranges and provided respectively to different types of power supplies with different efficiencies to generate the adjusted supply voltage to the power amplifier. The phase control loop adjusts the phase of the input signal based upon a phase error signal indicating a phase difference between phases of the input signal and the output signal to reduce phase distortion generated by the power amplifier.

A power amplifier controller circuit controls a power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The power amplifier controller circuit comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal. The amplitude control loop may also compensate for impedance mismatch with the load by increasing the power delivered from the power amplifier to the load, or decrease the output power of the power amplifier upon detection of excessive power dissipation in the power amplifier. The phase control loop adjusts the phase of the input signal based upon a phase error signal indicating a phase difference between phases of the input signal and the output signal to reduce phase distortion generated by the power amplifier.

Methods and apparatus for performing amplitude and phase imbalance correction operations on in-phase and quadrature phase signal components corresponding to a received signal are described. The imbalance correction operations relay on the use of relatively simple to implement feedback loops. The phase imbalance feedback loop relies on the tendency of transmitted symbols to be distributed uniformly around the origin of the I / Q plane if proper phase balance is present in the processed signal. Phase correction coefficients are generated over time as a function of the negated product of the processed in-phase and quadrature phase signal components. Amplitude correction coefficients are generated over time as a function of the difference in the squared values of the I and Q processed signal components.

A circuit for use with a power amplifier that amplifies an input signal. The circuit may comprise an amplitude correction circuit and an open-loop switching regulator. The amplitude correction circuit may be configured to generate a corrected envelope signal from an input envelope signal that represents an envelope of the input signal. The open-loop switching regulator may be connected to the amplitude correction circuit and may be for powering the power amplifier based on the corrected envelope signal. According to various embodiments, the corrected envelope signal generated by the amplitudecorrection circuit is a function of the input envelope signal and an error voltage of the open-loop switching regulator.

A power amplifier controller circuit controls a power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The power amplifier controller circuit comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal. The amplitude control loop may also compensate for impedance mismatch with the load by increasing the power delivered from the power amplifier to the load, or decrease the output power of the power amplifier upon detection of excessive power dissipation in the power amplifier. The phase control loop adjusts the phase of the input signal based upon a phase error signal indicating a phase difference between phases of the input signal and the output signal to reduce phase distortion generated by the power amplifier.

A method, system and apparatus for generating a cancellation signal in a RFID reader to isolate a transmit section and a receive section of a RFID reader, where the RFID reader generates a local reference signal from a broadcast transmit signal, receives a receive signal from a remote device, determines at least one correction factor, e.g., an amplitude correction factor, to generate a cancellation signal. The method, system and apparatus can further include combining a cancellation signal and a receive signal to minimize or cancel out interference and noise on the receive signal.

A lightning detection system provides an estimated location of a lightning stroke. The system includes sensors, and an analyzer. Each sensor provides messages having sensor identification, an amplitude responsive to the lightning stroke, and a time of detecting the lightning stroke. The analyzer applies time corrections and amplitude corrections to improve the accuracy of determining the location of the lightning stroke. Time adjustments and amplitude adjustments for the time and amplitude corrections are recalled from a matrix accessed according to a suggested or estimated location. The matrix may be organized by coordinates of longitude and latitude.

A power amplifier controller circuit controls a power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The power amplifier controller circuit comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal. The phase control loop adjusts the phase of the input signal based upon a phase error signal indicating a phase difference between phases of the input signal and the output signal to reduce phase distortion generated by the power amplifier. The amplitude control loop and the phase control loop may also adjust the gain and / or phase of the power amplifier, respectively.

A rotation-angle detection device includes: an amplitude adjustment unit that performs correction to match amplitude values of multiple detection signals output from multiple rotation detection units to output corrected signals, the rotation detection units changing outputs in accordance with a rotation angle of a rotor and being provided such that the rotation detection units output the detection signals having different phases; a vector generation unit that performs addition and subtraction on two signals out of the corrected signals to generate two vector component signals that are perpendicular to each other; an amplitude correction unit that performs correction to match amplitudes of the two vector component signals to output corrected vector component signals; and a rotation-angle searching unit that searches for the rotation angle of the rotor on basis of a vector that is represented by the two corrected vector component signals to output a detection angle.

An amplitude component and a phase component among modulating signals are supplied into a radio frequency wave input terminal and a power supply terminal of a radio frequency power amplifier, respectively, and an original modulated wave is obtained from an output of the radio frequency power amplifier. The output of the radio frequency power amplifier is detected by an output detecting section, correction data to a detection voltage closest to the detection voltage among correction datatables which have been measured in various temperature environments and stored in advance are selected by a selector, and correction of an amplitude component and a phase component is performed by phase-amplitude correction means. Thereby enabling EER operation without spectrum degradation.

Methods and apparatus for performing amplitude and phase imbalance correction operations on in-phase and quadrature phase signal components corresponding to a received signal are described. The imbalance correction operations relay on the use of relatively simple to implement feedback loops. The phase imbalance feedback loop relies on the tendency of transmitted symbols to be distributed uniformly around the origin of the I / Q plane if proper phase balance is present in the processed signal. Phase correction coefficients are generated over time as a function of the negated product of the processed in-phase and quadrature phase signal components. Amplitude correction coefficients are generated over time as a function of the difference in the squared values of the I and Q processed signal components.

A power amplifier controller circuit controls an adjustable impedance matching network at the output of a power amplifier to vary its load line to improve the efficiency of the RF PA. The PA controller circuit comprises an amplitude control loop that determines an amplitude correction signal. The amplitude loop is configured to control or correct for distortion from the adjustable matching network based upon the amplitude correction signal.

Methods and apparatus for calibrating In-phase and Quadrature imbalance within a receiver are described. A calibration process can inject a calibration tone to an RF or IF portion of a receiver. The receiver can frequency translate the tone to distinct I and Q calibration signals. The receiver upconverts the I and Q calibration signals to complementary sidebands or images using distinct and substantially matched upconverters. The complementary sidebands are mixed together to generate an error signal. The receiver determines a phase and amplitude correction based on the error signal.

A radio receiving apparatus capable of making compensation for both amplitude variations and phase variations and of suppressing image interference in a short period of time is provided.A correction value calculation section (110) combines a signal, obtained by multiplying a first digital signal by an amplitude correction candidate value and rotating the phase of the first digital signal, with a signal obtained by multiplying a second digital signal by a multiplicative inverse of the amplitude correction candidate value and performing, for the second digital signal, phase rotation which is in a quadrature relationship to phase rotation performed for the first digital signal, so as to obtain a first combined signal, obtain an inflection point of the first combined signal, and input, to a demodulation section (120), the amplitude correction candidate value and a phase correction candidate value, which correspond to the inflection point, as an amplitude correction value and a phase correction value, respectively. The demodulation section (120) makes compensation for the amplitudes and the phases and suppresses image interference, based on the amplitude correction value and the phase correction value.

An apparatus for providing real-time calibration for two or more microphones. A calibrator for receiving a left microphone signal and a right microphone signal and generating phase difference data. A phase and amplitude correction system for receiving one of the left microphone signal or the right microphone signal the phase difference data and generating calibration data for a beamformer. The beamformer receiving the calibration data, the left microphone signal and the right microphone signal and generating a monaural beamformed signal.

An RF power amplifier system adjusts the supply voltage to the power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the RF input signal and an attenuated amplitude of the RF output signal of the power amplifier. A variable gain amplifier (VGA) adjusts the amplitude of the RF input signal, thus providing a second means of adjusting the amplitude of the output of the power amplifier. The gain of the VGA or the supply voltage to the power amplifier is controlled based on the AC components of the amplitude correction signal, while the DC components of the amplitude correction signal are blocked from controlling the VGA or the supply voltage to the power amplifier. The DC level of the gain control of the VGA, the average supply voltage to the power amplifier, or the closed loop gain of the overall amplitude correction loop is controlled separately by a compression control signal.

Baseband signal generator 107 outputs a transmission baseband signal with a coefficient for setting antenna directivity multiplied and a gain control signal to transmit power amplifier 114 and transmit power amplifier 114 amplifies the transmission baseband signal with a gain corresponding to the gain control signal and transmits the signal from antenna 102. ATT 118 attenuates the output signal of amplifier 114 according to the gain control signal, amplitude / phase comparator 110 calculates amplitude and phase errors between the attenuated signal with a frequency equalized by frequency conversion sections 120 and 121 and the input signal of amplifier 114 and phase / amplitude correction section 108 corrects the transmission baseband signal and gain control signal so as to eliminate the errors. This makes it possible to correct the amplitude and phase shifts of the transmission signal during a communication with other apparatuses and reduce the size and cost of the apparatus.

A power amplifier controller circuit controls a power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The power amplifier controller circuit comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal. The phase control loop adjusts the phase of the input signal based upon a phase error signal indicating a phase difference between phases of the input signal and the output signal to reduce phase distortion generated by the power amplifier. The amplitude control loop and the phase control loop may also adjust the gain and / or phase of the power amplifier, respectively.

A power amplifier controller circuit controls a power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The power amplifier controller circuit comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal. The amplitude correction signal may also be split into two or more signals with different frequency ranges and provided respectively to different types of power supplies with different efficiencies to generate the adjusted supply voltage to the power amplifier. The phase control loop adjusts the phase of the input signal based upon a phase error signal indicating a phase difference between phases of the input signal and the output signal to reduce phase distortion generated by the power amplifier.

A position detector has a peak detector for detecting peak values of an A1 signal and a B1 signal serving as output signals of an analog to digital (AD) converter, an offset / amplitude correction section for generating an A2 signal and a B2 signal by correcting offsets and amplitude errors using the peak values detected by the peak detector, and a position data conversion section for converting the sinusoidal signals of an A phase and a B phase into position data.