Panasonic Corporation

Apple Inc.

Tropian, Inc.

Gary Lang Do

Wayne S Lee

Akihiko Matsuoka

Tomoya Urushihara

Earl William McCune, Jr

Thomas E Biedka

Wendell B Sander

Paul Cheng-Po Liang

Earl W McCune

David A Donovan

Gurusubrahmaniyan Subrahmaniyan Radhakrishnan

Marnie Dunsmore

A calibration system may be provided for calibrating wireless communications circuitry in an electronic device during manufacturing. The calibration system may include data acquisition equipment and calibration computing equipment for receiving and processing test and calibration signals from wireless communications circuitry to be calibrated. During testing and calibration operations, a device may be provided with initial pre-distortion calibration values. The initial pre-distortion calibration values may be generated at least in part based on calibration operations performed for other wireless electronic devices. The device may generate a test signal using the initial pre-distortion calibration values. The calibration system may determine whether the test signal is within an acceptable range of a known reference signal. If the test signal is outside of the acceptable range, the calibration system may generate a set of corrected pre-distortion calibration values to be used in generating wireless communications signals during normal operation of the device.

Systems for calibration of wireless electronic devices

A calibration system may be provided for calibrating wireless communications circuitry in an electronic device during manufacturing. The calibration system may include data acquisition equipment for receiving an amplitude-modulated calibration signal from the electronic device. The calibration system may include calibration computing equipment for extracting pre-distortion coefficients from the amplitude-modulated calibration signal. The calibration computing equipment may be configured to detect a bulk phase drift in the amplitude-modulated calibration signal. The calibration computing equipment may be configured to remove the bulk phase drift from the amplitude-modulated calibration signal. The wireless communications circuitry may include a power amplifier that distorts a signal generated by the wireless communications circuitry. The wireless communications circuitry may include a pre-distortion compensator for countering the distortion. The pre-distortion coefficients determined from the phase drift corrected amplitude-modulated calibration signal may be used by the pre-distortion compensator when countering the distortion.

Calibration systems for wireless electronic devices

Methods and apparatus for controlling power in a polar modulation transmitter. An exemplary polar modulation transmitter includes a radio frequency power amplifier (RF PA), a phase path having circuitry operable to generate a constant amplitude phase modulated signal, and an amplitude path including an envelope modulator circuit having first and second envelope modulation paths. The RF phase modulated signal is applied to an RF input of the RF PA, while an envelope modulated power supply signal generated by a selected one of the first and second envelope modulation paths is coupled to a power supply input of the RF PA. The second envelope modulation path is selected during times when the power required by the RF PA is below some predetermined power level. During times when the RF PA requires power above the predetermined power level, the first envelope modulation path is selected.

Polar modulation transmitter with envelope modulator path switching

The transmission apparatus and transmission power controlling method are able to keep high speed feedback control and control transmission power accurately. Polar modulation transmitter () is provided with LPF () that performs waveform shaping of output power of PA () and ADC () that obtains output power data for each mode by sampling filtered signals in compressed mode and filtered signals in uncompressed mode at the same phase as the filtered signals in compressed mode. In this way, the phases of sampling signals before and after the mode change are the same, so that it is possible to obtain sampling signals of the same condition before and after the mode change, from filtered signal waveforms. According to feedback control based on these sampling signals, even if drift components remain in the filtered signals, the influence can be ignored, so that it is possible to keep high speed feedback control, and estimate and control transmission power accurately.

Transmission apparatus and transmission power control method

A transmission apparatus has two modes of power amplifier operation, in which modeis inherently accurate, modeis inherently less accurate, and measurement of a power amplifier output from modeis used to correct a power amplifier output in mode. Modemay be a compressed mode and modemay be a non-compressed mode. The apparatus may include a power controller that provides overlapping scaling factor sets for modesandand controls transmission power using the scaling factor sets. Upon a mode transition, the controller uses the overlapping scaling factors and changes the scaling factor set for the mode of a destination of the transition based on actual measurement representative of transmission power, for example, by carrying out power alignment loop operations. A cellular mobile device may include such transmission apparatus. A polar modulation transmitter is also disclosed.

Transmission power controller

Even when there is limit placed upon transmission power control time, the transmission power control method enables accurate control transmission power. The transmission power control method includes: a first measuring step of measuring, in a symbol interval before a symbol interval where mode of the power amplifier changes, output power of the power amplifier before mode changes; a first setting step of setting target power of the power amplifier after mode changes based on a measurement result obtained in the first measuring step and a transmission power control signal; a second measuring step of measuring, in the symbol interval where mode of the power amplifier changes, output power of the power amplifier after mode changes, the output power being controlled using the target power set in the first setting step; and a second step of setting corrected target power based on a measurement result obtained in the second measuring step.

Transmission power control method and transmission apparatus

As explained above, according to embodiments of the present invention, by providing averaging sectionthat detects an average power value of amplitude component signals, and controlling transmission power based on the amount of drift in the average output power value of PAand the amount of drift in the average power value of amplitude component signals, when residual drift components are included in the average output power value of PA, the influence of residual drift components can be eliminated and transmission power can be controlled, so that it is possible to improve the accuracy of transmission power control. That is, deterioration of power estimation accuracy resulting from residual drift components can be reduced, so that it is possible to satisfy the restrictive requirement that the difference between transmission power be within, for example, the range of +/&#x2212;0.5 dB.

Polar modulation transmission apparatus and transmission power control method

A modulation system includes an amplitude modulation path and a phase modulation path coupled to the amplitude modulation path. One of the amplitude modulation path and the phase modulation path receive a reduced current such that the reduced current reduces power consumption by the system. Preferably, the amplitude modulation path receives the reduced current. The amplitude modulation path has a first set of components and a second set of components. The first set of components consumes less power by using slower operation. The second set of components consumes less power by effectively not operating, or being turned off.

Selective envelope modulation enabling reduced current consumption

Methods of and apparatus for digitally controlling, with sub-sample resolution, the relative timing of the magnitude and phase paths in a polar modulator. The timing resolution is limited by the dynamic range of the system as opposed to the sample rate. The methods and apparatus of the invention use a digital filter to approximate a sub-sample time delay. Various techniques for approximating a sub-sample time delay using digital signal processing may be used to achieve the approximation. Ideally, the filter will have an all-pass magnitude response and a linear phase response. In practice, the magnitude may be low-pass and the phase may not be perfectly linear. Such deviation from the ideal response will introduce some distortion. However, this distortion may be acceptably small depending on the particular signal being processed.

Digital time alignment in a polar modulator

The present invention, generally speaking, achieves a highly efficient line driver for high crest-factor signals such as DMT/ADSL signals. In an exemplary embodiment, a digital signal produced by a digital signal processor or the like is processed by a sigma-delta modulator (SDM) to produce one or more binary signal pairs. The signals of a signal pair are low-pass filtered, if necessary, and applied across the winding of a transformer. The transformer has a single secondary winding connected to the line and may has as many primary windings as the number of signal pairs. The transformer may have a unity turns ratio or may have a turns ratio for accomplishing voltage step-up. For one signal pair, the number of possible resulting signals levels on the secondary side is three, for two signal pairs five, etc. Using more than two signal levels, it becomes possible to recreate from the digital signals the corresponding analog waveform with the required accuracy. The circuit requires only a single supply voltage, is inherently balanced and provides high-voltage DC isolation.

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San Jose, CA, United States of America

Gary Lang Do