| Patent application number | Description | Published |
|---|
| 20080224776 | COMMON-MODE VOLTAGE CONTROLLER - A common-mode voltage controller for adjusting common-mode voltages between a first buffer and a second buffer at a subsequent stage or a preceding stage of the first buffer in a signal transmission circuit, comprising: a first reference voltage generation unit for generating a common-mode voltage corresponding to the first buffer; a second reference voltage generation unit for generating a common-mode voltage corresponding to the second buffer at the subsequent stage or the preceding stage; and a control signal generation unit for generating a control signal for controlling a common-mode voltage of the first buffer according to a difference voltage between an output of the first reference voltage generation unit and an output of the second reference voltage generation unit, and giving the control signal to the first buffer and first reference voltage generation unit. | 09-18-2008 |
| 20100127744 | DUTY CORRECTION CIRCUIT, DUTY CORRECTION SYSTEM, AND DUTY CORRECTION METHOD - A duty correction circuit is provided which includes a level shifter receives complementary differential input signals having a duty ratio and controls levels of the differential input signals; a TrTf control circuit receives output signals of the level shifter and controls edge angles of the output signals; a waveform shaping circuit receives output signals of the TrTf control circuit and shapes waveforms of the output signals; a first common mode comparator extracts common modes of the output signals of the TrTf control circuit and compares the common modes; and a second common mode comparator extracts common modes of output signals of the waveform shaping circuit and compares the common modes. The level shifter controls the levels based on outputs of the first common mode comparator and the TrTf control circuit controls the edge angles based on outputs of the second common mode comparator. | 05-27-2010 |
| 20110221524 | RADIO APPARATUS, DISTORTION CORRECTION DEVICE, AND DISTORTION CORRECTION METHOD - When a distortion correction coefficient, which is calculated according to a signal input to a power amplifier and a signal output from the power amplifier, is larger than a first threshold, a distortion correction coefficient corresponding to the input signal is updated to the first threshold. When the calculated distortion correction coefficient is equal to or smaller than the first threshold, the distortion correction coefficient corresponding to the input signal is updated to the calculated distortion correction coefficient. | 09-15-2011 |
| 20110221525 | RADIO APPARATUS, DISTORTION CORRECTION DEVICE, AND DISTORTION CORRECTION METHOD - An error between the power of an input signal, which is input to a power amplifier, and the power of an output signal, which is output from the power amplifier, is calculated. The calculated error is normalized according to the power of the input signal or the power of the output signal. A distortion correction coefficient, which is stored in a predetermined storage unit in association with the power of the input signal, is updated using the normalized error. | 09-15-2011 |
| 20110227643 | DISTORTION COMPENSATING APPARATUS, AMPLIFYING APPARATUS, TRANSMITTING APPARATUS, AND DISTORTION COMPENSATING METHOD - A distortion compensating apparatus that compensates signal distortion caused by an amplifier includes a distortion compensating process unit that using a distortion compensation coefficient, compensates distortion of an input signal; a memory unit storing therein the distortion compensation coefficient; and an address generating unit that generates a first address that is based on electrical power of the input signal and is for acquiring the distortion compensation coefficient from the memory unit, and a second address that is based on any one among the electrical power, phase of the input signal and amplitude of the input signal, is for acquiring the distortion compensation coefficient from the memory unit, and is normalized in a normalizing range determined according to the electrical power of the input signal. The distortion compensating process unit acquires the distortion compensation coefficient from the memory unit, based on the first and the second addresses to compensate the distortion. | 09-22-2011 |
| 20110227644 | DISTORTION COMPENSATING APPARATUS, AMPLIFYING APPARATUS, TRANSMITTING APPARATUS, AND DISTORTION COMPENSATING METHOD - A distortion compensating apparatus that compensates signal distortion caused by an amplifier includes a distortion compensating process unit that using a distortion compensation coefficient, compensates distortion of an input signal; a memory unit that stores the distortion compensation coefficient; and an address generating unit that generates a first address that is based on electrical power of the input signal and for acquiring the distortion compensation coefficient from the memory unit and that generates a second address that is based on a phase of the input signal and for acquiring the distortion compensation coefficient from the memory unit. The distortion compensating process unit acquires the distortion compensation coefficient from the memory unit based on the first and the second addresses to compensate the distortion. | 09-22-2011 |
| 20110304362 | CURRENT-SOURCE CIRCUIT - A current-source circuit includes a plurality of input-side transistors; a plurality of output-side transistors current-mirror-coupled to the plurality of input-side transistors; an output terminal from which an output current is output; and a switching control circuit to switch the plurality of input-side transistors and activate at least one of the plurality of input-side transistors sequentially. | 12-15-2011 |
| 20120039415 | DISTORTION COMPENSATION AMPLIFIER DEVICE AND DISTORTION COMPENSATION METHOD - A distortion compensation amplifier device for compensating for distortion of a transmission signal generated by amplifying the transmission signal and for outputting the compensated transmission signal. The distortion compensation amplifier includes a storage unit that stores therein distortion compensation coefficients; a processor that performs distortion compensation processing on the transmission signal by using one of the distortion compensation coefficients; and an amplifier that amplifies the transmission signal that has been subjected to the distortion compensation processing; wherein the processor calculates an average value of the distortion compensation coefficients stored in the storage unit, and calculates the distortion compensation coefficient on the basis of the transmission signal, and the average value. | 02-16-2012 |
