| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain satisfactory distortion compensation of an A/D converter(ADC) for an input signal in a wide dynamic range in a distortion compensation amplifier for compensating distortion in a nonlinear amplifier circuit such as a power amplifier. <P>SOLUTION: The size of the input power of an ADC10 is calculated at a power supply accumulator 14, based on the signal of a detector 8. A comparator 15 compares the scale of the input power of the ADC 10 with the optimal input power of the ADC 10 preliminarily set as a threshol. A first gain adjuster 16 executes gain adjustment so that the input power of the ADC 10 can be the same value as a threshold, and a second gain adjuster 17 executes gain adjustment again so that the original input power can be set for the output signal of the ADC10. Also, a signal passing through the ADC 10 during the gain adjustment is removed by a data selector 18, and input to a distortion compensation coefficient calculator 2c of a predistortion circuit 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
