摘要 |
A DC offset of a VGA is measured by selecting a ground contact of a switch. Then, the gain of the VGA is set at an appropriate value, monitoring contacts of the switch are successively selected, and the output values of an ADC for the respective cases are measured with the input to a DAC set at zero. Then, the DC offset of the VGA is removed, the DC offset value of each circuit block, such as DAC, in a transmitting part is calculated, and parameters are set so that the DC offset value of each circuit block is minimized.
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