Patent ID: 8436757
Filing Date: 2013-05-07
Classification: H03M

Abstract:
1. A complex bandpass ΔΣAD modulator, comprising: an analog-to-digital conversion unit configured to convert an analog complex signal into a digital complex signal; a digital-to-analog conversion unit configured to convert a complex signal output from the analog-to-digital conversion unit into an analog complex signal; a subtraction unit configured to subtract a complex signal output from the digital-to-analog conversion unit from an input complex signal input from the outside; a complex bandpass filter configured to allow a signal component in a predetermined frequency band out of a complex signal output from the subtraction unit to pass through; a noise extraction circuit unit configured to extract a quantized noise signal of the analog-to-digital conversion unit based on a complex signal input to the analog-to-digital conversion unit and the complex signal output from the digital-to-analog conversion unit, delay the extracted quantized noise signal by one sample time, phase-rotate the delayed signal by a predetermined angle, and feed back the phase-rotated signal to an input side of the analog-to-digital conversion unit; and an addition unit configured to add the input complex signal, a complex signal output from the complex bandpass filter, and the complex signal output from the noise extraction circuit unit and output the added signal to the analog-to-digital conversion unit.