Patent ID: 8094051
Filing Date: 2012-01-10
Classification: H03M

Abstract:
1. A cascaded analog-to-digital converter circuit, arranged for converting an analog RF input signal to a digital output signal, comprising: a first analog to digital converter stage having an input port for receiving the analog RF input signal and comprising an RF bandpass sigma delta converter configured to generate a first digital signal and a quantization error signal representative of the quantization error of the first digital signal from said analog RF input signal, respectively presented at a first and a second output port of the first analog to digital converter stage; a down-conversion mixer connected to the second output port of the first analog to digital converter stage and configured to down-convert the quantization error signal; a second analog to digital converter stage having an input port connected to the down-conversion mixer, and configured to generate a second digital signal from said down-converted quantization error signal presented at a third output port of the second analog to digital converter stage; a digital filter connected to the third output port of the second analog to digital converter stage and configured to generate the digital output signal by combining the first and second digital signals.