Patent ID: 8665014

Claim:
An I/Q demodulation apparatus with phase scanning, comprising: a ring oscillator outputting a plurality of phase signals of different phases, wherein the phase signals are grouped into a plurality of signal groups, and time delays of the phase signals correspond to an input voltage; a first latch unit coupled to the ring oscillator to sample the phase signals and output a plurality of latch results corresponding to the signal groups, wherein the first latch unit comprises a plurality of path latch units, the path latch units are triggered by different clock signals, and the path latch units one-to-one sample the signal groups, respectively; a decoding unit coupled to the first latch unit to respectively decode the latch results, and to output fine codes of a plurality of codes corresponding to the latch results; a counter unit coupled to the ring oscillator to respectively select a target phase signal from each of the signal groups, wherein the counter unit comprises a plurality of path counters, the path counters respectively one-to-one count the target phase signals to output a plurality of counting results corresponding to the signal groups; a second latch unit coupled to the counter unit to sample the counting results and output coarse codes of the plurality of codes corresponding to the counting results, wherein the second latch unit comprises a plurality of path latches, the path latches are triggered by different clock signals, and the path latches one-to-one sample the counting results, respectively; a first arithmetical unit coupled to the decoding unit and the second latch unit, the first arithmetical unit using a portion of the plurality of codes to perform an addition/subtraction operation so as to output an in-phase signal; and a second arithmetical unit coupled to the decoding unit and the second latch unit, the second arithmetical unit using another portion of the plurality of codes to perform an addition/subtraction operation so as to output a quadrature phase signal.