| 摘要 |
PROBLEM TO BE SOLVED: To provide a technology which suppresses false operation when correcting unnecessary DC off-set components superimposed on a base band signal.SOLUTION: A quadrature detection part 12 performs quadrature detection of an FM signal by a local oscillation signal and outputs a baseband signal. A first correction part 18 and a second correction part 20 perform correction of the baseband signal by a DC off-set correction value. A DC off-set detection part 22 performs polar coordinate conversion of the baseband signal and derives a DC off-set correction value in the way that amplitudes in each of a plurality of phase areas regulated on an IQ flat surface becomes close. An FM detection section 24 performs FM detection of the corrected baseband signal and generates a detection signal. A control part 26 controls frequency of the local oscillation signal so that a phase component polar coordinate converted by the DC off-set detection part 22 rotates.SELECTED DRAWING: Figure 4 |
