| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital tuner reducing the waveform inclination of an output signal. SOLUTION: The digital tuner is provided with: band pass filters 2 and 4 for selecting a reception-desired signal from input received signals; a mixer 7 for mixing the reception wished signal selected by the filters 2 and 4 with a local oscillation signal and performing frequency conversion; a level detector (a circuit composed of filters 11 and 12, level detectors 13 and 14, and a comparator 15) for detecting signal levels at two or more frequency values in a receiving band for a signal based on a signal outputted from the filter 4; and a waveform shaping circuit 8 for changing the waveform inclination inside a receiving band for a signal based on the input received signals according to a detection result of the level detecting section. COPYRIGHT: (C)2005,JPO&NCIPI |
