| 摘要 |
PROBLEM TO BE SOLVED: To provide a detection circuit which is provided at a multi-system compatible receiver for receiving a plurality of transmission signals having different modulation modes to discriminate modulation modes of the received signals, and is capable of discriminating various multi-modulation modes. SOLUTION: The detection circuit is provided with wave detectors 7, 8 having mutually different detection frequencies. The wave detectors 7, 8 detect signal levels of the detection frequencies in IF signals obtained by applying frequency conversion to the received signals on a mixer portion 20. A comparator 11 discriminates modulation modes of the received signals based on comparison results of the signal levels detected by the wave detectors 7, 8. COPYRIGHT: (C)2008,JPO&INPIT
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