| 摘要 |
PURPOSE:To simplify the circuit configuration and to obtain a miniaturized receiver whose cost is reduced and whose number of components is decreased by sharing a tuner even when the signal of a different modulation system (e.g. FM modulation or MSK modulation) is received. CONSTITUTION:The tuner (composed of a high frequency amplifier circuit 3, a variable tuning filter 5, a mixer circuit 8, IF amplifier circuits 9, 13, an intermediate frequency filter 11, a local oscillation circuit 10, an AGC circuit 14, a channel selection circuit 15) is shared for an FM demodulation circuit 20 and an MSK demodulation circuit 21. A switching circuit 22 selects either of the demodulation circuits by using data inputted to a terminal 35 in relation to channel selection data imparted to the channel selection circuit 15 from a terminal 32.
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