| 摘要 |
PURPOSE:To attain low cost by using a high frequency amplifier and a mixer in common and utilizing an FM demodulator so as to constitute an AM demodulator thereby decreasing the redundancy in the circuit constitution. CONSTITUTION:A broad band high frequency amplifier 8 and a mixer 7 are used in common both at satellite broadcast signal reception and ground broadcast reception, both the broadcast signals are converted into the same intermediate frequency by a local oscillator 8 and an undesired signal is eliminated from the intermediate frequency signal through an intermediate frequency filter 9 of a desired band. Then a phase synchronizing circuit 11 acting like the FM demodulator at the satellite broadcast signal reception is used for recovering a carrier at the ground broadcast signal reception and operated as the AM demodulator using a multiplier 13 applying multiplication with a ground broadcast signal. Thus, the satellite broadcast signal (FM signal) and the ground broadcast signal (AM signal) are received and demodulated by the same reception system.
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