| 摘要 |
The circuit comprises an input section(10) for receiving a transferred signal, a channel separating section for shifting an input modulated signal to the base band to separate an I-channel and a Q-channel signal, a third mixer(20), a lock detector(29) for receiving the I and the Q channel signal to output a lock detect signal(S1), a first loop filter(18) for filtering an output of the third mixer(20), a second loop filter(21) for filtering an output signal of an AFC(Automatic Frequency Control) section, a switch (26), a VCO(16) for outputting a local detect signal(S2), and a second logic sum circuit(28) for receiving the logic detect signal(S1) and the false detect signal(S2) to output a signal(S3) controlling the switch(26).
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