| 摘要 |
PURPOSE:To accurately demodulate a signal by simple constitution by sampling a binary signal, counting the sampled vale so as to obtain the logic value of a digital signal in response to the quantity of the said count. CONSTITUTION:An identification circuit 14 applies sampling as shown in arrows for a period (t) corresponding to the frequency of the sampling pulse to obtain each sampling representing a high level of a binary signal (b), the sampled value is counted for each period T corresponding to one period of an FSK signal (a), and when the count is larger than a prescribed value, it is discriminated to be a digital signal '1' and when the count is smaller than a prescribed value, it is discriminated to be a digital '1' and an output is sent accordingly. The noise component is eliminated from the output via a low pass filter 16 and the result is sent from an output terminal OUT as a demodulated output (d). |
