| 摘要 |
PURPOSE:To obtain an accurate demodulation data in a short time by providing plural voltage comparator means, plural band pass filters, a comparator means and a selection means to the demodulator. CONSTITUTION:A detection signal of a received intermediate frequency signal is compared with plural different comparison voltages at voltage comparator means 1,2 and an analog detection signal is changed into a digital signal. The digital signal is inputted to band pass filters 3, 4 having a center frequency being a half of the data transmission speed and waveform shaping is implemented and an output signal subjected to waveform shaping in each band filter is inputted to a comparator means 9, in which output levels of the output signals are compared and an output signal with a highest output level is identified. Then a selection means 10 receives the selection signal and the output digital signal of the voltage comparator means 1,2 having the output signal with the highest output level is selected as a demodulation data and outputted. Thus, an accurate demodulation data is obtained in a comparatively shorter time from the start of reception. |
