| 摘要 |
PURPOSE:To obtain a highly stable and miniaturized demodulator at a low cost by providing a frequency divider, a detection section and an A/D converter to the demodulator so as to reduce the number of oscillators. CONSTITUTION:A local oscillation signal fed to an orthogonal hybrid 45 is generated by a VCO 62, and the output of the VCO 62 frequency-divided by a frequency divider circuit 64 while its phase is corrected by an endless phase shifter 66 is supplied to A/D converters 54, 56 as a symbol clock. A coefficient of a transversal equalizer 58 is controlled so as to minimize a deciding error of a base band signal. A control section 60 provides a control signal to the VCO 62 so that the phase error of the base band signal is minimized. In this demodulator, the symbol clock is obtained by frequency-dividing the carrier frequency recovered by the VCO 62. Thus, the number of expensive oscillators being causes to hindrance to miniaturization is reduced. |
