| 摘要 |
PURPOSE:To enable equalization to chevron type fading, by extracting a suitable signal component from a reception spectrum and changing the characteristic of a band block type resonance circuit in a transmission line with this signal automatically. CONSTITUTION:In a radio digital system, a reception input is outputted via a reception amplifier 41, variable resonance circuit 1, buffer 42, band block type variable resonance circuit 46 and an output amplifier 43. The pilot signal of the lower end P1, center P2, upper end P3 is extracted at a pilot extracting circuit 40 from the power spectrum of the reception signal of the amplifier 43 and inputted to a control circuit 2. At the circuit 2, voltages VF1, VQ relating to the values of P2-P1, P2-(P1+P3)/2 are outputted at the circuit 2 to control the circuit 1 and equalize the chevron type fading. Further, the voltages VF1, VQ are converted into voltages VF2, VD at level conversion circuits 44, 45, respectively, and this signal controls a circuit 46 and equalize the chevron type fading. |
