| 摘要 |
PURPOSE:To automatically enable to receive the traffic information, by tracking the frequency of traffic signal through the change in the local oscillation frequency of one PLL and by setting the local oscillation frequency of another PLL to suitable value when it is caught. CONSTITUTION:Two phase locked loops 21a, 21b are provided with the reception section of normal super heterodyne system, and the frequency including traffic information signal is followed by changing the local oscillation frequency of one phase locked loop 21a. When this is caught, the local oscillation frequency of another phase locked loop 21b is set to suitable value. Further, the frequency converter 2 performs frequency conversion for the output reception signal of the high frequency amplifier 1 with the local oscillation output of the phase locked loops 21a and 21b. |
