| 摘要 |
PURPOSE:To simplify a circuit, and to reduce a cost by obtaining a second intermediate frequency signal from a sine-wave reference signal which the output of a PLL.IC with a crystal vibrator fixed thereto from an outside is obtained through a filter. CONSTITUTION:A crystal vibrator 2 is fixed to a PLL.IC1 from the outside, a square wave oscillation of a TTL level is operated between the crystal vibrator 2 and a timing generator 1a, and the first local oscillation signal whose frequency is different at every channel is generated. Then, only the fundamental wave of the oscillation signal is extracted through each filter of an LPF3, BPF4, and LPF5, and it is transmitted to a 2 multiplying circuit 6, and the second local oscillation signal is generated. Thus, it is not necessary to provide another crystal oscillation circuit for a sine-wave oscillation in order to obtain the second local oscillation signal, so that the circuit can be simplified, and the cost can be reduced. |
