| 摘要 |
PURPOSE:To obtain a local oscillating signal and a transmitting signal of a receiver having high frequency stability, by controlling two PLL circuits by an output of one reference oscillator. CONSTITUTION:A reference signal fREF1 from a frequency divider 12 is applied to one input of a phase comparator 14 constituting the PLL circuit and an output frequency-dividing an output from a voltage controlled oscillator 16 by a variable frequency divider 17 is applied to the other input. Thus, an output having a frequency of NfREF1 is obtained from the oscillator 16, where the frequency dividing ratio of a frequency divider 17 is denoted by 1/N. An output of the circuit 13 is transmitted to a receiver as a local oscillating signal and applied to a mixer 23 forming the PLL circuit 19. A reference signal fREP2 from a frequency divider 18 is applied to one input of a phase comparator 20 forming this circuit 19, and an output obtained by mixing 23 an output signal from a voltage controlled oscillator 22 and an output from the circuit 13 and frequency- dividing the output of the mixing at a frequency divider 24 (frequency dividing ratio 1/P), is applied to the other input. The output of the oscillator 22 is given to a transmitter. |
