| 摘要 |
PURPOSE:To obtain a transmitter-receiver equipped with a frequency synthesizer in which lock-up time is accelerated. CONSTITUTION:In the transmitter-receiver in which local frequencies of reception and transmission different from each other are supplied from the same frequency synthesizer, the frequency synthesizer 10 which PLL constitution generates a reference frequency by frequency-dividing output from a reference oscillator 50, and switches the frequency division ratio R of a reference frequency divider 17 to be supplied to a phase comparator 14 when the transmission and the reception are performed. The output of a VCO 11 is frequency-divided corresponding to such switching, and a comparison frequency is generated, and the frequency division ratio ND of a comparison frequency divider means (15, 16) to be supplied to the phase comparator 14 is set so as to be smaller. |
