| 摘要 |
PROBLEM TO BE SOLVED: To provide a PLL circuit capable of preventing the deterioration of phase noise characteristics and realizing a wide frequency range and a communication system using it. SOLUTION: The PLL circuit 10 is provided with a reference oscillator 1, first and second dividers 2a, 2b, a third divider 11, a phase comparator 3, a low area passing filter 4 and a voltage control oscillator 5. An oscillation signal output directly from the voltage control oscillator 5 is output from first output 12a, an oscillation signal output through the third divider 11 is output from second output 12b respectively, and used as the selective signal of a transmission channel and a receiving channel. |
