| 摘要 |
PURPOSE:To reduce the power consumption of the whole receiver by stopping a phase locked loop circuit which constitutes a local oscillation circuit except a VCO at a specific repetitive period in a stand-by mode, and oscillating the VCO asynchronously intermittently and using it. CONSTITUTION:While a reception part 2 expects a radio signal from an opposite part, a timing generating circuit 19 closes a switch 17 for a time t0 to supply electric power to a VCO control part 7. At the same time, a data generator 18 is operated to supply a frequency division ratio specifying signal to the VCO control part 7. Consequently, the VCO control part 7 compares the phase of a reference signal obtained by a reference oscillator 10 with the phase of a local oscillation signal outputted by the VCO6 to generate a frequency control voltage corresponding to the comparison result. Then the timing generating circuit 19 repeats the operation to close a phase locked loop system loop for the time t0 at intervals of a time ts. Consequently, the power consumption of the local oscillation circuit part can be reduced. |
