| 摘要 |
PROBLEM TO BE SOLVED: To prevent intrusion of a signal of an adjacent channel or an adjacent to adjacent channel to a band caused by deviation in a reception band or a deterioration in reception sensitivity attended with excess band of a desired wave outside of its pass band and deterioration in an adjacent channel or an adjacent to adjacent channel disturbance suppression ratio. SOLUTION: A SW 18 is provided to a feedback path between a filter FIL 14 and an oscillator OSC 12. An output voltage of the FIL 14 is monitored by a controller CONT 15 via an A/D converter 20. The CONT 15 receives a synchronization end signal from a quadrature phase shift keying circuit QPSK 9 to obtain an error between a center frequency of a desired wave and an oscillation frequency of a 2nd intermediate frequency conversion local oscillation signal based on a difference between a reference voltage and an output voltage of the FIL 14, and the SW 18 is set to a feedback loop non-connection state via a switch controller SWCONT 19 and corrects a frequency of the 2nd intermediate frequency conversion local oscillation signal form the OSC 1.11 via a PLLIC 13. |
