| 摘要 |
PURPOSE:To decrease a sensitivity difference in a receiving band, by turning off a diode switch so that tuning is performed, in case when control voltage which is higher than a set point has been applied to the diode switch. CONSTITUTION:In case when control voltage VD is higher than a value which has been set in advance is applied to an input terminal 6, an output of a comparator 7 becomes an L level, and a diode switch 4 which has been connected in parallel to a tuning circuit 2 is turned off. As a result, a tuning capacity comes not to be added to the circuit 2, a tuning frequency waveform is moved to the frequency side, and tuning is performed. In this way, a receiving sensitivity difference is improved. |
