| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an FM signal receiver 21 which is used for receiving a burst signal in compliance with the Bluetooth (R) or the like and includes a phase shifter or the like wherein a BPF 24 and an FM demodulation circuit 25 are configured with similar or correlative circuit configurations and the frequency characteristic of which is adjusted by using the same control signal, and which eliminates the effect of the offset of an amplifier 27 to enable the characteristic of the BPF 24 to be properly adjusted. <P>SOLUTION: A short-circuit switch 32 is provided between input/output terminals of the amplifier 27 to open a control circuit 31 in a reception operation and to short-circuit the control circuit 31 in an adjustment operation so that the frequency characteristic can be adjusted without using the amplifier 27 in the adjustment. Thus, even on the occurrence of an offset, the adjustment of the FM demodulation circuit 25 is executed by eliminating the effect of the FM demodulation circuit 25 on the frequency-voltage conversion and the similar adjustment is also applied to the BPF 24 so as to prevent the BPF 24 from being adjusted with deviation due to the effect of the offset. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
