| 摘要 |
PROBLEM TO BE SOLVED: To provide a received frequency converting device and a frequency band switching method, with which accuracy in switching parallel connected band pass filters can be freely selected by changing the number of bits and positions of frequency setting data to be read and an image frequency band cab be attenuated for a fixed quantity in the frequency band of the band pass filters of the number of parallel connected band pass filters. SOLUTION: This device is provided with band pass filters 3 and 4 parallel connected to the output side of a low noise amplifier 1, mixer 6 for outputting an intermediate frequency signal by mixing an output signal from one of band pass filters 3 and 4 and a local oscillation signal, changeover switch 2 for switching the input of the band pass filters 3 and 4, changeover switch 5 for switching the output of the band pass filters 3 and 4, and control circuit for reading one part of the frequency setting data of a PLL circuit and controlling the switching operation of the changeover switches 2 and 5 corresponding to the read value. |
