| 摘要 |
PROBLEM TO BE SOLVED: To provide a receiving circuit, used for a mobile phone which is compact and of low power consumption and can perform high-speed communication. SOLUTION: The receiving circuit, used for the mobile phone which transmits and receives multiband radio signals, includes a low-pass filter 104 which limits the reception frequency band, and the low-pass filter comprises a first filter 115 and a second filter 117, having a plurality of different pole positions wherein a desired filter is selected between the plurality of filters for each band for switching the filter constitution between the filter for disturbing wave removal and the filter having small sensitivity deterioration, and the filter part for which power off for reducing the power consumption is not necessary. Furthermore, since the plurality of filters are made to mutually interpolate their characteristics, redundant filter constitution can be avoided and the necessary area can be minimized, thereby reducing the cost. COPYRIGHT: (C)2008,JPO&INPIT
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