| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a filter device and a passband characteristic adjustment method that implement an adjustment function for a passband characteristic formed by passive elements comprising semiconductors in a smaller circuit scale than before. <P>SOLUTION: A filter device 8 for use in a receiving system of a communication apparatus includes: a filter circuit 4 for limiting an input received signal to a passband by a combination of passive elements comprising semiconductors; and a control circuit 9 for, at every receiving operation start, adjusting a frequency pass characteristic of the filter circuit so as to provide a maximum output of the input received signal by using a signal strength detected by a signal strength detection circuit disposed downstream of the filter circuit in the receiving system. <P>COPYRIGHT: (C)2012,JPO&INPIT |
