Intermediate frequency filter having variable pass band

摘要

Disclosed herein is an intermediate frequency filter having a variable pass band, which is capable of varying a pass band to minimize loss at a plurality of intermediate frequencies? The intermediate frequency (IF) includes a band pass filter unit arranged between a frequency conversion IC and a demodulation unit and configured to filter an IF signal output from the frequency conversion IC and output a resulting signal. A band varying unit is connected to the band pass filter unit and is configured to vary a pass band of the band pass filter unit. A switching unit connects or disconnects the band varying unit to or from the band pass filter unit. A control unit detects the IF signal and controls the switching unit in response to the IF signal so that the band varying unit is connected to or disconnected from the band pass filter unit.