Up-down converter

An up-down converter comprising:

• a first mixer configured to convert an input radio frequency (RF) signal into an intermediate frequency (IF) signal using a first local signal;
• an IF filter configured to filter the IF signal converted by the first mixer;
• a second mixer configured to convert the IF signal, which has been filtered by the IF filter, into an output RF signal using a second local signal;
• and
• a local oscillator configured to control a frequency of the first local signal and the second local signal based on a frequency of the input RF signal,
• wherein the input RF signal comprises a plurality of frequency bands, and the local oscillator controls the frequency of the first local signal and the second local signal so that the IF filter passes a first frequency band from among the plurality of frequency bands through a partial frequency section of a filtering band of the IF filter,
• wherein the partial frequency section comprises one end frequency of the filtering band, the one end frequency being closer to a second frequency band than an opposite end frequency of the filtering band, and
• wherein the second frequency band is closer to the first frequency band than any other frequency band of the plurality of the frequency bands.