A balanced/unbalanced filter module includes a switch including a first
port that inputs and outputs unbalanced signals in a first frequency
band, a second port that inputs and outputs unbalanced signals in a
second frequency band, and a third port that inputs and outputs
unbalanced signals in these two frequency bands. The switch switches a
signal path. An unbalanced I/O port of a first filter that passes signals
in the first frequency band is connected to the port. A port of a second
filter that passes signals in the second frequency band is connected to
the port. Individual balanced I/O ports of each of the first and second
filters are connected to first and second branch ports with substantially
the same electrical length. A balance coil for impedance matching is
provided between the first and second branch ports.