Abstract: A filter device for multi-band wireless communication includes a first circuit characterized by a first pass-band from a first frequency to a second frequency; a second circuit characterized by a second pass-band from a frequency no smaller than the first frequency to a third frequency, the third frequency being no higher than the second frequency but higher than the first frequency; a third circuit characterized by a third pass-band from a fourth frequency to a frequency no greater than the second frequency, the fourth frequency being no smaller than the first frequency but smaller than the second frequency; and a switch configured to connect the first circuit either to the second circuit to reconfigure a first filter with the second pass-band or to the third circuit to reconfigure a second filter with the third pass-band.