Frequency band variable filter, duplexer, and communication apparatus

摘要

There is disclosed a frequency band variable filter comprising: a plurality of resonators (R1, R2); a plurality of reactance elements respectively connected to the plurality of resonators via a plurality of switching elements (D11, D12); wherein a width of the frequency band in the on-state of the switching elements (D11, D12) is different from that in the off-state thereof.