Filter circuit, duplexer, and communication device

The embodiment of the invention discloses a filter circuit with better passive intermodulation performance, and the circuit comprises an input end for receiving a radio frequency signal, a series resonator unit, a parallel resonance unit and an output end, wherein the series resonator unit is connected between the input end and the output end; and the parallel resonator unit is matched with the series resonator unit to filter the radio frequency signal and output the radio frequency signal from the output end. The parallel resonator unit comprises at least two parallel resonator branches which are connected in parallel, the parallel resonator branches are connected between a first node between the input end and the output end and the grounding end, each parallel resonator branch comprises at least one parallel resonator, and the parallel resonator unit is the parallel resonator unit closest to the output end. The parallel resonator comprises a first electrode and a second electrode, and the electrodes connect