Radio frequency filter circuit, duplexer, radio frequency front end circuit, and communication apparatus

A radio frequency filter circuit comprising:

• a series-arm resonator that is connected in a path between an input terminal of the filter circuit and an output terminal of the filter circuit;
• a first parallel-arm resonator that is connected between a ground terminal and a node on the path;
• a second parallel-arm resonator that is connected between the node and the ground terminal;
• and
• a switch connected in series with the second parallel-arm resonator between the node and the ground terminal that is configured to selectively control an electrical connection between the node, the second parallel-arm resonator, and the ground terminal,
• wherein the second parallel-arm resonator and the switch are connected in parallel with the first parallel-arm resonator,
• wherein a resonant frequency of the first parallel-arm resonator is less than a resonant frequency of the series-arm resonator, and
• wherein a resonant frequency of the second parallel-arm resonator is greater than the resonant frequency of the first parallel-arm resonator.