Radio frequency filter, multiplexer, radio frequency front-end circuit, and communication device

A radio frequency filter having a first passband, the radio frequency filter comprising:

• a first circuit connected to a first node disposed on a path that connects a first input/output terminal and a second input/output terminal, and a second node disposed between the first node on the path and the second input/output terminal;
• and
• a second circuit connected to the first node and the second node, wherein
• the first circuit includes a first filter having a second passband that includes a portion of a frequency range of the first passband and a bandwidth narrower than a bandwidth of the first passband, and the second circuit includes
• a second filter having a third passband that includes a portion of a frequency range of the first passband and has a bandwidth narrower than the bandwidth of the first passband, wherein the second passband and the third passband at least partially overlap;
• a first phase shifter connected to a first terminal of the second filter;
• and
• a second phase shifter connected to a second terminal of the second filter,
• wherein when the second circuit is viewed from at least one of the first node or the second node, the second passband includes at least one frequency at which a phase shift caused by the first circuit and a phase shift caused by the second circuit are identical, and the third passband includes at least one frequency at which a phase shift caused by the first circuit and a phase shift caused by the second circuit are identical.

A radio frequency filter having a first passband, the radio frequency filter comprising:

• a first circuit connected to a first node disposed on a path that connects a first input/output terminal and a second input/output terminal, and a second node disposed between the first node on the path and the second input/output terminal;
• and
• a second circuit connected to the first node and the second node, wherein
• the first circuit includes a first filter having a second passband that includes a portion of a frequency range of the first passband and a bandwidth narrower than a bandwidth of the first passband, and the second circuit includes
• a second filter having a third passband that includes a portion of a frequency range of the first passband and has a bandwidth narrower than the bandwidth of the first passband, wherein the second passband and the third passband at least partially overlap;
• a first phase shifter connected to a first terminal of the second filter;
• and
• a second phase shifter connected to a second terminal of the second filter,
• wherein the third passband has a higher frequency range than a center frequency of the second passband,
• wherein a phase shift caused by the first phase shifter and a phase shift caused by the second phase shifter are adjusted to cause a sum total to be at least 312° and at most 362° at a lower edge frequency of the third passband, the sum total being a total of (i) a difference between a phase shift caused by the first filter and a phase shift caused by the second filter and (ii) a sum of the phase shift caused by the first phase shifter and the phase shift caused by the second phase shifter.