Acoustic wave filter

The-An acoustic wave filter comprising:

• an acoustic wave resonant circuit in or on at least one of a series arm or a parallel arm;
• wherein
• the acoustic wave resonant circuit includes a plurality of divided resonant devices connected to one another in series;
• a first divided resonant device among the plurality of divided resonant devices includes one first resonator;
• a second divided resonant device among the plurality of divided resonant devices includes two parallel divided resonators connected to each other in parallel;
• each of the first resonator and the parallel divided resonators includes an IDT electrode including a plurality of electrode fingers;
• an electrode finger pitch of the plurality of electrode fingers is different between at least one parallel divided resonator of the two parallel divided resonators and the first resonator;
• the acoustic wave resonant circuit includes one first divided resonant device and two second divided resonant devices;
• the two second divided resonant devices are connected to each other in series along a direction in which the electrode fingers extend;
• and
• as the two second divided resonant devices are viewed from the direction in which the electrode fingers extend, a center position between the electrode fingers at both ends of the IDT electrode of each of the two parallel divided resonators defining one second divided resonant device of the two second divided resonant devices is different from a center position between the electrode fingers at both ends of the IDT electrode of each of the two parallel divided resonators defining another second divided resonant device of the two second divided resonant devices.

An acoustic wave filter comprising:

• an acoustic wave resonant circuit in or on at least one of a series arm or a parallel arm;
• wherein
• the acoustic wave resonant circuit includes a plurality of divided resonant devices connected to one another in series;
• a first divided resonant device among the plurality of divided resonant devices includes one first resonator;
• a second divided resonant device among the plurality of divided resonant devices includes two parallel divided resonators connected to each other in parallel;
• a resonant frequency of at least one parallel divided resonator of the two parallel divided resonators is different from a resonant frequency of the first resonator;
• the acoustic wave resonant circuit includes one first divided resonant device and two second divided resonant devices;
• the two second divided resonant devices are connected to each other in series along a direction in which the electrode fingers extend;
• and
• as the two second divided resonant devices are viewed from the direction in which the electrode fingers extend, a center position between the electrode fingers at both ends of the IDT electrode of each of the two parallel divided resonators defining one second divided resonant device of the two second divided resonant devices is different from a center position between the electrode fingers at both ends of the IDT electrode of each of the two parallel divided resonators defining another second divided resonant device of the two second divided resonant devices.

An acoustic wave filter comprising:

• an acoustic wave resonant circuit in or on at least one of a series arm or a parallel arm;
• wherein
• the acoustic wave resonant circuit includes a plurality of divided resonant devices connected to one another in series;
• a first divided resonant device among the plurality of divided resonant devices includes one first resonator;
• a second divided resonant device among the plurality of divided resonant devices includes two parallel divided resonators connected to each other in parallel;
• a resonant frequency of at least one parallel divided resonator of the two parallel divided resonators is different from a resonant frequency of the first resonator;
• the acoustic wave resonant circuit includes two first divided resonant devices and one second divided resonant device;
• the two first divided resonant devices are connected to each other in series along a direction in which the electrode fingers extend;
• and
• as the two first divided resonant devices are viewed from the direction in which the electrode fingers extend, a center position between the electrode fingers at both ends of the IDT electrode of the first resonator defining one first divided resonant device of the two first divided resonant devices is different from a center position between the electrode fingers at both ends of the IDT electrode of the first resonator defining another first divided resonant device of the two first divided resonant devices.