Surface acoustic wave filter with angled reflection by piezoelectric substrate reflection edges, duplexer, and communication device

A surface acoustic wave filter comprising:

• a piezoelectric substrate;
• a first IDT disposed on the surface of the piezoelectric substrate;
• a second IDT disposed on the surface of the piezoelectric substrate and arranged so as not to be located along a straight line with the first IDT in the direction of surface acoustic wave propagation;
• at least one first reflection edge defined by an edge of the piezoelectric substrate, and arranged along a straight line with the first IDT in the surface acoustic wave propagation direction, so that a shear horizontal surface acoustic wave excited by the first IDT is input to the at least one first reflection edge, and is reflected therefrom at an angle relative to the input direction;
• and
• at least one second reflection edge defined by an edge of the piezoelectric substrate and arranged along a straight line with the second IDT in the surface acoustic wave propagation direction, so that the shear horizontal surface acoustic wave reflected from the first reflection edge is input to the at least one second reflection edge, and is reflected therefrom at an angle relative to the input direction, toward the second IDT.