Cascaded surface acoustic wave devices with apodized interdigital transducers

An electroacoustic device, comprising:

• a first surface acoustic wave (SAW) resonator comprising a first interdigital transducer (IDT) disposed between a first busbar and a second busbar;
• and
• a second SAW resonator comprising a second IDT disposed between the second busbar and a third busbar, wherein the second busbar is at an angle with respect to at least one of the first busbar or the third busbar, wherein the first IDT comprises a first set of fingers extending from the second busbar, and wherein lengths of the first set of fingers decrease as each of the first set of fingers gets closer to a side of the first IDT,
• wherein the second IDT comprises a second set of fingers extending from the second busbar, wherein lengths of the second set of fingers increase as each of the second set of fingers gets closer to a side of the second IDT, the side of the second IDT being on a same side of the electroacoustic device as the side of the first IDT,
• wherein the first IDT comprises a third set of fingers extending from the first busbar, the third set of fingers being interdigitated with the first set of fingers, wherein lengths of the third set of fingers decrease as each of the third set of fingers gets closer to the side of the first IDT,
• wherein the second IDT comprises a fourth set of fingers extending from the third busbar, the fourth set of fingers being interdigitated with the second set of fingers, and wherein lengths of the fourth set of fingers increase as each of the fourth set of fingers gets closer to the side of the second IDT.

A method for signal processing, comprising:

• receiving a signal at a first busbar;
• processing the signal via a first surface acoustic wave (SAW) resonator and a second SAW resonator, wherein:
• the first SAW resonator comprises a first apodized interdigital transducer (IDT) disposed between the first busbar and a second busbar;
• the second SAW resonator comprises a second apodized IDT disposed between the second busbar and a third busbar;
• and
• the second busbar is at an angle with respect to at least one of the first busbar or the third busbar, wherein the second busbar is longer than the first busbar and the third busbar, and wherein ends of the first busbar, the second busbar, and the third busbar are aligned on each side of the first busbar, the second busbar and the third busbar;
• and
• providing the processed signal at the third busbar.

An electroacoustic device, comprising:

• a first surface acoustic wave (SAW) resonator comprising a first apodized interdigital transducer (IDT) disposed between a first busbar and a second busbar;
• and
• a second SAW resonator comprising a second apodized IDT disposed between the second busbar and a third busbar, wherein the second busbar is at an angle with respect to at least one of the first busbar or the third busbar, wherein the first apodized IDT and the second apodized IDT are disposed above at least one piezoelectric layer, wherein the at least one piezoelectric layer is disposed between a substrate and at least one of the first apodized IDT and the second apodized IDT, wherein the substrate comprises:
• a substrate layer;
• a charge trap layer;
• and
• a compensation layer, the charge trap layer and the compensation layer being disposed between the substrate layer and the at least one piezoelectric layer.