Frequency control of spurious shear horizontal mode by adding high velocity layer in a lithium niobate filter

An electronic device comprising:

• a first filter and a second filter, each including surface acoustic wave (SAW) resonators disposed on a same piezoelectric substrate, the first filter having a passband different than a passband of the second filter;
• a dielectric film covering the SAW resonators of the first and second filters;
• and
• a high velocity layer disposed within the dielectric film covering the SAW resonators of the first filter and at least one of the SAW resonators of the second filter, the dielectric film covering the SAW resonators of the first filter having a same normalized thickness as a normalized thickness of the dielectric film covering the SAW resonators of the second filter, a normalized height of the high velocity layer disposed within the dielectric film covering the SAW resonators of the first filter being different from a normalized height of the high velocity layer disposed within the dielectric film covering the at least one of the SAW resonators of the second filter.

An electronic device comprising:

• a first surface acoustic wave (SAW) resonator and a second SAW resonator, each including interleaved interdigital transducer (IDT) electrodes, the first and second SAW resonators being formed on a same piezoelectric substrate, the first SAW resonator having IDT electrodes with a different finger pitch than the IDT electrodes of the second SAW resonator;
• a dielectric material layer disposed on the IDT electrodes of the first and second SAW resonators;
• and
• a high velocity layer disposed within the dielectric material layer disposed on the IDT electrodes of the first SAW resonator and within the dielectric material layer disposed on the IDT electrodes of the second SAW resonator, the dielectric material layer disposed on the IDT electrodes of the first SAW resonator having a same normalized thickness as a normalized thickness of the dielectric material layer disposed on the IDT electrodes of the second SAW resonator, a normalized height of the high velocity layer disposed within the dielectric material layer covering the IDT electrodes of the first SAW resonator being different from a normalized height of the high velocity layer disposed within the dielectric material layer covering IDT electrodes of the second SAW resonator.