Acoustic resonator and filter device with series dielectric capacitor

A filter device comprising:

• an acoustic resonator including:
• a substrate;
• a piezoelectric layer coupled to the substrate by one or more intermediate layers;
• an interdigital transducer (IDT) on a surface of the piezoelectric layer, the IDT including a pair of busbars having a plurality of interleaved fingers extending therefrom;
• and
• a capacitor electrically coupled in series to the acoustic resonator and integrated as a portion of a first busbar of the pair of busbars, the capacitor and a pair of metal layers and a dielectric layer disposed therebetween.

A radio frequency module comprising:

• a filter device including a plurality acoustic wave resonators connected in parallel;
• and
• a radio frequency circuit coupled to the filter device, the filter device and the radio frequency circuit being enclosed within a common package,
• wherein at least one acoustic wave resonator of the plurality of acoustic wave resonators of the filter device includes:
• a substrate;
• a piezoelectric layer coupled to the substrate by one or more intermediate layers;
• a conductor pattern on a surface of the piezoelectric layer, the conductor pattern including a pair of busbars having a plurality of interleaved fingers extending therefrom to form an interdigital transducer (IDT), and
• wherein the filter device further includes a dielectric capacitor electrically coupled in series to the acoustic resonator, the dielectric capacitor including a dielectric layer on a surface of a first busbar of the pair of busbars and at least one metal layer on a surface of the dielectric layer, such that the dielectric layer is between the first busbar and the at least one metal layer to form the dielectric capacitor.