Radio frequency acoustic device with laterally distributed reflectors

A bulk acoustic wave resonator device comprising:

• a piezoelectric material layer having an upper surface and a lower surface;
• a first metal layer having a lower surface disposed on the upper surface of the piezoelectric material layer;
• a second metal layer having an upper surface disposed on the lower surface of the piezoelectric material layer;
• and
• a laterally distributed raised frame including a first raised frame having an inner raised frame section and an outer raised frame section, and a second raised frame disposed beneath the first metal layer and the outer raised frame section, but not beneath the inner raised frame section, the inner raised frame section of the first raised frame being laterally disposed from a central active region of the bulk acoustic wave resonator device by a first distance, the outer raised frame section of the first raised frame being laterally disposed from the central active region of the bulk acoustic wave resonator device by a second distance, the second distance being greater than the first distance, the laterally distributed raised frame configured to improve reflection of lateral mode waves and to reduce conversion of main mode waves into lateral mode waves.