SURFACE ACOUSTIC WAVE FILTER Russian patent published in 2024 - IPC H03H9/64 H03H9/25 H03H9/02 H03H3/10 

FIELD: acoustoelectronics.

SUBSTANCE: invention relates to acoustoelectronics, particularly to ladder-type surface acoustic wave (SAW) radio-frequency filters. Ladder-type SAW filter comprises a hybrid layered plate consisting of a carrier monocrystalline silicon substrate of crystallographic orientation <100> and a thin active piezoelectric layer of monocrystalline lithium tantalate YXl/42°-slice. Piezoelectric layer is located on the polished surface of the bearing substrate, having surface roughness of Ra<0.7 nm and surface flatness TTV<10 mcm with the bearing substrate diameter of 76.2–100.0 mm.

EFFECT: providing simultaneously high coefficient of electromechanical coupling, reduced by more than 2 times temperature coefficient of frequency in temperature range from minus 60 °C to plus 85 °C, undistorted operating characteristics with low level of parasitic modes excitation, as well as out-of-band selectivity of not less than minus 40 dB relative to the level of minimum insertion loss of the filter.

7 cl, 8 dwg