MONOLITHIC PIEZOELECTRIC FILTER ADJUSTMENT PROCESS Russian patent published in 1997 - IPC

FIELD: monolithic piezoelectric filters provided with solid electrode on one side of crystal plate and two isolating electrodes on its other side to form two point resonators. SUBSTANCE: process includes sequential removal of electrode material layer by ion etching to equalize frequencies of point resonators and adjust intermediate frequency of filter. Novelty is that vertical shutter is placed between electrodes of two point resonators above crystal plate and two ion sources are installed on its both ends symmetrically at angle of 40±15 deg. in focus of maximum etching rate; frequencies of point resonators are equalized by etching point resonator having lower frequency using one ion source placed on same side relative to shutter as resonator; then intermediate frequency of filter is adjusted by ion etching of both point resonators using two ion sources simultaneously. EFFECT: facilitated procedure. 1 dwg