DEVICE USING SURFACE ACOUSTIC WAVES Russian patent published in 1995 - IPC

FIELD: radio engineering. SUBSTANCE: input opposite-rod converter 2, electrostatic shield 3 and output anodized converter 4 are positioned on operating surface 1 of piezoelectric substrate in common acoustic channel. Output counter 4 has two continuous coating electrodes 5 and 6 which are spaced by blanket which has constant width and is shaped as meander which constituents heights are proportional to given values of pulse response. Edges 10 and 11 of screen 3 that are not parallel as well as edge 12 of converter 4 that is closest to screen 3 have curvature caused by following condition: angle α_1,2,3 between tangent to any point of these curves and normal to direction of surface acoustic waves in this point conform to equation α/2W<α_1,2,3<45^°, where α is length of surface acoustic waves in central frequency and w is aperture of channel. Shape of edge 12 of two-electrode anodized converter 4 conforms to condition of equality of two total lengths of metal parts along aperture of acoustic channel at piece from edge of electrostatic shield 3 to coordinate of two-electrode anodized converter 4 which corresponds to maximum of its pulse response. EFFECT: increased electric characteristics of device due to decreased reflections caused by surface acoustic waves reflected from edges of electrostatic shield and converter. 4 dwg