WEIGHTED SAW (SURFACE ACOUSTIC WAVE) REFLECTOR USING DISTRIBUTED ACOUSTIC REFLECTIVE DOT

摘要

PROBLEM TO BE SOLVED: To provide a reflector with a high reflectance and a high frequency selectivity the reflectivity of which is not constrained by the critical dimension of the structure. SOLUTION: A reflective grating 18 having spaced apart grid lines 36 patterned on a piezoelectric substrate 12 for controlling the magnitude and phase of surface acoustic waves in a reflective filter 10 or resonator. The magnitude and phase of the surface acoustic wave are controlled by a sampling period 34 of the reflective grating 18 and the density and sequence of distributed acoustic reflective dots 42. The reflective dots 42 are randomly distributed within gaps 40 between the adjacent grid lines 36 or on top of the grid lines 36 of the reflective grating 18. The pattern of the reflective dots distributed within the gaps 40 or on the grid lines 36 is determined by the dot density, where the dot density varies from a lowest density of 0 to a maximum density of 1. COPYRIGHT: (C)2004,JPO&NCIPI