Surface acoustic wave gratings having selected reflectivity
AssigneeRF Monolithics, Inc.
InventorPeter V. Wright
Life of this patent
Estimating the term…
Abstract
An improved surface acoustic wave grating structure that utilizes four electrodes per 3.lambda./2 or 5.lambda./2 transduction length of a reflector grating structure that produces a desired net internal distributed reflectivity in both magnitude and phase.
Claims6
An improved surface acoustic wave reflector grating structure having a transduction length and comprising:
- a piezoelectric substrate;
- a pattern of electrodes on the substrate in the transduction length, the pattern being formed of four equal width, single-level, interdigitated electrodes substantially per each 11/2 transduction wavelengths of the grating structure;
- and
- a non-uniform spacing between said electrodes within the grating transduction length such that a desired reflectivity other than zero is obtained.
An improved surface acoustic wave reflector grating structure having a transduction length and comprising:
- a piezoelectric substrate;
- a pattern of electrodes on the substrate in the transduction length, the pattern being formed of four equal width, single-level, interdigitated electrodes substantially per each 21/2 transduction wavelengths of the grating structure;
- and
- a non-uniform spacing between said electrodes within the grating transduction length such that a desired reflectivity other than zero is obtained.
An improved surface acoustic wave grating structure having a transduction length and comprising:
- a pattern of equal width, single-level electrodes on a piezoelectric substrate, said electrodes extending over at least 11/2 transduction wavelengths;
- essentially four interdigitated electrodes per 11/2 wavelengths across the entire transduction length of the grating structure;
- and
- a non-uniform spacing between said electrodes within the grating transduction length such that a substantially unidirectional grating structure is obtained.
An improved surface acoustic wave grating structure having a transduction length and comprising:
- a pattern of equal width, single level electrodes on a piezoelectric substrate, said electrodes extending over at least 21/2 transduction wavelengths;
- essentially four interdigitated electrodes per 21/2 wavelengths across the entire transduction length of the grating structure;
- and
- a non-uniform spacing between said electrodes within said grating transduction length such that a substantially unidirectional grating structure is obtained.
Dependencies are inferred from the claim text.