Electronically graded multilayer ferroelectric composites
AssigneeThe United States of America as represented by the Secretary of the Army
InventorsLouise C. Sengupta, Eric Ngo, Michelina E. O'Day, Steven Stowell, Robert Lancto, Somnath Sengupta, Thomas V. Hynes
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Abstract
A laminated ceramic ferroelectric material has adjacent layers of Barium ontium Titanate (BSTO)--oxide composite stacked in order of descending oxide content and sized in thickness to produce a generally equal capacitance across each layer, resulting in a material having a graded dielectric constant for use in phased array antenna, for example. The oxides are from the metallic oxide group consisting of alumina, zirconia and magnesia and the layers are produced by tape casting.
Claims16
A laminated ceramic ferrolectric material having a graded dielectric constant comprising a plurality of adjacent layers, said layers having no air gaps between the discrete layers and formed of a composition comprising 0 to 100% of Ba.sub.1-x Sr.sub.x TiO.sub.3 wherein x is greater than 0.0 but less than 0.75, and 100 to 0% by weight of at least one low dielectric constant low dielectric loss oxide selected from the group consisting of Al.sub.2 O.sub.3 ZrO.sub.2 and MgO, wherein the ratio of said Ba.sub.1-x Sr.sub.x TiO.sub.3 to said oxide is different in each layer, said layers being arranged in order of decreasing dielectric constant and laminated together.
A laminated ceramic ferrolectric material having a selectively graded dielectric constant comprising a plurality of adjacent layers;
- said layers having no air gap between the discrete layers, each formed of composition of materials selected from the group consisting of Ba.sub.1-x Sr.sub.x TiO.sub.3 where x is greater than 0.00 but less than 0.75, at least one dielectric constant, low dielectric loss oxide and a low dielectric constant, low dielectric loss adjusting material, wherein the total combined % by weight of said Ba.sub.1-x Sr.sub.x TiO.sub.3, said oxide and said adjusting material equals 100% and each of said compositions contain a different ratio of said materials to produce layers having different dielectric constants;
- said layers being arranged in order of of decreasing dielectric constant and laminated together.
Dependencies are inferred from the claim text.