摘要:
Thin films of ferroelectric composite material comprising barium strontium titanate (BSTO) combined with magnesium oxide additive are produced by metalorganic decomposition. The barium strontium titanate magnesium oxide ferroelectric composite comprises Ba.sub.1-x Sr.sub.x TiO.sub.3 /MgO, wherein x is greater than 0.0 but less than or equal to 0.75 and preferably is 0.4, and wherein the weight ratio of BSTO to magnesium oxide may range from 99 to 40 weight percent BSTO to 1 to 60 weight percent magnesium oxide. These films have desirable electronic properties and may have application to both active microwave and dynamic random access memory devices, including low dielectric constant, low loss factor, high tunability, and high resistivity. The films produced are uniformly thick and impurity free, with thicknesses of only 0.4 microns.
摘要:
This invention provides a voltage tunable filter comprising an input connection point, an output connection point, and at least one circuit branch electrically coupled to the input connection point and the output connection point and including a voltage tunable dielectric varactor electrically connected to an inductor. The voltage tunable filter can be one of a low-pass, high-pass, band-pass, or band-stop filter. The varactor can include built-in DC blocking capacitors.
摘要:
Ceramic ferroelectric composite materials comprising barium strontium titte/magnesium and oxygen-containing compound composite further doped with rare earth (lanthanide) oxides. More particularly, these inventive composites are comprised of Ba.sub.1-x Sr.sub.x TiO.sub.3 /Mg--O based compound/rare earth oxide composite, wherein x is greater than or equal to 0.0 but less than or equal to 1.0, and wherein the weight ratio of BSTO to Mg compound may range from 99.75-20 wt. % BSTO to 0.25-80 wt. % Mg compound, and wherein said rare earth oxide additive comprises less than about 10 mole percent of the composite. The rare earth oxides of the composite include all oxides of the lanthanide series elements including scandium and yttrium, as well as combinations thereof. The magnesium-based compound may be selected from the group consisting of MgO, MgZrO.sub.3, MgZrSrTiO.sub.3, MgTiO.sub.3, and MgCO.sub.3. This new class of composite materials has enhanced electronic properties including: low dielectric constants; substantially decreased electronic loss (low loss tangents); increased tunability; increased temperature stability; decreased sintering temperatures; and low curie temperatures. The electronic properties of these new materials can be tailored for various applications including phased array antenna systems, capacitors, transmission wire, wireless communication, and pyroelectric guidance devices.
摘要:
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.
摘要:
A novel ceramic ferroelectric material having a low dielectric constant, extremely low loss and high tunability. The material is a composite comprising Barium Strontium Titanate (BSTO) and a ceramic material having a low dielectric constant. The preferred composite is represented by Ba.sub.1-x Sr.sub.x TiO.sub.3 --MgO, wherein x is greater than 0.00, but less than or equal to 0.75, and wherein the percent weight ratio between Ba.sub.1-x Sr.sub.x TiO.sub.3 and MgO ranges from approximately 99%-40% and 1%-60%, respectively. The novel materials possess superior electronic properties; and they may be employed in various antenna systems at both microwave and millimeter wave range frequencies.
摘要:
A novel ceramic ferroelectric material having a low dielectric constant, loss and high tunability. The material is a composite comprising Barium Strontium Titanate (BSTO) and a ceramic material having a low dielectric constant. The preferred composite is represented by Ba.sub.1-x Sr.sub.x TiO.sub.3 --ZrO.sub.2, wherein x is greater than 0.00, but less than or equal to 0.70, and wherein the percent weight ratio between Ba.sub.1-x Sr.sub.x TiO.sub.3 and ZrO.sub.2 ranges from approximately 99%-40% and 1%-60%, respectively. The novel materials possess superior electronic properties; and they may be employed in various antenna systems.
摘要:
A novel ceramic ferroelectric material having a low dielectric constant, loss and high tunability. The material is a composite comprising Barium Strontium Titanate (BSTO) and a ceramic material having a low dielectric constant. The preferred composite is represented by Ba.sub.1-x Sr.sub.x TiO.sub.3 -Al.sub.2 O.sub.3, wherein x is greater than 0.00, but less than or equal to 0.70, and wherein the percent weight ratio between Ba.sub.1-x Sr.sub.x TiO.sub.3 and Al.sub.2 O.sub.3 ranges from approximately 99%-40% and 1%-60%, respectively. The novel materials possess superior electronic properties; and they may be employed in various antenna systems.