Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Wolfgang Brand

Mareike K Klee

Robert Frederick Milsom

Christof Metzmacher

Hans Peter Loebl

Gijsbertus A Spierings

Wilhelm Georg Hermann

Henricus A Van Hal

Hendrikus J Van Haren

Mathieu J Ulenaers

The invention relates to a filter device equipped with at least one bulk acoustic wave resonator, which comprises a resonator unit and a reflection element () comprising several layers (). The layers () each comprise a mixture of at least two materials. Within each layer (), the composition of the mixture varies continuously and periodically relative to the layer thickness.

Filter system comprising a bulk acoustic wave resonator

The invention relates to a filter device equipped with at least one bulk acoustic wave resonator, which comprises a resonator unit and a reflection unit. The resonator unit comprises a first () and a second electrode () together with a textured piezoelectric layer () between the first () and second () electrodes.

Filter system with bulk wave resonator having a reflection layer composition that varies with the layer thickness

A component includes a substrate layer (1) of glass or Al.sub.2 O.sub.3, an anti-reaction layer (2) or a levelling layer (2), two electrode layers (3, 5) and a dielectric layer (4) as well as such a capacitor. Manufacture a component which provides for cost-effective, surface-mountable (SMD). The anti-reaction layer (2) on the glass substrate (1) or the levelling layer (2) on the Al.sub.2 O.sub.3 -substrate (1) is made of at least one specific material. An anti-reaction layer or a levelling layer (2) of one of the above-mentioned substances or a combination of several substances, enables a dielectric layer (4) to be provided by means of which a high capacitance value is achieved.

Component comprising a capacitor

A method is described of manufacturing ferroelectric bismuth-titanate layers Bi.sub.4 Ti.sub.3 O.sub.12 on a substrate, A solution containing bismuth and titanium is provided, in a stoichiometric ratio, in the form of a metallo-organic or inorganic compound which is homogeneously mixed in an organic solvent, being brought into contact with the substrate and thermally treated at a temperature in the range from 500.degree. C. to 650.degree. C., thereby forming bismuth-titanate Bi.sub.4 Ti.sub.3 O.sub.12.

Method of manufacturing ferroelectric bismuth-titanate layers on a

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Aachen, Germany

Wolfgang Brand