Koninklijke Philips Corporation N.v.

Nxp B.v.

Hans Peter Loebl

Mareike K Klee

Robert Frederick Milsom

Christof Metzmacher

Wolfgang Brand

Matthias Wendt

Olaf Wunnicke

Hendrik Klaas Jan Ten Dolle

A sensor includes a substrateand at least one resonator, which includes an acoustic reflector, a piezoelectric layer, a first and second electrodeplaced on the same side of the piezoelectric layer, and a sensing layer. The sensing layerreacts with a chemical or biological agent by absorption, adsorption, desorption or chemical reaction. As a result the individual frequency of a resonator changes and conclusions about the agent can be drawn. Such a sensor is very sensitive to an agent being sensed, especially when used in liquids.

Bulk acoustic wave sensor

The invention relates to an arrangement with two piezoelectric layers () and to a method of operating the arrangement as a filter. One () of the two piezoelectric layers () in the arrangement is situated between an electrode () and a middle electrode (), and the other one () of the two piezoelectric layers () is positioned between another electrode () and said middle electrode () such that a bulk acoustic wave resonator is formed. The one and the other electrode () and the middle electrode () are connected to circuitry means for applying high-frequency signals to at least one of the two piezoelectric layers () such that the bulk acoustic wave resonator has at least one resonance frequency when the circuitry means are in one switching state, and that the bulk acoustic wave resonator has at least one other resonance frequency different from the at least one resonance frequency when the circuitry means are in another switching state.

Arrangement with two piezoelectric layers, and method of operating a filter device

The invention relates to a resonator filter structure () for radio frequency (RF) filters, especially a bulk acoustic wave (BAW) filter structure. According to the invention, a resonator filter structure () is constructed with a BAW lattice filter section (), in which all of the BAW resonator elements (----) within the BAW lattice filter section () have substantially equal resonance frequencies. According to the invention, there are parallel capacitances (--) connected in parallel to the BAW resonators (--) of one branch type of the BAW lattice filter section (). Thus, anti-resonance frequency of the respective BAW resonator (--) is tuned. That results in a very narrow passband which corresponds approximately to the difference in anti-resonance frequencies between diagonal and horizontal branches of the lattice filter section (). The parallel capacitances (--) are used to tune the bandwidth: the smaller the capacitance, the smaller the bandwidth. Moreover, due to the lattice structure at one port of the resonator filter signal guidance will be balanced while at the other port signal guidance can be unbalanced or balanced according to the application needs.

Resonator filter structure having equal resonance frequencies

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.

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Monschau-Imgenbroich, Germany

Hans Peter Loebl