Abstract:
PROBLEM TO BE SOLVED: To provide a BAW (bulk acoustic wave) resonator which has a plurality of layers to increase the function of the resonator. SOLUTION: The BAW resonator includes a piezoelectric layer 102, a first electrode 104 on a front surface, a second electrode 106 on the opposite surface, a substrate 108, and an acoustic reflector 110 provided between the substrate 108 and the second electrode 106. The acoustic reflector 110 has a plurality of alternately-arranged layers made of a material having a high acoustic impedance and made of a material having a low acoustic impedance. The function of the acoustic reflector 110 is determined by the reflectivity of longitudinal wave and the reflectivity of traverse wave which exist in the BAW resonator 100 with a resonant frequency of the BAW resonator 100. The acoustic reflector 110 and layers 106a and 106b provided between the acoustic reflector 110 and the piezoelectric layer 102 are chosen so that transmittance of the longitudinal wave and transmittance of the traverse wave at the resonant frequencyare less than -10dB, referring to the number of these layers, the material and thickness thereof. COPYRIGHT: (C)2004,JPO
Abstract:
PROBLEM TO BE SOLVED: To provide a bulk acoustic wave filter having a suppressed side passbands particularly inside an attenuation band. SOLUTION: A bulk acoustic wave (BAW) filter (40) is manufactured from thin film bulk acoustic wave resonators. This BAW filter comprises a substrate (14), a resonator section (11) and an acoustic mirror section (12). Further it comprises a detuning component (31) positioned in the resonator section (11) to provide precise passband characteristics and an additional detuning component (41) in the acoustic mirror section (12) to suppress unwanted side-passband characteristics. COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide a method for manufacturing a layer having a locally-adapted or predetermined layer thickness characteristics. SOLUTION: (a) At least one layer (7) is formed on a substrate. (b) A removing shape for the formed layer is determined. (c) Irradiation of the upside of the layer, with at least one ion beam (9), is performed at least once so that the layer (7) is locally etched at the place of the ion beam according to the removal characteristics. As a result, the layer having the locally-adapted or predetermined layer thickness characteristic can be formed. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
The sequence of layers has a lower electrode (U), an upper electrode (O) and a piezoelectric or pyroelectric layer (S) which is located between them. An auxiliary layer (H) is located between the lower electrode (U) and said layer (S), said auxiliary layer ensuring that the orientation of the layer (S) is homogenous as it grows during the production process. The auxiliary layer (H) preferably consists essentially of amorphous silicon, amorphous silicon oxide or amorphous silicon nitride.
Abstract:
The invention relates to a method for producing a layer with a locally adapted or predefined layer thickness profile. Said method comprises the following steps: a) at least one layer (7) is applied to a substrate, b) a removal profile is determined for the applied layer and c) at least one ion beam (9) is guided over the layer at least once, in such a way that the layer (7) is etched locally at the site of the ion beam, in accordance with the removal profile, thus creating a layer with a locally adapted or predefined layer thickness profile.
Abstract:
At least one bottom electrode (U), a piezoelectric or pyroelectric layer (S) over said bottom electrode and a top electrode (O) over said layer are produced as parts of the layer sequence. The bottom electrode (U) is produced by depositing a conductive material and then chemically-mechanically polished in order to smooth out surface roughness. The thickness of the deposited conductive material is preferably reduced by 10 nm to 100 nm by the chemical-mechanical polishing process.
Abstract:
A filter circuit comprising an unsymmetrical gate (202) and a substrate (S). A series circuit consisting of a filter stage (206) and a balancing member (208) is arranged between the symmetrical gate (204) the unsymmetrical gate (202). The balancing member (208) and the filter stage (206) are formed on the substrate (S).
Abstract:
Un sistema en forma de red de superficies conductoras se utiliza para la formacion capacitiva de imagenes, en el cual entre los conductores (2) provistos para la medicion se utilizan conductores de apantallamiento (8). Durante varios ciclos de carga y descarga se conduce el potencial a cada uno de los conductores pertenecientes a un punto de la imagen, para evitar las corrientes de desplazamiento entre los condensadores de apantallamiento. Para la modificacion homogenea de los potenciales electricos en esos conductores puede por ejemplo utilizarse un conducto de compensacion con un amplificador operacional (9,10) retroacoplado.
Abstract:
In a method for manufacturing a piezoelectric oscillating circuit in thin film technology, wherein the oscillating circuit includes a predetermined natural frequency and a plurality of layers, first of all at least a first layer of the piezoelectric oscillating circuit is generated. Subsequently, by processing the first layer a frequency correction is performed. Subsequently, at least a second layer of the piezoelectric oscillating circuit is generated and processed for performing a second frequency correction.