Abstract:
A component working with guided acoustic waves includes a layer system configured to guide waves in a lateral plane. The layer system includes a piezoelectric layer, electrodes on the piezoelectric layer for exciting the wave, a dielectric layer with an acoustic impedance, and an adjustment layer with an acoustic impedance. A ratio of the acoustic impedance of the adjustment layer to the acoustic impedance of the dielectric layer is greater than 1.5.
Abstract:
Elements and methods for forming elements that operate with acoustic waves are disclosed. The element includes a piezoelectric electric substrate that has a first thermal coefficient of expansion, electrically conducting element structures on an upper side of the substrate, a compensation layer on an underside of the substrate, and an SiO2 layer over the element structures.
Abstract:
A component working with guided acoustic waves includes a layer system configured to guide waves in a lateral plane. The layer system includes a piezoelectric layer, electrodes on the piezoelectric layer for exciting the wave, a dielectric layer with an acoustic impedance, and an adjustment layer with an acoustic impedance. A ratio of the acoustic impedance of the adjustment layer to the acoustic impedance of the dielectric layer is greater than 1.5.
Abstract:
A component includes a filter having a first structure and a second structure. The component also includes a substrate on which the first and second structures are arranged. The first structure has an approximately uniform layer thickness and an approximately uniform composition. The second structure has an approximately uniform layer thickness and an approximately uniform composition. At least one of the layer thickness or composition of the first structure differs from the layer thickness or composition of the second structure.
Abstract:
The invention relates to modified double-layer clay minerals which are characterized in that they contain embedded organic molecules. Also disclosed are a method for the production thereof and the use thereof.
Abstract:
An electroacoustic transducer has reduced loss due to acoustic waves emitted in the transverse direction. For this purpose, a transducer comprises a central excitation area, inner edge areas flanking the central excitation area, outer edge areas flanking the inner edge areas, and areas of the busbar flanking the outer edge areas. The longitudinal speed of the areas can be set so that the excitation profile of a piston mode is obtained.
Abstract:
A component that operates with acoustic waves includes a substrate including a piezoelectric material, a first electrode plane in which bottom electrode structures including an acoustically active bottom electrode are arranged directly on the substrate, and a top electrode arranged above the bottom electrode plane and which is electrically conductively connected to the bottom electrode structures, wherein excitation of the acoustic waves during operation of the component is effected exclusively or predominantly through the bottom electrode structures.
Abstract:
A component includes a filter having a first structure and a second structure. The component also includes a substrate on which the first and second structures are arranged. The first structure has an approximately uniform layer thickness and an approximately uniform composition. The second structure has an approximately uniform layer thickness and an approximately uniform composition. At least one of the layer thickness or composition of the first structure differs from the layer thickness or composition of the second structure.
Abstract:
An apparatus including a piezoelectric substrate having at least one transducer electrode structure. The structure having a metallization formed by one or more metals with a mean specific density that is at least 50% higher than that of aluminum. The structure having a compensation layer that is applied fully or partially over the metallization. The compensation layer is of a material having a temperature dependence of elastic constants that counteracts the temperature coefficient of frequency of the substrate. The compensation layer has a thickness that is less than 15% of an acoustic wavelength of a wave capable of propagation in the structure.
Abstract:
SAW component with improved temperature coefficient of frequency To reduce losses in a SAW component assembled on a piezoelectric substrate (S), the mass load on the metallization (M) is increased until the propagation velocity of the surface wave comes to rest below the propagation velocity of the fast shear wave. To limit the increase in the temperature coefficient of frequency in this process, a metallization with a significantly higher specific density than [that of] Al is used. The temperature coefficient of frequency of the component is simultaneously reduced by a compensation layer (K) applied to essentially the entire surface, said compensation layer being made of a material having a temperature dependency of the elastic coefficient that counteracts that of the substrate-metallization combination.