摘要:
An object of the present invention is to provide an inexpensive thin film piezoelectric bulk acoustic wave resonator that allows fine-tuning of a resonant frequency. Another object is to provide an inexpensive filter with dramatically improved frequency characteristics, using thin film piezoelectric bulk acoustic wave resonators that can be formed on one substrate. A thin film piezoelectric bulk acoustic wave resonator of the present invention has a laminated structure including a piezoelectric thin film, and a first metal electrode film and a second metal electrode film between which part of the piezoelectric thin film is sandwiched; the first metal electrode film has a plurality of holes formed on an electrode plane opposite to the second metal electrode film and having a depth equivalent to at least the thickness of the first metal electrode film; and if a combined thickness of top and bottom electrode layers and the piezoelectric thin film is ht, the covering ratio σ of the electrode plane of the first metal electrode film satisfies a condition 0
摘要:
The MEMS switch comprises a first anchor formed over a substrate, a first spring connected to the first anchor, an upper electrode which is connected to the first spring and makes a motion above the substrate, elastically deforming the first spring, a lower electrode formed over the substrate, positioned under the upper electrode, a second spring connected to the upper electrode, and a second anchor connected to the second spring. When voltage is applied between the upper and lower electrodes and the upper electrode makes a downward motion, the second anchor is brought into contact with the substrate. As a result, the second spring is elastically deformed. When the upper electrode is subsequently brought into contact with the lower electrode, thereby the upper and lower electrodes are electrically connected. The first and second anchors, first and second springs, and upper electrode are formed of identical metal in integral structure.
摘要:
A surface acoustic wave device in the present invention is provided with a piezoelectric substrate, a supporting substrate being jointed to the piezoelectric substrate and including a material different in expansion coefficient from the piezoelectric substrate and an interdigital electrode for exciting a surface acoustic wave, the electrode being arranged on the surface of the piezoelectric substrate. Either the interdigital electrode or the piezoelectric substrate is configured so that the interdigital electrode is 40% or more to 70% or less as long as the piezoelectric substrate in the direction to which a surface acoustic wave propagates.
摘要:
A bulk acoustic wave resonator in which the problem of the technology for forming the diaphragm structure is resolved, which is more compact and improved the frequency accuracy, and the manufacturing method thereof, a filter using the same, a semiconductor integrated circuit device using the same, and a high frequency module using the same are provided. The bulk acoustic wave resonator according to the present invention comprises a substrate having a first surface and a second surface opposite to the first surface, and a staked resonator including a first electrode film in contact with the first surface, a piezoelectric film overlaying the first electrode film and a second electrode film overlaying the piezoelectric film. The substrate is provided with an air gap including a first aperture opening at the first surface and a second aperture opening at the second surface at the position corresponding to the staked resonator, respectively and having air gap generally vertical shape to the first surface, and another air gap having a tapered shape in the vicinity of the first surface.
摘要:
A piezoelectric thin film resonator is formed on a base substrate such as made of Si in which the resonance frequency is substantially determined by the lateral size not by the thickness of the resonator, whereby a resonator for use in TCXO, etc. is provided by the thin film technique, which enables to reduce the thickness of the film and the size of the resonator and integration with Si-based IC incorporating the resonator in one identical substrate.
摘要:
An apparatus for currency validation is disclosed in which a belt-pulley arrangement is provided in a housing to transport a bill along a passageway for identification of the bill by sensing the optical or magnetic characteristics of the bill. A lever with notches is mounted for rotation between a protective position protruded within the passageway and a release position retracted from the passageway. When a thin tool is inserted into the passageway, it is engaged with the notches of the lever to prevent movement of the lever from the protective to the release position.
摘要:
A surface acoustic wave device comprises a piezoelectric substrate and a plurality of electrode fingers which are located on the piezoelectric substrate along the propagation direction of a surface acoustic wave. The electrode fingers are located on the piezoelectric substrate at a pitch of about 1.5.lambda.o/2 (where a symbol .lambda.o indicates a wavelength of a surface acoustic wave with a frequency equivalent to the center frequency of the surface acoustic wave device). The width of each of the electrode fingers is about 1.5.lambda.o/4. The electrode fingers are located on the substrate so as to be electrically independent of an external circuit and each other.Since the width of electrode fingers is about 1.5.lambda.o/4, the surface acoustic wave device can be produced without fine processing techniques.
摘要:
A surface acoustic wave device comprises a piezoelectric substrate and a plurality of electrode fingers which are located on the piezoelectric substrate along the progagation direction of a surface acoustic wave. The electrode fingers are located on the piezoelectric substrate at a pitch of about 1.5.lambda.o/2 (where a symbol .lambda.o indicates a wavelength of a surface acoustic wave with a frequency equivalent to the center frequency of the surface acoustic wave device). The width of each of the electrode fingers is about 1.5.lambda.o/4. The electrode fingers are located on the substrate so as to be electrically independent of an external circuit and each other.Since the width of electrode fingers is about 1.5.lambda.o/4, the surface acoustic wave device can be produced without fine processing techniques.
摘要:
In a compact radio frequency module, a first chip forms a heater element and a second chip forms a device whose operating characteristics vary with temperature change or whose maximum operating temperature is lower than the maximum operating temperature of the first chip. A multilayer substrate has a plurality of dielectric layers and a plurality of conductor layers and mechanically supports the firs chip and the second chip with some of the conductor layers electrically connected with these chips. The module can conduct the heat generated by the first chip throughout the module; guide the heat generated by the first chip from the module's top face side to its bottom face side; and interrupt the heat conduction from the first conductor pattern on which the first chip is placed to the second conductor pattern on which the second chip is placed.
摘要:
A casing of a stacker is provided with an opening and a chamber for disposing a pusher within the casing adjacent to the opening so that the pusher can be removably attached within the stacker. Also provided in the pusher is a slit-shaped inlet connected with an exit of a passageway within a transporter. By removing the pusher from the stacker and attaching same to another stacker having its compartment of different capacity, bill storing capacity may easily be changed. In malfunction of the pusher, it may easily be exchanged with new one for easy maintenance.