摘要:
A thin-film piezoelectric acoustic wave resonator that has a large k2, can trap acoustic energy in a resonating part, does not excite spurious resonance, or can finely adjust resonance frequency and a high-frequency filter using the thin-film piezoelectric acoustic wave resonator are provided without increasing the number of processes. At both ends of a vibrating part (1), fixing parts (8) are physically connected, and between the vibrating part (1) and each of the fixing parts (8), an acoustic insulating part (10) and a phase rotating part (11) are physically connected. As with the vibrating part (1), the acoustic insulating part (10) and the phase rotating part (11) are made up of an upper metal film (3), a piezoelectric thin film, and a lower metal film, and an acoustic wave reflector (6) is provided on each of an upper surface, a lower surface, and side surfaces of the vibrating part (1), the acoustic insulating part (10), and the phase rotating part (11). The vibrating part (1) has a width smaller than its length (La) and also smaller than its thickness, and width/thickness is smaller than 1.
摘要:
A compact resonator has a wide bandwidth and a small variation of the specific vibration frequency. The resonator is a thin film tuning-fork type inflection resonator in which a thin film made of a piezoelectric material is formed on a substrate on which a lower electrode is formed, and an upper electrode is formed on the piezoelectric thin film.
摘要:
In a boundary elastic wave resonator formed with a cross finger type transducer (IDT) of a wave length λ of a boundary elastic wave, a silicon oxide film, and an aluminum nitride film above a surface of a θYX-LN single-crystal piezoelectric substrate having a predetermined cut angle θ, a film thickness h1 and a cut angle θ or the like of the silicon oxide film are optimized. For example, the film thickness h1 and the cut angle θ are made to be 127.5°≦θ≦129.5° and 20%≦h1/λ≦100%.
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 thin film piezoelectric bulk acoustic wave resonator has a multilayer structure including a piezoelectric thin film, a first metal electrode film, and a second metal electrode film. At least a part of the piezoelectric thin film is interposed between the first and second metal electrodes. A resonance part and a connection part are formed on an insulating substrate as films by a thin film forming apparatus. The resonance part vibrates in radial extension mode with a center of the piezoelectric thin film used as a node, the piezoelectric thin film of two resonance parts is polarized in a direction perpendicular to a film surface, and a width of the connection part is one-fourth or less of a width of two resonance parts.
摘要:
A piezoelectric film resonator for a radio-frequency circuit according to an aspect of the present invention includes a substrate and a multilayer film provided on the substrate. The multilayer film has a stacked structure in which at least two piezoelectric layers and at least three electrode layers disposed with each of the piezoelectric layers therebetween are stacked. At least one of the electrode layers is an electrode layer for excitation. The electrode layer for excitation has a structure in which a plurality of unit patterns as elements of the electrode layer for excitation are disposed periodically along a direction substantially perpendicular to a stacked direction of the stacked structure.
摘要:
The present invention provides a film bulk acoustic wave resonator (FBAR) filter that can keep the Q factor high. The FBAR filter comprises a first FBAR with a first resonant frequency and a second FBAR with a second resonant frequency, formed on a same substrate. The FBAR filter has such a structure that a first underlayer is formed between the substrate and a first bottom electrode layer and a second underlayer is formed between the substrate and a second bottom electrode layer, the first underlayer thickness being different from the second underlayer thickness.
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 surface acoustic wave device which includes a piezoelectric substrate, and an interdigital transducer formed on a planar surface of the piezoelectric substrate, and having first and second bus bars, a first plurality of electrode fingers connected to the first bus bar, and a second plurality of electrode fingers connected to the second bus bar. The first and second plurality of electrode fingers of the interdigital transducer have an electrode cross region in which the first and second plurality of electrode fingers are arranged alternatively. Each boundary between the first and second bus bars and a grating region of the first and second plurality of electrode fingers is arranged such that the boundary is not substantially parallel, with a transmission direction of surface acoustic waves excited by the interdigital transducer.
摘要:
Aluminum is used for the interdigital transducer mounted on a piezoelectric substrate to realize a surface acoustic wave transducer having a small capacity ratio, no spurious resonance, and a low loss. A .theta. rotated Y cut lithium niobate single crystal piezoelectric substrate is used for the piezoelectric material, a metal film of which principal ingredient is aluminum is used for the interdigital transducer, the direction of the interdigital transducer is made parallel to the X-axis of the lithium niobate single crystal, and thick h and electrode pitch P of the interdigital transducer have the following relationship: (.theta.+5).sup.2 /300+11/12.ltoreq.h/P.times.100-8.ltoreq.-0.0001.times.(.theta.+5).sup.3 +0.1625.times.(.theta.+5)+5.5 and -30.ltoreq..theta..ltoreq.20.