A system for a wireless communication infrastructure using single crystal devices. The wireless system can include a controller coupled to a power source, a signal processing module, and a plurality of transceiver modules. Each of the transceiver modules includes a transmit module configured on a transmit path and a receive module configured on a receive path. The transmit modules each include at least a transmit filter having one or more filter devices, while the receive modules each include at least a receive filter. Each of these filter devices includes a single crystal acoustic resonator device formed with a thin film transfer process with at least a first electrode material, a single crystal material, and a second electrode material. Wireless infrastructures using the present single crystal technology perform better in high power density applications, enable higher out of band rejection (OOBR), and achieve higher linearity as well.

A resonant member of a MEMS resonator oscillates in a mechanical resonance mode that produces non-uniform regional stresses such that a first level of mechanical stress in a first region of the resonant member is higher than a second level of mechanical stress in a second region of the resonant member. A plurality of openings within a surface of the resonant member are disposed more densely within the first region than the second region and at least partly filled with a compensating material that reduces temperature dependence of the resonant frequency corresponding to the mechanical resonance mode.

Methods of manufacturing a pressure sensor from an SOI wafer are provided. In preferred embodiments, the methods comprise forming a cavity in a SOI wafer by removing a first portion of a bottom silicon layer on the bottom side of the SOI wafer to a depth of an insulator layer; depositing a layer of a second material over the cavity; removing both the silicon layer and the insulator layer from a top side of the SOI wafer in a first plurality of areas above the cavity to form a diaphragm from the layer of a second material, wherein at least one support structure that spans the diaphragm is formed from material above the cavity that was not removed; and forming at least one piezoresistor in the SOI wafer over an intersection of the support structure and SOI wafer at an outside edge of the diaphragm.

There is provided a method for producing a piezoelectric element, which allows for forming a columnar microstructure with a small width and a high aspect ratio. The method is intended to produce a piezoelectric element 102 including a three-dimensional structure group 20 having a plurality of the three-dimensional structures 21 and 321 formed in a plate-like or columnar shape with a width of 30 μm or less and a height of 80 μm or more. The production method includes a first process of fabricating a plurality of plate-like or columnar precursor shapes 82a on a bulk material 81 formed of a Pb-based piezoelectric material, and a second process of reducing the width of the precursor shapes 82a to a predetermined value using an etching liquid.

In one arrangement, a vibration system includes a vibratable plate, a support member surrounding the vibratable plate, and a vibration-inducing member surrounding the support member. The vibration-inducing member is configured to radially expand and contract against the support member so as to produce axial vibration of the vibratable plate. In another arrangement, the vibratable plate has an outer circumference; a tubular member is concentrically disposed about the outer circumference of the plate, and an annular vibration-inducing member is concentrically disposed about the outer circumference of the tubular member. The vibration-inducing member is preferably a piezoelectric ring that is radially expandable and contractable against the wall of the tubular member to cause the plate to vibrate in the axial direction.

Film bulk acoustic resonator (FBAR) is provided. An exemplary FBAR includes a substrate; a first insulating material layer on the substrate, the first insulating material layer containing a first cavity; a second insulating material layer on the first insulating material layer, the second insulating material layer containing a second cavity and a third cavity spaced apart from the second cavity, the second cavity and the third cavity both in communication with the first cavity; a resonator sheet covering the second cavity and partially extending over the second insulating material layer; a third insulating material layer over the second insulating material layer and the resonator sheet, the third insulating material layer containing a fourth cavity, the fourth cavity in communication with the third cavity, and the fourth cavity partially overlapping the second cavity; and a capping layer on the third insulating material layer.

An acoustic wave device fabrication method includes: forming on a piezoelectric substrate a comb-shaped electrode and a wiring layer coupled to the comb-shaped electrode; forming on the piezoelectric substrate a first dielectric film having a film thickness greater than those of the comb-shaped electrode and the wiring layer, covering the comb-shaped electrode and the wiring layer, and being made of silicon oxide doped with an element or undoped silicon oxide; forming on the first dielectric film a second dielectric film having an aperture above the wiring layer; removing the first dielectric film exposed by the aperture of the second dielectric film by wet etching using an etching liquid causing an etching rate of the second dielectric film to be less than that of the first dielectric film so that the first dielectric film is left so as to cover an end face of the wiring layer and the comb-shaped electrode.

A crystal resonator includes: lower glass plates on which first electrodes are formed so as to extend from side surfaces to a bottom surface of the lower glass plates; a crystal plate which is provided over the lower glass plates and on which second electrodes to be coupled to the first electrodes are formed on a surface in contact with the lower glass plates; and an upper glass plate which is provided over the crystal plate; wherein the side surfaces of the lower glass plates on which the first electrodes are formed are provided with a protrusion that extends in parallel with a top surface and the bottom surface of the lower glass plates and that extends from one end to the other end of each of the side surfaces, and wherein the first electrodes are formed on the side surfaces that include surfaces of the protrusion.

Switchable and/or tunable filters, methods of manufacture and design structures are disclosed herein. The method of forming the filters includes forming at least one piezoelectric filter structure comprising a plurality of electrodes formed to be in contact with at least one piezoelectric substrate. The method further includes forming a micro-electro-mechanical structure (MEMS) comprising a MEMS beam in which, upon actuation, the MEMS beam will turn on the at least one piezoelectric filter structure by interleaving electrodes in contact with the piezoelectric substrate or sandwiching the at least one piezoelectric substrate between the electrodes.

An acoustic resonator comprises a first electrode, a second electrode and a piezoelectric layer disposed between the first electrode and the second electrode, and comprising a C-axis having an orientation. A polarization-determining seed layer (PDSL) is disposed beneath the piezoelectric layer, the seed layer comprising a metal-nonmetal compound. A method of fabricating a piezoelectric layer over a substrate comprises forming a first layer of a polarization determining seed layer (PDSL) over the substrate. The method further comprises forming a second layer of the PDSL over the first layer. The method further comprises forming a first layer of a piezoelectric material over the second layer of the PDSL; and forming a second layer of the piezoelectric material over the first layer of the piezoelectric material. The piezoelectric material comprises a compression axis (C-axis) oriented along a first direction.