An overview of the state of art in ferroelectric thin films is presented. First, we review applications: microsystems' applications, applications in high frequency electronics, and memories based on ferroelectric materials. The second section deals with materials, structure (domains, in particular), and size effects. Properties of thin films that are important for applications are then addressed: polarization reversal and properties related to the reliability of ferroelectric memories, piezoelectric nonlinearity of ferroelectric films which is relevant to microsystems' applications, and permittivity and loss in ferroelectric films-important in all applications and essential in high frequency devices. In the context of properties we also discuss nanoscale probing of ferroelectrics. Finally, we comment on two important emerging topics: multiferroic materials and ferroelectric one-dimensional nanostructures. (c) 2006 American Institute of Physics.

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Ferroelectric thin films: Review of materials, properties, and applications

Methods and apparatus for delivering content over network infrastructure are disclosed. In one embodiment, the network comprises a content-based (e.g., cable) network coupled to a radio or other service provider network, and a portion of the infrastructure comprises that nominally used for on-demand (OD) services such as VOD. Mobile or other consumer devices (e.g., cellular telephones, PDAs, etc.) capable of accessing the service provider network are able to access the on-demand and related “trick mode” functionality of the content-based network, as well as make use of ancillary functions such as billing modules associated with the content network.

Method and apparatus for on-demand content transmission and control over networks

Apparatus, systems and techniques for using composite left and right handed (CRLH) metamaterial (MTM) structure antenna elements and arrays to provide radiation pattern shaping and beam switching.

Metamaterial antenna arrays with radiation pattern shaping and beam switching

A method of fabricating a semiconductor structure including the steps of providing a silicon substrate (10) having a surface (12), forming on the surface (12) of the silicon substrate (10), by atomic layer deposition (ALD), a seed layer (20;20') characterised by a silicate material and forming, by atomic layer deposition (ALD) one or more layers of a high dielectric constant oxide (40) on the seed layer (20;20').

Method for fabricating a semiconductor structure including a metal oxide interface with silicon

A bar code reading terminal can, in one embodiment, include a two-dimensional image sensor and an imaging assembly. The terminal can be configured, in response to receipt of a trigger signal, to buffer a set of frames and subject each frame of the set of frames to a decode attempt. The terminal can also be configured to convert the convert the captured set of video frames into a compressed video format, and transfer the resulting video file to a file server or to one or more playback devices, in response to a user interface action, or in response to difficult read condition having been detected. The terminal can also be configured to establish two-way video- and audio-communication with a remote video- and audio-streaming device. The video capturing and streaming operation of the terminal can be controlled remotely from a playback device via web interface.

Bar code reading terminal with video capturing mode

A Bulk Acoustic Wave (BAW) filter, comprising at least one resonator structure that is disposed over a substrate, and an acoustic mirror that is disposed over the resonator structure. The acoustic mirror includes a plurality of layers. The acoustic mirror substantially isolates acoustic vibrations produced by the resonator from reaching beyond an upper surface of the acoustic mirror. The acoustic mirror also prevents environmental contaminants from coming into contact with the resonator. Also disclosed are surface-mountable BAW components.

Bulk acoustic wave (BAW) filter having a top portion that includes a protective acoustic mirror

A bulk acoustic wave device (20) having two resonators (92, 94) in a stacked-up configuration separated by a dielectric layer (50). The device (20) can be coupled to a lattice filter or a ladder filter to form a passband filter with an unbalanced input port (41) and two balanced output ports (16, 18). One or more such passband filters can be used, together with another lattice or ladder filter, to form a duplexer having an unbalanced antenna port, two balanced ports for one transceiver part and two balanced ports for another transceiver part.

Bulk acoustic wave resonator with two piezoelectric layers as balun in filters and duplexers

A resonator structure (1200, 1300, 1400), where a certain wave mode is piezoelectrically excitable, comprises at least two conductor layers (110, 120) and at least one piezoelectric layer (110) in between the conductor layers, said conductor layers and piezoelectric layer extending over a first area of the resonator structure, which first area is a piezoelectrically excitable area of the resonator structure. The resonator structure is characterized in that it comprises a frame-like zone (2, 4) confining a center area (3) within the first area, a cut-off frequency of the piezoelectrically excited wave mode in the layer structure of the frame-like zone is different from that in the layer structure of the center area, and width of the frame-like zone and acoustical properties of the layer structure in the frame-like zone are arranged so that displacement relating to the piezoelectrically excited strongest resonance mode is substantially uniform in the center area of the resonator.

Resonator structure and a filter comprising such a resonator structure

There is provided a Bulk Acoustic Wave Resonator-Stacked Crystal Filter (BAWR-SCF) filtering circuit or device. The BAWR-SCF circuit comprises a first pair of ports, a second pair of ports, a first lead that is connected between a first and a second one of the first pair of ports, and a second lead that is connected between a first and a second one of the second pair of ports. The BAWR-SCF circuit also comprises a first BAW resonator connected in series in the first lead, and a second BAW resonator connected between the first and second leads. The BAWR-SCF further comprises a Stacked Crystal Filter (SCF) having first and second terminals connected in the first lead between the first BAW resonator and the second one of the first pair of ports. The SCF also has a third terminal that is connected to a node of the second lead. The frequency response of the BAWR-SCF circuit has steeply-sloped upper and lower edges that are similar to those yielded by ladder filters which are constructed primarily of BAW resonators. The upper and lower notches of the BAWR-SCF circuit's frequency response are also similar to those yielded by ladder filters which are constructed primarily of BAW resonators. The BAWR-SCF circuit also provides stopband attenuation characteristics that are similar to those yielded by SCFs. Additional BAW resonators connected in a ladder configuration and/or SCFs may also be provided in the BAWR-SCF circuit.

Filters and duplexers utilizing thin film stacked crystal filter structures and thin film bulk acoustic wave resonators

In this paper a device structure eliminating the spurious modes arising from lateral standing Lamb waves is presented. The operating principle behind the device is described with the use of a simple model. Experimental results of ZnO and AlN based resonators in SMR configuration are given. Laser interferometer measurements are presented that confirm applicability of the idea.

Juha Ellä

Papers

Bulk acoustic wave (BAW) filter having a top portion that includes a protective acoustic mirror

Bulk acoustic wave resonator with two piezoelectric layers as balun in filters and duplexers

Resonator structure and a filter comprising such a resonator structure

Filters and duplexers utilizing thin film stacked crystal filter structures and thin film bulk acoustic wave resonators

Spurious resonance free bulk acoustic wave resonators