Hewlett-packard Company

Avago Technologies Wireless IP (singapore) Pte. Ltd.

John D Larson

Richard C Ruby

Paul D Bradley

Paul K Lum

J Fleming Dias

John N Dukes

Sergio Pissanetzky

David G Miller

Jeremy A Good

David A Wilson

Amin M Hanafy

Miller David G

H Edward Karrer

F Russell Huson

Method for fabricating an acoustical resonator on a substrate having a top surface. First, a depression in said top surface is generated. Next, the depression is filled with a sacrificial material. The filled depression has an upper surface level with said top surface of said substrate. Next, a first electrode is deposited on said upper surface. Then, a layer of piezoelectric material is deposited on said first electrode. A second electrode is deposited on the layer of piezoelectric material using a mass load lift-off process.

Manufacturing process for thin film bulk acoustic resonator (FBAR) filters

Method for fabricating an acoustical resonator on a substrate

A superconductive magnet assembly is disclosed. The superconductive magnet assembly includes a primary magnet formed of a coil of superconductive material, a magnet former supporting the primary coil, a plurality of gradient coils of superconductive material operative to produce field gradients during operation of the magnet, and a radiation shield within which the primary coil and the gradient coils are housed. The gradient coils are supported by the magnet former.

Superconductive magnet assembly

A C-shaped superconducting magnet for use in magnetic resonance imaging (MRI) equipment is disclosed. The magnet includes flux concentrators on opposing sides of the gap, for generating a vertical field therein; the flux concentrators include a plurality of coils, for carrying current in opposing directions, so as to generate an inwardly directed field to compensate for the gap. Injection correctors, each consisting of a horizontal coil, are disposed adjacent the flux concentrators. A flux return body, for example a superconducting solenoid or an iron yoke, provides a return path on the opposite side of the magnet from the gap. Flux deflectors guide return flux in a curved path from the flux return body to the injection correctors. The flux deflectors are constructed to include a superconducting coil which is wound about varying chords (or the full diameter) thereof, so that the induced flux is greater nearer the outside of the flux deflector, compensating for the tendency of the flux to crowd along the inner portion of the curved path. The return flux is thus provided to the injection correctors with sufficient uniformity to be corrected thereby.

Compact superconducting magnet for magnetic resonance imaging

An acoustic transducer assembly is provided having a one or two dimensional array of transducer elements, an electrical circuit element such as a circuit element and a backing for interconnecting transducer elements to corresponding contacts or traces of the circuit element. The backing is a block of acoustic attenuating material having a conductor extending therethrough between each transducer element and the corresponding circuit contact. The block has acoustic properties, including acoustic impedance and acoustic velocity, to achieve a desired degree of acoustic match with the transducer elements and/or to permit coupling of acoustic energy from the conductors into the block. The block may be of a single material or may have different volumes of two or more materials having different acoustic properties to achieve desired results. Multiple thin conductors or conducting fibers or foils may be utilized for each transducer element to reduce or eliminate acoustic coupling into the conductors. Acoustic coupling into the conductors may also be reduced by providing off-center contact with the transducer elements. Removal of acoustic energy from the conductors may be facilitated by covering each conductor with a material having a lower acoustic velocity than the conductor, which material is impedance matched to at least a portion of adjacent backing material.

Backing for acoustic transducer array

Apparatus and method for compensating for differences in time at which an incoming acoustic wave is received by an array of acoustic signal receivers to take account of the shape of the incoming wave and the non-zero incidence angle of its approach. Each receiver is provided with a time delay module that introduces a large or coarse scale time delay .DELTA.t.sub.L plus a small or fine scale time delay .DELTA.t.sub.S, where .DELTA.t.sub.L is an integral multiple of a coarse scale time interval length .DELTA.t.sub.c and .DELTA.t.sub.S may be varied continuously from 0 to a predetermined time interval length (.DELTA.t.sub.S).sub.max that may be made at least as large as .DELTA.t.sub.c.

Acoustic image acquisition using an acoustic receiving array with

Apparati and methods for magnetic resonance imaging a selected interrogation volume in a tissue of a human or animal body, to provide increased signal-to-noise ratios for fixed data acquisition times. The method involves excitation of magnetic resonance in a selected interrogation volume that may be as small as 500-3,000 cm.sup.3, through controllable focusing or steering of a rotating magnetic field signal used to induce magnetic resonance. The response signals issued by the excited volume element are then collected by focusing of these response signals, using a phased array of antennae for this purpose. Use of the invention with well known nuclear magnetic resonance excitation procedures, such as spin echo, echo planar, gradient recalled and backprojection, are discussed.

Radiofrequency focusing of magnetic resonance images

A two-dimensional phased array ultrasound imaging system distributes signal delays between its probe and its base section. The transducer elements are grouped and relative delays between elements of a group are introduced within the probe. Once the intragroup delays are introduced, the signals from the elements of a group are combined to generate a group signal. A group signal is generated for each group and, collectively, the group signals are transmitted to the base section via a multi-wire cable. Delays between groups are introduced at the base section. This distribution of delays maintains power dissipation within the probe at a tolerable level while requiring only a manageable number of data and signal lines between the probe and base section.

2-D phased array ultrasound imaging system with distributed phasing

Magnet structure for focusing of magnetic resonance images

Apparatus and method to provide a controllable one-dimensional array or two-dimensional array of delay times for an array of acoustic signals propagating in a plurality of bodies of piezoelectric material. Each piezoelectric body is provided with three or more pairs of electrodes, with the first and second electrodes of a pair being spaced apart and positioned on first and second surfaces, respectively, of the piezoelectric body. As an acoustic wave propagates longitudinally in the piezoelectric body, an electrical voltage signal is generated between each electrode pair as the wave passes between the two electrodes of that pair. Time delay is controlled by choice of the longitudinal position of each electrode pair along the piezoelectric body.

Acoustic image signal receiver providing for selectively activatable

Method for focusing of magnetic resonance images

In ultrasonic apparatus has a large aperture annular transducer array which is mechanically rotated in a scanning motion. The ultrasound beam is electronically steered to compensate for angular position error caused by the scanning motion by means of preselected delay patterns to thereby produce an ultrasound beam which undergoes a discrete step scan pattern of an object of interest. Also disclosed is a method of manufacturing the transducer array which involves segmenting the transducer after assembling the transducer components.

Pointing error compensation in large aperture annular arrays

Apparatus and method for representing slow motion of an oscillating heart by forming strobed images of the heart at a sequence of uniformly spaced times with controllable time interval lengths that are related to, but not identical to, the primary oscillation period T of the heart. The heart images may be formed at a sequence of times t=t.sub.0 +kMT.sub.h /N where t.sub.0 is an initial time, N is a positive integer, k=1,2, . . . , N-1 and M is a positive integer. Alternatively, the heart images may be formed at a sequence of times determined in part by the current oscillation cycle of the heart.

Slow motion cardiac imaging

The acoustic imaging transducer described herein incorporates an acoustic stack contained in an alumina housing which also provides structure for electrically connecting the transducer array elements to system signal processing electronics.

Acoustic imaging transducer

A method is provided to connect individual conductive traces to an array of individual piezoelectric elements by bonding a flexible circuit board containing conductive traces to the piezoelectric elements. The resultant bonded elements provide an array for an acoustic transducer.

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Palo Alto, CA, United States of America

John D Larson