Optimization of Pulse-Echo Array Transducer System for Identification of Specified Targets

2002 ◽  
pp. 373-380 ◽  
Author(s):  
Peder C. Pedersen ◽  
Li Wan
Keyword(s):  
Author(s):  
P.J. Benkeser ◽  
E.F. Goff ◽  
W.O. Rice

Author(s):  
Sibo Li ◽  
Wenbin Huang ◽  
Wei-Yi Chang ◽  
Xiaoning Jiang

Ultrasonography is well known as a relatively low cost and non-invasive modality for real-time imaging. In recent years, various high frequency array transducers have been developed and used for ophthalmology, dermatology, and small animal studies. This paper reports the development of a 48-element 40-MHz ultrasonic array using micromachined lead magnesium niobate-lead titanate (PMN-PT) single crystal 1–3 composite material. Array elements with a pitch of 100-micron were interconnected via a customized flexible circuit. Pulse-echo test showed an average center frequency of 40 MHz and a −6 dB fractional bandwidth of 52%. The −20 dB pulse length was evaluated as 120 ns. The electrical and acoustical separation showed the crosstalk less than - 24 dB. An image of a steel wire target phantom was acquired by stacking multiple A-lines. The results demonstrate resolutions exceeding 70 μm axially and 800 μm laterally. Those results imply the great potential of the developed array transducer for the high frequency medical imaging.


1981 ◽  
Vol 3 (4) ◽  
pp. 352-368 ◽  
Author(s):  
J. Fleming Dias

A technique for electrically connecting to the PZT elements in a phased array transducer of a cardiac imaging probe is described. The transducer is a stack consisting of a PZT substrate with metallized faces and is bonded to an acoustic absorber across a thin alumina substrate of proper acoustic impedance. The PZT substrate is sawed into an array of elements and a metal foil with an integrally moulded acoustic lens is bonded to the tops of the elements to form the common ground connection. The transducer stack is enclosed in an alumina box and the electrical connection to the PZT elements is made by silk-screened metallic conductors on the sides of the box. The stack transducer module is enclosed in a two part linen bakelite case which is sealed by injecting silicone rubber. A technique that was used to prepare the surface of the acoustic absorber, which resulted in wide bandwidth transducers, is described. Finally, we show the pulse-echo response of the completed transducer imaging a point target in water.


2006 ◽  
Vol 321-323 ◽  
pp. 501-504 ◽  
Author(s):  
Sung Jin Song ◽  
Joon Soo Park ◽  
Hak Joon Kim ◽  
Un Hak Seong ◽  
Suk Chull Kang ◽  
...  

In this study, the expanded multi-Gaussian beam model is adopted to develop a model to calculate the ultrasonic beam fields radiated from an ultrasonic phased array transducer. Combining this beam model with three other components including time delays, a far-field scattering model and a system efficiency factor, we develop a complete ultrasonic measurement model for predicting the phased array ultrasonic signals that can be captured from a flat-bottom hole in a steel specimen in a pulse-echo set-up using an array transducer mounted in a solid wedge. This paper describes the complete model developed with its key ingredients.


Author(s):  
Thomas M. Moore

In the last decade, a variety of characterization techniques based on acoustic phenomena have come into widespread use. Characteristics of matter waves such as their ability to penetrate optically opaque solids and produce image contrast based on acoustic impedance differences have made these techniques attractive to semiconductor and integrated circuit (IC) packaging researchers.These techniques can be divided into two groups. The first group includes techniques primarily applied to IC package inspection which take advantage of the ability of ultrasound to penetrate deeply and nondestructively through optically opaque solids. C-mode Acoustic Microscopy (C-AM) is a recently developed hybrid technique which combines the narrow-band pulse-echo piezotransducers of conventional C-scan recording with the precision scanning and sophisticated signal analysis capabilities normally associated with the high frequency Scanning Acoustic Microscope (SAM). A single piezotransducer is scanned over the sample and both transmits acoustic pulses into the sample and receives acoustic echo signals from the sample.


2012 ◽  
Vol 2 (5) ◽  
pp. 546-548
Author(s):  
P. Vasantharani P. Vasantharani ◽  
◽  
I.Sankeeda I.Sankeeda

2019 ◽  
Author(s):  
Roman Schlem ◽  
Michael Ghidiu ◽  
Sean Culver ◽  
Anna-Lena Hansen ◽  
Wolfgang Zeier

<p>The lithium argyrodites Li<sub>6</sub>PS<sub>5</sub>X (X = Cl, Br, I) have been gaining momentum as candidates for electrolytes in all-solid-state batteries. While these materials have been well-characterized structurally, the influences of the static and dynamic lattice properties are not fully understood. Recent improvements to the ionic conductivity of Li<sub>6</sub>PS<sub>5</sub>I (which as a parent compound is a poor ionic conductor) via elemental substitutions have shown that a multitude of influences affect the ionic transport in the lithium argyrodites, and that even poor conductors in this class have room left for improvement.</p><p>Here we explore the influence of isoelectronic substitution of sulfur with selenium in Li<sub>6</sub>PS<sub>5-<i>x</i></sub>Se<i><sub>x</sub></i>I. Using a combination of X-ray diffraction, impedance spectroscopy, Raman spectroscopy, and pulse-echo speed of sound measurements,we explore the influence of the static and dynamic lattice on the ionic transport. The substitution of S<sup>2-</sup>with Se<sup>2- </sup>broadens the diffusion pathways and structural bottlenecks, as well as leading to a softer more polarizable lattice, all of which lower the activation barrier and lead to an increase in the ionic conductivity. This work sheds light on ways to systematically understand and improve the functional properties of this exciting material family. </p>


2020 ◽  
pp. 17-27
Author(s):  
А.А. Шелухин

In this article, the analysis of the acoustic path during the ultrasonic pulse echo testing of the rail head in production is carried out. The influence of the parameters of the applied piezoelectric transducers on the distribution of sensitivity for the sounding scheme used in the existing installations is estimated and the real sensitivity of detecting defects of the «non-metallic inclusion» type is estimated.


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