Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49380
I. Schropp, L. Reindl, H. Grassl, R. Weigel
As a design tool for high-precision long broadband SAW (surface acoustic wave) delay lines, a computationally simple model for strip waveguides has been improved by inclusion of parametric fits to measured anisotropy, dispersion, and attenuation of Rayleigh wave propagation both on free and metallized surfaces of LiNbO/sub 3/. A heuristic approach was used to account for the effect of anisotropy in the case of an imaginary transverse propagation constant, and for the observed increased attenuation in waveguides compared to unbounded surfaces. The model does not rely on material properties as computed from fundamental material constants, and uses only one adjustable parameter which is not directly obtained from surface wave measurements. The phase nonlinearly can be predicted with an accuracy up to +or-0.5 degrees / mu s over a relative bandwidth on the order of 50%.<>
{"title":"Accurate prediction of dispersion and attenuation of long metal strip SAW waveguides on anisotropic substrate","authors":"I. Schropp, L. Reindl, H. Grassl, R. Weigel","doi":"10.1109/ULTSYM.1988.49380","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49380","url":null,"abstract":"As a design tool for high-precision long broadband SAW (surface acoustic wave) delay lines, a computationally simple model for strip waveguides has been improved by inclusion of parametric fits to measured anisotropy, dispersion, and attenuation of Rayleigh wave propagation both on free and metallized surfaces of LiNbO/sub 3/. A heuristic approach was used to account for the effect of anisotropy in the case of an imaginary transverse propagation constant, and for the observed increased attenuation in waveguides compared to unbounded surfaces. The model does not rely on material properties as computed from fundamental material constants, and uses only one adjustable parameter which is not directly obtained from surface wave measurements. The phase nonlinearly can be predicted with an accuracy up to +or-0.5 degrees / mu s over a relative bandwidth on the order of 50%.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"364 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133301554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49440
S. Wenzel, B. A. Martin, Richard M. White
Integrated-circuit fabrication techniques were used to make a versatile silicon-based sensor that uses elastic wave propagation in a plate that is thin compared with the wavelength. In-plane tension raises the velocity of the lowest antisymmetric flexural wave (474 m/s) above that predicted for a pure Lamb wave (422 m/s). Because of the low velocity, when in contact with a fluid the device excites an evanescent disturbance that extends just tens of micrometers from the membrane. The device is quite sensitive to loading: contact with a 6- mu l droplet of water shifts the oscillation frequency downward 36%, in excellent agreement with theory. The device could operate as a microphone, biosensor, chemical vapor or gas detector, scale, manometer, densitometer, viscometer, radiometer, or thermometer. It is concluded that the sensor offers unique means for separating out the influences of multiple measurands.<>
{"title":"Generalized Lamb-wave multisensor","authors":"S. Wenzel, B. A. Martin, Richard M. White","doi":"10.1109/ULTSYM.1988.49440","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49440","url":null,"abstract":"Integrated-circuit fabrication techniques were used to make a versatile silicon-based sensor that uses elastic wave propagation in a plate that is thin compared with the wavelength. In-plane tension raises the velocity of the lowest antisymmetric flexural wave (474 m/s) above that predicted for a pure Lamb wave (422 m/s). Because of the low velocity, when in contact with a fluid the device excites an evanescent disturbance that extends just tens of micrometers from the membrane. The device is quite sensitive to loading: contact with a 6- mu l droplet of water shifts the oscillation frequency downward 36%, in excellent agreement with theory. The device could operate as a microphone, biosensor, chemical vapor or gas detector, scale, manometer, densitometer, viscometer, radiometer, or thermometer. It is concluded that the sensor offers unique means for separating out the influences of multiple measurands.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133942882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49489
C. Meyer, E. H. Chiang, D. Fitting, D. M. Williams, A. Buda
In order to assess the potential image quality of catheter-based ultrasonic imaging and its implications for diagnostic as well as therapeutic use, the authors imaged, in vitro, human renal, iliac, and femoral arteries obtained from autopsy. Ultrasonic imaging was performed using 20- and 30-MHz focused disk transducers of 2-mm and 1-mm-diameter active apertures, respectively. Correlative images from a 2-T, high-resolution magnetic resonance imager (MRI), as well as specimen photomicrographs were also taken. Preliminary results suggest that images of diagnostic quality can be routinely obtained, and catheter-based ultrasonic imaging can serve as an effective adjunct to vascular angioplasty and surgery.<>
{"title":"Feasibility and diagnostic value of catheter-based ultrasonic systems for intravascular imaging: in vitro comparisons with MRI","authors":"C. Meyer, E. H. Chiang, D. Fitting, D. M. Williams, A. Buda","doi":"10.1109/ULTSYM.1988.49489","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49489","url":null,"abstract":"In order to assess the potential image quality of catheter-based ultrasonic imaging and its implications for diagnostic as well as therapeutic use, the authors imaged, in vitro, human renal, iliac, and femoral arteries obtained from autopsy. Ultrasonic imaging was performed using 20- and 30-MHz focused disk transducers of 2-mm and 1-mm-diameter active apertures, respectively. Correlative images from a 2-T, high-resolution magnetic resonance imager (MRI), as well as specimen photomicrographs were also taken. Preliminary results suggest that images of diagnostic quality can be routinely obtained, and catheter-based ultrasonic imaging can serve as an effective adjunct to vascular angioplasty and surgery.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132672357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49340
J. Hines, B. Abbott, M. A. West, D. Malocha
The authors describe an innovative technique for determining a two-dimensional impulse response diffraction model for a SAW (surface acoustic wave) device from the wave equation using an impulse driver. The approach presented is unique in that it determines the point-to-point impulse response for the isotropic case using the basic wave equation of motion, and utilizes a double integral reduction technique to determine the tap-to-tap response. This takes into account diffraction effects, and provides an impulse response which is valid for the broadband case. Results of the analysis are presented for both the isotropic and anisotropic case.<>
{"title":"A new approach to broadband SAW diffraction theory","authors":"J. Hines, B. Abbott, M. A. West, D. Malocha","doi":"10.1109/ULTSYM.1988.49340","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49340","url":null,"abstract":"The authors describe an innovative technique for determining a two-dimensional impulse response diffraction model for a SAW (surface acoustic wave) device from the wave equation using an impulse driver. The approach presented is unique in that it determines the point-to-point impulse response for the isotropic case using the basic wave equation of motion, and utilizes a double integral reduction technique to determine the tap-to-tap response. This takes into account diffraction effects, and provides an impulse response which is valid for the broadband case. Results of the analysis are presented for both the isotropic and anisotropic case.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116681144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49359
C.M. Panasik, W.R. Paxman, J. Culver
A digitally controlled programmable transversal filter (DCPTF) has been developed that uses a 32-tap LiNbO/sub 3/ delay line and two LSI GaAs ICs to digitally control tap weight magnitude and sign. Compared to previously reported PTR devices, this third-generation device is significantly reduced in size and power, yet retains state-of-the-art performance. The device is completely programmable, constrained only by the bandwidth (100 MHz centered at 100 MHz) and the number of taps. The DCPTF is designed in 16-tap blocks to easily expand the number of taps. A calibration method is presented which removes nonideal GaAs FET (field-effect transistor) array gain states due to process variations. The on/off ratio of each individual tap is greater than 35 dB. The DCPTF is demonstrated as a bandpass filter with programmable center frequency and bandwidth.<>
{"title":"A 32 tap digitally controlled programmable transversal filter","authors":"C.M. Panasik, W.R. Paxman, J. Culver","doi":"10.1109/ULTSYM.1988.49359","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49359","url":null,"abstract":"A digitally controlled programmable transversal filter (DCPTF) has been developed that uses a 32-tap LiNbO/sub 3/ delay line and two LSI GaAs ICs to digitally control tap weight magnitude and sign. Compared to previously reported PTR devices, this third-generation device is significantly reduced in size and power, yet retains state-of-the-art performance. The device is completely programmable, constrained only by the bandwidth (100 MHz centered at 100 MHz) and the number of taps. The DCPTF is designed in 16-tap blocks to easily expand the number of taps. A calibration method is presented which removes nonideal GaAs FET (field-effect transistor) array gain states due to process variations. The on/off ratio of each individual tap is greater than 35 dB. The DCPTF is demonstrated as a bandpass filter with programmable center frequency and bandwidth.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114916657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49446
M. Yoneyama, S. Watanabe, H. Kitagawa, T. Okamoto, T. Morita
With the goal of recognizing and faithfully reconstructing objects using ultrasonic waves, the authors devised a system which combines existing acoustic holography with neural networks. The merits of this system is its ability to analyze rather vague ultrasonic waves received by an array of receivers and then to faithfully reconstruct the image. The first step in this research has been the recognition of planar objects.<>
{"title":"Neural network recognizing 3-dimensional object through ultrasonic scattering waves","authors":"M. Yoneyama, S. Watanabe, H. Kitagawa, T. Okamoto, T. Morita","doi":"10.1109/ULTSYM.1988.49446","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49446","url":null,"abstract":"With the goal of recognizing and faithfully reconstructing objects using ultrasonic waves, the authors devised a system which combines existing acoustic holography with neural networks. The merits of this system is its ability to analyze rather vague ultrasonic waves received by an array of receivers and then to faithfully reconstruct the image. The first step in this research has been the recognition of planar objects.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122079994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49549
G. L. Bullock, B. Shivaram
The authors propose a novel scheme to achieve focusing of sound waves in superfluid /sup 3/He. This scheme exploits the magnetic field dependence of the superfluid phase diagram and the difference in the sound propagation characteristics of the A- and B-phases. Central to the scheme is the dispersion caused by the sound wave's strong interaction with order-parameter collective modes that exist in the B-phase. Details of a magnet that will be used to achieve such a lens are presented.<>
{"title":"A novel acoustic lens in superfluid /sup 3/He","authors":"G. L. Bullock, B. Shivaram","doi":"10.1109/ULTSYM.1988.49549","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49549","url":null,"abstract":"The authors propose a novel scheme to achieve focusing of sound waves in superfluid /sup 3/He. This scheme exploits the magnetic field dependence of the superfluid phase diagram and the difference in the sound propagation characteristics of the A- and B-phases. Central to the scheme is the dispersion caused by the sound wave's strong interaction with order-parameter collective modes that exist in the B-phase. Details of a magnet that will be used to achieve such a lens are presented.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123226143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49506
C. Cachard, G. Giménez, D. Vray
An effort is made to determine, at each instant, the direction and the magnitude of the velocity of a flow-carried target, provided this target moves within the field monitored by the measuring device. Four transducers (one transmitter and three receivers) are used because the Doppler phenomenon is three-dimensional in the present case. The interaction between the incident ultrasonic wave and the scattering target is modeled by means of a complex envelope. Targets in the form of bubbles injected in the flow are tracked experimentally for a duration of 1 s as they move along a three-dimensional trajectory. This trajectory is reconstructed from velocity results. The proposed 3-D ultrasonic Doppler velocimeter measures the velocity vector and allows reconstruction of the trajectory for targets of 10- mu m minimum size, included in a measurement field of some cubic centimeters, with maximum velocity of some meters per second.<>
{"title":"Ultrasonic Doppler device for measurement of time-dependent and space-dependent flow speed","authors":"C. Cachard, G. Giménez, D. Vray","doi":"10.1109/ULTSYM.1988.49506","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49506","url":null,"abstract":"An effort is made to determine, at each instant, the direction and the magnitude of the velocity of a flow-carried target, provided this target moves within the field monitored by the measuring device. Four transducers (one transmitter and three receivers) are used because the Doppler phenomenon is three-dimensional in the present case. The interaction between the incident ultrasonic wave and the scattering target is modeled by means of a complex envelope. Targets in the form of bubbles injected in the flow are tracked experimentally for a duration of 1 s as they move along a three-dimensional trajectory. This trajectory is reconstructed from velocity results. The proposed 3-D ultrasonic Doppler velocimeter measures the velocity vector and allows reconstruction of the trajectory for targets of 10- mu m minimum size, included in a measurement field of some cubic centimeters, with maximum velocity of some meters per second.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131013000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49550
P. Parent, C. Chou, B. Khuri-Yakub
The authors have developed an amplitude- and phase-measuring acoustic microscope to detect surface defects a few micrometers deep in ceramic ball bearings. The system is capable of measuring phase variation on the order of 1 degrees . The phase detection capability is necessary to detect shallow surface depressions when no crack is present at the bottom of the depression, and the detection of the defect, through V(z) variation, requires operating the system in the gigahertz frequency range. A C-scan system is operational and allows the detection of fissures and gouges, even when shallow. A novel B-scan system has been designed in order to detect smaller cracks and to get full coverage of the bearings.<>
{"title":"Ball bearing inspection with an acoustic microscope","authors":"P. Parent, C. Chou, B. Khuri-Yakub","doi":"10.1109/ULTSYM.1988.49550","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49550","url":null,"abstract":"The authors have developed an amplitude- and phase-measuring acoustic microscope to detect surface defects a few micrometers deep in ceramic ball bearings. The system is capable of measuring phase variation on the order of 1 degrees . The phase detection capability is necessary to detect shallow surface depressions when no crack is present at the bottom of the depression, and the detection of the defect, through V(z) variation, requires operating the system in the gigahertz frequency range. A C-scan system is operational and allows the detection of fissures and gouges, even when shallow. A novel B-scan system has been designed in order to detect smaller cracks and to get full coverage of the bearings.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"25 12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130191497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49353
E. Born, E. Willibald-Riha, K. Hofmann, B. C. Grabmaier, G. Talsky
A method called derivative spectrophotometry of higher-order (DSHO) is proposed for quality control to detect stoichiometry variations in lithium niobate crystals. The measured parameter is the wavelength of the absorption edge, which is strongly affected by the composition of the substrate in terms of the Li/sub 2/O mole fraction. Thus this measurement can be performed with high accuracy of within +or-0.05% and is not influenced by the crystal cut, thickness, and surface finish. It is concluded that this method enables crystal producers and customers of wafers to maintain a high-quality standard of the SAW material with respect to relevant physical properties.<>
{"title":"Detection of non-congruent lithium niobate crystals using the non-destructive derivative spectrophotometry","authors":"E. Born, E. Willibald-Riha, K. Hofmann, B. C. Grabmaier, G. Talsky","doi":"10.1109/ULTSYM.1988.49353","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49353","url":null,"abstract":"A method called derivative spectrophotometry of higher-order (DSHO) is proposed for quality control to detect stoichiometry variations in lithium niobate crystals. The measured parameter is the wavelength of the absorption edge, which is strongly affected by the composition of the substrate in terms of the Li/sub 2/O mole fraction. Thus this measurement can be performed with high accuracy of within +or-0.05% and is not influenced by the crystal cut, thickness, and surface finish. It is concluded that this method enables crystal producers and customers of wafers to maintain a high-quality standard of the SAW material with respect to relevant physical properties.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131012110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：