Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49345
K. Anemogiannis, F. Mueller, W. Ruile, G. Riha
A low-loss surface acoustic wave (SAWs) filter configuration is presented that uses a dual-track configuration with a transducer coupling between the tracks. This filter was developed to obtain a high stopband rejection, small passband ripple, and small size, which is needed in mobile communication systems. A partial finger-splitting and an optimized binary withdrawal weighting were also incorporated into the design together with a nonresonant unidirectional configuration. Filters at 450 MHz were fabricated on 36 degrees rotYX-LiTaO/sub 3/ using a simple single-layer technology. An insertion loss of 3 to 4 dB was achieved over a bandwidth of 6.5 MHz with a passband ripple of less than +or-0.5 dB. The stopband rejection is better than 50 dB.<>
{"title":"High performance low-loss SAW filters for mobile radio with improved stopband rejection","authors":"K. Anemogiannis, F. Mueller, W. Ruile, G. Riha","doi":"10.1109/ULTSYM.1988.49345","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49345","url":null,"abstract":"A low-loss surface acoustic wave (SAWs) filter configuration is presented that uses a dual-track configuration with a transducer coupling between the tracks. This filter was developed to obtain a high stopband rejection, small passband ripple, and small size, which is needed in mobile communication systems. A partial finger-splitting and an optimized binary withdrawal weighting were also incorporated into the design together with a nonresonant unidirectional configuration. Filters at 450 MHz were fabricated on 36 degrees rotYX-LiTaO/sub 3/ using a simple single-layer technology. An insertion loss of 3 to 4 dB was achieved over a bandwidth of 6.5 MHz with a passband ripple of less than +or-0.5 dB. The stopband rejection is better than 50 dB.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"53 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":"131493569","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.1988.49454
D. H. Turnbull, M. Sherar, F. Foster
An important problem in transducer design is the accurate determination of electromechanical coupling coefficients for piezoelectric materials. The authors report on novel methods for determining both k/sub t/ the thickness mode coefficient, and k/sub 31/, an important parameter for transducer arrays. The coupling coefficients are computed near piezoelectric resonances using Krimholtz-Leedom-Matthaei (KLM) equivalent circuit models. These models have been modified to account for the mechanical losses of the material through an effective attenuation coefficient which can be estimated independently of the coupling coefficient. This measurement theory is applied to three different transducer materials: PVDF (polyvinylidene fluoride), PZT5A and a PZT (lead zinc titanate)/epoxy composite.<>
{"title":"Determination of electromechanical coupling coefficients in transducer materials with high mechanical losses","authors":"D. H. Turnbull, M. Sherar, F. Foster","doi":"10.1109/ULTSYM.1988.49454","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49454","url":null,"abstract":"An important problem in transducer design is the accurate determination of electromechanical coupling coefficients for piezoelectric materials. The authors report on novel methods for determining both k/sub t/ the thickness mode coefficient, and k/sub 31/, an important parameter for transducer arrays. The coupling coefficients are computed near piezoelectric resonances using Krimholtz-Leedom-Matthaei (KLM) equivalent circuit models. These models have been modified to account for the mechanical losses of the material through an effective attenuation coefficient which can be estimated independently of the coupling coefficient. This measurement theory is applied to three different transducer materials: PVDF (polyvinylidene fluoride), PZT5A and a PZT (lead zinc titanate)/epoxy composite.<<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":"126293826","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.1988.49491
M. Holland, J.G. Miller
A two-dimensional receiving array was used to measure both phase-insensitively and phase-sensitively the average power and power spectrum of a backscattered (160 degrees ) ultrasonic field. The effects of introducing phase-distorting media in front of the receiving array on the phase-insensitively and phase-sensitively derived quantitative energy measurements were investigated under conditions of planar, spherical, and correlation focusing. A transmitting transducer was found at the surface of a glass-bead phantom and a two-dimensional pseudoarray receiver was achieved by translating an apodized planar transducer in a 13*13 grid pattern. Phase-insensitive determination of average power exhibited a maximum 0.9-dB variation for measurements made with all combinations of phase-distorting media and focusing schemes, whereas the corresponding phase-sensitively derived values varied by as much as 9.4 dB.<>
{"title":"Phase-insensitive and phase-sensitive quantitative imaging of scattered ultrasound using a two-dimensional pseudo-array","authors":"M. Holland, J.G. Miller","doi":"10.1109/ULTSYM.1988.49491","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49491","url":null,"abstract":"A two-dimensional receiving array was used to measure both phase-insensitively and phase-sensitively the average power and power spectrum of a backscattered (160 degrees ) ultrasonic field. The effects of introducing phase-distorting media in front of the receiving array on the phase-insensitively and phase-sensitively derived quantitative energy measurements were investigated under conditions of planar, spherical, and correlation focusing. A transmitting transducer was found at the surface of a glass-bead phantom and a two-dimensional pseudoarray receiver was achieved by translating an apodized planar transducer in a 13*13 grid pattern. Phase-insensitive determination of average power exhibited a maximum 0.9-dB variation for measurements made with all combinations of phase-distorting media and focusing schemes, whereas the corresponding phase-sensitively derived values varied by as much as 9.4 dB.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"8 10 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":"130355995","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.1988.49475
A. Korpel, D. Mehrl
The authors propose, analyze, and demonstrate a Bragg diffraction imaging system that is predominantly anastigmatic in that is relies on only one weakly correcting cylinder lens in an easily adjustable, noncritical position. It is showing that the proposed system constitutes a simple and effective means of ultrasonic imaging if aspect ratio distortion is not of primary importance.<>
{"title":"Bragg diffraction imaging with predominantly spherical lenses","authors":"A. Korpel, D. Mehrl","doi":"10.1109/ULTSYM.1988.49475","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49475","url":null,"abstract":"The authors propose, analyze, and demonstrate a Bragg diffraction imaging system that is predominantly anastigmatic in that is relies on only one weakly correcting cylinder lens in an easily adjustable, noncritical position. It is showing that the proposed system constitutes a simple and effective means of ultrasonic imaging if aspect ratio distortion is not of primary importance.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"39 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":"129600387","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.1988.49358
B. Schmukler, M. Hoskins
The ACT (acoustic charge transfer) current capacity for a fixed transfer inefficiency is fount to decrease linearly with applied barrier field in good agreement with an empirical model based on one-dimensional theory. In the absence of barrier fields, a residual current capacity loss is observed which ranges from 10-14% of the extrapolated unperturbed current capacity and increases with decreasing SAW (surface acoustic wave) potential. The frequency-response roll-of for a fixed current level is undetectable below a threshold barrier field and increases exponentially with barrier field above the threshold. In addition, the diffusion barrier height reduction between adjacent SAW potential wells is experimentally found to be linear with respect to applied barrier field and independent of current level. Finally, a means to estimate the impact of grating structures and gaps between Schottky plates on current capacity is given.<>
{"title":"Barrier induced transfer inefficiency and current limiting in acoustic charge transport devices","authors":"B. Schmukler, M. Hoskins","doi":"10.1109/ULTSYM.1988.49358","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49358","url":null,"abstract":"The ACT (acoustic charge transfer) current capacity for a fixed transfer inefficiency is fount to decrease linearly with applied barrier field in good agreement with an empirical model based on one-dimensional theory. In the absence of barrier fields, a residual current capacity loss is observed which ranges from 10-14% of the extrapolated unperturbed current capacity and increases with decreasing SAW (surface acoustic wave) potential. The frequency-response roll-of for a fixed current level is undetectable below a threshold barrier field and increases exponentially with barrier field above the threshold. In addition, the diffusion barrier height reduction between adjacent SAW potential wells is experimentally found to be linear with respect to applied barrier field and independent of current level. Finally, a means to estimate the impact of grating structures and gaps between Schottky plates on current capacity is given.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"40 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":"133066584","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.1988.49515
K. Hynynen
The current ultrasound techniques for inducing elevated temperatures in malignant tumors are reviewed. Emphasis is placed on the mechanically scanned and focused systems that are presently under clinical evaluation. Some of the clinical results are reviewed, and the potential and limitations of ultrasound as a clinical tool for hyperthermia induction are evaluated on the basis of clinical experience. In addition, some of the future technical possibilities are discussed.<>
{"title":"Present status of ultrasound hyperthermia","authors":"K. Hynynen","doi":"10.1109/ULTSYM.1988.49515","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49515","url":null,"abstract":"The current ultrasound techniques for inducing elevated temperatures in malignant tumors are reviewed. Emphasis is placed on the mechanically scanned and focused systems that are presently under clinical evaluation. Some of the clinical results are reviewed, and the potential and limitations of ultrasound as a clinical tool for hyperthermia induction are evaluated on the basis of clinical experience. In addition, some of the future technical possibilities are discussed.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"1 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":"130271790","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.1988.49371
P. Edmonson, C. Campbell, S. F. Yuen
A theoretical and experimental study of pulse expansion and compression is reported for a 100-MHz SAW (surface acoustic wave) quadraphase code generator with 1250 IDT (interdigital transducer) fingers on ST-quartz as derived from a combined 5*5 Barker sequence. Techniques are also examined for increasing the peak-to-sidelobe ratio of the compressed pulse, using a series SAW suppression filter whose IDT apodization is derived from the inverse spectral ripple factor of the combined Barker code.<>
{"title":"Study of SAW pulse compression using 5*5 Barker codes with quadraphase IDT geometries","authors":"P. Edmonson, C. Campbell, S. F. Yuen","doi":"10.1109/ULTSYM.1988.49371","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49371","url":null,"abstract":"A theoretical and experimental study of pulse expansion and compression is reported for a 100-MHz SAW (surface acoustic wave) quadraphase code generator with 1250 IDT (interdigital transducer) fingers on ST-quartz as derived from a combined 5*5 Barker sequence. Techniques are also examined for increasing the peak-to-sidelobe ratio of the compressed pulse, using a series SAW suppression filter whose IDT apodization is derived from the inverse spectral ripple factor of the combined Barker code.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"36 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113986259","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.1988.49496
O. Bonnefous
The basic elements of the wavelet representation are described. Each step of the decomposition corresponds to a certain scale analysis. It is then possible to select the significative objects before the recomposition of the signal. Thus objects with different sizes can be distinguished. If the speckle of an echographic image and its associated signal-to-noise ratio are known, the speckle can be removed after a comparison with the level of the component corresponding to the speckle size. For different scales, the components may correspond to anatomic objects, texture, or edges. The differentiation of these objects can produce images (after reconstruction) where only the useful information is present. Extended to 2D functions and applied to echographic images, this decomposition-segmentation-recomposition process extracts objects in the axial and transverse directions. The resulting images give a good representation of objects without any loss of resolution, since the speckle is well removed.<>
{"title":"Wavelet decomposition and recomposition of echographic images","authors":"O. Bonnefous","doi":"10.1109/ULTSYM.1988.49496","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49496","url":null,"abstract":"The basic elements of the wavelet representation are described. Each step of the decomposition corresponds to a certain scale analysis. It is then possible to select the significative objects before the recomposition of the signal. Thus objects with different sizes can be distinguished. If the speckle of an echographic image and its associated signal-to-noise ratio are known, the speckle can be removed after a comparison with the level of the component corresponding to the speckle size. For different scales, the components may correspond to anatomic objects, texture, or edges. The differentiation of these objects can produce images (after reconstruction) where only the useful information is present. Extended to 2D functions and applied to echographic images, this decomposition-segmentation-recomposition process extracts objects in the axial and transverse directions. The resulting images give a good representation of objects without any loss of resolution, since the speckle is well removed.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"33 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":"114934833","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.1988.49450
T. Nakamoto, T. Moriizumi
An experiment of odor identification using a neural network is described. A quartz-resonator array with different coating films was used, and its output pattern was recognized using a neural network. Various odors of commercially available liquors were identifiable by the network following training. The sensing system was adaptive to environmental variations during the cyclic process of the data sampling and training. High recognition probability was maintained even under temperature variations.<>
{"title":"Odor sensor using quartz-resonator array and neural-network pattern recognition","authors":"T. Nakamoto, T. Moriizumi","doi":"10.1109/ULTSYM.1988.49450","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49450","url":null,"abstract":"An experiment of odor identification using a neural network is described. A quartz-resonator array with different coating films was used, and its output pattern was recognized using a neural network. Various odors of commercially available liquors were identifiable by the network following training. The sensing system was adaptive to environmental variations during the cyclic process of the data sampling and training. High recognition probability was maintained even under temperature variations.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"26 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":"128668949","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.1988.49513
D. Cathignol, J. Chapelon, V. Newhouse, M. Shankar
The authors propose a novel method for bubble sizing, based on the double frequency technique, in which f/sub i/ (the imaging frequency) is pulsed at a frequency f/sub r/. The received signal from a range cell at a given depth is processed in the same way as in a conventional pulsed Doppler velocimeter. In most cases the pump frequency f/sub p/ is greater than f/sub r/, and the demodulated signal is undersampled. If f/sub p/ is different from nf/sub r/, it is shown by min mod f/sub p/+or-nf/sub r/ mod that the longitudinal resolution and the lateral resolution are the same as in conventional Doppler flowmeters (less than 1 mm), and that the measurement of the bubble size is not affected by the pulsed field.<>
{"title":"Bubble sizing with a high spatial resolution","authors":"D. Cathignol, J. Chapelon, V. Newhouse, M. Shankar","doi":"10.1109/ULTSYM.1988.49513","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49513","url":null,"abstract":"The authors propose a novel method for bubble sizing, based on the double frequency technique, in which f/sub i/ (the imaging frequency) is pulsed at a frequency f/sub r/. The received signal from a range cell at a given depth is processed in the same way as in a conventional pulsed Doppler velocimeter. In most cases the pump frequency f/sub p/ is greater than f/sub r/, and the demodulated signal is undersampled. If f/sub p/ is different from nf/sub r/, it is shown by min mod f/sub p/+or-nf/sub r/ mod that the longitudinal resolution and the lateral resolution are the same as in conventional Doppler flowmeters (less than 1 mm), and that the measurement of the bubble size is not affected by the pulsed field.<<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":"133824819","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}
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