Pub Date : 1999-10-17DOI: 10.1109/ULTSYM.1999.849484
Seung-Hee Lee, Y. Roh, Woo-Seok Han, Yeon-Bo Kim
This paper describes development of a new ultrasonic traveling wave motor of a quite simple structure that can move bi-directionally in both self moving and non-self moving modes. With the finite element method, we design and verify validity of the new structure, and determine its optimal structure and boundary conditions for proper generation of the traveling wave. Based on the results, a prototype of the motor is fabricated and characterized, which thereby proves practical applicability of the new structure.
{"title":"Design and fabrication of ultrasonic traveling wave bi-directional linear motors","authors":"Seung-Hee Lee, Y. Roh, Woo-Seok Han, Yeon-Bo Kim","doi":"10.1109/ULTSYM.1999.849484","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849484","url":null,"abstract":"This paper describes development of a new ultrasonic traveling wave motor of a quite simple structure that can move bi-directionally in both self moving and non-self moving modes. With the finite element method, we design and verify validity of the new structure, and determine its optimal structure and boundary conditions for proper generation of the traveling wave. Based on the results, a prototype of the motor is fabricated and characterized, which thereby proves practical applicability of the new structure.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133497320","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849487
Chunsheng Zhao, Guiqin Wang, Long Jin
This paper developed a new type of self-correction ultrasonic motor using standing wave. It differs from current self-correction ultrasonic motors in driving and control method. In operating stage of self-correction, the slits on rotor of the motor stay always at the projection teeth on the stator when two signals applied simultaneously to piezoelectric element which is adhered to stator are in phase for the new type of self-correction motor, but in opposite phase for current types of self-correction motor. It is notable that the projection teeth are located on the crests and troughs of a vibration mode of the stator for the new self-correction motor, but on the nodal diameters of a vibration mode of stator for current types. The experiments have shown that the self-correction function of the new type of self-correction motor is stronger than that of current types of self-correction motor. The rotation mechanism of the new type of self-correction motor is described in the paper.
{"title":"A new type of self-correction ultrasonic motor using standing wave","authors":"Chunsheng Zhao, Guiqin Wang, Long Jin","doi":"10.1109/ULTSYM.1999.849487","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849487","url":null,"abstract":"This paper developed a new type of self-correction ultrasonic motor using standing wave. It differs from current self-correction ultrasonic motors in driving and control method. In operating stage of self-correction, the slits on rotor of the motor stay always at the projection teeth on the stator when two signals applied simultaneously to piezoelectric element which is adhered to stator are in phase for the new type of self-correction motor, but in opposite phase for current types of self-correction motor. It is notable that the projection teeth are located on the crests and troughs of a vibration mode of the stator for the new self-correction motor, but on the nodal diameters of a vibration mode of stator for current types. The experiments have shown that the self-correction function of the new type of self-correction motor is stronger than that of current types of self-correction motor. The rotation mechanism of the new type of self-correction motor is described in the paper.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133516816","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849352
S. Doberstein, V. Malyukhov, V. Razgonyaev
This paper presents wideband three-transducer SAW filters using unidirectional IDTs on U-shaped MSCs. In the filters a self-matching effect is used when a static capacitance of an IDT is compensated by an acoustic radiation susceptance. 30-70 MHz filters on 128° YX, 64° YX, 41° YX LiNbO3 have shown an insertion loss of 1 dB, 3-dB fractional bandwidth of 3.5-10% with low ripple of 0.1 dB, stopband attenuation of 10-15 dB. 165, 169 MHz SAW filters for the front-end stages of mobile transceivers have shown an insertion loss of 1-1.8 dB, 3-dB bandwidth of 5.7-11 MHz with a ripple of 0.2 dB, stopband attenuation of 12-40 dB. The filters did not require matching networks, were mounted in the SMD packages (5×5×1.8 mm).
{"title":"Wideband three-transducer SAW filters using unidirectional IDTs on U-shaped MSCs with insertion loss of 1 dB","authors":"S. Doberstein, V. Malyukhov, V. Razgonyaev","doi":"10.1109/ULTSYM.1999.849352","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849352","url":null,"abstract":"This paper presents wideband three-transducer SAW filters using unidirectional IDTs on U-shaped MSCs. In the filters a self-matching effect is used when a static capacitance of an IDT is compensated by an acoustic radiation susceptance. 30-70 MHz filters on 128° YX, 64° YX, 41° YX LiNbO3 have shown an insertion loss of 1 dB, 3-dB fractional bandwidth of 3.5-10% with low ripple of 0.1 dB, stopband attenuation of 10-15 dB. 165, 169 MHz SAW filters for the front-end stages of mobile transceivers have shown an insertion loss of 1-1.8 dB, 3-dB bandwidth of 5.7-11 MHz with a ripple of 0.2 dB, stopband attenuation of 12-40 dB. The filters did not require matching networks, were mounted in the SMD packages (5×5×1.8 mm).","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132293592","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849496
Lin Fa, J. Castagna, J. Hovem
By utilizing the concepts of the radiation resistance and radiation quality of harmonic vibration, both the effective force of surrounding coupling fluid on a thin spherical shell transducer during excitation by a driving-voltage signal and its transient response function can be determined by developing an equivalent circuit. The transducer acts like an electrical-acoustic filter. The properties of both driving-voltage signal and the transducer determine that of the radiated acoustic signal.
{"title":"Derivation and simulation of source function for acoustic logging","authors":"Lin Fa, J. Castagna, J. Hovem","doi":"10.1109/ULTSYM.1999.849496","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849496","url":null,"abstract":"By utilizing the concepts of the radiation resistance and radiation quality of harmonic vibration, both the effective force of surrounding coupling fluid on a thin spherical shell transducer during excitation by a driving-voltage signal and its transient response function can be determined by developing an equivalent circuit. The transducer acts like an electrical-acoustic filter. The properties of both driving-voltage signal and the transducer determine that of the radiated acoustic signal.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114356760","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849519
R. Addison, A. Mckie
Laser-based ultrasound offers the capability for performing ultrasonic inspections in remote and limited access areas by coupling the lasers through optical fibers. The key factors needed for successfully implementing a fiber-based remote and limited access LBU system will be described. We report on design tradeoffs and preliminary experiments that have been conducted with a fiber-based inspection system.
{"title":"System considerations for remote and limited access laser-based ultrasound","authors":"R. Addison, A. Mckie","doi":"10.1109/ULTSYM.1999.849519","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849519","url":null,"abstract":"Laser-based ultrasound offers the capability for performing ultrasonic inspections in remote and limited access areas by coupling the lasers through optical fibers. The key factors needed for successfully implementing a fiber-based remote and limited access LBU system will be described. We report on design tradeoffs and preliminary experiments that have been conducted with a fiber-based inspection system.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114359462","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849218
J. Lazenby, D.-L.D. Liu
2D arrays and parallel beamforming are useful technologies for 3D scanning. 2D arrays are also considered to be valuable for phase aberration correction. However, many researchers have investigated sparse 2D arrays to limit the number of needed beamforming channels. Therefore, the authors investigate whether sparse 2D arrays and parallel beamforming are compatible with cross correlation based phase aberration estimates. The van Cittert-Zernike theorem is applied to some models of transmit apertures for random and periodic sparse arrays and parallel beamforming. The theoretical results show that these approaches all degrade the performance of the cross correlation phase aberration estimator. The theoretical results are compared to experimental data from sparse 1D arrays, as well as measurements from a broad transmit beam suitable for parallel beam formation. The experimental measurements confirm the theoretical predictions.
{"title":"Cross correlation phase aberration estimates with sparse arrays and parallel beamforming","authors":"J. Lazenby, D.-L.D. Liu","doi":"10.1109/ULTSYM.1999.849218","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849218","url":null,"abstract":"2D arrays and parallel beamforming are useful technologies for 3D scanning. 2D arrays are also considered to be valuable for phase aberration correction. However, many researchers have investigated sparse 2D arrays to limit the number of needed beamforming channels. Therefore, the authors investigate whether sparse 2D arrays and parallel beamforming are compatible with cross correlation based phase aberration estimates. The van Cittert-Zernike theorem is applied to some models of transmit apertures for random and periodic sparse arrays and parallel beamforming. The theoretical results show that these approaches all degrade the performance of the cross correlation phase aberration estimator. The theoretical results are compared to experimental data from sparse 1D arrays, as well as measurements from a broad transmit beam suitable for parallel beam formation. The experimental measurements confirm the theoretical predictions.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114377401","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849448
H. Fang, Jia-shi Yang, Q. Jiang
This paper represents an analysis of surface waves propagating in rotating piezoelectric solids. The analysis shows that the effect of rotation on wave speed may be of first- or second-order of the rotation rate, depending on the propagation direction and the orientation of the material. For certain materials there exist two surface waves corresponding to the Rayleigh wave and the Bleustein-Gulyaev wave. For some other materials there exists one surface wave only.
{"title":"Gyroscopic effect on surface waves in piezoelectrics","authors":"H. Fang, Jia-shi Yang, Q. Jiang","doi":"10.1109/ULTSYM.1999.849448","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849448","url":null,"abstract":"This paper represents an analysis of surface waves propagating in rotating piezoelectric solids. The analysis shows that the effect of rotation on wave speed may be of first- or second-order of the rotation rate, depending on the propagation direction and the orientation of the material. For certain materials there exist two surface waves corresponding to the Rayleigh wave and the Bleustein-Gulyaev wave. For some other materials there exists one surface wave only.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114744867","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849280
Jcirgen Arendt Jensen, Isabel Rodriguez Lacasa
Modern ultrasound scanners estimate the blood velocity by tracking the movement of the blood scatterers along the ultrasound beam. This is done by emitting pulsed ultrasound fields and finding the shift in position from pulse to pulse by correlating the received signals. Only the velocity component along the beam direction is found, and this is a serious limitation in the current scanners, since most blood vessels are parallel to the skin surface. A method to find the velocity across the vessel has been suggested by Bonnefous (1988). Here a number of parallel receive beams are measured and used in a correlation estimator to find the velocity across the beam. This approach is extended in this paper by making beamforming along the direction of the flow. A fairly broad beam is emitted and the received signal is then focused along a selected direction. This direction can be along the ultrasound beam or across it or in any direction to the beam. The focused lines, thus, follow the flow and a cross-correlation of lines from different pulses can find the movement of the blood particles between pulse emissions and, thus, the blood velocity. The new approach is investigated using the Field II simulation program. Simulations are shown for a parabolic velocity profile for flow-to-beam angles of 30, 45, 60, and 90 degrees using a 64 elements linear array with a center frequency of 3 MHz, a pitch of 0.3 mm, and an element height of 5 mm. The peak velocity in the parabolic flow was 0.5 m/s, and the pulse repetition frequency was 3.5 kHz. Using four pulse-echo lines, the parabolic flow profile was found with a standard deviation of 0.028 m/s at 60 degrees and 0.092 m/s at 90 degrees (transverse to the ultrasound beam), corresponding to accuracies of 5.6% and 18.4%. Using ten lines gave standard deviations of 0.021 m/s and 0.089 m/s, respectively, corresponding to accuracies of 4.2% and 17.8%.
{"title":"Estimation of blood velocity vectors using transverse ultrasound beam focusing and cross-correlation","authors":"Jcirgen Arendt Jensen, Isabel Rodriguez Lacasa","doi":"10.1109/ULTSYM.1999.849280","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849280","url":null,"abstract":"Modern ultrasound scanners estimate the blood velocity by tracking the movement of the blood scatterers along the ultrasound beam. This is done by emitting pulsed ultrasound fields and finding the shift in position from pulse to pulse by correlating the received signals. Only the velocity component along the beam direction is found, and this is a serious limitation in the current scanners, since most blood vessels are parallel to the skin surface. A method to find the velocity across the vessel has been suggested by Bonnefous (1988). Here a number of parallel receive beams are measured and used in a correlation estimator to find the velocity across the beam. This approach is extended in this paper by making beamforming along the direction of the flow. A fairly broad beam is emitted and the received signal is then focused along a selected direction. This direction can be along the ultrasound beam or across it or in any direction to the beam. The focused lines, thus, follow the flow and a cross-correlation of lines from different pulses can find the movement of the blood particles between pulse emissions and, thus, the blood velocity. The new approach is investigated using the Field II simulation program. Simulations are shown for a parabolic velocity profile for flow-to-beam angles of 30, 45, 60, and 90 degrees using a 64 elements linear array with a center frequency of 3 MHz, a pitch of 0.3 mm, and an element height of 5 mm. The peak velocity in the parabolic flow was 0.5 m/s, and the pulse repetition frequency was 3.5 kHz. Using four pulse-echo lines, the parabolic flow profile was found with a standard deviation of 0.028 m/s at 60 degrees and 0.092 m/s at 90 degrees (transverse to the ultrasound beam), corresponding to accuracies of 5.6% and 18.4%. Using ten lines gave standard deviations of 0.021 m/s and 0.089 m/s, respectively, corresponding to accuracies of 4.2% and 17.8%.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117074518","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849301
D. Kouamé, J. Girault, A. Ouahabi, F. Patat
Cerebral emboli detection is a problem of considerable practical importance for monitoring vascular pathologies. If in most practical in vivo or in vitro experiments, big-size emboli detection seems comfortable, small-size emboli detection remains a challenge. The aim of this paper is to evaluate the performances of micro-emboli detections using statistical tools. The authors first introduce for this purpose a specific decision information through Autoregressive (AR) modeling. To overcome the problem of empirical detection threshold choice and quantify the reliability of the emboli detection, the chosen decision information makes it possible to link the threshold with the probability of false alarm (PFA). The authors then extend this approach to classical detection methods based on nonparametric analysis in order to perform comparisons, by using computer simulation of embolic signal. It is shown that reliable detection is not possible by the classical approaches when the Embolus-to-Blood Ratio (EBR) is lower than 10 dB since in this case the PFA is by far above 10%, whereas the authors' approach can detect small-size emboli with EBR as low as 5 dB since the PFA is then below 5%. In vivo measurements are finally performed in order to validate the authors' approach.
{"title":"Reliability evaluation of emboli detection using a statistical approach","authors":"D. Kouamé, J. Girault, A. Ouahabi, F. Patat","doi":"10.1109/ULTSYM.1999.849301","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849301","url":null,"abstract":"Cerebral emboli detection is a problem of considerable practical importance for monitoring vascular pathologies. If in most practical in vivo or in vitro experiments, big-size emboli detection seems comfortable, small-size emboli detection remains a challenge. The aim of this paper is to evaluate the performances of micro-emboli detections using statistical tools. The authors first introduce for this purpose a specific decision information through Autoregressive (AR) modeling. To overcome the problem of empirical detection threshold choice and quantify the reliability of the emboli detection, the chosen decision information makes it possible to link the threshold with the probability of false alarm (PFA). The authors then extend this approach to classical detection methods based on nonparametric analysis in order to perform comparisons, by using computer simulation of embolic signal. It is shown that reliable detection is not possible by the classical approaches when the Embolus-to-Blood Ratio (EBR) is lower than 10 dB since in this case the PFA is by far above 10%, whereas the authors' approach can detect small-size emboli with EBR as low as 5 dB since the PFA is then below 5%. In vivo measurements are finally performed in order to validate the authors' approach.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116102021","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849361
J. Knuuttila, J. Koskela, P. Tikka, M. Salomaa, C. Hartmann, V. Plessky
We discuss an acoustic loss mechanism in leaky surface-acoustic wave resonators on 36°YX-cut lithium tantalate substrate. Our recent acoustic field scans performed with an optical Michelson interferometer revealed a spatially asymmetric acoustic field atop the busbars of a resonator, giving rise to acoustic beams which escape the resonator area and lead to undesired losses. Here, we link the phenomenon with the inherent crystalline anisotropy of the substrate crystal: the shape of the slowness curves and the asymmetry of the polarization for the leaky surface-acoustic waves propagating at an angle with respect to the crystal X-axis.
{"title":"Asymmetric acoustic radiation in leaky SAW resonators on lithium tantalate","authors":"J. Knuuttila, J. Koskela, P. Tikka, M. Salomaa, C. Hartmann, V. Plessky","doi":"10.1109/ULTSYM.1999.849361","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849361","url":null,"abstract":"We discuss an acoustic loss mechanism in leaky surface-acoustic wave resonators on 36°YX-cut lithium tantalate substrate. Our recent acoustic field scans performed with an optical Michelson interferometer revealed a spatially asymmetric acoustic field atop the busbars of a resonator, giving rise to acoustic beams which escape the resonator area and lead to undesired losses. Here, we link the phenomenon with the inherent crystalline anisotropy of the substrate crystal: the shape of the slowness curves and the asymmetry of the polarization for the leaky surface-acoustic waves propagating at an angle with respect to the crystal X-axis.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"218 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115525813","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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