Pub Date : 1997-10-05DOI: 10.1109/ULTSYM.1997.663083
Q.M. Zhang, X. Geng
A model is derived for the analysis of the dynamic behavior of 1-3 piezocomposites. Based on this model, the effective parameters and their dependence on the aspect ratio of the unit cell of a 1-3 composite, can be evaluated. From the model we show that the mechanical quality factor of a composite can be lower than that of both the ceramic and polymer. The predictions are compared with experimental results and the agreement between the two is quite satisfactory.
{"title":"Acoustic and electromechanical behavior of 1-3 piezocomposites for ultrasonic transducer applications","authors":"Q.M. Zhang, X. Geng","doi":"10.1109/ULTSYM.1997.663083","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.663083","url":null,"abstract":"A model is derived for the analysis of the dynamic behavior of 1-3 piezocomposites. Based on this model, the effective parameters and their dependence on the aspect ratio of the unit cell of a 1-3 composite, can be evaluated. From the model we show that the mechanical quality factor of a composite can be lower than that of both the ceramic and polymer. The predictions are compared with experimental results and the agreement between the two is quite satisfactory.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"20 1","pages":"557-560 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76044228","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 : 1997-10-05DOI: 10.1109/ULTSYM.1997.663014
E. Henry, S. Ballandras, E. Bigler, G. Marianneau, G. Martin, S. Camou
Most Surface Acoustic Wave (SAW) devices exhibit a very small sensitivity to thermal effects. However, even on instrinsically compensated crystal cuts, the deposition of metal strips at the surface (transducers or reflectors) induces important changes in the thermoelastic properties of the device. A theoretical approach based on the Sinha-Tiersten perturbation method is proposed to model the influence of metallization on SAW properties on (ST,X) quartz, namely the temperature stability of the phase velocity of Rayleigh waves. Since this perturbation method only gives access to the first order Temperature Coefficient of Frequency (TCF), it is combined with a conventional calculation of the second order TCF to predict the evolution of the turnover temperature. The proposed calculation also requires temperature derivatives of the elastic constants of the metal which can be calculated for different materials. More classical approaches are also considered based on the calculation of surface permittivity using thermally varied elastic constants. Finally, theoretical results are compared to experimental data measured on SAW devices on (ST,X) quartz using Aluminium, Gold or Chromium gratings.
{"title":"Influence of metallization on temperature stability of SAW devices","authors":"E. Henry, S. Ballandras, E. Bigler, G. Marianneau, G. Martin, S. Camou","doi":"10.1109/ULTSYM.1997.663014","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.663014","url":null,"abstract":"Most Surface Acoustic Wave (SAW) devices exhibit a very small sensitivity to thermal effects. However, even on instrinsically compensated crystal cuts, the deposition of metal strips at the surface (transducers or reflectors) induces important changes in the thermoelastic properties of the device. A theoretical approach based on the Sinha-Tiersten perturbation method is proposed to model the influence of metallization on SAW properties on (ST,X) quartz, namely the temperature stability of the phase velocity of Rayleigh waves. Since this perturbation method only gives access to the first order Temperature Coefficient of Frequency (TCF), it is combined with a conventional calculation of the second order TCF to predict the evolution of the turnover temperature. The proposed calculation also requires temperature derivatives of the elastic constants of the metal which can be calculated for different materials. More classical approaches are also considered based on the calculation of surface permittivity using thermally varied elastic constants. Finally, theoretical results are compared to experimental data measured on SAW devices on (ST,X) quartz using Aluminium, Gold or Chromium gratings.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"286 1","pages":"221-225 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77149309","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 : 1997-10-05DOI: 10.1109/ULTSYM.1997.663306
K. Erikson, A. Hairston, A. Nicoli, J. Stockwell, T. White
Ultrasonic imaging in the low MHz frequency range with large, dense arrays presents many design and fabrication challenges. Conventional ultrasound systems use micro-coaxial cable to connect the array to the front end electronics. While coax technology has improved dramatically in the past decade, interconnecting 16384 array elements with separate wires remains a formidable challenge. In addition to this practical issue, the capacitance of a long coaxial cable (/spl sim/40 pF/m) is much larger than that of a typical 2D array element (<1 pF), creating a voltage divider that severely reduces the signal-to-noise ratio of the channel. A 2D composite piezoelectric receiver array bonded directly to four large custom integrated circuits is described. This 128/spl times/128 (16384 total) element Transducer Hybrid Array (THA) of 200 /spl mu/m unit cell spacing is intended for a 3D real-time imaging system for medical and underwater applications. By reducing the interconnect length to less than 20 /spl mu/m, cable capacitance is no longer a problem. Massively parallel, on-chip signal processing enables true real-time three-dimensional imaging. Favorable tradeoffs using composite piezoelectric materials, enabled by this high-density flip-chip interconnection technology are discussed.
{"title":"A 128/spl times/128 ultrasonic transducer hybrid array","authors":"K. Erikson, A. Hairston, A. Nicoli, J. Stockwell, T. White","doi":"10.1109/ULTSYM.1997.663306","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.663306","url":null,"abstract":"Ultrasonic imaging in the low MHz frequency range with large, dense arrays presents many design and fabrication challenges. Conventional ultrasound systems use micro-coaxial cable to connect the array to the front end electronics. While coax technology has improved dramatically in the past decade, interconnecting 16384 array elements with separate wires remains a formidable challenge. In addition to this practical issue, the capacitance of a long coaxial cable (/spl sim/40 pF/m) is much larger than that of a typical 2D array element (<1 pF), creating a voltage divider that severely reduces the signal-to-noise ratio of the channel. A 2D composite piezoelectric receiver array bonded directly to four large custom integrated circuits is described. This 128/spl times/128 (16384 total) element Transducer Hybrid Array (THA) of 200 /spl mu/m unit cell spacing is intended for a 3D real-time imaging system for medical and underwater applications. By reducing the interconnect length to less than 20 /spl mu/m, cable capacitance is no longer a problem. Massively parallel, on-chip signal processing enables true real-time three-dimensional imaging. Favorable tradeoffs using composite piezoelectric materials, enabled by this high-density flip-chip interconnection technology are discussed.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"115 1","pages":"1625-1629 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79192557","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 : 1997-10-05DOI: 10.1109/ULTSYM.1997.663340
M. Lukacs, M. Sayer, S. Foster
PZT coatings have been produced in the thickness range of 5-200 microns using a composite sol gel process (M. Lukacs et al., 1996). The application of this process in the fabrication of high frequency transducers suitable for ultrasound biomicroscopy (UBM) has been investigated. Curved single element transducers have been produced in a range of 70-165 MHz with -6dB bandwidths as high as 52% and minimum insertion losses ranging from -47 to -58 dB. Laser micromachining techniques for patterning linear array structures to operate at similar frequencies have been developed. Trenches <10 /spl mu/m wide with a 50% taper through 20 /spl mu/m of ceramic have been achieved with a pulsed frequency doubled Nd:YAG laser. Trenches 5 /spl mu/m wide with straight walls have been achieved using a pulsed KrF excimer laser.
{"title":"Single element and linear array PZT ultrasound biomicroscopy transducers","authors":"M. Lukacs, M. Sayer, S. Foster","doi":"10.1109/ULTSYM.1997.663340","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.663340","url":null,"abstract":"PZT coatings have been produced in the thickness range of 5-200 microns using a composite sol gel process (M. Lukacs et al., 1996). The application of this process in the fabrication of high frequency transducers suitable for ultrasound biomicroscopy (UBM) has been investigated. Curved single element transducers have been produced in a range of 70-165 MHz with -6dB bandwidths as high as 52% and minimum insertion losses ranging from -47 to -58 dB. Laser micromachining techniques for patterning linear array structures to operate at similar frequencies have been developed. Trenches <10 /spl mu/m wide with a 50% taper through 20 /spl mu/m of ceramic have been achieved with a pulsed frequency doubled Nd:YAG laser. Trenches 5 /spl mu/m wide with straight walls have been achieved using a pulsed KrF excimer laser.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"35 1","pages":"1709-1712 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76653769","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 : 1997-10-05DOI: 10.1109/ULTSYM.1997.663095
P. Fomitchov, A. Kromine, S. Krishnaswamy, J. Achenbach
Knowledge of the spatial and temporal parameters of ultrasonic beams, as well as details of interaction of such beams with small defects is necessary for effective application of ultrasonic techniques to nondestructive evaluation (NDE). The work presented here employs a fiber-optic Sagnac interferometer to characterize acoustical fields generated by conventional piezoelectric transducers (PZT) and a laser ultrasonic source, and the scattering of such ultrasonic fields by flaws. The high spatial resolution of this interferometer and its ability to provide absolute ultrasonic displacements make this device very suitable for: (i) profiling and calibration of ultrasonic beams generated by PZT transducers or laser sources, and (ii) precision measurement of ultrasonic fields scattered by flaws.
{"title":"Application of a Sagnac interferometer for the characterization of scattered ultrasonic fields","authors":"P. Fomitchov, A. Kromine, S. Krishnaswamy, J. Achenbach","doi":"10.1109/ULTSYM.1997.663095","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.663095","url":null,"abstract":"Knowledge of the spatial and temporal parameters of ultrasonic beams, as well as details of interaction of such beams with small defects is necessary for effective application of ultrasonic techniques to nondestructive evaluation (NDE). The work presented here employs a fiber-optic Sagnac interferometer to characterize acoustical fields generated by conventional piezoelectric transducers (PZT) and a laser ultrasonic source, and the scattering of such ultrasonic fields by flaws. The high spatial resolution of this interferometer and its ability to provide absolute ultrasonic displacements make this device very suitable for: (i) profiling and calibration of ultrasonic beams generated by PZT transducers or laser sources, and (ii) precision measurement of ultrasonic fields scattered by flaws.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"15 1","pages":"609-612 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74347307","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 : 1997-10-05DOI: 10.1109/ULTSYM.1997.661772
P. Laugier, P. Giat, C. Chappard, C. Roux, G. Berger
Current commercial ultrasound "bone densitometers" process only the through-transmitted signals while failing to extract additional information contained in the scattered signals. This work was conducted to investigate the clinical interest of a backscatter ultrasound technique for bone characterization in 24 healthy premenopausal (group N), 24 postmenopausal (group PM), and 13 osteoporotic patients with fractures (group O). Pulse-echo measurements of the backscatter power were performed at the calcaneus (heel bone) using an ultrasound bone imaging scanner. The pulse-echo waveforms backscattered by the internal trabecular micro-architecture were recorded to compute the integrated backscatter coefficient (BUB, dB) in the frequency range 200-600 kHz. BUB was compared to the slope of the frequency-dependent attenuation (BUA, dB/MHz) derived from signals transmitted through the bone and to bone mineral density. Measurements were averaged in an operator-independent automatic ROI. The short-term reproducibility was 1.4%, and 3.5% for BUA, and BUB respectively. Femoral bone mass density (BMD) was measured in all subjects and calcaneal BMD was measured in a subset of 30 patients. The correlation between ultrasound and calcaneal BMD was moderate for BUB (r=0.55, p<10/sup -3/) and strong for BUA (r=0.82, p<10/sup -4/). Significant differences were found in ultrasound parameters and BMD between fracture and non-fracture groups. There was a significant difference in BMD and ultrasound parameters between young normal controls and healthy post-menopausal women. In summary, reflection ultrasound appears to be promising in osteoporosis and larger studies are clearly warranted.
{"title":"Clinical assessment of the backscatter coefficient in osteoporosis","authors":"P. Laugier, P. Giat, C. Chappard, C. Roux, G. Berger","doi":"10.1109/ULTSYM.1997.661772","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.661772","url":null,"abstract":"Current commercial ultrasound \"bone densitometers\" process only the through-transmitted signals while failing to extract additional information contained in the scattered signals. This work was conducted to investigate the clinical interest of a backscatter ultrasound technique for bone characterization in 24 healthy premenopausal (group N), 24 postmenopausal (group PM), and 13 osteoporotic patients with fractures (group O). Pulse-echo measurements of the backscatter power were performed at the calcaneus (heel bone) using an ultrasound bone imaging scanner. The pulse-echo waveforms backscattered by the internal trabecular micro-architecture were recorded to compute the integrated backscatter coefficient (BUB, dB) in the frequency range 200-600 kHz. BUB was compared to the slope of the frequency-dependent attenuation (BUA, dB/MHz) derived from signals transmitted through the bone and to bone mineral density. Measurements were averaged in an operator-independent automatic ROI. The short-term reproducibility was 1.4%, and 3.5% for BUA, and BUB respectively. Femoral bone mass density (BMD) was measured in all subjects and calcaneal BMD was measured in a subset of 30 patients. The correlation between ultrasound and calcaneal BMD was moderate for BUB (r=0.55, p<10/sup -3/) and strong for BUA (r=0.82, p<10/sup -4/). Significant differences were found in ultrasound parameters and BMD between fracture and non-fracture groups. There was a significant difference in BMD and ultrasound parameters between young normal controls and healthy post-menopausal women. In summary, reflection ultrasound appears to be promising in osteoporosis and larger studies are clearly warranted.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"33 1","pages":"1101-1104 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75096096","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 : 1997-10-05DOI: 10.1109/ULTSYM.1997.663048
B. Tittmann, R. Lerch, H. Landes, S. Madden, H. Tavossi
This paper describes the FEM-BEM simulation of and measurements on an acoustic transmission line consisting of three connected components; a long thin tube, a narrow solid cylinder, and a long narrow column of water. The total path length corresponded to about 8500 wavelengths at the highest frequency used, 5 MHz. Applications for this topic are in the field of high resolution ranging and is particularly important in leadscrew position measurement, where high precision over long travel lengths are required. The new aspects of this study lie firstly, in the development of special hybrid FEM-BEM simulation techniques to handle the extremely long lengths, secondly in the optimum choice of waveguide modes, and thirdly in the details of the experimental measurements, especially, when applied to industrial leadscrew position detection. Current techniques for measuring leadscrew positions are based on electromagnetic sensors and give a range resolution of only about 10 mm. The ultrasonic range detection provided a precision of 1 mm.
{"title":"Wave propagation in long compound acoustic transmission line: numerical simulation and measurement","authors":"B. Tittmann, R. Lerch, H. Landes, S. Madden, H. Tavossi","doi":"10.1109/ULTSYM.1997.663048","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.663048","url":null,"abstract":"This paper describes the FEM-BEM simulation of and measurements on an acoustic transmission line consisting of three connected components; a long thin tube, a narrow solid cylinder, and a long narrow column of water. The total path length corresponded to about 8500 wavelengths at the highest frequency used, 5 MHz. Applications for this topic are in the field of high resolution ranging and is particularly important in leadscrew position measurement, where high precision over long travel lengths are required. The new aspects of this study lie firstly, in the development of special hybrid FEM-BEM simulation techniques to handle the extremely long lengths, secondly in the optimum choice of waveguide modes, and thirdly in the details of the experimental measurements, especially, when applied to industrial leadscrew position detection. Current techniques for measuring leadscrew positions are based on electromagnetic sensors and give a range resolution of only about 10 mm. The ultrasonic range detection provided a precision of 1 mm.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"2 1","pages":"401-404 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75590083","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 : 1997-10-05DOI: 10.1109/ULTSYM.1997.662992
S. Balashov, C. M. Cabreira, C. Finardi
Low loss filters based on Single Phase Unidirectional Transducers (SPUDT) could be characterized as a separate class of Surface Acoustic Wave (SAW) filters because they overcome the main SAW filters limitation-6 dB bidirectional insertion loss. For the substrate with the high value of electroacoustic coupling coefficient k/sup 2/ the main effect used to obtain unidirectionality is electrical regeneration which could be treated directly by the Green's Function Model (GFM). The GFM being applicable to an interdigital transducer (IDT) with arbitrary topology is difficult to be applied to the IDT with large number of periods because computation time increases in power law with growth of the IDT length reaching very quickly unacceptable values. In this paper we present the method for calculation of arbitrary SAW filter parameters based on the GFM. Symmetry consideration being used for presentation of the central region of the long IDT, computation time decreases dramatically. At the same time edge effects of the IDT are correctly taken into account. The method developed works both for high and low k/sup 2/ value substrates. Results of calculation of SPUDT characteristics with the help of method proposed are presented.
基于单相单向换能器(SPUDT)的低损耗滤波器可以作为表面声波(SAW)滤波器的一个独立类别，因为它克服了主要表面声波滤波器的限制-6 dB双向插入损耗。对于高电声耦合系数k/sup 2/的基板，获得单向性的主要作用是电再生，可直接用格林函数模型(Green’s Function Model, GFM)进行处理。GFM适用于任意拓扑的数字间换能器(IDT)，但由于计算时间随着IDT长度的增长呈幂律增长，很快达到不可接受的值，因此很难应用于周期较大的IDT。本文提出了一种基于GFM的任意声表面波滤波器参数的计算方法。利用对称的考虑来表示长IDT的中心区域，大大减少了计算时间。同时，正确地考虑了IDT的边缘效应。所开发的方法适用于高/低k/sup / value衬底。给出了利用该方法计算SPUDT特性的结果。
{"title":"Modified Green's function approach to analysis of long SAW transducers","authors":"S. Balashov, C. M. Cabreira, C. Finardi","doi":"10.1109/ULTSYM.1997.662992","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.662992","url":null,"abstract":"Low loss filters based on Single Phase Unidirectional Transducers (SPUDT) could be characterized as a separate class of Surface Acoustic Wave (SAW) filters because they overcome the main SAW filters limitation-6 dB bidirectional insertion loss. For the substrate with the high value of electroacoustic coupling coefficient k/sup 2/ the main effect used to obtain unidirectionality is electrical regeneration which could be treated directly by the Green's Function Model (GFM). The GFM being applicable to an interdigital transducer (IDT) with arbitrary topology is difficult to be applied to the IDT with large number of periods because computation time increases in power law with growth of the IDT length reaching very quickly unacceptable values. In this paper we present the method for calculation of arbitrary SAW filter parameters based on the GFM. Symmetry consideration being used for presentation of the central region of the long IDT, computation time decreases dramatically. At the same time edge effects of the IDT are correctly taken into account. The method developed works both for high and low k/sup 2/ value substrates. Results of calculation of SPUDT characteristics with the help of method proposed are presented.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"201 1","pages":"123-126 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80144256","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 : 1997-10-05DOI: 10.1109/ULTSYM.1997.662981
V. B. Chvets, P. G. Ivanov, V. M. Makarov, V. S. Orlov
Transversal filters with very high shape factor have been developed based on multiharmonic and withdrawal weighted transducers with isolated sections. The developed simulation technique provides excellent results both for in-line filter structures and those with multistrip couplers. The experimental results are presented for IF filters manufactured on YZ-LiNbO/sub 3/ and ST-quartz substrates. In-line filters exhibit SF in the range 1.15-1.2 and for MSC filters, SF values 1.05-1.1 have been obtained. For all filters the stopband rejection is more than 50 dB.
{"title":"SAW filters with very high shape factor","authors":"V. B. Chvets, P. G. Ivanov, V. M. Makarov, V. S. Orlov","doi":"10.1109/ULTSYM.1997.662981","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.662981","url":null,"abstract":"Transversal filters with very high shape factor have been developed based on multiharmonic and withdrawal weighted transducers with isolated sections. The developed simulation technique provides excellent results both for in-line filter structures and those with multistrip couplers. The experimental results are presented for IF filters manufactured on YZ-LiNbO/sub 3/ and ST-quartz substrates. In-line filters exhibit SF in the range 1.15-1.2 and for MSC filters, SF values 1.05-1.1 have been obtained. For all filters the stopband rejection is more than 50 dB.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"28 1","pages":"65-68 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84460214","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 : 1997-10-05DOI: 10.1109/ULTSYM.1997.663041
L. Scandelari, N. Noury, P. Benech, E. Chamberod
We present the temperature-dependent characteristics of a Lamb wave device used as a liquid density sensor. Its fabrication process was simplified using a P(VF/sub 2/-VF/sub 3/) film stuck on a non-piezoelectric medium. The lowest order antisymmetric Lamb waves (A/sub 0/ mode) are used for measurements. We measured the phase and group velocities of the waves for different concentrations of NaCl and we analyzed the temperature dependent performance of our device. The synchronism frequency decreases almost 1.4 kHz per Celsius degree increase. Insertion loss decreases with increasing temperature.
{"title":"Temperature-dependent characteristics of a density sensor based on Lamb waves generated with a P(VF/sub 2/-VF/sub 3/) film","authors":"L. Scandelari, N. Noury, P. Benech, E. Chamberod","doi":"10.1109/ULTSYM.1997.663041","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.663041","url":null,"abstract":"We present the temperature-dependent characteristics of a Lamb wave device used as a liquid density sensor. Its fabrication process was simplified using a P(VF/sub 2/-VF/sub 3/) film stuck on a non-piezoelectric medium. The lowest order antisymmetric Lamb waves (A/sub 0/ mode) are used for measurements. We measured the phase and group velocities of the waves for different concentrations of NaCl and we analyzed the temperature dependent performance of our device. The synchronism frequency decreases almost 1.4 kHz per Celsius degree increase. Insertion loss decreases with increasing temperature.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"32 1","pages":"367-370 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90287011","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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