Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193447
L. Matsiev
Application of quartz tuning fork resonators to high throughput gravimetric measurements is described. It is demonstrated that tuning fork resonators can be successfully used for accurate measurement of mass in the tens-of-micrograms range without incurring restrictions on sample shape, size, mechanical properties or sample adhesion and position on sensor surface. Experimental results on sensor calibration and weighing small samples of materials are presented.
{"title":"Tuning fork QCM. Application to powder and gel technology","authors":"L. Matsiev","doi":"10.1109/ULTSYM.2002.1193447","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193447","url":null,"abstract":"Application of quartz tuning fork resonators to high throughput gravimetric measurements is described. It is demonstrated that tuning fork resonators can be successfully used for accurate measurement of mass in the tens-of-micrograms range without incurring restrictions on sample shape, size, mechanical properties or sample adhesion and position on sensor surface. Experimental results on sensor calibration and weighing small samples of materials are presented.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127022422","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193443
M. Rychagov, S. Tereshchenko, Y. Masloboev, M. Simon, L. Lynnworth
Quadrature integration of flow velocity along prescribed parallel paths has been one of the preferred solutions for accurate computation of volumetric flowrate Q for over thirty years. The present work extends the quadrature volumetric flowmetering method to determining from sound speed c/sub 3/ along the same quadrature paths, the fluid temperature T, density /spl rho/ and mass flowrate M/sub F/ in the presence of a density gradient. Quadrature integration of /spl rho//sub i/ /spl times/ V/sub i/ products V/sub i/ obtained from c/sub 3i/ is useful to the extent the fluid is sufficiently pure and defined so that the uncertainty in sound speed c/sub i/ along each path generates only a small uncertainty in density pi along those same paths. Instead of "useful to the extent" one could just as well say "limited to the extent." Recognizing this limitation, it is interesting to compare the density and mass flowrate determined from (a) ultrasonic measurements of propagation across the fluid, as indicated above, with density and mass flowrate determinations based on two other known methods. These two methods are: (b) reflection coefficient measurement of fluid characteristic impedance Z, which would seem capable of leading to /spl rho/ after dividing by c; and determining /spl rho/ based on (c) torsional wavespeed in a waveguide of noncircular cross section.
{"title":"Mass flowmeters for fluids with density gradient","authors":"M. Rychagov, S. Tereshchenko, Y. Masloboev, M. Simon, L. Lynnworth","doi":"10.1109/ULTSYM.2002.1193443","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193443","url":null,"abstract":"Quadrature integration of flow velocity along prescribed parallel paths has been one of the preferred solutions for accurate computation of volumetric flowrate Q for over thirty years. The present work extends the quadrature volumetric flowmetering method to determining from sound speed c/sub 3/ along the same quadrature paths, the fluid temperature T, density /spl rho/ and mass flowrate M/sub F/ in the presence of a density gradient. Quadrature integration of /spl rho//sub i/ /spl times/ V/sub i/ products V/sub i/ obtained from c/sub 3i/ is useful to the extent the fluid is sufficiently pure and defined so that the uncertainty in sound speed c/sub i/ along each path generates only a small uncertainty in density pi along those same paths. Instead of \"useful to the extent\" one could just as well say \"limited to the extent.\" Recognizing this limitation, it is interesting to compare the density and mass flowrate determined from (a) ultrasonic measurements of propagation across the fluid, as indicated above, with density and mass flowrate determinations based on two other known methods. These two methods are: (b) reflection coefficient measurement of fluid characteristic impedance Z, which would seem capable of leading to /spl rho/ after dividing by c; and determining /spl rho/ based on (c) torsional wavespeed in a waveguide of noncircular cross section.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127356276","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193453
B. Sinha, Qingchen Liu
A finite-difference formulation of equations of motion for elastic waves in prestressed formations has been used to calculate synthetic waveforms at an array of receivers in a liquid-filled borehole. Equations of motion for elastic waves in prestressed materials are derived from rotationally invariant equations of nonlinear elasticity. These equations describe the influence of borehole hydrostatic (mud) pressure as well as formation stresses on acoustic waves produced by either a monopole or dipole transmitter placed on the borehole axis. The synthetic waveforms are processed by a modified matrix pencil algorithm for isolating both dispersive and non-dispersive arrivals in the wavetrain. Computational results show that a difference in the maximum and minimum horizontal stresses causes dipole dispersion crossovers that can be used as an indicator of stress-induced anisotropy dominating the data. On the other hand, an increase in the overburden stress causes both the Stoneley and dipole dispersions to shift toward higher velocities by varying amounts at various frequencies. Any increase in the mud pressure introduces an altered annulus surrounding the borehole surface. This annulus exhibits radial variations in the near-wellbore radial and hoop stresses. Both the Stoneley and dipole dispersions show increasing velocities at higher frequencies. Changes in borehole acoustic wave velocities caused by a change in any one of the formation principal stresses yield frequency-dependent overburden, maximum horizontal, and minimum horizontal stress coefficients of velocities. These stress coefficients of velocities can be used to invert measured changes in borehole dispersions at various depths for corresponding changes in formation stresses.
{"title":"Acoustic waves in pressurized boreholes in formations with triaxial stresses","authors":"B. Sinha, Qingchen Liu","doi":"10.1109/ULTSYM.2002.1193453","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193453","url":null,"abstract":"A finite-difference formulation of equations of motion for elastic waves in prestressed formations has been used to calculate synthetic waveforms at an array of receivers in a liquid-filled borehole. Equations of motion for elastic waves in prestressed materials are derived from rotationally invariant equations of nonlinear elasticity. These equations describe the influence of borehole hydrostatic (mud) pressure as well as formation stresses on acoustic waves produced by either a monopole or dipole transmitter placed on the borehole axis. The synthetic waveforms are processed by a modified matrix pencil algorithm for isolating both dispersive and non-dispersive arrivals in the wavetrain. Computational results show that a difference in the maximum and minimum horizontal stresses causes dipole dispersion crossovers that can be used as an indicator of stress-induced anisotropy dominating the data. On the other hand, an increase in the overburden stress causes both the Stoneley and dipole dispersions to shift toward higher velocities by varying amounts at various frequencies. Any increase in the mud pressure introduces an altered annulus surrounding the borehole surface. This annulus exhibits radial variations in the near-wellbore radial and hoop stresses. Both the Stoneley and dipole dispersions show increasing velocities at higher frequencies. Changes in borehole acoustic wave velocities caused by a change in any one of the formation principal stresses yield frequency-dependent overburden, maximum horizontal, and minimum horizontal stress coefficients of velocities. These stress coefficients of velocities can be used to invert measured changes in borehole dispersions at various depths for corresponding changes in formation stresses.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127499088","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193515
A. Fiorillo, G. D'Angelo
The sophisticated sonar system of bats is capable of extracting a complete set of information in order to locate and characterize the prey. Curved piezopolymer transducers were already used in the same frequency range to generate ultrasonic waves in air. In this article we investigate the possibility to process echo-signals by using a neural network, similarly to the biological model. We analyse frequency modulated signals, which are only a part of the most complex bat echo signal, in order to measure the target distance through the time of flight evaluation. Chirps are first amplified with a low noise CMOS amplifier, than are properly filtered and rectified in order to obtain a pulse time sequence. Finally the pulse signal is processed by the first level of a neural network to recognize the right pulse time sequence and evaluate the time of flight. Simulated results carried out by using both Matlab and Spice programs, will be presented with reference to piezo-polymer transducers application.
{"title":"Echo signals processing with neural network in bat-like sonars based on PVDF","authors":"A. Fiorillo, G. D'Angelo","doi":"10.1109/ULTSYM.2002.1193515","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193515","url":null,"abstract":"The sophisticated sonar system of bats is capable of extracting a complete set of information in order to locate and characterize the prey. Curved piezopolymer transducers were already used in the same frequency range to generate ultrasonic waves in air. In this article we investigate the possibility to process echo-signals by using a neural network, similarly to the biological model. We analyse frequency modulated signals, which are only a part of the most complex bat echo signal, in order to measure the target distance through the time of flight evaluation. Chirps are first amplified with a low noise CMOS amplifier, than are properly filtered and rectified in order to obtain a pulse time sequence. Finally the pulse signal is processed by the first level of a neural network to recognize the right pulse time sequence and evaluate the time of flight. Simulated results carried out by using both Matlab and Spice programs, will be presented with reference to piezo-polymer transducers application.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129143951","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193411
S. Ballandras, V. Laude, T. Pastureaud, M. Wilm, W. Daniau, A. Reinhardt, W. Steichen, R. Lardat
A modelling approach able to address complicated SAW periodic structures with non homogeneous geometry has been developed and implemented. It is based on the combination of finite element analysis and a boundary element method. Validation of the computation is reported. An example of simulation of a passivated STW resonator is used for theory/experiment assessment.
{"title":"A FEA/BEM approach to simulate complex electrode structures devoted to guided elastic wave periodic transducers","authors":"S. Ballandras, V. Laude, T. Pastureaud, M. Wilm, W. Daniau, A. Reinhardt, W. Steichen, R. Lardat","doi":"10.1109/ULTSYM.2002.1193411","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193411","url":null,"abstract":"A modelling approach able to address complicated SAW periodic structures with non homogeneous geometry has been developed and implemented. It is based on the combination of finite element analysis and a boundary element method. Validation of the computation is reported. An example of simulation of a passivated STW resonator is used for theory/experiment assessment.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132978150","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192587
A. Criton, R. Steel, P. Hoskins, W. Mcdicken, H. Routh
Tissue Doppler Imaging (TDI) can assess tissue motion in vascular and cardiac imaging. However, a major drawback of these measurements is that the motion estimation is limited to the component along the ultrasound beam axis. Cardiac and vessel wall motion studies have shown that complex three-dimensional motions can be observed, and that there is a clinical need to fully assess the three components of the vector motion. This work describes how TDI can be extended by acquiring a real time two-component velocity vector via a dual beam vector Doppler technique. A vector Doppler velocity estimator using a small interbeam angle can suffer from both bias and large variance. This estimator is also strongly dependent on the settings of the echographic system. To reduce the large bias and variance, most vector velocity techniques use a very large ensemble length (EL) (>20), which does not allow real time implementation. We propose a new processing technique, which reduces the bias and the standard deviation of the vector velocity estimate. The new method assumes that the vector velocity angle varies slowly over the cardiac cycle. The angle can then be estimated using a large time window. The performance of this new technique has been tested experimentally using a tissue mimicking rotating phantom. It is shown that the factors influencing the results are the EL, the precision of the TDI estimates and the time window. The results indicate that the variance and bias of velocity magnitude and orientation estimates decrease with increasing EL, increasing precision of the TDI estimates and increasing time window. Using an EL of 9, 8 bits for the velocity estimate, and an observation time of one second, a 5-degree bias of the angle estimate is observed, with a variance below 7 degree averaged over all angles. A 10% bias of the velocity magnitude is observed, with a variance of 1%. In conclusion, TDI can be improved with vector Doppler providing two-dimensional tissue motion estimation, enabling more accurate biomechanical tissue property assessment.
{"title":"Real time vector Doppler for tissue motion","authors":"A. Criton, R. Steel, P. Hoskins, W. Mcdicken, H. Routh","doi":"10.1109/ULTSYM.2002.1192587","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192587","url":null,"abstract":"Tissue Doppler Imaging (TDI) can assess tissue motion in vascular and cardiac imaging. However, a major drawback of these measurements is that the motion estimation is limited to the component along the ultrasound beam axis. Cardiac and vessel wall motion studies have shown that complex three-dimensional motions can be observed, and that there is a clinical need to fully assess the three components of the vector motion. This work describes how TDI can be extended by acquiring a real time two-component velocity vector via a dual beam vector Doppler technique. A vector Doppler velocity estimator using a small interbeam angle can suffer from both bias and large variance. This estimator is also strongly dependent on the settings of the echographic system. To reduce the large bias and variance, most vector velocity techniques use a very large ensemble length (EL) (>20), which does not allow real time implementation. We propose a new processing technique, which reduces the bias and the standard deviation of the vector velocity estimate. The new method assumes that the vector velocity angle varies slowly over the cardiac cycle. The angle can then be estimated using a large time window. The performance of this new technique has been tested experimentally using a tissue mimicking rotating phantom. It is shown that the factors influencing the results are the EL, the precision of the TDI estimates and the time window. The results indicate that the variance and bias of velocity magnitude and orientation estimates decrease with increasing EL, increasing precision of the TDI estimates and increasing time window. Using an EL of 9, 8 bits for the velocity estimate, and an observation time of one second, a 5-degree bias of the angle estimate is observed, with a variance below 7 degree averaged over all angles. A 10% bias of the velocity magnitude is observed, with a variance of 1%. In conclusion, TDI can be improved with vector Doppler providing two-dimensional tissue motion estimation, enabling more accurate biomechanical tissue property assessment.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132993746","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193477
C. Jolly, A. Coron, M. Pérez, P. Laugier, A. Saied
The surgery of cataract (phakoemulsification) requires the use of devices that limit the corneal incision burn. The current study aims at evaluating corneal microincision and burn induced by different phacotips using 80 MHz three dimensional (3D) ultrasonography. The study was performed in vitro on 4 fresh pig eyes. Three pig-eyes underwent clear corneal phacoemulsification, using 3 various phacomicrotips. One pig-eye served as control and underwent Clear Corneal Incision (CCI). After surgery, 3D data were acquired from the entire corneal incision volume of each eye using an 80 MHz ultrasound backscatter microscope. The -6dB axial resolution of the system was 25 /spl mu/m at focus. Thermal effects of the phakotips and generation of corneal burns were evaluated on both B-scan images and 3D volume-rendered images of the corneal tunnel reconstructed after manual delineation and selection of the incision regions. Ultrasound images allowed the visualization of corneal tunnel shape and thermal damage due to the different phakotips on the tissue. Comparative study showed the ability of high resolution 3D ultrasonography in detecting the efficiency of phakomicrotips in the prevention of corneal burns.
{"title":"80 MHz three-dimensional ultrasound imaging of corneal lesions induced by cataract surgery","authors":"C. Jolly, A. Coron, M. Pérez, P. Laugier, A. Saied","doi":"10.1109/ULTSYM.2002.1193477","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193477","url":null,"abstract":"The surgery of cataract (phakoemulsification) requires the use of devices that limit the corneal incision burn. The current study aims at evaluating corneal microincision and burn induced by different phacotips using 80 MHz three dimensional (3D) ultrasonography. The study was performed in vitro on 4 fresh pig eyes. Three pig-eyes underwent clear corneal phacoemulsification, using 3 various phacomicrotips. One pig-eye served as control and underwent Clear Corneal Incision (CCI). After surgery, 3D data were acquired from the entire corneal incision volume of each eye using an 80 MHz ultrasound backscatter microscope. The -6dB axial resolution of the system was 25 /spl mu/m at focus. Thermal effects of the phakotips and generation of corneal burns were evaluated on both B-scan images and 3D volume-rendered images of the corneal tunnel reconstructed after manual delineation and selection of the incision regions. Ultrasound images allowed the visualization of corneal tunnel shape and thermal damage due to the different phakotips on the tissue. Comparative study showed the ability of high resolution 3D ultrasonography in detecting the efficiency of phakomicrotips in the prevention of corneal burns.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126455793","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192577
D. Goertz, J. Yu, R. Kerbel, P. Burns, F. Foster
The effect of antivascular therapy on blood flow in superficial mouse tumors was monitored using high frequency Doppler flow imaging techniques (HFD). Volumetric flow imaging of established melanomas detected a significant reduction in blood flow 4 hours after injection of the tumor vascular targeting agent ZD6126 followed by a recovery of flow by 24 hours after injection. Measurements of tumor perfusion in situ by Hoechst perfusion staining correlated with the ultrasound results. This study demonstrates the feasibility of high frequency flow imaging as a quantitative tool for following longitudinally the effects of antivascular therapy on blood flow in superficial tumors.
{"title":"Monitoring antivascular therapy with high frequency ultrasound flow imaging","authors":"D. Goertz, J. Yu, R. Kerbel, P. Burns, F. Foster","doi":"10.1109/ULTSYM.2002.1192577","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192577","url":null,"abstract":"The effect of antivascular therapy on blood flow in superficial mouse tumors was monitored using high frequency Doppler flow imaging techniques (HFD). Volumetric flow imaging of established melanomas detected a significant reduction in blood flow 4 hours after injection of the tumor vascular targeting agent ZD6126 followed by a recovery of flow by 24 hours after injection. Measurements of tumor perfusion in situ by Hoechst perfusion staining correlated with the ultrasound results. This study demonstrates the feasibility of high frequency flow imaging as a quantitative tool for following longitudinally the effects of antivascular therapy on blood flow in superficial tumors.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123018621","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193381
K. Yamanouchi, T. Ishii
The important properties required for SAW substrates are a large electromechanical coupling coefficients (k/sup 2/), small temperature coefficient of frequency (TCF), low propagation loss, etc. LiNbO/sub 2/ has good properties as the SAW substrate with a large size. Unfortunately LiNbO/sub 3/ possesses the large values of TCF. We developed the SiO/sub 2//Rotated Y-cut, X-Propagating LiNbO/sub 3/ leaky SAW substrates with a large k/sup 2/(over 0.2) and zero TCF at very thin thickness of SiO/sub 2/ of H//spl lambda/ = 0.2 (H:SiO/sub 2/ film thickness, /spl lambda/ :SAW wave-length) and zero propagation attenuation in the case of moralized surface. In this paper, the theoretical and experimental results of SAW filters, resonators and resonator filters are described. The low loss filters using FEUDT showed the insertion loss of below 2dB at the center frequency of 400MHz and bandwidth of 20MHz. Also, the resonator showed the band width of 70MHz at the center frequency of 500MHz and resonator filters showed the band width of 80MHz at the center frequency of 500MHz.
{"title":"Low loss wide band filters and resonator filters using high temperature stable high electromechanical coupling surface acoustic wave substrates","authors":"K. Yamanouchi, T. Ishii","doi":"10.1109/ULTSYM.2002.1193381","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193381","url":null,"abstract":"The important properties required for SAW substrates are a large electromechanical coupling coefficients (k/sup 2/), small temperature coefficient of frequency (TCF), low propagation loss, etc. LiNbO/sub 2/ has good properties as the SAW substrate with a large size. Unfortunately LiNbO/sub 3/ possesses the large values of TCF. We developed the SiO/sub 2//Rotated Y-cut, X-Propagating LiNbO/sub 3/ leaky SAW substrates with a large k/sup 2/(over 0.2) and zero TCF at very thin thickness of SiO/sub 2/ of H//spl lambda/ = 0.2 (H:SiO/sub 2/ film thickness, /spl lambda/ :SAW wave-length) and zero propagation attenuation in the case of moralized surface. In this paper, the theoretical and experimental results of SAW filters, resonators and resonator filters are described. The low loss filters using FEUDT showed the insertion loss of below 2dB at the center frequency of 400MHz and bandwidth of 20MHz. Also, the resonator showed the band width of 70MHz at the center frequency of 500MHz and resonator filters showed the band width of 80MHz at the center frequency of 500MHz.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126400079","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192479
G. Caliano, R. Carotenuto, A. Caronti, M. Pappalardo
The electrostatic capacitive, silicon micro fabricated, ultrasonic transducer (cMUT), approached in the last years, is a new promising alternative to the piezoelectric transducer for echographic probes. The cMUT transducer inherently has a larger bandwidth for immersion application and, because it takes advantage of the well established microelectronic technology it is, potentially, less expensive and gives much more flexibility in the design of complex 1D and 2D arrays than piezoelectric transducers. In perspective, a further advantage of the cMUT is the possibility to be integrated with the front-end electronics on the same silicon wafer. In this paper the design and the fabrication process of a 64-elements cMUT probe is described. We are fabricating an array with a pitch of 0.245 mm, kerf 27 Am, elevation 14 mm, glued on a commercial backing and soldered using a typical connection-comb to permit the electrical connection to the printing circuits, as used in commercial probes. With the addition of the biasing voltage, the probe is ready to be connected to a commercial echographic system, like Technos/spl reg/ (ESAOTE). Due to the inherently large bandwidth, the probe can be used as a linear array at about 7 MHz, and as a phased array at about MHZ..
{"title":"cMUT echographic probes: design and fabrication process","authors":"G. Caliano, R. Carotenuto, A. Caronti, M. Pappalardo","doi":"10.1109/ULTSYM.2002.1192479","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192479","url":null,"abstract":"The electrostatic capacitive, silicon micro fabricated, ultrasonic transducer (cMUT), approached in the last years, is a new promising alternative to the piezoelectric transducer for echographic probes. The cMUT transducer inherently has a larger bandwidth for immersion application and, because it takes advantage of the well established microelectronic technology it is, potentially, less expensive and gives much more flexibility in the design of complex 1D and 2D arrays than piezoelectric transducers. In perspective, a further advantage of the cMUT is the possibility to be integrated with the front-end electronics on the same silicon wafer. In this paper the design and the fabrication process of a 64-elements cMUT probe is described. We are fabricating an array with a pitch of 0.245 mm, kerf 27 Am, elevation 14 mm, glued on a commercial backing and soldered using a typical connection-comb to permit the electrical connection to the printing circuits, as used in commercial probes. With the addition of the biasing voltage, the probe is ready to be connected to a commercial echographic system, like Technos/spl reg/ (ESAOTE). Due to the inherently large bandwidth, the probe can be used as a linear array at about 7 MHz, and as a phased array at about MHZ..","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"225 1-2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114157379","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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