Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49376
S. Hanna
A novel and simple technique for realizing tunable and planar microwave bandpass filters has been investigated. The use of coupled magnetostatic wave (MSW) resonators for realizing these filters is demonstrated. Due to their low magnetic losses, epitaxially grown single-crystal yttrium iron garnet (YIG) films are used for the MSW propagation. The individual resonators are rectangular YIG films. The microwave signals are coupled to and from resonators using microstrip structures. The MSW resonators are magnetically coupled to realize multiple filters. Experimental results demonstrate the enhancement of the bandwidth and the improvement in the out-of-band rejection. Using two-coupled resonators the 3-dB bandwidth increased from 4-7 MHz (for single resonators) to more than 10 MHz. The out-of-band rejection was improved by 10 dB using the coupled resonators for realizing the filters. Since this technique is based on microstrip circuitry it can be easily integrated with other microwave integrated circuits in a system. The utilization of IC fabrication techniques ensures the potential for high degree of yield and reproducibility at reasonable cost. Applications for FW systems, such as tunable integrated channelizers, using the MSW coupled resonators are discussed.<>
{"title":"Microwave filters based on coupled MSW resonators and their applications","authors":"S. Hanna","doi":"10.1109/ULTSYM.1988.49376","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49376","url":null,"abstract":"A novel and simple technique for realizing tunable and planar microwave bandpass filters has been investigated. The use of coupled magnetostatic wave (MSW) resonators for realizing these filters is demonstrated. Due to their low magnetic losses, epitaxially grown single-crystal yttrium iron garnet (YIG) films are used for the MSW propagation. The individual resonators are rectangular YIG films. The microwave signals are coupled to and from resonators using microstrip structures. The MSW resonators are magnetically coupled to realize multiple filters. Experimental results demonstrate the enhancement of the bandwidth and the improvement in the out-of-band rejection. Using two-coupled resonators the 3-dB bandwidth increased from 4-7 MHz (for single resonators) to more than 10 MHz. The out-of-band rejection was improved by 10 dB using the coupled resonators for realizing the filters. Since this technique is based on microstrip circuitry it can be easily integrated with other microwave integrated circuits in a system. The utilization of IC fabrication techniques ensures the potential for high degree of yield and reproducibility at reasonable cost. Applications for FW systems, such as tunable integrated channelizers, using the MSW coupled resonators are discussed.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"29 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":"132676115","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.1988.49488
K. Shung, L. Pagan-Carlo
Since ultrasonic backscatter is intimately related to the echogenicity of a biological tissue in an ultrasonic image, it has been studied by many investigators in vitro. In the present study, an effort has been made to determine whether in vitro data can be extrapolated to in vivo situations. Ultrasonic backscatter collected from exposed organs in vivo on dogs was compared with that collected from tissues immediately following excision and up to 8 hours thereafter. It is shown that the in vivo and in vitro data do not differ significantly if the organs are properly prepared and stored.<>
{"title":"A comparison of ultrasonic backscatter measured in vivo and in vitro","authors":"K. Shung, L. Pagan-Carlo","doi":"10.1109/ULTSYM.1988.49488","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49488","url":null,"abstract":"Since ultrasonic backscatter is intimately related to the echogenicity of a biological tissue in an ultrasonic image, it has been studied by many investigators in vitro. In the present study, an effort has been made to determine whether in vitro data can be extrapolated to in vivo situations. Ultrasonic backscatter collected from exposed organs in vivo on dogs was compared with that collected from tissues immediately following excision and up to 8 hours thereafter. It is shown that the in vivo and in vitro data do not differ significantly if the organs are properly prepared and stored.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"267 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":"133171730","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.1988.49507
S. Tanisawa, H. Hirose
Flow-velocity measurement in the case in which the intensity of ultrasound is known to be generated by vortex and turbulent flow in the fluid is considerably influenced by external electrical and sonic noises because the desired sound intensity is very weak. Therefore, some serious measurement problems exist with regard to the proportionality and linearity between the flow velocity and ultrasound pressure level, and the reproducibility of spectrum distribution for the same flow velocity. In this study the intensity of flow-induced sound was increased by artificially introducing air bubbles and attaching an obstacle across the pipe, resulting in linearity and reproducibility. Spectrum analyses suggest that the spectra-dependent sound intensity may be used for the measurement of flow velocity with linearity and reproducibility if filtering and band choice are appropriately realized.<>
{"title":"Dependence of actively generated sound noise spectrum on flow-velocity","authors":"S. Tanisawa, H. Hirose","doi":"10.1109/ULTSYM.1988.49507","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49507","url":null,"abstract":"Flow-velocity measurement in the case in which the intensity of ultrasound is known to be generated by vortex and turbulent flow in the fluid is considerably influenced by external electrical and sonic noises because the desired sound intensity is very weak. Therefore, some serious measurement problems exist with regard to the proportionality and linearity between the flow velocity and ultrasound pressure level, and the reproducibility of spectrum distribution for the same flow velocity. In this study the intensity of flow-induced sound was increased by artificially introducing air bubbles and attaching an obstacle across the pipe, resulting in linearity and reproducibility. Spectrum analyses suggest that the spectra-dependent sound intensity may be used for the measurement of flow velocity with linearity and reproducibility if filtering and band choice are appropriately realized.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133195524","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.1988.49545
S. Adenwalla, Z. Zhao, J. Ketterson, D. Hinks, A. Schenstrom, Y. Hong, M. Xu, M. Levy, B. Sarma
Attenuation measurements of longitudinal ultrasound in superconducting UPt/sub 3/ show a peak, below H/sub c2/, that depends strongly on the orientation of the field relative to the c-axis. This peak is seen only with longitudinal and not with transverse sound. It is show that, as the field is tipped away from the c axis into the basal plane. H/sub FL/ decreases from 1.3 T to 0.58 T (at the lowest temperature). The temperature dependence of H/sub FL/ for all orientations of the field is the same-a flat region, followed by a slow decrease in H/sub FL/ with increasing temperature.<>
{"title":"Ultrasonic attenuation measurements of the flux lattice phase transition in the heavy fermion superconductor UPt/sub 3/","authors":"S. Adenwalla, Z. Zhao, J. Ketterson, D. Hinks, A. Schenstrom, Y. Hong, M. Xu, M. Levy, B. Sarma","doi":"10.1109/ULTSYM.1988.49545","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49545","url":null,"abstract":"Attenuation measurements of longitudinal ultrasound in superconducting UPt/sub 3/ show a peak, below H/sub c2/, that depends strongly on the orientation of the field relative to the c-axis. This peak is seen only with longitudinal and not with transverse sound. It is show that, as the field is tipped away from the c axis into the basal plane. H/sub FL/ decreases from 1.3 T to 0.58 T (at the lowest temperature). The temperature dependence of H/sub FL/ for all orientations of the field is the same-a flat region, followed by a slow decrease in H/sub FL/ with increasing temperature.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"43 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":"133454116","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.1988.49346
L. Solie, H.P. Fredricksen, S. Lins, C. Nelson
It is shown that the hyperbolically tapered transducer is capable of launching a relatively narrow SAW (surface acoustic wave) beam from some point across a wide transducer aperture. The center of this narrow SAW beam varies linearly with frequency across the transducer. Thus, the transducer performs the spatial frequency sorting as it launches a wave. This makes it an ideal candidate for a filter bank or frequency-division multiplexer. A 14-channel multiplexer has been developed with a total bandwidth of 120 MHz centered at 180 MHz, (1 octave) out-of-band rejection of 40 dB and an insertion loss of 19 dB. Cascading filters demonstrates an out-of-band rejection of over 80 dB with an insertion loss around 30 dB.<>
{"title":"A SAW filter bank using hyperbolically tapered transducers","authors":"L. Solie, H.P. Fredricksen, S. Lins, C. Nelson","doi":"10.1109/ULTSYM.1988.49346","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49346","url":null,"abstract":"It is shown that the hyperbolically tapered transducer is capable of launching a relatively narrow SAW (surface acoustic wave) beam from some point across a wide transducer aperture. The center of this narrow SAW beam varies linearly with frequency across the transducer. Thus, the transducer performs the spatial frequency sorting as it launches a wave. This makes it an ideal candidate for a filter bank or frequency-division multiplexer. A 14-channel multiplexer has been developed with a total bandwidth of 120 MHz centered at 180 MHz, (1 octave) out-of-band rejection of 40 dB and an insertion loss of 19 dB. Cascading filters demonstrates an out-of-band rejection of over 80 dB with an insertion loss around 30 dB.<<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":"133713173","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.1988.49529
M. Nakajima, T. Itoh, M. ShingYouuchi, I. Akiyama, S. Yuta
The operating principle of an ultrasonic speckle velocimetry technique of flow-velocity measurement is described. This method allows the quick determination of the velocity of an object on the basis of a simple statistical process involving counting the local intensity fluctuations of the echo signal from the object. The results of a basic experiment to verify the effectiveness of the proposed method are presented. It is also shown that there is a linear relationship between the flow speed and the number of speckle intensity fluctuations.<>
{"title":"Ultrasonic speckle velocimetry","authors":"M. Nakajima, T. Itoh, M. ShingYouuchi, I. Akiyama, S. Yuta","doi":"10.1109/ULTSYM.1988.49529","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49529","url":null,"abstract":"The operating principle of an ultrasonic speckle velocimetry technique of flow-velocity measurement is described. This method allows the quick determination of the velocity of an object on the basis of a simple statistical process involving counting the local intensity fluctuations of the echo signal from the object. The results of a basic experiment to verify the effectiveness of the proposed method are presented. It is also shown that there is a linear relationship between the flow speed and the number of speckle intensity fluctuations.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"48 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":"131892702","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.1988.49544
B. Golding, W. H. Haemmerle, L. Schneemeyer, J. Waszczak
Anisotropic sound propagation at 1 GHz in single-crystal YBa/sub 2/Cu/sub 3/O/sub 7/ is described. Longitudinal phonons have been studied from 0.01 K to 300 K, with emphasis on the temperature region near the superconducting transition T/sub c/ at 88 K. A discontinuous sound velocity is observed at T/sub c/ for propagation parallel and perpendicular to the c axis. Strain derivatives of T/sub c/ are evaluated using mean field theory. Below 1 K the temperature-dependent sound velocity has positive slope, which indicates tunneling of defects.<>
{"title":"Gigahertz ultrasound in single crystal superconducting YBa/sub 2/Cu/sub 3/O/sub 7/","authors":"B. Golding, W. H. Haemmerle, L. Schneemeyer, J. Waszczak","doi":"10.1109/ULTSYM.1988.49544","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49544","url":null,"abstract":"Anisotropic sound propagation at 1 GHz in single-crystal YBa/sub 2/Cu/sub 3/O/sub 7/ is described. Longitudinal phonons have been studied from 0.01 K to 300 K, with emphasis on the temperature region near the superconducting transition T/sub c/ at 88 K. A discontinuous sound velocity is observed at T/sub c/ for propagation parallel and perpendicular to the c axis. Strain derivatives of T/sub c/ are evaluated using mean field theory. Below 1 K the temperature-dependent sound velocity has positive slope, which indicates tunneling of defects.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"3 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":"134487902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49549
G. L. Bullock, B. Shivaram
The authors propose a novel scheme to achieve focusing of sound waves in superfluid /sup 3/He. This scheme exploits the magnetic field dependence of the superfluid phase diagram and the difference in the sound propagation characteristics of the A- and B-phases. Central to the scheme is the dispersion caused by the sound wave's strong interaction with order-parameter collective modes that exist in the B-phase. Details of a magnet that will be used to achieve such a lens are presented.<>
{"title":"A novel acoustic lens in superfluid /sup 3/He","authors":"G. L. Bullock, B. Shivaram","doi":"10.1109/ULTSYM.1988.49549","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49549","url":null,"abstract":"The authors propose a novel scheme to achieve focusing of sound waves in superfluid /sup 3/He. This scheme exploits the magnetic field dependence of the superfluid phase diagram and the difference in the sound propagation characteristics of the A- and B-phases. Central to the scheme is the dispersion caused by the sound wave's strong interaction with order-parameter collective modes that exist in the B-phase. Details of a magnet that will be used to achieve such a lens are presented.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123226143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-10-02DOI: 10.1109/ULTSYM.1988.49428
B. Khuri-Yakub, J.H. Kim, C. Chou, P. Parent, G. Kino
Air transducers in the 0.5-10-MHz frequency range are made with either one or two matching layers for broadband and efficient coupling of ultrasound into air. The authors present a design for the optimum value of the impedance of a second matching layer of maximum bandwidth and insertion loss. Theoretical designs predict a functional bandwidth of 30% and a two-way insertion loss of 35 dBs for a device operating at 1 MHz. Experimental results are in excellent agreement with theory. Silica aerogel samples are characterized, and designs that demonstrate their potential as matching layers for air transducer applications are shown. Also, results of transmission imaging through carbon-epoxy and Kevlar-epoxy samples are shown.<>
{"title":"A new design for air transducers","authors":"B. Khuri-Yakub, J.H. Kim, C. Chou, P. Parent, G. Kino","doi":"10.1109/ULTSYM.1988.49428","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49428","url":null,"abstract":"Air transducers in the 0.5-10-MHz frequency range are made with either one or two matching layers for broadband and efficient coupling of ultrasound into air. The authors present a design for the optimum value of the impedance of a second matching layer of maximum bandwidth and insertion loss. Theoretical designs predict a functional bandwidth of 30% and a two-way insertion loss of 35 dBs for a device operating at 1 MHz. Experimental results are in excellent agreement with theory. Silica aerogel samples are characterized, and designs that demonstrate their potential as matching layers for air transducer applications are shown. Also, results of transmission imaging through carbon-epoxy and Kevlar-epoxy samples are shown.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"353 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":"124463595","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.1988.49402
Crystal Resonators, Michel Planat
It is shown that the universality and main characteristics of 1/f noise can be understood on the basis of a dispersive wave approach. However, it is noted that 1/f noise in quartz crystals seems to come from nonlinear dispersion. A clear correlation between 1/f noise level and phonon-phonon interactions between 4 K and 50 K has been observed for 10-MHz resonators. This confirms previous correlations observed at room temperature between the noise and the quality factor of bulk and surface wave resonators. A drastic increase of noise is also observed at very low temperature in connection with a glassy-like loss mechanism. On the theoretical side, the wave amplitude is shown to increase at very low frequencies due to the dispersive lattice, leading to nonlinearities. It is shown that the experimental findings can be understood with the help of a one-dimensional nonlinear wave model of the double-well potential type.<>
{"title":"Nature of 1/f phase noise in quartz crystal resonators","authors":"Crystal Resonators, Michel Planat","doi":"10.1109/ULTSYM.1988.49402","DOIUrl":"https://doi.org/10.1109/ULTSYM.1988.49402","url":null,"abstract":"It is shown that the universality and main characteristics of 1/f noise can be understood on the basis of a dispersive wave approach. However, it is noted that 1/f noise in quartz crystals seems to come from nonlinear dispersion. A clear correlation between 1/f noise level and phonon-phonon interactions between 4 K and 50 K has been observed for 10-MHz resonators. This confirms previous correlations observed at room temperature between the noise and the quality factor of bulk and surface wave resonators. A drastic increase of noise is also observed at very low temperature in connection with a glassy-like loss mechanism. On the theoretical side, the wave amplitude is shown to increase at very low frequencies due to the dispersive lattice, leading to nonlinearities. It is shown that the experimental findings can be understood with the help of a one-dimensional nonlinear wave model of the double-well potential type.<<ETX>>","PeriodicalId":263198,"journal":{"name":"IEEE 1988 Ultrasonics Symposium Proceedings.","volume":"129 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":"123183337","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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