{"title":"Observations on Non-Linearities in SAW Devices Employing Narrow-Aperture Slanted Chirp Transducers","authors":"M. Lewis","doi":"10.1109/ULTSYM.1985.198485","DOIUrl":"https://doi.org/10.1109/ULTSYM.1985.198485","url":null,"abstract":"Acoustic non-linearities can be observed when narrow-aperture high frequency surface acoustic wave devices are operated at high power levels. Previous investigations into this topic have mainly been concerned with the generation of harmonic frequencies from a single input tone. The present paper extends this work in two respects. Firstly, it describes an experimental and theoretical investigation into a problem of considerable practical interest, namely the generation of third-order intermodulation products in the presence of two (or more) input frequencies. The second topic of this paper is a description of a two-dimensional SAW structure (employing slanted chirp tranducers) in which such intermodulation effects are minimised by causing different frequency components to traverse physically distinct paths. Some possible applications of such devices are described.","PeriodicalId":240321,"journal":{"name":"IEEE 1985 Ultrasonics Symposium","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125069595","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}
{"title":"Backscatter of Acoustic Signals from Inhomogeneities in Composites","authors":"A. Buoncristiani, B. T. Smith","doi":"10.1109/ULTSYM.1985.198680","DOIUrl":"https://doi.org/10.1109/ULTSYM.1985.198680","url":null,"abstract":"","PeriodicalId":240321,"journal":{"name":"IEEE 1985 Ultrasonics Symposium","volume":"454 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122942813","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}
{"title":"Ultrasonic Transducer Arrays Made from Composite Piezoelectric Materials","authors":"A. Shaulov, W. A. Smith","doi":"10.1109/ULTSYM.1985.198590","DOIUrl":"https://doi.org/10.1109/ULTSYM.1985.198590","url":null,"abstract":"A method for providing a curved composite ultrasound transducer of a relatively large size. A blank of piezoceramic material has its rear side reticulated with a series of relatively coarse grooves. The front side of the material is reticulated with a series of relatively deep fine grooves to provide a matrix of upstanding piezoceramic rods. The spaces between the rods on the front side of the blank are therefore filled with a curable polymeric resin (epoxy). The resin filling the blank spaces on the front side is partially cured. After partial curing, the blank is placed into a spherical compression mold and molded so that its front side is formed concave and its rear side convex. The resin is cured while holding the molded blank under pressure in the mold until the resin has cured. After curing, the blank is removed from the mold and the back side is ground away to provide a spherically curved transducer having a multiplicity of individual piezoceramic rods disposed in a matrix of cured resin.","PeriodicalId":240321,"journal":{"name":"IEEE 1985 Ultrasonics Symposium","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123551062","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}
{"title":"A High Time Resolution Polarimeter Spectrometer for Radio Astronomy","authors":"P. J. Hall","doi":"10.1109/ULTSYM.1985.198492","DOIUrl":"https://doi.org/10.1109/ULTSYM.1985.198492","url":null,"abstract":"This paper describes a high time resolution radio polarimeter spectrometer based on SAW spectrum analysers. The bandwidth of the prototype instrument is about 30 Xz; time and frequency resolutions of the basic processor are 2.4 us and 650 kHz. Spectra for the Stokes wave polarization parameters are obtainable, allowing complete characterization of incident radiation. The data rate problem usually encountered when SAW chirp Fourier transformers are interfaced to digital post-transformation processors has been overcome with the development of a fast, digital spectrum integrator. This allows the SAW IF processor to work in conjunction with general-purpose computers, giving an observing system with an overall time resolution of around 150 ps. The radiometric efficiency of the new instrumentation compares favourably with that of other radio astronomy spectrometers.","PeriodicalId":240321,"journal":{"name":"IEEE 1985 Ultrasonics Symposium","volume":" 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113951791","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}
{"title":"Evaluation of Scattering Loss in Polycrystalline Materials by Line-Focus-Beam Acoustic Microscope","authors":"J. Kushibiki, Y. Matsumoto, N. Chubachi","doi":"10.1109/ULTSYM.1985.198603","DOIUrl":"https://doi.org/10.1109/ULTSYM.1985.198603","url":null,"abstract":"An application of the line-focus-beam acoustic microscope system is investigated to the structural and quantitative analysis of polycrystalline materials. This is made by measuring frequency dependence of propagation attenuation of leaky SAWs which are excited on the boundary between a coupling liquid of water and sample to be examined. A sample of Mn-Zn ferrite with average grain size of 8 um is employed for the investigation at a frequency range from 50 to 300 MHz. A measured propagation attenuation shows remarkable frequency dependence. The scattering loss for leaky SAWs is estimated from the measured propagation attenuation based on theoretical analysis of the propagation characteristics, taking the scattering effect at the grain boundary into consideration. Further, the relation of scattering loss between bulk wave and leaky SAW properties of materials is discussed by measurements of propagation attenuation of longitudinal waves for the same sample. By the experiments, the scattering loss for shear waves is measured to be about seven times as large as that of longitudinal waves. This result reveals that the scattering characteristics of leaky SAWs are dominated by the scattering loss of shear wave components.","PeriodicalId":240321,"journal":{"name":"IEEE 1985 Ultrasonics Symposium","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129944025","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}
{"title":"A Coupling Method for Non-Destructive Evaluation Using an Interdigital Transducer","authors":"T. Nomura, T. Yasuda","doi":"10.1109/ULTSYM.1985.198678","DOIUrl":"https://doi.org/10.1109/ULTSYM.1985.198678","url":null,"abstract":"","PeriodicalId":240321,"journal":{"name":"IEEE 1985 Ultrasonics Symposium","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130934750","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}
{"title":"KLN Transducer Model Implementation Using Transfer Matrices","authors":"A. R. Selfridge, S. Gehlbach","doi":"10.1109/ULTSYM.1985.198637","DOIUrl":"https://doi.org/10.1109/ULTSYM.1985.198637","url":null,"abstract":"","PeriodicalId":240321,"journal":{"name":"IEEE 1985 Ultrasonics Symposium","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121955352","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}
{"title":"An Algorithm for Flaw Detection and Sizing in Offshore Steel Structures","authors":"A. Brown, A. Al-Khalili","doi":"10.1109/ULTSYM.1985.198563","DOIUrl":"https://doi.org/10.1109/ULTSYM.1985.198563","url":null,"abstract":"maintain a history of the flan throughout the volume of material sampled. Sucessive samples taken at different locations are then accumulated to produce a sharp image of the flan. This paper describes an algorithm for locating and sizing flaws in steel structures, in particular offshore oil rigs. The algorithm depends on the use of electronic beam steering and a personal computer mouse to correlate flaw data with position. The mouse is rolled over the surface to be investigated. At each new location, the probe collects","PeriodicalId":240321,"journal":{"name":"IEEE 1985 Ultrasonics Symposium","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115861752","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}
{"title":"Efficient Modeling of Transduction and Reflection Properties of Finite Aperiodic SAW Transducers","authors":"O. Manner, A. Baghai-Wadji, E. Ehrmann-Falkenau","doi":"10.1109/ULTSYM.1985.198481","DOIUrl":"https://doi.org/10.1109/ULTSYM.1985.198481","url":null,"abstract":"Our paper describes the modeling of finite, aperiodic SAW transducers of arbitrary polarity sequence and phasing in the presence of reflections caused by field shorting and mass loading. Electrostatic interactions are described by a chargepotential interrelation (CPI) matrix, and the coupling to surface waves by a mixed nodal impedance/scattering (MNIS) formalism which completely accounts for electroacoustic interactions within the transducer. Starting with the solution of the electrostatic problem, we compute the acoustically induced charge distribution, the excited SAW, and the reflection coefficient, input conductance and susceptance of the IDT. The susceptance is obtained directly without the need of a Hilbert transform. By exploiting special properties of the CPI and MNIS matrices, we present an algorithm whose computer time and memory requirements increase only linearly with the finger count of the IDT. As an example, the Hanma-Hunsinger singlephase unidirectional transducer (SPUDT) configuration is analyzed and its tripletransit suppression performance evaluated. This SPUDT is of particular interest because it requires no extra metallization step.","PeriodicalId":240321,"journal":{"name":"IEEE 1985 Ultrasonics Symposium","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121206140","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}