De nouvelles technologies de couches minces sont indispensables pour integrer les dispositifs a onde acoustique de surface ayant un coefficient de variation thermique nul avec des dispositifs semiconducteurs actifs sur une meme pastille, ce qui donnerait un circuit integre a haute frequence sur support de silicium ou support de silicium sur saphir. Les couches minces de AlN ont un interet dans le domaine du GHz a cause de la vitesse de propagation elevee. Des lignes a retard a coefficient de variation thermique nul fonctionnant au-dela de 1 GHz sont fabriquees avec une combinaison AlN/saphir. Croissance cristalline; evaluation des parametres; pertes de propagation, dispersion en frequence, epaisseur de couches; coefficient de variation thermique du retard; insertion dans le circuit integre; effet de la temperature sur le correlateur d'ondes acoustiques de surface
{"title":"Zero-Temperature-Coefficient SAW Devices on AlN Epitaxial Films","authors":"K. Tsubouchi, Nobuo","doi":"10.1109/T-SU.1985.31647","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31647","url":null,"abstract":"De nouvelles technologies de couches minces sont indispensables pour integrer les dispositifs a onde acoustique de surface ayant un coefficient de variation thermique nul avec des dispositifs semiconducteurs actifs sur une meme pastille, ce qui donnerait un circuit integre a haute frequence sur support de silicium ou support de silicium sur saphir. Les couches minces de AlN ont un interet dans le domaine du GHz a cause de la vitesse de propagation elevee. Des lignes a retard a coefficient de variation thermique nul fonctionnant au-dela de 1 GHz sont fabriquees avec une combinaison AlN/saphir. Croissance cristalline; evaluation des parametres; pertes de propagation, dispersion en frequence, epaisseur de couches; coefficient de variation thermique du retard; insertion dans le circuit integre; effet de la temperature sur le correlateur d'ondes acoustiques de surface","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117189645","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}
Abstmct-High performance has been achieved in SAW convolvers using diffraction-corrected multistrip beam compressors. However, two different levels of metalization are required for optimum performance. A significant simplification of device fabrication was achieved with the design of convolvers using small-aperture chirp transducers, which require only one metalization layer. A design procedure is described that makes the transducers focusing to minimize diffraction loss. Experimental results are presented, which show that performance of this new design surpasses conventional designs in several respects. I. INTRODUCTION M ONOLITHIC acoustic surface wave convolvers on YZ-LiNb03 combine high-speed signal processing capability with ruggedness, small size, and relatively low cost of the device-thanks to the simplicity of its construction. However, the intrinsic nonlinearity of the substrate material polarization, which is used to generate the mixing product of the two input signals, is low and limits the efficiency of the device. High efficiency is crucial to achieve high dynamic range and economize input power. Since the introduction of beamwidth compression [l] to boost device efficiency, the elastic convolver has been developed to high performance in several laboratories [2], [3], [4] by optimization of its various components. The aim of such optimization was to increase the device efficiency by eliminating sources of loss in the acoustic path and providing good match at all electrical ports, while tailoring the device characteristics to minimize signal distortion and suppress spurious signals [5]. This means that the convolution efficiency vs. frequency should be reasonably flat and smooth in magnitude and linear in phase over the desired bandwidth. Notably reflections of acoustic waves in the device have to be suppressed to avoid selfconvolution of one input signal. The distributed output signal has to be collected from the integrating electrode in such a way as to avoid electromagnetic propagation loss or destructive interference of various signal components due to long-line effects. By these considerations one arrives at a standard design scheme as shown in Fig. 1. Interdigital transducers, which convert the input signals, typically are unapodized to avoid
{"title":"Small-Aperture Focusing Chirp Transducers vs. Diffraction-Compensated Beam Compressors in Elastic SAW Convolvers","authors":"H. Grassl, H. Engan","doi":"10.1109/T-SU.1985.31651","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31651","url":null,"abstract":"Abstmct-High performance has been achieved in SAW convolvers using diffraction-corrected multistrip beam compressors. However, two different levels of metalization are required for optimum performance. A significant simplification of device fabrication was achieved with the design of convolvers using small-aperture chirp transducers, which require only one metalization layer. A design procedure is described that makes the transducers focusing to minimize diffraction loss. Experimental results are presented, which show that performance of this new design surpasses conventional designs in several respects. I. INTRODUCTION M ONOLITHIC acoustic surface wave convolvers on YZ-LiNb03 combine high-speed signal processing capability with ruggedness, small size, and relatively low cost of the device-thanks to the simplicity of its construction. However, the intrinsic nonlinearity of the substrate material polarization, which is used to generate the mixing product of the two input signals, is low and limits the efficiency of the device. High efficiency is crucial to achieve high dynamic range and economize input power. Since the introduction of beamwidth compression [l] to boost device efficiency, the elastic convolver has been developed to high performance in several laboratories [2], [3], [4] by optimization of its various components. The aim of such optimization was to increase the device efficiency by eliminating sources of loss in the acoustic path and providing good match at all electrical ports, while tailoring the device characteristics to minimize signal distortion and suppress spurious signals [5]. This means that the convolution efficiency vs. frequency should be reasonably flat and smooth in magnitude and linear in phase over the desired bandwidth. Notably reflections of acoustic waves in the device have to be suppressed to avoid selfconvolution of one input signal. The distributed output signal has to be collected from the integrating electrode in such a way as to avoid electromagnetic propagation loss or destructive interference of various signal components due to long-line effects. By these considerations one arrives at a standard design scheme as shown in Fig. 1. Interdigital transducers, which convert the input signals, typically are unapodized to avoid","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124539322","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}
Abstmct-The theory of the gap-coupled surface acoustic wave p'n diode storage correlator operated in the flash mode is presented. The circuit model used in the analysis of both the storage and the read-out processes is reviewed. The effect of the minority carrier lifetime and the voltage dependence of the diode capacitance are included for the first time in the analysis of the flash-mode writing process. A straightforward transmission line theory approach is developed to find the surface wave amplitude excited by the diode potential during the readout process. The calculated predictions of this theory are in good agreement with experimental data and tend to confirm the possibility of ohtaining efficient storage with a single write-in short pulse. HE FLASH technique was applied to the p'n diode SAW storage correlator by Gautier et al. [l], who were unable to store any signal in the diodes with one write-in short pulse when using a planar vidicon array with a long minority carrier lifetime (60 p). This negative result is explained as follows. The pulse used to charge the array has a duration of 5-10 ns. With a long minority carrier lifetime the holes injected from the p-island into the n-side do not recombine and a large number of these carriers will tend to diffuse back across the junction after the pulse is turned off. The general consensus then was that the use of diffused diode devices was limited to narrow bandwidth signal applications because of the long charging times required; i.e., that the parametric technique should be used in conjunction with diffused pn diodes. Using a V-groove mesa diode structure, Borden and Kino [2] demonstrated that p+n diodes can be charged with a single short pulse and that the charge is stored for milliseconds. They attributed their success to the fact that with such structures the minority carrier lifetime is several orders of magnitude shorter than the planar vidicon array used by other groups. However, the large magnitude of the storage time which they reported seems to contradict the obvious fact that a reduction in the minority carrier lifetime will undoubtedly reduce the storage time. Loh et al. [3], commenting on Borden and Kino's results, concluded that the deliberate introduction of asymmetric, rather than symmetric, trapping levels was responsible for their success in efficiently charging a pfn diode with a single short pulse since the presence of these
{"title":"Theory of the p + n Diode SAW Storage Correlator in the Flash Mode","authors":"M. Nokali","doi":"10.1109/T-SU.1985.31657","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31657","url":null,"abstract":"Abstmct-The theory of the gap-coupled surface acoustic wave p'n diode storage correlator operated in the flash mode is presented. The circuit model used in the analysis of both the storage and the read-out processes is reviewed. The effect of the minority carrier lifetime and the voltage dependence of the diode capacitance are included for the first time in the analysis of the flash-mode writing process. A straightforward transmission line theory approach is developed to find the surface wave amplitude excited by the diode potential during the readout process. The calculated predictions of this theory are in good agreement with experimental data and tend to confirm the possibility of ohtaining efficient storage with a single write-in short pulse. HE FLASH technique was applied to the p'n diode SAW storage correlator by Gautier et al. [l], who were unable to store any signal in the diodes with one write-in short pulse when using a planar vidicon array with a long minority carrier lifetime (60 p). This negative result is explained as follows. The pulse used to charge the array has a duration of 5-10 ns. With a long minority carrier lifetime the holes injected from the p-island into the n-side do not recombine and a large number of these carriers will tend to diffuse back across the junction after the pulse is turned off. The general consensus then was that the use of diffused diode devices was limited to narrow bandwidth signal applications because of the long charging times required; i.e., that the parametric technique should be used in conjunction with diffused pn diodes. Using a V-groove mesa diode structure, Borden and Kino [2] demonstrated that p+n diodes can be charged with a single short pulse and that the charge is stored for milliseconds. They attributed their success to the fact that with such structures the minority carrier lifetime is several orders of magnitude shorter than the planar vidicon array used by other groups. However, the large magnitude of the storage time which they reported seems to contradict the obvious fact that a reduction in the minority carrier lifetime will undoubtedly reduce the storage time. Loh et al. [3], commenting on Borden and Kino's results, concluded that the deliberate introduction of asymmetric, rather than symmetric, trapping levels was responsible for their success in efficiently charging a pfn diode with a single short pulse since the presence of these","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121298528","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}
Wen-Chung Wang, H. Schachter, B. Elasir, Z.S. Wu, S. Onishi
The nonlinear acoustoelectric interactions due to two con- tra-directed surface acoustic waves (SAW) for device geometries, consist- ing of semiconductor thin films, are analyzed in a unified and coherent manner. Main features of the nonlinear interactions to be addressed are biphased characteristics, signal enhancement, symmetry, and surface conditions. The geometries discussed are those utilizing the transverse, the normal and the tangential components of electric fields induced by two contra-directed SAW's through piezoelectric coupling. Experimental results are included. ARIOUS TYPES of acoustoelectric signal processors have been reported ( l)-(21). However, most of the structures discussed so far are with semiconductors of infinite thickness; i.e., larger than several Debye lengths. In this paper the nonlinear acoustoelectric interactions due to two contra- directed surface acoustic waves (SAW) for device geometries, particularly consisting of semiconductor thin films, are analyzed in a unified and coherent manner. Main features of the nonlinear interactions to be addressed are biphased characteristics, signal enhancement, symmetry, and surface conditions. Geometries to be discussed are those utilizing the transverse, the normal and the tangential components of electric fields induced by two contra-directed SAW's through piezoelectric coupling. Assuming that the surface acoustic waves are propagating in the z-direction, substrate surface is in the xz plane and the surface normal is in the y direction. Then, the transverse, normal, and tangential correspond to the directions of x, y, and z, respectively. In the transverse-mode operation, the nonlinear signal generation due to two contra-directed SAW's at both the sum and difference frequencies are zero in the absence of dc biasing due to the symmetry of the device
{"title":"Acoustoelectric Interactions in Thin-Film Semiconductors Induced by Two Contra-Directed Surface Acoustic Waves","authors":"Wen-Chung Wang, H. Schachter, B. Elasir, Z.S. Wu, S. Onishi","doi":"10.1109/T-SU.1985.31648","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31648","url":null,"abstract":"The nonlinear acoustoelectric interactions due to two con- tra-directed surface acoustic waves (SAW) for device geometries, consist- ing of semiconductor thin films, are analyzed in a unified and coherent manner. Main features of the nonlinear interactions to be addressed are biphased characteristics, signal enhancement, symmetry, and surface conditions. The geometries discussed are those utilizing the transverse, the normal and the tangential components of electric fields induced by two contra-directed SAW's through piezoelectric coupling. Experimental results are included. ARIOUS TYPES of acoustoelectric signal processors have been reported ( l)-(21). However, most of the structures discussed so far are with semiconductors of infinite thickness; i.e., larger than several Debye lengths. In this paper the nonlinear acoustoelectric interactions due to two contra- directed surface acoustic waves (SAW) for device geometries, particularly consisting of semiconductor thin films, are analyzed in a unified and coherent manner. Main features of the nonlinear interactions to be addressed are biphased characteristics, signal enhancement, symmetry, and surface conditions. Geometries to be discussed are those utilizing the transverse, the normal and the tangential components of electric fields induced by two contra-directed SAW's through piezoelectric coupling. Assuming that the surface acoustic waves are propagating in the z-direction, substrate surface is in the xz plane and the surface normal is in the y direction. Then, the transverse, normal, and tangential correspond to the directions of x, y, and z, respectively. In the transverse-mode operation, the nonlinear signal generation due to two contra-directed SAW's at both the sum and difference frequencies are zero in the absence of dc biasing due to the symmetry of the device","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126757100","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}
Abstmct-The development of surface acoustic wave (SAW) convolvers and correlators is reviewed. This is followed by the introduction of a new type of monolithic metal-zinc oxide-silicon dioxide-silicon storage correlator. Fabrication and operation of the implant isolated storage correlator, which relies on ion implantation for confinement of storage regions, is detailed. A capacitance-time measurement procedure for evaluation of the charge storage capability of the device is described, and correlation output information is used to estimate the effective recombination rate of the inversion layer charges. Finally, operational characteristics are examined and the new bias stable device is shown to exhibit a 3-dB storage time in excess of 0.5 S. The cited storage time exceeds reported storage times of other structures fabricated in the ZnO-Si0,-Si layered medium configuration.
{"title":"Implant-Isolated SAW Storage Correlator","authors":"S. S. Schwartz, R. Gunshor, R. Pierret","doi":"10.1109/T-SU.1985.31655","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31655","url":null,"abstract":"Abstmct-The development of surface acoustic wave (SAW) convolvers and correlators is reviewed. This is followed by the introduction of a new type of monolithic metal-zinc oxide-silicon dioxide-silicon storage correlator. Fabrication and operation of the implant isolated storage correlator, which relies on ion implantation for confinement of storage regions, is detailed. A capacitance-time measurement procedure for evaluation of the charge storage capability of the device is described, and correlation output information is used to estimate the effective recombination rate of the inversion layer charges. Finally, operational characteristics are examined and the new bias stable device is shown to exhibit a 3-dB storage time in excess of 0.5 S. The cited storage time exceeds reported storage times of other structures fabricated in the ZnO-Si0,-Si layered medium configuration.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124071577","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}
Abstmcr-The correlators considered are fabricated on substrates of GaAs and do not employ overlay films. Radio frequency (RF) input to a correlator is accomplished through the use of conventional interdigital transducers. The output port of the memory correlator is composed of an interdigital structure, each tap of which connects to a GaAs Schottky diode at the edge of the acoustic beam. Resistive channel effects in side-fed Schottky diodes are analyzed and discussed. Detailed operating characteristics for the storage process and its linearity are presented. Similarly detailed analyses of the varactor properties and the correlation process are examined. First principles prediction of the correlator efficiency is shown to be within a few tenths of a dB of the experimental values. Physical bounds on the RF power requirements from the drive circuitry of the memory correlator are presented as a function of the handwidth-time (BT) product for this architecture.
{"title":"Principles of Strip-Coupled SAW Memory Correlators","authors":"R. Wagers","doi":"10.1109/T-SU.1985.31656","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31656","url":null,"abstract":"Abstmcr-The correlators considered are fabricated on substrates of GaAs and do not employ overlay films. Radio frequency (RF) input to a correlator is accomplished through the use of conventional interdigital transducers. The output port of the memory correlator is composed of an interdigital structure, each tap of which connects to a GaAs Schottky diode at the edge of the acoustic beam. Resistive channel effects in side-fed Schottky diodes are analyzed and discussed. Detailed operating characteristics for the storage process and its linearity are presented. Similarly detailed analyses of the varactor properties and the correlation process are examined. First principles prediction of the correlator efficiency is shown to be within a few tenths of a dB of the experimental values. Physical bounds on the RF power requirements from the drive circuitry of the memory correlator are presented as a function of the handwidth-time (BT) product for this architecture.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134516432","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}
Abstmct-The use of SAW convolvers in both communication and signal-processing applications is discussed, with special emphasis given to their role in spread spectrum communications. In particular, noise analysis of the convolver will be presented, which accounts for both external and internal sources of noise.
{"title":"The Use of SAW Convolvers in Spread-Spectrum and Other Signal-Processing Applications","authors":"A. Chatterjee, P. Das, L. Milstein","doi":"10.1109/T-SU.1985.31659","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31659","url":null,"abstract":"Abstmct-The use of SAW convolvers in both communication and signal-processing applications is discussed, with special emphasis given to their role in spread spectrum communications. In particular, noise analysis of the convolver will be presented, which accounts for both external and internal sources of noise.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115739179","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}
Surface acoustic wave (SAW) convolvers and support circuitry have been developed to provide matched filtering of wideband waveforms having lime-bandwidth products exceeding IO3 and continu- ously changing spreading codes for both spread-spectrum communication and wideband radar applications. For spread-spectrum Communication, additional signal processing techniques have been developed to provide correlation of waveforms having time-bandwidth products of IO6 or more with a search window of microseconds for a 100-MHz signal as well as to perform antimultipath processing for data demodulation and for ranging. For wideband radar, high-speed optoelectronic track-and-hold circuits for range gating as well as buffering and charge-coupled-device matrix- matrix-product chips for Doppler processing are being incorporated along with a SAW convolver to provide 0.75-m range resolution and 32 Doppler bins for each of 1280 range bins.
{"title":"Applications of SAW Convolvers to Spread-Spectrum Communication and Wideband Radar","authors":"Iwen Yao, J. Cafarella","doi":"10.1109/T-SU.1985.31660","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31660","url":null,"abstract":"Surface acoustic wave (SAW) convolvers and support circuitry have been developed to provide matched filtering of wideband waveforms having lime-bandwidth products exceeding IO3 and continu- ously changing spreading codes for both spread-spectrum communication and wideband radar applications. For spread-spectrum Communication, additional signal processing techniques have been developed to provide correlation of waveforms having time-bandwidth products of IO6 or more with a search window of microseconds for a 100-MHz signal as well as to perform antimultipath processing for data demodulation and for ranging. For wideband radar, high-speed optoelectronic track-and-hold circuits for range gating as well as buffering and charge-coupled-device matrix- matrix-product chips for Doppler processing are being incorporated along with a SAW convolver to provide 0.75-m range resolution and 32 Doppler bins for each of 1280 range bins.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127233033","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":"Special Issue on SAW Convolvers and Correlators","authors":"Wen‐Chung Wang","doi":"10.1109/T-SU.1985.31644","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31644","url":null,"abstract":"","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"1203 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117305376","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}
Abstmcl-A spread-spectrum system for the transmission of packet voice is presented. A continuously variable slope delta (CVSD) modulator is used to encode speech signals at 16 kilobits per second (kbps). The resulting binary data stream is transmitted in bursts containing 1024 message bits. The bit rate within a burst is 84 kbps, with binary code shift keying (CSK) being employed for data representation. The spreading modulation is direct-sequence (DS) with a code rate of 21.4 MHz. The receiver signal processing is based on the application of SAW elastic convolvers to programmable matched filtering of the continuously changing code patterns. Synchronization is accomplished with the aid of an eleven-hit preamble preceding each data packet. Experimental results on the performance of the spread spectrum modem are presented and compared with theory.
{"title":"An Application of SAW Convolvers to Spread-Spectrum Transmission of Packet Voice","authors":"M. Kowatsch, J. Lafferl, A. Ersoy","doi":"10.1109/T-SU.1985.31661","DOIUrl":"https://doi.org/10.1109/T-SU.1985.31661","url":null,"abstract":"Abstmcl-A spread-spectrum system for the transmission of packet voice is presented. A continuously variable slope delta (CVSD) modulator is used to encode speech signals at 16 kilobits per second (kbps). The resulting binary data stream is transmitted in bursts containing 1024 message bits. The bit rate within a burst is 84 kbps, with binary code shift keying (CSK) being employed for data representation. The spreading modulation is direct-sequence (DS) with a code rate of 21.4 MHz. The receiver signal processing is based on the application of SAW elastic convolvers to programmable matched filtering of the continuously changing code patterns. Synchronization is accomplished with the aid of an eleven-hit preamble preceding each data packet. Experimental results on the performance of the spread spectrum modem are presented and compared with theory.","PeriodicalId":371797,"journal":{"name":"IEEE Transactions on Sonics and Ultrasonics","volume":"61 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1985-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120846202","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：