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1993 IEEE Aerospace Applications Conference Digest最新文献

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Tin whiskers: a case study 锡晶须:一个案例研究
1993 IEEE Aerospace Applications Conference Digest Pub Date : 1993-01-31 DOI: 10.1109/AERO.1993.255322
M.E. McDowell
{"title":"Tin whiskers: a case study","authors":"M.E. McDowell","doi":"10.1109/AERO.1993.255322","DOIUrl":"https://doi.org/10.1109/AERO.1993.255322","url":null,"abstract":"Pure electroplated tin is susceptible to the growth of fibrous whiskers that can produce short circuits and, under some conditions, vacuum metal arcs capable of sustaining hundreds of amps. Typical whiskers are 3-4 mu m in diameter and approach 2 mm in length; they are strong enough to penetrate one layer of conformal coating. The physical and electrical properties of tin whiskers and the reasons for their growth are discussed. A methodology to disposition to use of tin in existing spacecraft hardware is presented. It permits the use of tin when growth conditions are strongly adverse or when the tin-plated components are conformally coated. In cases where whisker growth is considered possible and problematic, removal and replacement, or careful cleaning and conformal coating is required.<<ETX>>","PeriodicalId":136219,"journal":{"name":"1993 IEEE Aerospace Applications Conference Digest","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125855106","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}
引用次数: 24
Spurious phase modulation by crystal filters 晶体滤波器的杂散相位调制
1993 IEEE Aerospace Applications Conference Digest Pub Date : 1993-01-31 DOI: 10.1109/AERO.1993.255334
L. Mallette, K. Ishikawa, J. Varney
{"title":"Spurious phase modulation by crystal filters","authors":"L. Mallette, K. Ishikawa, J. Varney","doi":"10.1109/AERO.1993.255334","DOIUrl":"https://doi.org/10.1109/AERO.1993.255334","url":null,"abstract":"A spurious phase modulation (PM) problem discovered during a satellite thermal vacuum test was traced to a supposedly passive component: a crystal filter. While a literature search showed that this phenomenon has been observed in the past, the effect does not seem to be widely known and is a possible problem in some current designs. The PM was noted in a passive four-pole lattice-type crystal bandpass filter at high drive levels over a narrow temperature range. The modulation sidebands were within the 3-dB bandwidth of the filter and 20 dB below the carrier.<<ETX>>","PeriodicalId":136219,"journal":{"name":"1993 IEEE Aerospace Applications Conference Digest","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132108298","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}
引用次数: 0
Sequential mode adaptive array processing 顺序模式自适应阵列处理
1993 IEEE Aerospace Applications Conference Digest Pub Date : 1993-01-31 DOI: 10.1109/AERO.1993.255332
B. Mahafza, P. Thompson, N. Audeh
{"title":"Sequential mode adaptive array processing","authors":"B. Mahafza, P. Thompson, N. Audeh","doi":"10.1109/AERO.1993.255332","DOIUrl":"https://doi.org/10.1109/AERO.1993.255332","url":null,"abstract":"An approach to operating and processing adaptive arrays to automatically sense and eliminate unwanted signals in the radar echoes while enhancing the reception of the desired target returns is presented. The algorithm is based on synthetic sample aperture radar (SSAMAR) operation and signal processing. No matrix inversion is required, and the weights are computed in a scalar fashion. Jammers are nulled to about -70 dB while the target pattern is improved. The system signal-to-noise ratio is greatly improved. Examples derived from computer simulation are presented to validate and illustrate the technique.<<ETX>>","PeriodicalId":136219,"journal":{"name":"1993 IEEE Aerospace Applications Conference Digest","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123208613","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}
引用次数: 0
Performance modeling of simultaneous TDRSS support of Space Station and Space Shuttle 空间站和航天飞机同步TDRSS支持的性能建模
1993 IEEE Aerospace Applications Conference Digest Pub Date : 1993-01-31 DOI: 10.1109/AERO.1993.255338
C. Tsang
{"title":"Performance modeling of simultaneous TDRSS support of Space Station and Space Shuttle","authors":"C. Tsang","doi":"10.1109/AERO.1993.255338","DOIUrl":"https://doi.org/10.1109/AERO.1993.255338","url":null,"abstract":"Performance modeling of simultaneous tracking and data-relay satellite system (TDRSS) support of existing Space Shuttle and planned Space Station communications is discussed. Eight Ku- and S-band forward and return links are considered. The modeling of each of the communications link includes the modulation format, data rate, convolutional coding, pseudonoise coding, high power amplification, filtering, synchronization, and detection. The interference link models include the modulation format, data rate, pseudonoise coding, filtering, high power amplification, and signal-to-interference ratio. The communication links, with the models described, are simulated by computer and the performance results are presented in an accompanying paper (see ibid., p.11-19).<<ETX>>","PeriodicalId":136219,"journal":{"name":"1993 IEEE Aerospace Applications Conference Digest","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128404499","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}
引用次数: 1
On definition and use of systems engineering processes, methods and tools 关于系统工程过程、方法和工具的定义和使用
1993 IEEE Aerospace Applications Conference Digest Pub Date : 1992-07-01 DOI: 10.1109/AERO.1993.255323
A. Stone, C. Scott, S. Rahmani
{"title":"On definition and use of systems engineering processes, methods and tools","authors":"A. Stone, C. Scott, S. Rahmani","doi":"10.1109/AERO.1993.255323","DOIUrl":"https://doi.org/10.1109/AERO.1993.255323","url":null,"abstract":"A case study on the development and deployment of a systems engineering process for use on commercial avionics systems is discussed. The systems engineering process is presented in the context of the overall product development process, called the common process, which identifies goals, objectives, major milestones and top level activities for the systems engineering, hardware engineering, software engineering, project management and authorization/budgeting processes. The systems engineering development plan is described. The scope of the systems engineering process and its major activities are described. Emphasis is on using techniques that reduce cultural and organizational impact and improve the likelihood that the changes are accepted.<<ETX>>","PeriodicalId":136219,"journal":{"name":"1993 IEEE Aerospace Applications Conference Digest","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125495995","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}
引用次数: 1
Performance results of a 300 degrees linear phase modulator for spaceborne communications applications 星载通信用300度线性相位调制器性能分析
1993 IEEE Aerospace Applications Conference Digest Pub Date : 1900-01-01 DOI: 10.1109/AERO.1993.255335
N. Mysoor, R. Mueller
{"title":"Performance results of a 300 degrees linear phase modulator for spaceborne communications applications","authors":"N. Mysoor, R. Mueller","doi":"10.1109/AERO.1993.255335","DOIUrl":"https://doi.org/10.1109/AERO.1993.255335","url":null,"abstract":"A phase modulator capable of large linear phase deviation, low loss, and wideband operation with good thermal stability is described. The phase modulator was developed for deep space spacecraft transponder (DST) applications at X-band (8.415 GHz) and Ka-band (32 GHz) downlinks. The design uses a two-stage circulator-coupled reflection phase shifter with constant gamma hyperabrupt varactors and an efficient modulator driver circuit to obtain a phase deviation of +or-2.5 rad with better than 8% linearity. The measured insertion loss is 6.6 dB+or-0.35 dB at 8415 MHz. It is shown that measured carrier and relative sideband amplitudes resulting from phase modulation by sinewave and square modulating functions agree well with the predicted results.<<ETX>>","PeriodicalId":136219,"journal":{"name":"1993 IEEE Aerospace Applications Conference Digest","volume":"1 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":"129273622","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}
引用次数: 2
Advanced transponders for deep space applications 用于深空应用的先进应答器
1993 IEEE Aerospace Applications Conference Digest Pub Date : 1900-01-01 DOI: 10.1109/AERO.1993.255336
T.M. Nguyen, S. Kayalar, H. Yeh, C. Kyriacou
{"title":"Advanced transponders for deep space applications","authors":"T.M. Nguyen, S. Kayalar, H. Yeh, C. Kyriacou","doi":"10.1109/AERO.1993.255336","DOIUrl":"https://doi.org/10.1109/AERO.1993.255336","url":null,"abstract":"Three architectures for advanced deep space transponders are proposed. The architectures possess various digital techniques such as fast Fourier transform (FFT), digital phase-locked loop (PLL), and digital sideband aided carrier detection with analog or digital turn-around ranging. Preliminary results on the design and conceptual implementation are presented. Modifications to the command detector unit (CDU) are also presented.<<ETX>>","PeriodicalId":136219,"journal":{"name":"1993 IEEE Aerospace Applications Conference Digest","volume":"59 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":"123979796","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}
引用次数: 3
Microwave feed systems for NASA's beam-waveguide reflector antennas 用于NASA波束波导反射器天线的微波馈电系统
1993 IEEE Aerospace Applications Conference Digest Pub Date : 1900-01-01 DOI: 10.1109/AERO.1993.255328
F. Manshadi
{"title":"Microwave feed systems for NASA's beam-waveguide reflector antennas","authors":"F. Manshadi","doi":"10.1109/AERO.1993.255328","DOIUrl":"https://doi.org/10.1109/AERO.1993.255328","url":null,"abstract":"The major features of a beam waveguide (BWG) antenna and the variety of feed system configurations that can be used with this type of antenna are described. The first BWG antenna built by NASA (DSS 13), and its microwave feed systems and their major components, such as the low noise amplifiers, passive microwave components, and the frequency selective mirrors used for multiple frequency operation or diplexing purpose, are discussed.<<ETX>>","PeriodicalId":136219,"journal":{"name":"1993 IEEE Aerospace Applications Conference Digest","volume":"24 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":"123597138","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}
引用次数: 0
Cost and reliability study for a large array of small reflector antennas for JPL/NASA Deep Space Network (DSN) JPL/NASA深空网络(DSN)大阵列小反射面天线的成本与可靠性研究
1993 IEEE Aerospace Applications Conference Digest Pub Date : 1900-01-01 DOI: 10.1109/AERO.1993.255327
V. Jamnejad, T. Cwik, G. Resch
{"title":"Cost and reliability study for a large array of small reflector antennas for JPL/NASA Deep Space Network (DSN)","authors":"V. Jamnejad, T. Cwik, G. Resch","doi":"10.1109/AERO.1993.255327","DOIUrl":"https://doi.org/10.1109/AERO.1993.255327","url":null,"abstract":"A study performed to estimate the cost of an array of small aperture reflector antennas to be used instead of or in conjunction with the current large reflector antennas of the JPL/NASA Deep Space Network (DSN) is described. The arrays are used for servicing present and future NASA missions that involve smaller spacecraft with limited power and smaller, lower-gain antennas. The advantages of the array configuration in terms of cost and reliability are discussed. A probabilistic determination of the reliability and availability of the array as a function of the number of array elements and the availability of individual array elements is made. The impact of additional marginal elements on the operational availability of the array is studied. Parametric cost and reliability plots are presented and directions for further investigation are outlined.<<ETX>>","PeriodicalId":136219,"journal":{"name":"1993 IEEE Aerospace Applications Conference Digest","volume":"41 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":"123557590","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}
引用次数: 5
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