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Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)最新文献

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The design and simulation of FIFO using self-timed based asynchronous circuit elements 基于自定时异步电路元件的FIFO设计与仿真
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711467
H. T. Bahbouh, A. Ezzat Salama, A. Khalil
{"title":"The design and simulation of FIFO using self-timed based asynchronous circuit elements","authors":"H. T. Bahbouh, A. Ezzat Salama, A. Khalil","doi":"10.1109/NRSC.1998.711467","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711467","url":null,"abstract":"The objective of this paper is to introduce the basic elements utilized in the design of asynchronous circuits. CMOS designs are implemented. The performance of these elements is evaluated using SPICE simulator. FIFO pipelined structure was implemented utilizing self-timed asynchronous elements.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"445 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133904082","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
Characterisation of depolarisation of radio signals by single trees at 20 GHz 用20千兆赫的单树来描述无线电信号的去极化
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711457
R. Stephens, M. Al-Nuaimi, R. Caldeirinha
{"title":"Characterisation of depolarisation of radio signals by single trees at 20 GHz","authors":"R. Stephens, M. Al-Nuaimi, R. Caldeirinha","doi":"10.1109/NRSC.1998.711457","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711457","url":null,"abstract":"Measurements investigating how vegetation depolarises a propagating signal have been performed and presented for a number of different trees. From the measurements it can be seen that significant depolarisation takes place at the rotation angles which coincide with the measured nulls of the 360/spl deg/ attenuation patterns especially for the conifer trees. In some cases, it has been seen that the transmitted vertical linearly polarised wave has been depolarised to a near horizontally polarised wave by the vegetation material. The depolarisation occurs as a result of the various components of the tree having currents induced in them. The various tree components are then re-transmitting the waves at different polarisations resulting in an overall depolarisation of the originally transmitted wave. With the metal tree it can be seen that the amount of depolarisation increases as more and more branches are added to the structure. This shows that the various components of the tree are responsible for the depolarisation of the incident signal.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128316184","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: 9
Performance prediction of superconducting transmission lines using an improved two-fluid model 基于改进双流体模型的超导输电线路性能预测
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711514
M. Eleiwa
{"title":"Performance prediction of superconducting transmission lines using an improved two-fluid model","authors":"M. Eleiwa","doi":"10.1109/NRSC.1998.711514","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711514","url":null,"abstract":"The two-fluid model, coupled with London equations, which account for both perfect conductivity and perfect diamagnetism, is used to yield the classical model of superconductivity. The classical model fails at temperatures close to the critical temperature. Therefore, this paper suggests an improved model, in which the temperature dependence of the superconducting parameters, are evaluated using Ginzburg-Landau theory, only near Tc. The improved model is then applied to characterize high Tc superconductors; YBCO, for example. The improved model is verified by comparing the calculated parameters for different superconductors with the corresponding published data. The model is then used to predict the performance of superconducting TEM transmission lines. The analysis reveals how the superconducting lines are advantageous over their ohmic (copper, for example) counterparts because they not only reduce signal attenuation but also allow dispersionless wave propagation.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"02 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130634818","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
The penetration of nuclear electromagnetic pulses (EMP) through shielded communication cables 核电磁脉冲(EMP)通过屏蔽通信电缆的穿透
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711517
S. El-Khamy, S. Shaaban, A. El-Gendy
{"title":"The penetration of nuclear electromagnetic pulses (EMP) through shielded communication cables","authors":"S. El-Khamy, S. Shaaban, A. El-Gendy","doi":"10.1109/NRSC.1998.711517","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711517","url":null,"abstract":"In this paper, we investigate the penetration characteristics of short electromagnetic pulses generated by nuclear explosions (EMP) through communication cables. A model is developed for determining the transient currents and voltages induced within a long coaxial cable by a short electromagnetic pulse. The two cases of cables located above (aerial cables) and within a half-space lossy dielectric (buried cables) are considered. The induced sheath currents and internal voltages are computed in both frequency and time domains. The effects of different cable parameters as well as the angle of wave incidence have been investigated and discussed for both aerial and buried coaxial cables.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115535859","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
VLSI array processor implementation of quasi-block state-space IIR digital filters VLSI阵列处理器实现准块状态空间IIR数字滤波器
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711464
E. Abdel-Raheem, A. Tawfik
{"title":"VLSI array processor implementation of quasi-block state-space IIR digital filters","authors":"E. Abdel-Raheem, A. Tawfik","doi":"10.1109/NRSC.1998.711464","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711464","url":null,"abstract":"A new array processor implementation of IIR digital filters is proposed with a high input sampling rate which is not limited by the speed of the processor elements involved. The proposed implementation is based on the quasi-block state-space description of IIR digital filters corresponding to the case of parallel combination of second-order sections. Performance comparison (in terms of hardware complexity and speed) of the proposed implementation with another existing implementation is also presented.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126578392","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
A novel squeezable elliptical arrays for sector scanning antennas 扇形扫描天线的一种新型可压缩椭圆阵列
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711456
S. El-Khamy, A. Abou-Hashem
{"title":"A novel squeezable elliptical arrays for sector scanning antennas","authors":"S. El-Khamy, A. Abou-Hashem","doi":"10.1109/NRSC.1998.711456","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711456","url":null,"abstract":"A new method of beam steering and scanning using elliptical arrays is analyzed in this paper. The analysis is based on the idea that the elliptical array with the same feeding and geometry of the circular array that adjusted originally to give a main beam at a certain direction will orient the main beam towards another direction according to a certain transformation. The elliptical array can be obtained by mechanically squeezing the circular array elements. The new technique of scanning has a great advantage over classical mechanical scanning systems represented in keeping the antenna aperture itself fixed. This advantage yields no need for the large amount of power exhausted in mechanically moving the heavy antenna system beside the mechanical problems of that system.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128868807","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
Error rate of coherent modulation techniques for land mobile satellite channel 陆地移动卫星信道相干调制技术的误差率
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711476
S. El-Agooz, G. Mabrouk, E. Eweda
{"title":"Error rate of coherent modulation techniques for land mobile satellite channel","authors":"S. El-Agooz, G. Mabrouk, E. Eweda","doi":"10.1109/NRSC.1998.711476","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711476","url":null,"abstract":"This paper evaluates the error rate of four coherent modulation techniques namely quadrature phase shift keying (QPSK), quadrature partial response signaling (QPRS), 16-ary phase shift keying (16-ary PSK), and 16-ary quadrature amplitude modulation (16-QAM). The channel exhibits fading and shadowing as well as additive white Gaussian noise. Fading and shadowing cause both envelope and phase variations of the received signal. For QPSK, 16-ary PSK, and 16-QAM signaling schemes a raised-cosine pulse of 0.235 roll-off factor has been used. Regarding the envelop variations, the paper shows that QPRS and 16-QAM have approximately the same bit error rate performance. However, 16-QAM has a spectral efficiency twice that of QPRS. QPSK has the lowest bit error probability but it also has the lowest spectral efficiency. The 16-ary PSK has the highest bit error probability compared with the other modulation schemes. Regarding the phase variations, the performance of all techniques at high signal-to-noise ratio (SNR) becomes independent of SNR and the performance of 16-ary PSK becomes dominant.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133260211","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
Automatic recognition of the sonar signals using neural network 利用神经网络对声纳信号进行自动识别
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1900-01-01 DOI: 10.1109/NRSC.1998.711495
O. Abdel Allim, H. Fahmy Hashem
{"title":"Automatic recognition of the sonar signals using neural network","authors":"O. Abdel Allim, H. Fahmy Hashem","doi":"10.1109/NRSC.1998.711495","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711495","url":null,"abstract":"Much work has been performed in the area of automatic recognition of sonar signals in order to reduce the operator load when confronted with many beams of data concurrently. This paper describes a neural network system which is capable of recognizing different types of sonar signals. The given results show that neural network techniques have potential as possible implementation solutions for the recognition functions of targets with complex geometrical shape.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","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":"122628546","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
Wideband measurements and modeling of the indoor radio channel at 10 GHz. II. Time domain analysis 10ghz室内无线信道的宽带测量和建模。2时域分析
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1900-01-01 DOI: 10.1109/NRSC.1998.711459
A. Abouraddy, S. Elnoubi, A. El-Shafei
{"title":"Wideband measurements and modeling of the indoor radio channel at 10 GHz. II. Time domain analysis","authors":"A. Abouraddy, S. Elnoubi, A. El-Shafei","doi":"10.1109/NRSC.1998.711459","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711459","url":null,"abstract":"For pt.I see ibid., p.B13/1 to B13/8. In this paper the time domain (impulse response) of the indoor radio channel at 10 GHz is investigated. A discrete mathematical model is used to compute the rms delay spread and the maximum delay spread of the channel for different thresholds defined with respect to the peak line-of-sight component. Results concerning the number of received multipath components and the probability of occupancy of a certain delay time are given.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"140 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":"122414647","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
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