{"title":"High speed PLL frequency synthesizer with synchronous frequency sweep","authors":"M. A. El-Ela","doi":"10.1109/NRSC.1999.760886","DOIUrl":"https://doi.org/10.1109/NRSC.1999.760886","url":null,"abstract":"A technique for achieving high switching speed of the phase locked loop circuits is introduced and analyzed. This technique is based on using a pretuned signal that helps the PLL to reach the steady state condition in a relatively short time. This signal is temporally superimposed on the loop filter output to tune the voltage controlled oscillator of the loop. The system mathematical model was derived and proved effective in increasing the system stability and decreasing the settling time. Computer simulation and experimental results confirm the theoretical analysis.","PeriodicalId":250544,"journal":{"name":"Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127668932","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":"CAD optimization of hetero-FET structures for efficient operation at millimeter-wave frequencies","authors":"A. Abou-Elnour","doi":"10.1109/NRSC.1999.760931","DOIUrl":"https://doi.org/10.1109/NRSC.1999.760931","url":null,"abstract":"A computationally efficient self-consistent model for characterizing the operation and optimizing the structure of heterostructure field effect transistors (hetero-FETs) is introduced. Using this model one can accurately determine quantization effects inside devices which have complicated structures and different compound materials. The model will be applied to show how the layer structure of different Hetero-FETs can be optimized in order to improve their performance at high frequencies of operation.","PeriodicalId":250544,"journal":{"name":"Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120936032","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 eigen space approach for the synthesis of circular arrays","authors":"A.-E.-F.A. Abou-Hashem, S. El-Khamy","doi":"10.1109/NRSC.1999.760880","DOIUrl":"https://doi.org/10.1109/NRSC.1999.760880","url":null,"abstract":"An eigen space non-iterative technique for the synthesis of both linear and circular arrays is examined. The technique is applicable in the case of equi-spaced linear arrays with equal phase and symmetric excitation coefficients and circular arrays with quadrant symmetry, with the number of elements divisible by 4. The technique is based on formulating the synthesis process as a least-squared optimization problem. Some design examples are presented to illustrate the potential and the quality of the considered technique.","PeriodicalId":250544,"journal":{"name":"Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121135523","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 generic processing structure decomposing the beamforming process of 2-D and 3-D arrays of sensors into sub-sets of coherent process","authors":"A. Tawfik","doi":"10.1109/NRSC.1999.760909","DOIUrl":"https://doi.org/10.1109/NRSC.1999.760909","url":null,"abstract":"This paper details the development of a generic beamforming structures for multidimensional sensor arrays with passive and active capabilities. A new approach of the implementation of conventional beamforming for planar, cylindrical and spherical arrays is proposed. This approach is based on decomposing the 2-D and 3-D beamforming process into sets of line and/or circular array beamformers which lead to an efficient implementation. Furthermore, this new approach makes the incorporation of adaptive schemes feasible.","PeriodicalId":250544,"journal":{"name":"Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116494563","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 efficient image compression technique using variable quadtree resolution and neural networks","authors":"A. Wahdan, A. Badr, T. Mostafa","doi":"10.1109/NRSC.1999.760900","DOIUrl":"https://doi.org/10.1109/NRSC.1999.760900","url":null,"abstract":"We propose to realize the use of quadtree image decomposition with neural networks for the target of obtaining compression results better than the algorithms that are based mainly on neural networks. The process of iterative image decomposition is based mainly on a constant block identifier which depends on the characteristics of the human visual system.","PeriodicalId":250544,"journal":{"name":"Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122489545","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":"Frequency-hopped multi-user chirp modulation (FH/M-CM) for multipath fading channels","authors":"S. El-Khamy, S. Shaaban, E.A. Thabet","doi":"10.1109/NRSC.1999.760890","DOIUrl":"https://doi.org/10.1109/NRSC.1999.760890","url":null,"abstract":"The multi-user chirp modulation (M-CM) technique was introduced previously by the author as an efficient multiple-access technique using chirp modulation spread-spectrum signals. To further improve the performance of M-CM in multipath dispersive channels we suggest the application of frequency hopping (FH) to M-CM. The band of M-CM multiplexed signals is frequency-hopped within the allowed channel bandwidth. The application of FH is shown to highly improve the performance of M-CM signals in multipath fading dispersive channels. The considered channel model is a generalized channel model that allows dispersion and flat fading due to multipath propagation. Closed form expressions for the upper bound on the error probability for FH/M-CM is derived and investigated for different cases of channel dispersion and multiple-access parameters.","PeriodicalId":250544,"journal":{"name":"Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125699547","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":"Realization of FPGA-based two dimensional discrete cosine transform","authors":"H.B. Helal, A. Salama, S. Mashali","doi":"10.1109/NRSC.1999.760887","DOIUrl":"https://doi.org/10.1109/NRSC.1999.760887","url":null,"abstract":"A new algorithm for the computation of a 2-D DCT is presented, the computational complexity as measured in terms of the number of multiplications and additions is kept to a minimum, the algorithm is amenable to implementation using field programmable gate arrays (FPGAs). An example of a 4/spl times/4 2-D DCT is presented, and its performance is evaluated.","PeriodicalId":250544,"journal":{"name":"Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125927827","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 powerful simulation technique suitable for performance studies of various CSMA/CD LANs","authors":"S.A. El-Hadi, S. El-Ramly, I. El-Emary","doi":"10.1109/NRSC.1999.760899","DOIUrl":"https://doi.org/10.1109/NRSC.1999.760899","url":null,"abstract":"One of the growing area in the communication industry is the inter-network of the increased proliferation of computers, particularly via local area network (LAN). Many commercial LAN which use CSMA/CD as an access protocol, claim the ability to support hundreds of stations. We present a tool for use in performance studies of such networks when the number of stations is large. The proposed tool is a simulation technique, which requires partitioning the network stations into a few primary stations and the remainder as background stations. The background stations are modeled as a group by a background algorithm based on a dynamic CSMA/CD model which uses a set of probabilities and sampling to produce in a recurrent manner, a stochastic sequence of busy/idle periods. Through simulation results, it is proved that the suggested simulation technique is more powerful and efficient than discrete-event simulation specially when the number of network stations is large enough because the probabilistic simulation technique proposed in this paper needs less rum time on the computer and small storage capacity.","PeriodicalId":250544,"journal":{"name":"Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131356554","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":"DIBL coefficient in short-channel NMOS transistors","authors":"H. Ghitani","doi":"10.1109/NRSC.1999.760932","DOIUrl":"https://doi.org/10.1109/NRSC.1999.760932","url":null,"abstract":"A study of the drain induced barrier lowering (DIBL) effect in short-channel NMOS transistors is presented. The study is based on the two dimensional analytical solution of Poisson equation in the depletion region under the gate. A closed form analytical expression for the DIBL coefficient is derived and its temperature dependence is investigated. The numerical results obtained are in close agreement with the experimental data. The derived expression could be efficiently used in circuit simulation programs.","PeriodicalId":250544,"journal":{"name":"Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124384045","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 dose rate meter and a personal pocket dosimeter realization in a single chip","authors":"I. Mahmoud","doi":"10.1109/NRSC.1999.760944","DOIUrl":"https://doi.org/10.1109/NRSC.1999.760944","url":null,"abstract":"A single chip realization of a circuit, which implements both accumulated doses and dose rate meter functions, is described. A PIC 16C84 microcontroller is combined with a H.V. power supply, a GM detector and a shaping circuit to form the proposed single chip personal dosimeter instrument. Battery checking function is also implemented. The accumulated doses are read reliably without adding any PIC RS-232 level translator chips. The reader can be either a stand-alone device with RS-232 port for remote transmission to any PC or a PC with a parallel port. Very low power consumption (<2 mA at 5 V, 4 MHz); wide operating voltage range (2 to 6 V), simplicity and maintainability (single 18-pin DIP chip of PIC 16C84) are assured. These attractive features in conjunction with enhanced functionality and flexibility of programmed devices make it an excellent choice for personal dosimeter instruments.","PeriodicalId":250544,"journal":{"name":"Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)","volume":"397 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115924667","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}