Pub Date : 1996-03-19DOI: 10.1109/NRSC.1996.551110
A.I. Balinacy, K. Awadalla, H. Sharshar, S.H. Zainud-Dean
Extensive theoretical investigation of open rectangular loop antenna has been carried out and presented. This antenna consists of a rectangular wire frame, which is open circuited at the mid point of one of its sides and fed from the middle of the opposite side. A monopole version of this antenna is also possible if a ground plane is positioned in the plane perpendicular, to the plane of the antenna, passing by its axis of symmetry and containing the open circuit and the feed points. The radiation characteristics have been determined for perimeter to radius ratio p/a of 200, 400 and 600 respectively for antenna perimeters up to two wavelengths, for different ratios of rectangle sides Hb/Ha. The investigations reveal the broadbanding potential of this type of antenna.
{"title":"Radiation characteristics of open rectangular loop antenna","authors":"A.I. Balinacy, K. Awadalla, H. Sharshar, S.H. Zainud-Dean","doi":"10.1109/NRSC.1996.551110","DOIUrl":"https://doi.org/10.1109/NRSC.1996.551110","url":null,"abstract":"Extensive theoretical investigation of open rectangular loop antenna has been carried out and presented. This antenna consists of a rectangular wire frame, which is open circuited at the mid point of one of its sides and fed from the middle of the opposite side. A monopole version of this antenna is also possible if a ground plane is positioned in the plane perpendicular, to the plane of the antenna, passing by its axis of symmetry and containing the open circuit and the feed points. The radiation characteristics have been determined for perimeter to radius ratio p/a of 200, 400 and 600 respectively for antenna perimeters up to two wavelengths, for different ratios of rectangle sides Hb/Ha. The investigations reveal the broadbanding potential of this type of antenna.","PeriodicalId":127585,"journal":{"name":"Thirteenth National Radio Science Conference. NRSC '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122107354","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}
Pub Date : 1996-03-19DOI: 10.1109/NRSC.1996.551122
S. El-Khamy, F. A. Salem
This paper presents a method of accurate identification using a radar sensor incorporating the matched frequency-hopping spread-spectrum (MFH/SS) technique. Our work is based on the fact that targets of different shapes have different frequency signatures. This means that each target is characterized by a special frequency dependence of the scattering cross-section. Our approach to identifying objects is based on matching the radar receiver circuit to the selected hopping frequencies which give maximum backscattering contribution for different identified targets at different look directions. Also, we suggest a single radar sensor incorporating modified techniques, MFH combined with angle diversity (AD) and cumulative matched frequency hopping (CMFH) for three-dimensional target identification. The results of a simulation study are presented showing the effectiveness of incorporating the MFH/SS technique in the radar sensor for enhancing target identification and provide the redundancy and complementarity provided by multiple sensors.
{"title":"A novel target identification and discrimination scheme using matched spread-spectrum techniques","authors":"S. El-Khamy, F. A. Salem","doi":"10.1109/NRSC.1996.551122","DOIUrl":"https://doi.org/10.1109/NRSC.1996.551122","url":null,"abstract":"This paper presents a method of accurate identification using a radar sensor incorporating the matched frequency-hopping spread-spectrum (MFH/SS) technique. Our work is based on the fact that targets of different shapes have different frequency signatures. This means that each target is characterized by a special frequency dependence of the scattering cross-section. Our approach to identifying objects is based on matching the radar receiver circuit to the selected hopping frequencies which give maximum backscattering contribution for different identified targets at different look directions. Also, we suggest a single radar sensor incorporating modified techniques, MFH combined with angle diversity (AD) and cumulative matched frequency hopping (CMFH) for three-dimensional target identification. The results of a simulation study are presented showing the effectiveness of incorporating the MFH/SS technique in the radar sensor for enhancing target identification and provide the redundancy and complementarity provided by multiple sensors.","PeriodicalId":127585,"journal":{"name":"Thirteenth National Radio Science Conference. NRSC '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124046935","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}
Pub Date : 1996-03-19DOI: 10.1109/NRSC.1996.551426
K. H. Badr, H. El-Motaafy, E. El-Badawy, M. Bayoumy
The design and implementation of MW balanced amplifier operating at 3.5 GHz have been performed using microstrip technology. A duroid substrate of relative permittivity 2.2, and Motorola MRF-9411, L packaged MW transistors are used. A network computer analysis program has been developed to asses the amplifier performance, and its results are compared to the practical measurements of the implemented schematic. The amplifier provides a power gain of 9 dB with input and output VSWR of 1.65, and 1.35 respectively. Such an amplifier can be used in satellite communication, electronic support measure (ESM) receivers, and airborne radar.
{"title":"Design and implementation of MW balanced amplifier using branch-line couplers","authors":"K. H. Badr, H. El-Motaafy, E. El-Badawy, M. Bayoumy","doi":"10.1109/NRSC.1996.551426","DOIUrl":"https://doi.org/10.1109/NRSC.1996.551426","url":null,"abstract":"The design and implementation of MW balanced amplifier operating at 3.5 GHz have been performed using microstrip technology. A duroid substrate of relative permittivity 2.2, and Motorola MRF-9411, L packaged MW transistors are used. A network computer analysis program has been developed to asses the amplifier performance, and its results are compared to the practical measurements of the implemented schematic. The amplifier provides a power gain of 9 dB with input and output VSWR of 1.65, and 1.35 respectively. Such an amplifier can be used in satellite communication, electronic support measure (ESM) receivers, and airborne radar.","PeriodicalId":127585,"journal":{"name":"Thirteenth National Radio Science Conference. NRSC '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121190598","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}
Pub Date : 1996-03-19DOI: 10.1109/NRSC.1996.551139
S. El-Khamy, S. Shaaban, E.A. Thabet
This paper treats the partially coherent detection of continuous phase chirp modulation (CPCM) signals. The optimum partially coherent receiver structures are described. Suboptimum receivers are also described and the corresponding bounds on error rate are calculated for optimum signal parameters. The optimum signal parameters are obtained for each degree of channel coherency by using a search program for the error probability versus the signal parameters.
{"title":"Partially coherent detection of continuous phase chirp (CPCM) signals","authors":"S. El-Khamy, S. Shaaban, E.A. Thabet","doi":"10.1109/NRSC.1996.551139","DOIUrl":"https://doi.org/10.1109/NRSC.1996.551139","url":null,"abstract":"This paper treats the partially coherent detection of continuous phase chirp modulation (CPCM) signals. The optimum partially coherent receiver structures are described. Suboptimum receivers are also described and the corresponding bounds on error rate are calculated for optimum signal parameters. The optimum signal parameters are obtained for each degree of channel coherency by using a search program for the error probability versus the signal parameters.","PeriodicalId":127585,"journal":{"name":"Thirteenth National Radio Science Conference. NRSC '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122324760","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}
Pub Date : 1996-03-19DOI: 10.1109/NRSC.1996.551153
M. Abdelaziz, S. Zakhary, A. A. Ghanem, A. Abdelghaffar
A new design of a broad beam RF ion source is made to deliver currents of 100 /spl mu/A up to 30 mA with extraction voltages 200 V up to 2 kV. Its plasma intensifying system is made with both addition of electrons from an immersed filament in the discharge and axial magnetic field of 70 up to 300 G. Uniform beam density distribution is made with a planner graphite cathode which has a number of holes of varying diameter arranged to produce perveance matching with the normal Gaussian distribution of the beam density variation of the output current is studied with the variation of extraction magnetic field intensity, discharge pressure and electron injection into the plasma. The influence of electron injection into the plasma is found to have a great effect on increasing the extracted current to about four times its value without electron injection. The increase of extraction voltage is limited with the use of electron injection at V/sub ex/>2kV due to the presence of breakdown inside the discharge tube.
{"title":"Preliminary results of a broad beam RF ion source with electron plasma interaction","authors":"M. Abdelaziz, S. Zakhary, A. A. Ghanem, A. Abdelghaffar","doi":"10.1109/NRSC.1996.551153","DOIUrl":"https://doi.org/10.1109/NRSC.1996.551153","url":null,"abstract":"A new design of a broad beam RF ion source is made to deliver currents of 100 /spl mu/A up to 30 mA with extraction voltages 200 V up to 2 kV. Its plasma intensifying system is made with both addition of electrons from an immersed filament in the discharge and axial magnetic field of 70 up to 300 G. Uniform beam density distribution is made with a planner graphite cathode which has a number of holes of varying diameter arranged to produce perveance matching with the normal Gaussian distribution of the beam density variation of the output current is studied with the variation of extraction magnetic field intensity, discharge pressure and electron injection into the plasma. The influence of electron injection into the plasma is found to have a great effect on increasing the extracted current to about four times its value without electron injection. The increase of extraction voltage is limited with the use of electron injection at V/sub ex/>2kV due to the presence of breakdown inside the discharge tube.","PeriodicalId":127585,"journal":{"name":"Thirteenth National Radio Science Conference. NRSC '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125964391","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}
Pub Date : 1996-03-19DOI: 10.1109/NRSC.1996.551425
R. Seireg, A. Vacroux
Transition counting is one of the schemes which is used for testing digital circuits. A relation for the aliasing error probability has been deduced which depends on the length of the input pattern. Previously, we have proved that the final value for aliasing error probability for both linear and counting techniques are similar. However, the practical results indicate that the linear technique has a better performance than the counting technique. We study the dynamic behavior for the counting technique. The results are discussed and compared with the results obtained from the linear technique which supports the empirical and practical conclusions for the superiority of the LFSR.
{"title":"Comparing the dynamic behavior between LFSRs and counting techniques","authors":"R. Seireg, A. Vacroux","doi":"10.1109/NRSC.1996.551425","DOIUrl":"https://doi.org/10.1109/NRSC.1996.551425","url":null,"abstract":"Transition counting is one of the schemes which is used for testing digital circuits. A relation for the aliasing error probability has been deduced which depends on the length of the input pattern. Previously, we have proved that the final value for aliasing error probability for both linear and counting techniques are similar. However, the practical results indicate that the linear technique has a better performance than the counting technique. We study the dynamic behavior for the counting technique. The results are discussed and compared with the results obtained from the linear technique which supports the empirical and practical conclusions for the superiority of the LFSR.","PeriodicalId":127585,"journal":{"name":"Thirteenth National Radio Science Conference. NRSC '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128231926","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}
Pub Date : 1996-03-19DOI: 10.1109/NRSC.1996.551118
H. El Sorady, A. Shoukry, S. Bassiouny
The statistical approach to pattern recognition is among the early approaches applied in this field of research. This paper presents a mixed statistical parametric and neural networks approach for classifiers design. Statistical parametric techniques have the advantage of being mathematically tractable but are often non-optimal due to the need of making some assumptions about the shape of the distribution of the input data samples (e.g. being a multivariate normal distribution) and the need to estimate the distribution parameters (e.g. the mean vector and the covariance matrix) from the training data. On the other hand, neural networks classifiers are model (distribution) free. Therefore, they can be used to improve the performance of an initially given statistical classifier. Computer simulation results are given that show the efficiency of the proposed technique.
{"title":"Improving the parametric Gaussian classifier using neural networks","authors":"H. El Sorady, A. Shoukry, S. Bassiouny","doi":"10.1109/NRSC.1996.551118","DOIUrl":"https://doi.org/10.1109/NRSC.1996.551118","url":null,"abstract":"The statistical approach to pattern recognition is among the early approaches applied in this field of research. This paper presents a mixed statistical parametric and neural networks approach for classifiers design. Statistical parametric techniques have the advantage of being mathematically tractable but are often non-optimal due to the need of making some assumptions about the shape of the distribution of the input data samples (e.g. being a multivariate normal distribution) and the need to estimate the distribution parameters (e.g. the mean vector and the covariance matrix) from the training data. On the other hand, neural networks classifiers are model (distribution) free. Therefore, they can be used to improve the performance of an initially given statistical classifier. Computer simulation results are given that show the efficiency of the proposed technique.","PeriodicalId":127585,"journal":{"name":"Thirteenth National Radio Science Conference. NRSC '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114354322","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}
Pub Date : 1996-03-19DOI: 10.1109/NRSC.1996.551137
K.A.M. Soliman
A fast frequency hopping (FFH) spread spectrum technique (SS) using Gaussian minimum shift keying (GMSK) signals for data modulation and a centre sampling differential detector (CSDD) in restricted bandwidth (BW) Rayleigh channels is analyzed. The performance of the proposed system is analyzed in a two-path Rayleigh fading channel taking into account frequency-selective fading (FSF), carrier random frequency shift, intersymbol interference (ISI), Doppler frequency shift, cochannel interference (CCI) and additive white Gaussian noise (AWGN), while the receiver (RX) rejects a specified amount of adjacent channel interference (ACI). For the interference, we adopt a model which includes N statistically independent faded CCI. It is shown that the CSDD scheme is sensitive to frequency offset and there is a significant improvement in the error rate performance by utilizing the frequency diversity inherent in the FFH system compared to other systems. Therefore, this system can accommodate more users than the others and a better spectrum efficiency can be achieved.
{"title":"Performance of FFH-GMSK signals with CSDD scheme in frequency-selective Rayleigh channels with CCI","authors":"K.A.M. Soliman","doi":"10.1109/NRSC.1996.551137","DOIUrl":"https://doi.org/10.1109/NRSC.1996.551137","url":null,"abstract":"A fast frequency hopping (FFH) spread spectrum technique (SS) using Gaussian minimum shift keying (GMSK) signals for data modulation and a centre sampling differential detector (CSDD) in restricted bandwidth (BW) Rayleigh channels is analyzed. The performance of the proposed system is analyzed in a two-path Rayleigh fading channel taking into account frequency-selective fading (FSF), carrier random frequency shift, intersymbol interference (ISI), Doppler frequency shift, cochannel interference (CCI) and additive white Gaussian noise (AWGN), while the receiver (RX) rejects a specified amount of adjacent channel interference (ACI). For the interference, we adopt a model which includes N statistically independent faded CCI. It is shown that the CSDD scheme is sensitive to frequency offset and there is a significant improvement in the error rate performance by utilizing the frequency diversity inherent in the FFH system compared to other systems. Therefore, this system can accommodate more users than the others and a better spectrum efficiency can be achieved.","PeriodicalId":127585,"journal":{"name":"Thirteenth National Radio Science Conference. NRSC '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133964174","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}
Pub Date : 1996-03-19DOI: 10.1109/NRSC.1996.551135
E. A. Soliet
The recursive least square (RLS) algorithm is insensitive to the dispersions of the correlation matrix. Consequently, the usage of the RLS algorithm to update the adaptive recursive filter coefficients are attractive for the system modeling and identification fields. In this paper, an error function RLS (EFRLS) algorithm is derived for the adaptive recursive filter. Furthermore, a scaled version of the EFRLS algorithm is proposed where the computation complexity is significantly reduced. The scaled EFRLS algorithm can be realized in real time using the available digital signal processors. The convergence to the optimal solution of both the EFRLS algorithm and its scaled version is ensured while the general RLS algorithm fails to converge to the optimal solution for the multimodal performance criterion.
{"title":"RLS solution for the adaptive recursive filter","authors":"E. A. Soliet","doi":"10.1109/NRSC.1996.551135","DOIUrl":"https://doi.org/10.1109/NRSC.1996.551135","url":null,"abstract":"The recursive least square (RLS) algorithm is insensitive to the dispersions of the correlation matrix. Consequently, the usage of the RLS algorithm to update the adaptive recursive filter coefficients are attractive for the system modeling and identification fields. In this paper, an error function RLS (EFRLS) algorithm is derived for the adaptive recursive filter. Furthermore, a scaled version of the EFRLS algorithm is proposed where the computation complexity is significantly reduced. The scaled EFRLS algorithm can be realized in real time using the available digital signal processors. The convergence to the optimal solution of both the EFRLS algorithm and its scaled version is ensured while the general RLS algorithm fails to converge to the optimal solution for the multimodal performance criterion.","PeriodicalId":127585,"journal":{"name":"Thirteenth National Radio Science Conference. NRSC '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114701916","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}
Pub Date : 1996-03-19DOI: 10.1109/NRSC.1996.551130
H. Elkamchouchi, A. Motawea
The design of a radio-frequency or a microwave amplifier, for any load and source impedance, using an analytical design method based on the Smith chart equations is presented. Five different cases are considered namely; (i) maximum gain, (ii) minimum noise figure at both the input and output, (iii) minimum noise figure at the input and maximum gain at the output, (iv) minimum noise figure at the input and a certain gain for the whole network, and (v) broadband output network amplifier design. These designs use the scattering parameters of the transistor and the Smith chart equations and are limited to lossless L-sections only. It is observed that the obtained circuit parameters are accurate compared to those obtained manually working with a Smith chart. Also the broadband design is exact and do not follow the trial and error method used by other authors.
{"title":"Smith chart based analytical design of lumped transistor amplifiers","authors":"H. Elkamchouchi, A. Motawea","doi":"10.1109/NRSC.1996.551130","DOIUrl":"https://doi.org/10.1109/NRSC.1996.551130","url":null,"abstract":"The design of a radio-frequency or a microwave amplifier, for any load and source impedance, using an analytical design method based on the Smith chart equations is presented. Five different cases are considered namely; (i) maximum gain, (ii) minimum noise figure at both the input and output, (iii) minimum noise figure at the input and maximum gain at the output, (iv) minimum noise figure at the input and a certain gain for the whole network, and (v) broadband output network amplifier design. These designs use the scattering parameters of the transistor and the Smith chart equations and are limited to lossless L-sections only. It is observed that the obtained circuit parameters are accurate compared to those obtained manually working with a Smith chart. Also the broadband design is exact and do not follow the trial and error method used by other authors.","PeriodicalId":127585,"journal":{"name":"Thirteenth National Radio Science Conference. NRSC '96","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123959644","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}
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