Abstract—Mobile WiMAX is a broadband wireless solution that enables convergence of mobile and fix... more Abstract—Mobile WiMAX is a broadband wireless solution that enables convergence of mobile and fixed broadband networks through a common wide area broadband radio access technology and flexible network architecture. It adopts Orthogonal Frequency Division Multiple Access (OFDMA) for improved multi-path performance in Non-Line-Of-Sight (NLOS) environments. Scalable OFDMA (SOFDMA) is introduced in the IEEE 802e[1]. WIMAX system uses one of different types of channel coding but The mandatory channel coding scheme is based on binary nonrecursive Convolutional Coding (CC). There are other several optional channel coding schemes such as block turbo codes, convolutional turbo codes, and low density parity check (LDPC). In this paper a comparison between the performance of WIMAX using turbo code and using convolutional product code (CPC) [2] is made. Also a combination between them had been done. The CPC gives good results at different SNR values compared to both the turbo system, and the co...
IEEE Transactions on Antennas and Propagation, 1984
ABSTRACT Simple closed formula is given to determine the resistive part of the loop antenna input... more ABSTRACT Simple closed formula is given to determine the resistive part of the loop antenna input impedance. An equivalent transmission line is used to determine the reactive part of the input impedance for the same loop, and the antenna in both cases may have any regular configuration. This method has proved to be accurate for a loop perimeter up to 0.5 lambda for the resistive part and up to 0.8 lambda for the reactive part.
Abstract—A design of multilayer dielectric resonator antenna transmitarray for fixed radio freque... more Abstract—A design of multilayer dielectric resonator antenna transmitarray for fixed radio frequency identification (RFID) reader applications is presented at 5.8GHz. Three layers square dielectric resonator antenna (DRA) elements are mounted on dielectric substrate and used as a unit cell in the transmitarray. A circularly polarized 9×9 square DRA transmitarray is designed at 5.8GHz for far-field RFID applications. The transmitarray produces maximum gain of 20.2 dB. The right-hand circular polarization level is lower than −31 dB at the designed frequency with SLL of −22 dB. A design of 9 × 9 near-field focused DRA transmitarray for fixed RFID at 5.8GHz is investigated. The properties of the near field-focused transmitarray are compared with that of the far field transmitarray designed at the same operating frequency. 1.
The radiation characteristics of the single-element cylindrical dielectric resonator antenna moun... more The radiation characteristics of the single-element cylindrical dielectric resonator antenna mounted on the surface of a metallic hollow circular cylindrical structure are explained. The effect of the radius of curvature on the return loss, input impedance, standing wave ratio, and radiation patterns is investigated. The finite element method and the method based on the finite integration technique are used to calculate the radiation characteristics of the antenna.
Proceedings of the Twenty-First National Radio Science Conference, 2004. NRSC 2004., 2004
The electromagnetic characteristics of a Koch fractal antenna as an element and as an array are e... more The electromagnetic characteristics of a Koch fractal antenna as an element and as an array are extensively examined. The method of moments is used to analyze the antenna structure. The characteristics of the Koch fractal monopole antenna on portable radio equipment are investigated. The use of the Koch fractal monopole can reduce the length of the antenna, decrease the current
ABSTRACT Nanoantennas have been introduced for different applications as solar-cell, medical imag... more ABSTRACT Nanoantennas have been introduced for different applications as solar-cell, medical imaging, and fast data communications. The material properties of good conducting metals introduce plasmonic behavior at terahertz frequencies. The electrical properties of different good conducting metals are modelled using the Drude model and have been investigated for reflectarray/ transmitarray operation. The radiation characteristics of nano-dielectric resonator antenna (NDRA) reflectarray at 633 nm have been investigated. The unit-cell consists of NDR mounted on the metallic supporting plane. A parametric study for the NDR unit cell dimensions and material has been introduced. The NDR unit-cell with silver supporting plane has been designed and analyzed for reflectarray applications at 633 nm. The radiation characteristics of the NDRA transmitarray has been introduced for 633 nm applications. The NDR unit-cell consists of two NDRs mounted on the top and bottom of the metallic supporting plane. A comparison between the radiation characteristics of 17×17 and 21×21 NDRA transmitarray has been introduced. A compromise between the nano-transmitarray size, maximum gain, and operating bandwidth is applied to terahertz applications. The finite integral technique is used to carry a full wave analysis to design an NDRA reflectarray and an NDRA transmitarray..
Octafilar helical antenna (OFHA) is proposed for handheld ultra‐high‐frequency (UHF) radio freque... more Octafilar helical antenna (OFHA) is proposed for handheld ultra‐high‐frequency (UHF) radio frequency identification (RFID) reader. The investigated antenna configuration consists of OFHA placed on reader device in the presence of human hand model. The antenna is designed at UHF band centered at 915 MHz. The antenna return loss, axial ratio, gain, co‐polarized and cross‐ polarized field components are calculated using the finite element method (FEM) and compared with that calculated by finite integration technique (FIT) for verification of the simulated results. A comparison between the performance of the quadrifilar helical antenna (QFHA) and the octafiliar helical antenna (OFHA) designed at 915 MHz in the presence of the reader device and human hand model is investigated. The OFHA introduces high gain, high front to back ratio, good axial ratio and omnidirectional coverage.
Computer solutions of monopole antennas at the center of circular ground planes have previously b... more Computer solutions of monopole antennas at the center of circular ground planes have previously been applied to the calculation of their input impedance through the use of magnetic edge currents. An alternative approach based on approximate physical currents is shown to give good agreement for both radiation patterns and input impedances.
In this paper, the performances of the neural-network approach for discrimination of the landmine... more In this paper, the performances of the neural-network approach for discrimination of the landmine depth from the ground surface and the landmine radius are carried out. A sensor for landmines detection consists of two microstrip antennas is used. One of the antennas is used as transmitting antenna and the second is considered as receiving antenna. Circular cylindrical shape metallic landmine is used. The neural-network process data are obtained from the FDTD formulation of the electromagnetic scattering. The inputs in the input layer of the neural network are the magnitude of the mutual coupling between the microstrip antennas, |..S21| while the outputs are landmine depth from the ground surface and landmine radius. Good agreement with exact profile has been observed. The computation time and computer memory of the inverse problem are considerably reduced.
A novel compact circularly-polarized (CP) multi-band square microstrip antenna with diagonal slot... more A novel compact circularly-polarized (CP) multi-band square microstrip antenna with diagonal slots and a pair of truncated corners is introduced. To prevent interference problems due to compact microstrip antenna, an efficient electromagnetic band gap (EBG) structure is included. The EBG is used to reject the surface waves. This rejection of surface waves improves operational band width, gain and directivity. Details of the simulation results are presented and discussed.
This paper presents a new radio frequency identification (RFID) chipless tag operating in the fre... more This paper presents a new radio frequency identification (RFID) chipless tag operating in the frequency span 3.5-4.3 GHz. This frequency band can be used for chipless RFID systems in the case of car-to-infrastructure (C2I) communication and may be used in automatic reading of road signs. It focuses on the integration of the antenna and multiresonator structures to form the chipless RFID tag. The tag consists of triangle microstrip filter. A 6-bit chipless tag is designed. The bits are encoded into the spectrum hence the tag has a unique spectral signature. The chipless tag is comprised of a vertically polarized circular UWB microstrip monopole receiving tag antenna, a multiresonating circuit and a horizontally polariz ed circular UWB microstrip monopole transmitting tag antenna. The multiresonating circuit is designed by cascading triangle resonators next to the microstrip line with different positions of cutting slot in the triangle side so that a multiple resonances occur. The sim...
Abstract—Mobile WiMAX is a broadband wireless solution that enables convergence of mobile and fix... more Abstract—Mobile WiMAX is a broadband wireless solution that enables convergence of mobile and fixed broadband networks through a common wide area broadband radio access technology and flexible network architecture. It adopts Orthogonal Frequency Division Multiple Access (OFDMA) for improved multi-path performance in Non-Line-Of-Sight (NLOS) environments. Scalable OFDMA (SOFDMA) is introduced in the IEEE 802e[1]. WIMAX system uses one of different types of channel coding but The mandatory channel coding scheme is based on binary nonrecursive Convolutional Coding (CC). There are other several optional channel coding schemes such as block turbo codes, convolutional turbo codes, and low density parity check (LDPC). In this paper a comparison between the performance of WIMAX using turbo code and using convolutional product code (CPC) [2] is made. Also a combination between them had been done. The CPC gives good results at different SNR values compared to both the turbo system, and the co...
IEEE Transactions on Antennas and Propagation, 1984
ABSTRACT Simple closed formula is given to determine the resistive part of the loop antenna input... more ABSTRACT Simple closed formula is given to determine the resistive part of the loop antenna input impedance. An equivalent transmission line is used to determine the reactive part of the input impedance for the same loop, and the antenna in both cases may have any regular configuration. This method has proved to be accurate for a loop perimeter up to 0.5 lambda for the resistive part and up to 0.8 lambda for the reactive part.
Abstract—A design of multilayer dielectric resonator antenna transmitarray for fixed radio freque... more Abstract—A design of multilayer dielectric resonator antenna transmitarray for fixed radio frequency identification (RFID) reader applications is presented at 5.8GHz. Three layers square dielectric resonator antenna (DRA) elements are mounted on dielectric substrate and used as a unit cell in the transmitarray. A circularly polarized 9×9 square DRA transmitarray is designed at 5.8GHz for far-field RFID applications. The transmitarray produces maximum gain of 20.2 dB. The right-hand circular polarization level is lower than −31 dB at the designed frequency with SLL of −22 dB. A design of 9 × 9 near-field focused DRA transmitarray for fixed RFID at 5.8GHz is investigated. The properties of the near field-focused transmitarray are compared with that of the far field transmitarray designed at the same operating frequency. 1.
The radiation characteristics of the single-element cylindrical dielectric resonator antenna moun... more The radiation characteristics of the single-element cylindrical dielectric resonator antenna mounted on the surface of a metallic hollow circular cylindrical structure are explained. The effect of the radius of curvature on the return loss, input impedance, standing wave ratio, and radiation patterns is investigated. The finite element method and the method based on the finite integration technique are used to calculate the radiation characteristics of the antenna.
Proceedings of the Twenty-First National Radio Science Conference, 2004. NRSC 2004., 2004
The electromagnetic characteristics of a Koch fractal antenna as an element and as an array are e... more The electromagnetic characteristics of a Koch fractal antenna as an element and as an array are extensively examined. The method of moments is used to analyze the antenna structure. The characteristics of the Koch fractal monopole antenna on portable radio equipment are investigated. The use of the Koch fractal monopole can reduce the length of the antenna, decrease the current
ABSTRACT Nanoantennas have been introduced for different applications as solar-cell, medical imag... more ABSTRACT Nanoantennas have been introduced for different applications as solar-cell, medical imaging, and fast data communications. The material properties of good conducting metals introduce plasmonic behavior at terahertz frequencies. The electrical properties of different good conducting metals are modelled using the Drude model and have been investigated for reflectarray/ transmitarray operation. The radiation characteristics of nano-dielectric resonator antenna (NDRA) reflectarray at 633 nm have been investigated. The unit-cell consists of NDR mounted on the metallic supporting plane. A parametric study for the NDR unit cell dimensions and material has been introduced. The NDR unit-cell with silver supporting plane has been designed and analyzed for reflectarray applications at 633 nm. The radiation characteristics of the NDRA transmitarray has been introduced for 633 nm applications. The NDR unit-cell consists of two NDRs mounted on the top and bottom of the metallic supporting plane. A comparison between the radiation characteristics of 17×17 and 21×21 NDRA transmitarray has been introduced. A compromise between the nano-transmitarray size, maximum gain, and operating bandwidth is applied to terahertz applications. The finite integral technique is used to carry a full wave analysis to design an NDRA reflectarray and an NDRA transmitarray..
Octafilar helical antenna (OFHA) is proposed for handheld ultra‐high‐frequency (UHF) radio freque... more Octafilar helical antenna (OFHA) is proposed for handheld ultra‐high‐frequency (UHF) radio frequency identification (RFID) reader. The investigated antenna configuration consists of OFHA placed on reader device in the presence of human hand model. The antenna is designed at UHF band centered at 915 MHz. The antenna return loss, axial ratio, gain, co‐polarized and cross‐ polarized field components are calculated using the finite element method (FEM) and compared with that calculated by finite integration technique (FIT) for verification of the simulated results. A comparison between the performance of the quadrifilar helical antenna (QFHA) and the octafiliar helical antenna (OFHA) designed at 915 MHz in the presence of the reader device and human hand model is investigated. The OFHA introduces high gain, high front to back ratio, good axial ratio and omnidirectional coverage.
Computer solutions of monopole antennas at the center of circular ground planes have previously b... more Computer solutions of monopole antennas at the center of circular ground planes have previously been applied to the calculation of their input impedance through the use of magnetic edge currents. An alternative approach based on approximate physical currents is shown to give good agreement for both radiation patterns and input impedances.
In this paper, the performances of the neural-network approach for discrimination of the landmine... more In this paper, the performances of the neural-network approach for discrimination of the landmine depth from the ground surface and the landmine radius are carried out. A sensor for landmines detection consists of two microstrip antennas is used. One of the antennas is used as transmitting antenna and the second is considered as receiving antenna. Circular cylindrical shape metallic landmine is used. The neural-network process data are obtained from the FDTD formulation of the electromagnetic scattering. The inputs in the input layer of the neural network are the magnitude of the mutual coupling between the microstrip antennas, |..S21| while the outputs are landmine depth from the ground surface and landmine radius. Good agreement with exact profile has been observed. The computation time and computer memory of the inverse problem are considerably reduced.
A novel compact circularly-polarized (CP) multi-band square microstrip antenna with diagonal slot... more A novel compact circularly-polarized (CP) multi-band square microstrip antenna with diagonal slots and a pair of truncated corners is introduced. To prevent interference problems due to compact microstrip antenna, an efficient electromagnetic band gap (EBG) structure is included. The EBG is used to reject the surface waves. This rejection of surface waves improves operational band width, gain and directivity. Details of the simulation results are presented and discussed.
This paper presents a new radio frequency identification (RFID) chipless tag operating in the fre... more This paper presents a new radio frequency identification (RFID) chipless tag operating in the frequency span 3.5-4.3 GHz. This frequency band can be used for chipless RFID systems in the case of car-to-infrastructure (C2I) communication and may be used in automatic reading of road signs. It focuses on the integration of the antenna and multiresonator structures to form the chipless RFID tag. The tag consists of triangle microstrip filter. A 6-bit chipless tag is designed. The bits are encoded into the spectrum hence the tag has a unique spectral signature. The chipless tag is comprised of a vertically polarized circular UWB microstrip monopole receiving tag antenna, a multiresonating circuit and a horizontally polariz ed circular UWB microstrip monopole transmitting tag antenna. The multiresonating circuit is designed by cascading triangle resonators next to the microstrip line with different positions of cutting slot in the triangle side so that a multiple resonances occur. The sim...
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