Browsing by Author "Hassan K.M."

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    Analysis of optical code division multiple access passive networks for different encoder delay elements
    (2006) Morsy M.A.; Hassan K.M.; Morshed A.H.; Elhennawy A.; Electronics and Comm. Eng. Dept.; Faculty of Engineering; Modern Sciences and Arts University; Dokki; Giza; Egypt; Electrical and Comp. Eng. Dept.; Higher Technological Institute; 10 of Ramadan City; Egypt; Electronics and Comm. Eng. Dept.; Faculty of Engineering; Ain Shams University; 1 El-Sarayat St.; Abbassia; Cairo 11517; Egypt
    One of the most important core technologies in the development of optical code division multiple access (OCDMA) local area networks is the optical encoder/decoder embodiment technology which codes information to fixed patterns at the transmitting side and decodes information at the receiving side. The selection of optimized encoding method for network composition is necessary to accommodate a maximum number of subscribers that have simultaneous access over the local area network and the bandwidth of subscriber services available on it. When composing this encoder/decoder optically, passive elements are exclusively used, if possible, so as to make the composition method simple and economical. In this paper we present an analysis of OCDMA passive communication networks focusing on the modeling of optical encoder/decoder blocks for different types of delay elements. The main objective of the paper is to study the performance of these networks including the effect of the passive encoder/decoder parameters such as splitter and optical delay line losses. Different types of delay lines are proposed including optical fibers and fiber Bragg gratings (FBG) as delay elements for the selection of the optical delay line which achieves a better performance. A statistical model of an OCDMA network has been developed and used for this study, including the effect of different passive encoder/decoder parameters, multiple access interference and noise. � 2006 IEEE.
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    Wide band high selective compact metamaterial antenna for 2 GHz wireless applications
    (Institute of Electrical and Electronics Engineers Inc., 2014) Abdalla M.A.; Awad A.A.; Hassan K.M.; Electromagnetic Fields Group; Electronic Engineering Dep.; MTC College; Cairo; Egypt; Communication and Electronics Dept; MSA University; Cairo; Egypt
    This paper presents a new compact, wide band and high selective, metamaterial antenna for 2 GHz wireless applications. The proposed antenna is designed using metamaterial half wave length stepped impedance resonator. The antenna is centred at 2.1 GHz with 21% fractional bandwidth and wide/high selective harmonics rejection in the frequencies up to 4 GHz. The antenna's radiator length is 18 mm which introduces 50% length reduction compared to narrow band microstrip patch antenna. The design procedures of the proposed antenna are discussed. The antenna's performance is examined in terms of full wave simulation and experimental measurements. 2014 IEEE.