Browsing by Author "Ibrahim, Ahmed A"

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All-textile inspired-folded dipole antennas for on/ off-body communications medical applications
(Alexandria University, 2022-03) Kareem, Farah R; El Atrash, Mohamed; Ibrahim, Ahmed A; Abdalla, Mahmoud Ap
Two textile-based printed inspired Folded Dipole Antennas (FDAs) are presented in this paper for health monitoring of Covid-19 infected patients. The first antenna has an overall size of 80 mm 20 mm and is mounted on the human’s chest, while the second one is backed by a 2 4 textile Artificial Magnetic Conductor (AMC) array structure and is mounted on a surgical mask that covers the human’s mouth. The first antenna is designed to work at center frequency, band- width, and gain of 2.45 GHz, 116.6 MHz and 2.45 dB, respectively. The second antenna works at 2.4 GHz with bandwidth of 76.6 MHz and gain of 2.71 dB. The SAR results equal 0.524 W/ Kg and 0.255 W/Kg at 1 g and 10 g, respectively, for the first antenna and 0.0174 W/Kg and 0.0091 W/Kg, respectively, for the second one. The previous specifications of the two antennas enable them to be utilized in wearable applications and Wi-Fi services. 2022 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).
Dual-band all textile antenna with AMC for heartbeat monitor and pacemaker control applications
(Cambridge University press, 01/12/2021) Kareem, Farah R; El Atrash, Mohamed; Ibrahim, Ahmed A; Abdalla, Mahmoud A
Currently reading: Abstract Get access Share Cite Rights & Permissions [Opens in a new window] Abstract All textile integrated dual-band monopole antenna with an artificial magnetic conductor (AMC) is proposed. The proposed design operates at 2.4 and 5.8 GHz for wearable medical applications to monitor the heartbeat. A flexible and low-profile E- shaped CPW dual-band textile antenna is integrated with a 4 × 4 dual-band textile AMC reflector to enhance the gain and specific absorption rate (SAR). The SAR is reduced by nearly 95% at both 1 and 10 g. The design was measured on the body with a 2 mm separation. The simulated and measured results appear in high agreement in the case of with and without AMC array integration. The measurement was performed in the indoor environment and in an anechoic chamber to validate the design based on reflection coefficient and radiation pattern measurements.
Four ports MIMO printed antenna with high isolation for UWB and X-band systems
(Cambridge University Press, 2023-11) Ibrahim, Ahmed A; Eltokhy, Amira; Daw, Ahmed Fawzy
In this work, a compact size 4 ports multiple input multiple output (MIMO) slot antenna with the connected ground for Ultra-Wide Band (UWB) and X band applications is introduced and discussed. The single antenna is a cross-shaped slot antenna in the ground plane and a 50 Ω microstrip line with a small L-stub is used to feed the antenna on the other side. The suggested MIMO antenna has four identical elements arranged to be orthogonal to each other to enhance the MIMO system performance. The antenna elements are connected with a small strip to compose the proposed connected ground antennas. The suggested MIMO antenna has an overall size of 47 mm × 47 mm. The antenna has tested and simulated bandwidth with S11 < −10 dB extended from 4– 14 GHz and has isolation greater than 20 dB between ports without utilizing the decoupling elements and with good consistency between results. The MIMO antenna has peak gain and efficiency, envelope correlation coefficient, diversity gain, and channel capacity loss of 5.6 dBi and 80%, <5 × 10–3, 10 dB, and <0.4 bit/s/Hz, respectively which prove that our antenna can be suggested for the UWB MIMO applications.