Browsing by Author "Allam, A.M.M.A."

Now showing 1 - 11 of 11

Citation - Scopus: 1
Beamforming Network for 5g Applications
(Institute of Electrical and Electronics Engineers Inc., 2023) Raafat, M.A.; Allam, A.M.M.A.; Helala, M.A.; Ghanem, M.G.; Fawzy, Diaa E.; Abbas, M.A.; Abo, Sree, M.F.
This paper is devoted to the design, analysis, and implementation of switched beamforming network operating at 5.2 GHz for 5G applications. It is intended to launch four beams. The Butler matrix feeding network is presented to electronically switch the beam in the desired direction. This work achieves a good approach to alleviate the problem of cross-over implementation and fabrication. A Four-element array of printed antennas is designed and fabricated. The network and array are implemented on Rogers RT/duroid 5880 substrate with a relative permittivity of 2.2 and a thickness of 1.04 mm. The different scattering parameters are simulated using both ADS and CST which conduct good agreement between the simulated and measured results. © 2023 IEEE.
Design and Implementation of an Antenna for Automotive Applications at 76.5 Ghz
(Institute of Electrical and Electronics Engineers Inc., 2024) Mohamed, M.S.A.; Esam, G.; Allam, A.M.M.A.; Alexan, W.; Gadelmavla, Diaa; Şahin, Osman Nuri
This paper presents an antenna candidate for automotive cars and MIMO radar applications. It is implemented on Rogers RO4003C with a relative dielectric constant of 3.55 and a thickness of 0.203 mm. Linearly and circularly polarized versions of printed antennas are presented and operate at 76.5 GHz, which meets the characteristics of the required application. One of the antennas is selected and fabricated for validation. The results of the reflection coefficient fo und good agreement between the simulated and measured ones. Further antenna parameters like 3D and 2D radiation patterns, realized gain and axial ratio are illustrated. © 2024 IEEE.
Citation - Scopus: 3
Design and Implementation of Smart Watch Textile Antenna for Wi-Fi Bio Medical Applications in Millimetric Wave Band
(Institute of Electrical and Electronics Engineers Inc., 2023) Allam, A.M.M.A.; Ghanem, M.G.; Fawzy, Diaa E.; Raafat, M.A.; Abbas, M.A.; Abo, Sree, M.F.; El-Din, M.S.H.S.
This paper is devoted to the design and implementation of smart watch textile antenna for Wi-Fi bio-medical applications in millimetric wave bands. The antenna is implemented on the leather textile-based substrate to be embedded in a smart watch. It enables the watch to pick up Wi-Fi signals without the need to be connected to a mobile through Bluetooth. It operates at 60 GHz or WiGig (Wireless Gigabit Alliance) band with a wide band for higher-rate applications. It also could be implemented over many stratified layers of the body organisms to be used in the diagnosis of many diseases like diabetes and cancer. The structure is designed and simulated using CST (Studio Suite) program. The wearable patch antenna has an octagon shape and it is implemented on leather material that acted as a flexible substrate with a size of 5.632 x 6.4 x 2 mm 3, relative permittivity of 2.95, and loss tangent of 0.006. The feeding is carried out using differential feed (discrete port in CST). This work provides five antenna implementations; antenna without ground, a ground is added at the back of the antenna in order to increase the antenna gain, the substrate dimensions are increased to 15 x 30 mm2 to resemble the real hand watch size, layers of skin and fat are added under the ground of the antenna to study the effect of human body tissues human on the antenna performance. Finally, the whole structure is bent. It is found that the antenna can achieve a simulated peak realized gain in dB of 5.68, 7.28, 6.15, 3.03, and 4.37 for antenna without ground, antenna with the ground, antenna with larger substrate dimensions, antenna with skin and fat, and bent structure, respectively. The antenna with ground exhibits high gain, while adding the human organisms absorption, the gain is degraded because of human absorption. The bent structure contributes to higher gain. © 2023 IEEE.
Developement of 4-Ports Mimo Cp Antennas for Radar Applications
(Institute of Electrical and Electronics Engineers Inc., 2024) Said, A.; Allam, A.M.M.A.; Fawzy, D.E.; Sahin, O.N.
This paper introduces a printed four-port MIMO antenna with advantages such as compact size, excellent MIMO diversity performance, and simple geometry for radar applications at 10 GHz. It is small size makes it suitable for integrating various telecommunication devices for multiple applications, with a prototype measuring 32 mm × 32 mm × 4.3 mm. The mutual coupling between the individual elements significantly im-pacts the MIMO system's diversity properties, and an effective technique of orthogonally positioning the antenna elements to each other increases their isolation resulting in superior MIMO diversity performance. It is evaluated through S-parameters and MIMO diversity parameters to ensure its suitability for future radar applications. It is validated through measurements, and the results showed a good match between simulated and measured results. The different diversity parameters such as (Envelope Correlation Coefficient (ECC), Diversity Gain (DG), Channel Capacity Loss (CCL), Multiplexing Efficiency (ME), Total Active Reflection Coefficient (TARC) are simulated and measured. It is found that all values are within the standard norms which indicates the availability for MIMO radar applications. © 2024 IEEE.
Development of a Split Ring Resonator Sensor for Vibration Detection
(Institute of Electrical and Electronics Engineers Inc., 2024) Zengin, E.B.; Fawzy, D.E.; Allam, A.M.M.A.; Şahin, O.N.
The main focus of this work is the development of a metamaterial-based vibration sensor for the detection of earthquake amplitudes. The sensor is composed of two metamaterial layers made of FR-4 substrates with Circular Split Ring Resonators (CSRR) arranged in a back-to-back configuration on each substrate. The variation of the spacing between the plates results in an alteration of the electric field and thus changes in the resonance frequencies of the whole system. The system is designed and optimized to resonate in the GSM 1.8 GHz band, which ultimately results in a self-sustaining sensor. A clear relationship between the spacing of the two layers and the shift in the resonance frequency has been obtained. It also changes the magnitude of the reflected and absorbed energy from the sensor. This spacing in turn can be directly correlated with the vibration amplitudes. The system can be integrated into a warning system with the ability to quantify the structural resilience of buildings against potentially damaging vibrations. Different unit cell geometries of metamaterial surface are tested before selecting the CSRR geometry to develop highly sensitive sensors operating in the GSM frequency band at 1.8 GHz. © 2024 IEEE.
Citation - Scopus: 15
Metamaterial-Based Mm-Wave Phased Array for Broadband Cellular Networks
(Institute of Electrical and Electronics Engineers Inc., 2023) Amar, A.S.I.; Parchin, N.O.; Fawzy, Diaa E.; Allam, A.M.M.A.; Eid, A.M.; Soliman, M.A.
A new broadband phased array antenna with wide-scan and high-gain beam-scanning are desirable to meet the requirements of future cellular networks. This paper discusses the characteristics of a new beam-steerable array design having broad bandwidth for 5G communications. The discussion is focused on smartphones, due to their small size and complexity. The design procedure is straightforward and accomplished on a mainboard of future smart handheld devices. The introduced phased array design involves eight metamaterial-based dipole resonators with a 1×8 linear form. The resonators have small sizes with microstripline feedings. For -10 dB, the design represents 28-38 GHz covering several bands in the 5G spectra. © 2023 IEEE.
Citation - Scopus: 1
Mimo Slot Antenna With Polarization Diversity and Dual Notched Bands for Uwb Applications
(Institute of Electrical and Electronics Engineers Inc., 2023) Parchin, N.O.; Amar, A.S.I.; Fawzy, D.E.; Allam, A.M.M.A.; Eid, A.M.; Ibrahim, A.G.A.
This paper introduces a 4-port MIMO slot antenna system with dual notched bands, which is designed for future wireless communications. The antenna structure consists of four modified U-shaped radiation stubs with a shared ground plane, arranged in a planar form. The results demonstrate that the antenna operates effectively across frequencies ranging from 2.1 to 10.7 GHz, covering the entire ultra-wideband (UWB) spectrum. Moreover, two notched filtering characteristics have been incorporated at 3.3 to 4.2 GHz and 5 to 6 GHz, utilizing modified radiation stub resonators. These notches effectively suppress interference from C-band, WLAN, and WiMAX interfaces. The performance of the proposed antenna design has been thoroughly evaluated in terms of its fundamental characteristics. The results show that the antenna achieves satisfactory scattering parameters, 3D radiation patterns, efficiency, and gain levels. The designed UWB antenna system fulfills the requirements for MIMO and diversity applications. © 2023 IEEE.
Citation - Scopus: 2
A Multi-Band Textile-Based Mtm Absorber for Energy Harvesting Applications
(Institute of Electrical and Electronics Engineers Inc., 2023) Allam, A.M.M.A.; Helala, M.A.; Fawzy, Diaa E.; Abbas, M.A.; Sree, M.F.A.; Parchin, N.O.; Amar, A.S.I.
This paper is devoted to design and implementation of multi-band textile based Metamaterial absorber operating at K and Ku bands to be deployed in energy harvesting system. The unit cell of the absorber comprises a ground plane of copper annealed, Felt textile and top ground layer with etched Jerusalem cross surrounded with etched square ring. It provides three highly resonant peaks at 16.7 GHz, 18.6GHz, and 22.45 GHz, with absorption percentages of 99.8%, 96.5%, and 99.7%, respectively. The full width at half maximum (FWHM) is 3.35 GHz (19%) at 17.6 GHz. In addition, the absorber provides a wideband of absorption for oblique incidence up to 20 degrees and also at different bending radii. The relative permittivity and permeability are studied to demonstrate it effect on the absorption mechanism. A negative index of refraction is achieved over a band of 6.5 GHz from 16 GHz to 22.5 GHz, which leads to perfect absorptivity. © 2023 IEEE.
Citation - Scopus: 3
A Novel Substrate Integrated Gap Waveguide Ultra Wide-Band Circular Directional Coupler for Ku Band Applications
(Institute of Electrical and Electronics Engineers Inc., 2023) Cengiz, Mehmet Faruk; Allam, A.M.M.A.; Fawzy, Diaa E.
This study presents a new circular compact Ultra Wide-Band (UWB) substrate integrated gap waveguide (SIGW) based 3 dB hybrid coupler for Ku band applications. The coupling section is a circular structure with an elliptic slot and additional via to achieve equal-power division in two ports and isolation in the 4th port. To optimize the design parameters of the hybrid coupler, the Finite Integration Time-Domain (FITD) approach is employed. The operating frequency of the coupler is between 12.14 to 15.4 GHz with a central frequency of 13.5 GHz, a bandwidth of 3.26 GHz, and a Fractional Band Width (FBW) being 23.67%. A phase difference throughout the operational spectrum around 90° has been attained. The coupler is fabricated with an overall dimension of 33.8 x 33.8 mm2. The measured and simulated scattering parameters demonstrate satisfactory agreement. © 2023 European Association for Antennas and Propagation.
Citation - Scopus: 1
Re-Configurable Power Divider Based on Printed Ridge Gap Waveguide Technology
(Institute of Electrical and Electronics Engineers Inc., 2023) Ali, M.M.M.; Shams, S.I.; Elsaadany, M.; Fawzy, Diaa E.; Allam, A.M.M.A.; Abbas, M.A.; Abo, Sree, M.F.
Future Millimeter Wave (mmWave) band communication systems are predicted to be involved in different and diverse fields. These systems will be smart with high speed that enable the emergence of fundamental and advanced services. In order to realize these systems we need the use of reconfigurable microwave components implemented based on modern guiding structures. Power dividers are considered one of the essential components for the feeding antenna system. In this paper, Re-configurable Printed Ridge Gap Waveguide (RPRGW) is deployed to implement a power divider. The simulated results show a wide bandwidth of 16 % at 38.5 GHz. These results demonstrate the merit of using this technology to implement various microwave components suitable for smart communication systems. © 2023 IEEE.
Citation - Scopus: 1
An Ultra-Wideband Textile-Based Perfect Superstrate Metamaterial Absorber for 6g Applications
(Institute of Electrical and Electronics Engineers Inc., 2023) Allam, A.M.M.A.; Helala, M.A.; Ghanem, M.G.; Raafat, M.A.; Fawzy, Diaa E.; Akarsu, Gokberk; Abbas, M.A.
This paper presents an ultra-wideband textile-based perfect Metamaterial absorber for 6G applications. The design geometry of the unit cell is based on a modified split ring resonator and optimized akin to the word 6G. It enables a wideband in sub-THz at the standard of FCC. The structure consists of three layers; the ground layer, the textile layer, and MTM resonators. The two resonators are 6G and L shaped. The structure is optimized in terms of the different dimensions of both resonators. For more enhancement of the absorptivity band, superstrate textile material is added on top of the resonator's structure. It enhances the band by 6 %. The structure is subjected to different angles of incidence to study the sensitivity of the absorber to that angle. It contributes a bandwidth of 17.135 GHz up to 30 degrees and an FWHM of more than 33.332 GHz up to 45 degrees. The textile material used is felt having a permittivity of 1.27, thickness of 0.6 mm, and tangent loss of 0.016. The overall size of the absorber is 2.4 mm x 2.4 mm x 1.27 mm. © 2023 IEEE.