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

Now showing 1 - 12 of 12

Design a Wide Band Microstrip Line Fed Antenna for Tcas Avionic System
(IEEE, 2019) Abdelsade, Moustafa Samy; Allam, A. M. M. A.; Fawzy, Diaa
This paper presents the design and fabrication of a directional antenna for the Traffic alert and Collision Avoidance Avionic System (TCAS). A patch antenna in a circular shape made from copper. Roger 5880 with h=3.18 nun; epsilon(r)=2.2, and loss tangent of 0.0009 is taken as a substrate material. It is fed using a microstrip line of 50 ohm. It operates at the targeted frequencies. Defected ground technique is used to increase the antenna bandwidth. A conducting plane supports the antenna structure at an optimized distance to achieve high gain. The proposed antenna conducts with parameters that satisfy the conventional TCAS 11 directional antenna radiation parameters except with higher gain which tends to 5.15 dB and 5.6 dB in the transmission and reception respectively that increase the range of he surveillance area. Low side lobe level and an efficient beamwidth are archived for bearing angle calculation efficiency and to cover the full 360 degrees respectively.
Citation - WoS: 11
Citation - Scopus: 15
Design and Development of a Graphene-Based Reconfigurable Patch Antenna Array for Thz Applications
(Walter De Gruyter Gmbh, 2023) Lamri, Isam Eddine; Ahmad, Sarosh; Nakmouche, Mohammed Farouk; Ghaffar, Adnan; Fawzy, Diaa E.; Allam, A. M. M. A.; Ali, Esraa Mousa
This paper presents a graphene-based antenna array for terahertz (THz) applications. The suggested antenna array has four radiating square shaped patches fed by a coplanar waveguide (CPW) technique. The proposed antenna array operates at the three frequencies with operational bandwidths of 1.173-1.210 THz (at 1.19 THz), 1.270-1.320 THz (at 1.3 GHz), and 1.368-1.346 THz (at 1.4 GHz). The total area of the antenna array is reported as 1000 x 1000 mu m(2), printed on a Silicon substrate with a thickness of 20 mu m and a dielectric constant of epsilon( r ) = 11.9. To enhance the structure's performance and optimize the feeding network, a parametric analysis was performed using the FDTD technique. Furthermore, the key properties of the proposed antenna array, such as resonance frequency, peak gain, and radiation efficiency, may be changed by adjusting the chemical potentials of the graphene in the antenna array. The use of graphene's chemical potential tuneability yields exceptional results comparing to the recent research outputs, with a peak gain and radiation efficiency of 10.45 dB and 70%, respectively. These results show the performance of the suggested design for constructing antenna arrays for use in THz applications.
Citation - Scopus: 2
Design of Triple-Band Bandpass Filter Using Inverted Microstrip Ridge Gap Waveguide for Ka-Band Applications
(IEEE, 2022) Cengiz, Mehmet Faruk; Nakmouche, Mohammed Farouk; Fawzy, Diaa E.; Allam, A. M. M. A.; Akarsu, Gokberk; Taher, Hany
In this paper, a triple-band inverted microstrip Ridge Gap Waveguide (RGW) filter is designed using a double octagonal ring resonator (RR) with corner cuts. The design parameters are optimized using the Finite Difference Time Domain (FDTD) method (CST studio simulator). The filter is implemented on Rogers RT5880 (epsilon(r) =2.2, thickness of 0.787 mm and loss tangent tan delta = 0.0009). It is selected because of its low losses at high frequencies. The proposed design operates within the Ka frequency band (27-40 GHz), with resonance frequencies of 32.32 GHz, 35.75 GHz, and 38.12 GHz. The return losses reach levels of about -35 dB, -25 dB, and -32 dB for the three bands, respectively. The filter exhibits a low insertion losses of about 0.6 dB, 1.1 dB, and 0.9 dB at the three resonant frequencies, respectively.
Citation - WoS: 1
Citation - Scopus: 4
Development of a Novel Ultra-Wideband Textile-Based Metamaterial Absorber for Mm-Wave Band Applications
(IEEE, 2022) Akarsu, Gokberk; Cengiz, Mehmet Faruk; Fawzy, Diaa E.; Zengin, E. Buse; Allam, A. M. M. A.; Taher, Hany; Cleary, Frances
This work proposes an ultra-wideband Metamaterial (MM) absorber for smart electronic textile (etextile) applications. The design is based on a novel cell geometry composed of two combined letter patches (A&S) printed on a grounded textile substrate. This unit cell geometry is specifically developed and optimized for millimeter-wave (mm-wave) applications. In this study, different types of textiles are considered, namely, Felt, Denim, and Polyester, and the achieved -10 dB reflective fractional bandwidths are about 50.36%, 44.49% and 41.42%, respectively. A comparison between conventional counterparts PCB-based dielectrics (FR-4 and Rogers RT-5880) and textile-based fabrics (Felt, Denim, and Polyester) indicates that the bandwidths exhibited by textile fabrics are significantly wider. This study also demonstrates that the bending of textile-based materials has an inverse effect on the -10 dB bandwidth, as the material's surface curvature increases. The current design is more compact, thin, and more efficient in terms of absorptivity in comparison to other reported absorbers and structures in the literature. The obtained results can be considered promising for the development of ultra-wideband e-textile-based applications such as energy harvesting, health monitoring, and camouflage systems.
Citation - WoS: 7
Citation - Scopus: 23
Low Profile Dual Band H-Slotted Dgs Based Antenna Design Using Ann for K/Ku Band Applications
(IEEE, 2021) Nakmouche, Mohammed Farouk; Allam, A. M. M. A.; Fawzy, Diaa E.; Lin, Ding Bing
In this manuscripts, H-slotted DGS based antenna configuration for K/Ku applications is designed, fabricated and measured using ROHDE & SCHWARZ ZVB20 network analyzer. Simulation studies are performed using Electromagnetic Simulation Software CST Studio Suite. Moreover, a development of Artificial Neural Networks (ANN) model is implemented based on feed-forward back-propagation and Bayesian regularization learning algorithm. The optimal position for H-slotted DGS antenna performance is predicted in terms of reflection coefficient and resonance frequency. The antenna is implemented on Rogers RT/Duroid 5880 with relative dielectric constant of 0.0009 and thickness 0.38 mm. It operates at both 15.04 GHz (from 14.87 GHz to 15.208 GHz) and 24.77 GHz (from 24.404 GHz to 25.137 GHz). The antenna achieves gains of 5.59 dB and 6.10 dB and efficiencies of 87 % and 80 % at both frequencies, respectively. The simulation using CST, predicted ANN and measurement results are in good agreement.
Citation - WoS: 8
Citation - Scopus: 12
A Novel 5g Wideband Metamaterial Based Absorber for Microwave Energy Harvesting Applications
(IEEE, 2021) Akarsu, Gokberk; Nakmouche, Mohammed Farouk; Fawzy, Diaa E.; Allam, A. M. M. A.; Baskoy, Kadir; Cengiz, Mehmet Faruk
This paper proposes a novel design of a compact and thin metamaterials (MMs) based wideband absorber aiming at specific microwave energy harvesting for 5G applications. The developed unit cell is obtained by combining two letters-like patches printed on a grounded dielectric substrate. The developed operating band is achieved based on the superposition of the two-resonances generated by the two letters. The simulations are based on Rogers RT5880 (thickness of 1.575 mm, dielectric constant of epsilon r=2.2, loss tangent of tan delta=0.009) and FR-4 substrates (thickness of 1.2 mm dielectric constant of epsilon r=4.3, loss tangent of tan delta=0.02). The obtained results show a wide 10 dB absorption bandwidth in the frequency range between 18 GHz and 30 GHz with absorptivity close to 99% for normal and oblique incident up top to 30 degrees in the case of Rogers RT5880. An absorptivity rate of 96% is obtained for the cased of FR-4 because of high dielectric losses. The obtained results are reasonable compared to other studies in the literatures.
Citation - WoS: 6
Citation - Scopus: 7
A Novel Circular Reconfigurable Metasurface-Based Compact Uwb Hybrid Coupler for Ku-Band Applications
(IEEE-Inst Electrical Electronics Engineers Inc, 2022) Abbas, Mohamed Atef; Cengiz, Mehmet Faruk; Allam, A. M. M. A.; Fawzy, Diaa E.; Elhennawy, Hadia M. M.; Sree, Mohamed Fathy Abo
A novel circular reconfigurable metasurface (MS) based compact ultra-wideband (UWB) hybrid coupler is developed for Ku-band applications. The coupler is developed using the substrate-integrated gap waveguide (SIGW) technology. The coupler structure consists of two layers, the bottom layer represents the artificial magnetic surface of the periodic structures and the ridges in between that guide the wave in the required direction with minimum dispersion. It involves the coupling section with a centered etched slot and two additional vias to achieve the basic hybrid coupler properties. This layer is nominated as the ridge layer. The second layer is a circular shape of a dielectric gap loaded with the top ground. The top ground is left solid for a non-reconfigurable coupler. Concerning the reconfigurable coupler, this layer contains an artificial metasurface of Jerusalem cross elements where the copper is etched around. This layer is nominated as the gap layer. This MS surface is mechanically rotated to offset the magnitude and phase of the signal going to the through and coupled ports. The findings obtained from the simulations show that the reconfiguration can be accomplished by rotating the MS around the source coupler's central axis. The rotation is tested between 0 & DEG; to 180 & DEG; in the counter-clockwise direction. The operating frequency range of the coupler is between 11.94 to 16.91 GHz, which covers approximately the whole Ku-band. The coupler delivers continuously adjustable amplitude between 2.6 and 4.8 dB while the phase differences within 77 & DEG; to 105 & DEG; over a fractional bandwidth (FBW) of 34.45%. It is manufactured using PCB technology and measured using network analyzer. A strong agreement is achieved between simulations and measurements. The proposed coupler can be used in traditional beam-forming and beam-steering networks by changing the rotation angle or the operating frequency. The developed coupler can replace the Butler and Bless matrices with their complication, heavy number of phase shifters, and crossover problems. The current work can be extended to operate in the mm-Wave band by changing the dimension and the material of the unit cell of the ridge layer of the coupler.
Citation - WoS: 2
A Novel Substrate Integrated Gap Waveguide Ultra Wide-Band Circular Directional Coupler for Ku Band Applications
(IEEE, 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 4(th) 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 mm(2). The measured and simulated scattering parameters demonstrate satisfactory agreement.
Citation - WoS: 2
Citation - Scopus: 3
On the Design of Reconfigurable Wideband Ridge Gap Waveguide Amplifier Modules
(IEEE, 2020) Elsaadany, Mahmoud; Shams, Shoukry, I; Ali, Mohamed Mamdouh M.; Sebak, Abdelrazik; Gagnon, Ghyslain; Fawzy, Diaa E.; Allam, A. M. M. A.
The near-to-launch 5G standard for wireless communications did not seal the ultimate use the mm-wave bands. As a result, the future 6G standard is expected to proceed in more efficient utilization of these bands. One of the most critical elements in the RF link is the amplifier, especially when the attenuation of the channel is relatively high which is the case for the mm-wave bands. In this work, a reconfigurable design of a wideband amplifier is presented to operate in the band 34 GHz to 38 GHz. The line parameters are investigated to study the tune-ability of this configuration. In particular, changing the parasitic loading by varying lines width can achieve a matching level beyond 15 dB over partial band operations based on the configuration. The availability of such a reconfigurable module will pave the way for efficient 6G development.
Citation - Scopus: 4
Optimizing Ridge Gap Waveguide Based Slot Antenna Shape for Maximum Gain and Bandwidth for Satellite Applications
(IEEE, 2022) Cengiz, Mehmet Faruk; Akarsu, Gokberk; Fawzy, Diaa E.; Allam, A. M. M. A.
This work proposes different V-band antennas optimized to operate at 70 GHz with various geometric slots. The development is based on substrate integrated gap waveguide (SIGW) technology. Five geometries are considered, namely, rectangular, circular, hexagon, T-shape, and U-shape, with the target of maximizing the realized gain and bandwidth. The Finite Difference Time Domain (FDTD) technique is used to optimize the design parameters (CST studio simulator). The overall size of the developed antenna is 8.4x7.2x0.87 mm(3). The maximum obtained realized gain is found to be 10.98 dBi for the antenna with a rectangular slot. The circular slot antenna shows the highest S-11 < -10 dB bandwidth of 5.35 GHz in the range 66.53-71.88 GHz. The developed slot antennas are very appropriate for point-to-point wireless communication systems and inter-satellite and mobile satellite applications.
Citation - WoS: 5
Citation - Scopus: 12
Ridge Gap Waveguide Wideband Hybrid Directional Coupler for Ka-Band Applications
(IEEE, 2020) Soliman, Mohamed Yasser; Ali, Mohamed Mamdouh M.; Shams, Shoukry, I; Sree, Mohamed Fathy Abo; Fawzy, Diaa E.; Allam, A. M. M. A.
The fifth generation (5G) is the next wireless mobile communication technology that targets to provide huge capacity, low latency and high data speeds. Like any new wireless technology, 5G requires the development of exciting techniques, where access to high frequency spectrum can achieve the desired characteristics. In addition, new systems must be developed and designed using wide bandwidth microwave components, which should be implemented with modern and efficient guiding structures. Among all the microwave components, directional coupler is essential device as it can be used to realize many subsystems such as beamforming networks. In order to keep up with the huge changes in future technologies, couplers still requires noticeable improvement, where wide bandwidth and low loss should be achieved throughout using modern guiding technology such as Ridge Gap Waveguide (RGW). In this paper, a design of ultra-wideband 3 dB quadrature hybrid directional coupler using RGW technology is introduced. The proposed coupler has a compact size of 1.58 lambda x 1.4 lambda and achieves a relative bandwidth of 44.7 % at 33.5 GHz, which cover the whole ka-band. In addition, a stable 90 degrees phase difference between the coupling and transmission coefficients is obtained over the whole frequency band.
Citation - WoS: 1
Citation - Scopus: 1
Sigw Based Bi-Directional Coupler for Ku-Band Applications
(IEEE, 2022) Ghaly, Maher H.; El-Din, M. S. H. Salah; Allam, A. M. M. A.; Fawzy, Diaa E.
In this paper, a bi-directional coupler based on substrate integrated gap waveguide (SIGW) is presented for Ku-band applications. The proposed coupler is considered to be the first bi-directional coupler that is realized using gap waveguide technology. It operates at frequency band of 14-17 GHz. The quasi-transverse electromagnetic (Q-TEM) SIGW based coupler is excited through a co-planar waveguide (CPW). The proposed design is characterized by its compactness, planar profile structure and low signal dispersion. The design parameters were optimized using Finite Difference Time Domain (FDTD) method of analysis (CST microwave studio). The presented coupler is designed to be used as a feeding network for radar beam steering applications, adaptive antennas and beam forming networks. Furthermore, it can be considered as a good candidate in terms of power conservation concept.