Browsing by Author "Taher H."

Now showing 1 - 5 of 5

Citation - Scopus: 3
Development of a Symmetric Metamaterial Absorber With Bandwidth Improvements for 5g Millimeter-Wave Applications
(Institute of Electrical and Electronics Engineers Inc., 2022) Akarsu, Gokberk; Buse Zengin E.; Nakmouche M.F.; Cengiz, Mehmet Faruk; Fawzy, Diaa E.; Allam A.M.M.A.; Taher H.
This study presents the development of a one-layer symmetrical Metamaterial Absorber (MMA) for millimeter-wave (mm-wave) applications. The target is to enhance the narrow band behavior and to achieve ultra-wideband with high absorptivity rates. The design is based on octagonal shaped cut rings and octagonal patches printed on grounded rigid substrate. A novel unit cell is developed and enhanced with the use of lumped elements technique to obtain ultra-wideband absorbers with high absorptivity rates. It is implemented on Rogers RT5880 with dielectric relative permittivity ? r=2.2, dielectric loss tangent of tan ?=0.0009, thermal conductivity of 0.2 W/m. K and with a 1.575 mm thickness. The characteristics of the MMA are examined in term of different resistive values, geometries, and angle of incidence. The obtained results show great enhancements in both the-10 dB bandwidth and in the absorptivity rates. The narrow bandwidth of the symmetrical design is enhanced by a factor of about 200 with average absorptivity of about 98% over the whole bandwidth. The current design is a very suitable for applications in the mm-wave. © 2022 IEEE.
Citation - WoS: 6
Citation - Scopus: 15
Development of a Wideband Substrate Integrated Waveguide Bandpass Filter Using H-Slotted Dgs
(Institute of Electrical and Electronics Engineers Inc., 2019) Nakmouche M.F.; Taher H.; Fawzy D.E.; Allam A.M.M.A.
In the current work, a new Wideband Substrate Integrated Waveguide Bandpass Filter (SIW-BPF) is presented. The target is to allow vertical roaming between the X and Ku band applications. As a first step, we performed a parametric study of different etched slot geometries namely, H-Slotted, T-Slotted, and U-Slotted DGS in order to examine the effects of altering different geometrical parameters of the unit on its response. H-Slotted DGS shows the highest FBW with 82.89% on the average compared to other geometries. As a second step, the cell size and the numbers of the H-Slotted DGS were optimized with the use of finite element method with the following constraints taken into consideration: low cost fabrication, high Q-Factor, compact size and easy integration. One of the designs was chosen for fabrication to validate the designed circuit. The measured results show that our optimized filter achieves an insertion loss of 2.01 dB at 8.5 GHz, a return loss higher than 11 dB and fractional bandwidth of 90.87% for a single cell and a fractional bandwidth of 80.05% for multiple cells. The measured results are in good agreement with the simulated results. © 2019 IEEE.
Citation - WoS: 1
Citation - Scopus: 2
Development of Ultra-Wideband Textile-Based Metamaterial Absorber for Mm-Wave Band Applications
(Institute of Electrical and Electronics Engineers Inc., 2022) Akarsu G.; Taher H.; Zengin E.B.; Nakmouche M.F.; Fawzy D.E.; Allam A.M.M.A.; Cleary F.
This work presents a state-of-the-art development of an ultrawide absorber for wearable smart electronic textile applications. The design is based on a novel cell geometry that is previously developed and applied for RF energy harvesting applications. Different textile types were considered in this study, namely, Felt, Denim and Polyester and the achieved-10 dB reflective fractional bandwidths are about 42.828%, 43.65%, and 42.834% respectively. A comparison with traditional counterparts (FR-4 and Rogers dielectrics) shows that the bandwidth exhibited by textile materials is greatly wider. The bending effect of the textile materials is considered in this study and found that the-10 dB bandwidth is inversely proportional with the decrease in the surface curvature of the material. Compared to the currently developed absorbers and similar structures reported in the literature show that the current design is more compact, lighter, and more efficient in terms of the absorptivity. The current results can be considered as starting promising steps for the development of ultra-wideband electronic textiles-based applications such as energy harvesting, health monitoring, smart materials, sensors, and infrared camouflage. © 2022 European Association for Antennas and Propagation.
Citation - WoS: 5
Citation - Scopus: 19
Dual Band Siw Patch Antenna Based on H-Slotted Dgs for Ku Band Application
(Institute of Electrical and Electronics Engineers Inc., 2020) Nakmouche M.F.; Fawzy D.E.; Allam A.M.M.A.; Taher H.; Sree M.F.A.
A dual band Substrate Integrated Waveguide; SIW microstrip patch antenna based on periodic H-Defected Ground Structure; H-DGS is designed for Ku band applications. SIW techniques provide low cost, small size and convenient integration with planer circuit. The proposed antenna structure is designed on a Roger 5058 substrate with a thickness of 1.6 mm, 2.2 of dielectric constant and tangent loss of 0.0009. The performance analysis of the proposed antennas is performed using finite element methods, and the simulation results show a gain and directivity of 7.03 dB and 7.38 dB respectively at 12.67 GHz center frequency and at 14.56 GHz a gain of 7.77 dB and directivity of 8.13 dB. The proposed antenna overall radiation efficiency is 95.25% and 95.60% at 12.67 GHz and 14.56 GHz, respectively. The obtained measurements show good agreement with the simulation results. The proposed antenna is compact, simple in structure, and can be used in a variety of applications in the Ku band. © 2020 IEEE.
Citation - WoS: 3
Citation - Scopus: 13
Parametric Study of Different Shapes-Slotted Substrate Integrated Waveguide for Wideband Applications
(IEEE Computer Society, 2019) Nakmouche M.F.; Taher H.; Fawzy D.E.; Kahraman G.
On the way to design Substrate Integrated Waveguide Bandpass Filter (SIW-BPF) for wideband applications a parametric study of the slot geometry etched on a SIW structure is the preliminary step to design such filter. Three different structures, namely, H-Slotted, T- Slotted, and U-Slotted SIW is investigated in order to examine the effect of altering different geometrical parameter of the unit on its response. H-Slotted Electromagnetic Band Gap (EBG) shows the highest Fractional Band Width (FBW), which is about 90% compared to the others, consequently it could be used to design a wideband SIW-BPF. © 2018 IEEE.