N. A. Murad
Universiti Teknologi Malaysia

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Diagnosis of Faulty Sensors in Antenna Array using Hybrid Differential Evolution based Compressed Sensing Technique Shafqat Ullah Khan; M. K. A. Rahim; I. M. Qureshi; N. A. Murad
International Journal of Electrical and Computer Engineering (IJECE) Vol 7, No 2: April 2017
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (279.752 KB) | DOI: 10.11591/ijece.v7i2.pp961-966

Abstract

In this work, differential evolution based compressive sensing technique for detection of faulty sensors in linear arrays has been presented. This algorithm starts from taking the linear measurements of the power pattern generated by the array under test. The difference between the collected compressive measurements and measured healthy array field pattern is minimized using a hybrid differential evolution (DE). In the proposed method, the slow convergence of DE based compressed sensing technique is accelerated with the help of parallel coordinate decent algorithm (PCD). The combination of DE with PCD makes the  minimization faster and precise. Simulation results validate the performance to detect faulty sensors from a small number of measurements.
Switchable Wideband Metamaterial Absorber and AMC reflector for X-band Applications and Operations M. M. Gajibo; M. K. A. Rahim; N. A. Murad; O. Ayop; H. A. Majid
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 16, No 4: August 2018
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v16i4.9065

Abstract

A single layered metamaterial structure with capabilities of switching from a wideband metamaterial absorber to an AMC reflector and vice versa is presented in this paper. A flame retardant 4 substrate with physical thickness of 1.60mm was used. The absorption rate, reflection rate, reflection phase and surface current distribution were studied and discussed. The operational incidental wave angles were varied from 0o to 65o. A peak reflection of about 90% was achieved at 11.20 GHz with a usable bandwidth (-90 to +90) of 3.01 GHz by the AMC reflector. The metamaterial absorber demonstrated a wideband performance (from 8.10 GHz to 14.30 GHz). It achieved 100% absorption at 11.20 GHz and not less than 65
Harmful Gases Profiling in Meru Menora Tunnel using SICK Sensor A. N. Baharun; N. A. Murad; N. N. N. A. Malik
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 15, No 2: June 2017
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v15i2.6141

Abstract

This paper discusses the study on the measured harmful gases due to traffic emission in the Meru Menora Tunnel, a Malaysia highway tunnel. The hazardous gasses data would help in promoting essential ventilation system inside the tunnel for the health and safety of the users. The emission gasses concentration reading is divided into two main components comprise of Nitrogen Dioxide (NO2), and Carbon Monoxide (CO). Other than that, the visibility also been measured by using SICK sensor. The measurement has been done during normal, festive and school holiday seasons. Festive season shows the highest number of traffic and thus giving the worst air quality. Ventilation fan system can be activated based on the concentration level of gases and visibility in the tunnel.
Evaluation of Double Loop IC Module for Inductive Coupled Fed RFID Tag Wire Embedded Antenna N. A. Murad; M. H. M. Salleh; N. Q. Azmi; A. R. Tanvir; A. A. Z. A Nizam
Indonesian Journal of Electrical Engineering and Informatics (IJEEI) Vol 8, No 3: September 2020
Publisher : IAES Indonesian Section

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.52549/ijeei.v8i3.1284

Abstract

This paper presents an evaluation on double loop integrated circuit module for inductive couple fed RFID Tag. The inductive couple feed gives advantage especially for flexible wire embedded antenna in controlling the manufacturing varians as the chip is not directly connected to the antenna. Thus electrostatic discharged effect and manufacturing errors can be minimized. An inductor loop is directly connected to the RFID chip before it is placed to indirectly coupled the energy from a meandered dipole antenna. The coupled energy should be enough to turn on the chip to communicate with the reader. The inductive coupled energy is achieved by manipulating the near field magnetic field between the antenna body and the inductor loop. To evaluate the performance, the antenna and the inductive feeding loop is designed to operate at RFID UHF band (860 MHz – 960 MHz) and simulated using CST software. The antenna body impedance is evaluated to match the impedance of the chip and the loop. It is confirmed that the double loop inductor has higher inductance values and thus should be counted in conjugate impedance between the antenna body and the chip module. The tag with overall dimension of 60 mm x 16 mm can be read at distance at least 9 meters through out the band.
Polarization insensitive switchable metamaterial absorber/reflector for X-band applications M. G. Mustapha; M. K. A. Rahim; N. A. Murad; O. Ayop; S. Tuntrakool; M. A. Baba; A. Y. Iliyasu; Mohd Ezwan Jalil
Bulletin of Electrical Engineering and Informatics Vol 9, No 6: December 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/eei.v9i6.2196

Abstract

A unit cell of squared shaped polarization-insensitive switchable metamaterial absorber/reflector is presented. The structure operates at 10.20 GHz under both absorber mode and reflector mode configurations. Copper wire bridging the gaps to form a circular shape structure were used as switches for operation mode selections. The structure was designed on an FR4 substrate, and the incidental wave angles were varied from 0 to 50 degrees. The structure demonstrated almost 100% absorption at resonance, 3.314 GHz percentage bandwidth at 80% as an absorber. On the other hand, as reflector, it demonstrated almost a 90% reflection and a usable bandwidth of 3.327 GHz.
X-band Operations Metamaterial Absorber with Extended Circular Ring Topology for Size Reduction M. M. Gajibo; M. K. A. Rahim; N. A. Murad; O. Ayop; B. D. Bala; H. A. Majid
Indonesian Journal of Electrical Engineering and Computer Science Vol 6, No 1: April 2017
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v6.i1.pp180-184

Abstract

A metamaterial electromagnetic wave absorber consisting of a big circular ring patch with four smaller suppression circular rings is presented in this report. The metamaterial electromagnetic wave absorber introduces the concept of size reduction by suppressing the resonance frequency. An FR4 substrate was used and the incidental wave angles were varied from 00 to 600. Simulations results shows peak absorption of 100% was achieved at 10.7 GHz by the absorber for both TE and TM polarization incident waves. Minimum absorption for both TE and TM mode of 90.6% was achieved under TE mode. The metamaterial absorber was being tested with and Ultra-wide band antenna and the results were reported.
Entire X-band region metamaterial absorber and reflector with a microstrip patch switch for X-band applications M.M. Gajibo; M. K. A. Rahim; N. A. Murad; O. Ayop; H.A. Majid; M. Aminu-Baba; R. Dewan
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 3: September 2019
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v15.i3.pp1452-1457

Abstract

A metamaterial structure capable of operating as a wide band absorber as well as an AMC reflector is presented in this report. A microstrip patch copper was used as a switch to switch between the two modes. An FR4 substrate was used and the incidental wave angles were varied from 00 to 600. Simulations results showed that the absorber was able achieve 96% absorption at 13.05 GHz and 100% absorption at 10.00 GHz and 12.00 GHz. Furthermore, it archived over 85% absorption for the entire X-band frequency range. The AMC reflector also was able to achieve 84.97%, 82.88% and 78.69% for incident angles 00, 200 and 400 respectively. Unfortunately, the structure is polarization sensitive.