M. K. A. Rahim
Universiti Teknologi Malaysia

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Journal : Bulletin of Electrical Engineering and Informatics

Wideband millimeter-wave substrate integrated waveguide cavity-backed antenna for satellites communications Najib AL-Fadhali; Huda A. Majid; Rosli Omar; M. F. Ismail; M. K. A. Rahim; Abdul Rashid O. Mumin; B. A. F. Esmail
Bulletin of Electrical Engineering and Informatics Vol 9, No 5: October 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (369.635 KB) | DOI: 10.11591/eei.v9i5.2238

Abstract

This paper presents a new type of wideband waveguide (SIW) cavity-backed patch antenna for millimeter wave (mmW). The antenna proposed applies to applications of 31-36 GHz Ka-band such as satellites communications. The SIW is intended with settings for particular slots. The antenna is constructed on Rogers RT5880 (lossy) with 2.2 dielectric constant, l.27 mm thickness, and 0.0009 loss tangent. It is simulated in the programming of computer simulation technology (CST) Microwave Studio. The simulated results show that the SIW antenna resonates across 31 to 36 GHz bands, which means that this new antenna covers all applications within this range. The reflection coefficients in targeting range are below 10 dB. The antenna achieves good efficiency and gain with 80% and 8.87 dBi respectively.
Negative refraction metamaterial with low loss property at millimeter wave spectrum B. A. F. Esmail; H. A. Majid; F. A. Saparudin; M. Jusoh; A. Y. Ashyap; Najib Al-Fadhali; M. K. A. Rahim
Bulletin of Electrical Engineering and Informatics Vol 9, No 3: June 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (628.434 KB) | DOI: 10.11591/eei.v9i3.1853

Abstract

The design of the millimeter-wave (MMW) metamaterials (MMs) unit cell operates at 28 GHz is presented and numerically investigated. The proposed structure composed of a modified split ring resonator (MSRR) printed on both sides of the substrate layer. Popular MM structures such as S-shape, G-shape, and Ω-shape are adjusted to operate at the 28 GHz for comparison purpose. MSRR achieves a wide bandwidth of 1.1 GHz in comparison with its counterparts at the resonance frequency. Moreover, the proposed structure presents very low losses by providing the highest transmission coefficient, S21, at the corresponding frequency region. The radiation loss is substantially suppressed and the negativity of the constitutive parameters of the proposed MM structure is maintained. By applying the principle of the electromagnetically induced transparency (EIT) phenomenon, the MSRR unit cell induces opposite currents on both sides of the substrate which leads to canceling out the scattering fields and suppresses the radiation loss. The constitutive parameters of the MM structures are retrieved using well known retrieval algorithm. The proposed structure can be used to enhance the performance of fifth generation (5G) antenna such as the gain and bandwidth.
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.