MKA Rahim

University of Technology Malaysia | UTM · Department of Communication Engineering

The paper focuses on investigating the fractal shape placement of metasurface reflectors at the X-band frequency for Reflecting Intelligent Surface (RIS). The proposed reflector adopts a square shape, with the fractal intersection on a Rogers RO5880 substrate measuring 0.51 mm in thickness. The graph illustrating the S-parameter and reflection phas...

This paper focuses on designing a new structure of beamforming networks with an array antenna to control the beams. The 3×4 array antenna structure connects to the 3×3 Rotman lens beamformers to achieve this goal. The middle time delay line is around 14 mm. The design allows the x-axis to cover +25, 0, −25 degrees. Therefore, this work targets fift...

In this research study, a metamaterial (MTM) based 1 × 4 linear antenna array is designed with an integrated butler matrix (BM) beamforming network (BFN) to execute the switched-beam antenna array (SAA) operation, which can be employed for sub-6 GHz 5G applications. The proposed SAA is designed and simulated using CST microwave studio and then fabr...

This paper introduces an innovative 4×4 dual-band Butler matrix (BM) characterized by compactness and an enhanced frequency ratio (K). The design employs meandered lines and an interdigital capacitor unit cell based composite right/left-handed transmission-line (CRLH-TL) metamaterial (MTM) structure. The BM integrates compact dual-band 3 dB branch-...

This work presents the design and implementation of active antennas as a part of a healthcare monitoring system that is based on the Internet of Things (IoT). The monitoring system comprises a SEN11547 pulse sensor and an LM35 temperature sensor for measuring heart rate in Beats Per Minute (BPM) and body temperature in Degree Celsius (°C). This dat...

The Fifth generation (5G) wireless communication system aims to provide high bandwidth, high sensitivity, high gain and power capability. Millimeter wave technology then proposed for these demands with various range of features such as higher bandwidth, low interference, and frequency reuse. However, millimeter wave technology has a key disadvantag...

This study presents the design and fabrication of a novel series feed array antenna structure consisting of eight elements, each integrated with 0.5mm air vias and separated by 0.9mm distances. The research investigates the impact of air vias on millimeter wave 5G applications, utilizing Roger 5880 substrate (εr = 2.2, loss tangent = 0.0009, thickn...

Traditional phased array antennas rely on costly phase shifters to steer beams by manipulating the phase of induced currents in each antenna element. In this study, we introduce a 1-bit coding metasurface as an alternative to traditional phased array antennas for beam control and modulation of electromagnetic waves. The metasurface operates at 5.8...

This study introduces a compact branch-line coupler (BLC) based on metamaterial (MTM) technology that can operate in sub-6 GHz 5G frequency bands. Conventional vertical and horizontal sections of the BLC were replaced with T-shaped TLs and interdigital capacitor (IDC) unit cells incorporated into the BLC sections to improve their performance and re...

This paper presents the substrate comparison on the multiband reflector performance at X-band frequency for an Intelligent Reflecting Surface (IRS). Functioning as a multiband reflector, the proposed reflector is using a circular multi-ring resonator on several substrates such as RO5880, F4BMX220, RO4003C, and FR4, with slightly different substrate...

The detection of partial discharge (PD) activities in high-voltage equipment can be conducted according to several mechanisms of signal detection, including electromagnetic wave signal detection, acoustic signal detection, chemical reactions, electrical signal detection, and optical emission detection. Recently, multiple methods of detection and lo...

This paper describes the integration of a plate Luneburg lens with a microstrip patch antenna (MPA) with a complementary split ring resonator (CSRR) at 17 GHz frequency. The main advantage of the method is the compact size of the optimized MPA with CSRR such that the radiation pattern of the antennas successfully overlaps at −3 dB. The overlapping...

Detection of partial discharge (PD) activities in high-voltage equipment can be done according to the several mechanisms of signal detection, which are electromagnetic wave signal detection, acoustic signal detection, chemical reactions, electrical signal detection, or optical emission detection. Recently, multiple methods of detection and localiza...

A low-profile and wide-angle radiation pattern reconfigurable antenna is designed, analyzed, and fabricated for wireless sensor network (WSN) applications, which operate at a 2.5-GHz frequency. This work aims to minimize the number of switches and optimize the parasitic size and ground plane to achieve a steering angle of more than 30° using a low...

A design of a compact wideband quadrature coupler based on metamaterial is presented at 3.5 GHz. The quadrature coupler is a significant component in beamforming networks with problems of narrow bandwidth and bulky size. The proposed quadrature coupler is designed with the implementation of composite right/left-handed (CRLH) arms metamaterial trans...

A design of a compact wideband quadrature coupler based on metamaterial is presented at 3.5 GHz. The quadrature coupler is a significant component in beamforming networks with problems of narrow bandwidth and bulky size. The proposed quadrature coupler is designed with the implementation of composite right/left-handed (CRLH) arms metamaterial trans...

A design of a wideband low loss 3 × 3 Nolen matrix is presented at 3.5 GHz. The proposed Nolen matrix is designed with the implementation of three branch-line couplers and two phase shifters. The interdigital capacitor unit cell is implemented in both the coupler and phase shifter to reduce the size and improve the bandwidth. The proposed 3 × 3 Nol...

In this paper, the design, simulation, fabrication, and characterization study of a low-cost and directional hybrid four-element (2 × 2 configuration) Minkowski–Sierpinski fractal antenna array (MSFAA) for the high-efficiency IEEE 802.11ax WLANs (Wi-Fi 6E) and the sub-6 GHz 5G wireless system is presented. Each element of the array is separated by...

The design and analysis of a compact dual-band wearable antenna for WBAN applications is presented. The antenna was prototyped on a semi-flexible Rogers Duroid RO3003™ with compact dimensions of 41 × 44 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> which corresponds to 0.33 λ <sub xmlns:mm...

This paper discusses about systematic design approach of Reactance Compensated Class-E. The theory behind conventional Class-E is described then differences between Reactance Compensation Class-E is explained and derived. The reactance compensated Class-E gives better high efficiency bandwidth. The range of shunt capacitor value that can maintain h...

Current wireless communications urgently need to provide huge data rates, high gain and high directivity radiation pattern beams. Therefore, beamforming networks (BFNs) are introduced to provide these needs. Butler matrix (BM) is a type of beamforming network, which can be realized using fixed network circuits and feeds the antenna array. BM at hig...

This paper presents the impact of surface roughness on the performance of a three –dimensional (3D) metal printed waveguide coupler designed at 28 GHz. The surface roughness is a significant factor that may affect 3D printed structures and post processing may be needed. It may degrade the performance of the printed devices in term of the reflection...

This paper presents a slotted planar microstrip patch antenna for the 5th generation communication. The planar microstrip patch antenna is designed with a square patch and two longitude slots at 3.5 GHz, using FR4 substrate and feds by a coplanar waveguide structure (CPW). The proposed antenna was simulated, analysed, and optimized using computer s...

This paper presents the design and simulation of a meandered bowtie frequency reconfigurable wearable antenna for a 5G health monitoring application. The antenna is based on a transdermal patch as the substrate, hence it offers convenience when it is applied on a user as compared to other recent developed wearable antennas. The antenna can cater to...

Beam reconfigurable Transmitarray antennas require the unit cell phase variation capability. This paper presents a new reconfigurable Transmitarray unit cell design using PIN diodes at the Ku-band. The unit cell is comprised of three layers having four PIN diodes used in every unit cell layer. This results in phase controlling by switching the PIN...

A compact triple-band operation ultra-wideband (UWB) antenna with dual-notch band characteristics is presented in this paper. By inserting three metamaterial (MTM) square split-ring resonators (MTM-SSRRs) and a triangular slot on the radiating patch, the antenna develops measured dual-band rejection at 4.17–5.33 GHz and 6.5–8.9 GHz in the UWB frequ...

This paper presents the design of a compact super wideband (SWB) antenna. The basic structure of the antenna is the slotted elliptical shape and partial ground proposed to achieve SWB property. The antenna is designed on the FR4 substrate material with a compact size of 20 ×20 mm2. The simulation results demonstrate that the reflection coefficient...

In this paper, the design of the second iteration of Log Periodic Fractal Koch Antennas (LPFKA) with and without slot implementation is designed for Ultra High Frequency (UHF) band applications. The slot implementation is applied on each of the radiating elements to reduce the antenna’s size and to prevent the shifting of a lower frequency to a hig...

This paper presents a dual-band slot antenna using substrate integrated waveguide (SIW) technology at 26 and 28 GHz. High loss is one of the main challenges faced by 5G base station network due to the severe path loss at high frequency. Hence, high gain antennas are required for 5G base station applications to overcome path loss issue. Hence, this...

In this paper, the reconfigurable metamaterial is proposed to deflect the radiated beam of the bow-tie antenna at a 5G band of 3.5 GHz. The split square resonator (SSR) is designed at a sub-6 GHz band and reconfigured to produce different refractive indices. For obtaining the desired deflection angles, 3 × 7 SSR unit cells with ON and OFF configura...

In this article, two distinct kinds of metamaterial (MTM) antennas are proposed for fifth-generation (5G) indoor distributed antenna systems (IDAS). Both antennas operate in the sub-6 GHz 5G band, i.e., 3.5 GHz. The antenna’s radiating structure is based on a combination of triangular and rectangular patches, as well as two complementary split-ring...

Acquiring an optically transparent feature on the wideband frequency selective surface (FSS), particularly for smart city applications (building window and transportation services) and vehicle windows, is a challenging task. Hence, this study assessed the performance of optically transparent mosaic frequency selective surfaces (MFSS) with a conduct...

Beamforming networks for multiple beam antennas are believed to be in the vanguard of technological developments in mmWave for 5G wireless applications. The basic idea of beamforming technique is the application of multiple antenna elements radiating the same signal at an identical phase and wavelength, into one strong signal pointed to a specific...

This paper discusses the simulations and measurements of the antenna with and without slot implementation in terms of reflection coefficient (S11) and radiation pattern. The slot implementation on each of the radiating elements on the 2nd iteration log periodic fractal Koch antenna (LPFKA) was described in this paper. This method is utilised to red...

This paper proposes multiple linear array millimeter wave MPAs that could operate at various frequencies depending on the angular rotation of the CSRR structure. The main contribution of this work is the range of frequencies of the linear array MPA found when the position of the CSRR structure is changed angularly. This is achieved by positioning t...

This paper presents a wideband planar microstrip antenna based on split ring resonator left-handed metamaterial (SRR-LHM) type at 3.5 GHz frequency for mid-band 5G mobile applications. The need to design a wideband antenna with good gain realising the proposed lower band spectrum for 5G technology is urgently demanded. To meet the requirements, mic...

This paper describes the design of an antenna based on Substrate Integrated Waveguide (SIW). The structure consists of slot antenna designed to operate at Ka band frequency. The effect of introducing slots and two feedline have been extensively studied. The basic structure is designed on a substrate with dielectric constant of 2.2 with a thickness...

This paper presents a wideband planar microstrip antenna with metamaterial unit cell at 3.5 GHz for mid band frequency 5G applications. The planar microstrip antenna is designed with square patch and two longitude slots at 3.5 GHz. The metamaterial unit cell is designed individually based on split ring resonator (left-handed metamaterial) SRR LHM t...

This paper proposes two different types of metamaterial (MTM) antennas for fifth-generation (5G) mid-band frequency operation. The radiating patch of the proposed antenna is based on the combined Minkowski-Sierpinski carpet fractal structure. On the ground plane, two different types of MTM structures: Complementary split-ring resonator (CSRR), and...

In this paper, a circularly polarized Transmitarray antenna design for the Ku-band frequency range is presented. The transmitarray antenna with 121 elements is designed using a four-layer double square ring with a center patch unit cell. The Unit cell parametric analysis shows a high transmission coefficient magnitude of -1.26 dBi and a wide phase...