Browsing by Author "Kamarudin, M. R."

Now showing 1 - 5 of 5
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    Compact and Low-profile Textile EBG-based Antenna for Wearable Medical Applications
    (IEEE, 2017-07-27) Ashyap, A. Y. I.; Abidin, A. A.; Dahlan, S. H.; Shah, S. M.; Kamarudin, M. R.; Alomainy, A.
    A compact wearable antenna with a novel miniaturized EBG structure at 2.4 GHz for medical application is presented in this letter. The design demonstrates a robust, compact and low-profile solution to meet the requirements of wearable applications. The EBG structure reduces the back radiation and the impact of frequency detuning due to the high losses of human body. In addition, the structure improves the front-to-back ratio (FBR) by 15.5 dB. The proposed compact antenna with dimensions of 46 × 46 × 2.4 mm3 yields an impedance bandwidth of 27% (2.17-2.83 GHz), with a gain enhancement of 7.8 dBi and more than 95 % reduction in the SAR. Therefore, the antenna is a promising candidate for integration into wearable devices applied in various domains, specifically biomedical technology.
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    A compact frequency reconfigurable hybrid DRA for LTE/Wimax applications
    (Hindawi Publishing, 2017-09-25) Aqeel, S.; Kamarudin, M. R.; Khan, A. A.; Saleem, J.; Nasir, J.; Kazim, J. R.; Owais, O.
    A compact hybrid antenna structure with frequency reconfiguration capabilities is presented in this article. The proposed design employs a combination of a rectangular DR element and a coupling slot on the structure’s ground plane (GP). The slot shifts the fundamental DRA mode by introducing a slow wave effect and its resonant behavior helps to achieve an omni-directional pattern at low frequencies. The slot is loaded with a series of PIN diode switches whose ON/OFF combinations alter the effective slot length. Slot loading with PIN diodes results in frequency reconfiguration of the proposed structure with a large tuning range of 76.2 % (between 1.73 to 3.86 GHz). A parametric analysis was performed to investigate the effects of slot length, width and position on the reflection coefficients of the proposed structure. A prototype of the proposed design was fabricated and results were measured. The measured results show a close agreement with the simulated ones. The proposed design is suitable for DCS 1800 MHz, PCS 1900 MHZ, UMTS, LTE 2500-2700 MHz, and Wimax 3.5 GHz.
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    A review of wideband reflectarray antennas for 5G communication systems
    (IEEE, 2017-08-31) Dahri, M. H.; Jamaluddin, M. H.; Inam, M.; Kamarudin, M. R.
    The advancement in the current communication technology makes it incumbent to analyze the conventional features of reflectarray antenna for future adaptability. This work thoroughly reviews the design and experimental features of reflectarray antenna for its bandwidth improvement in microwave and millimeter wave frequency ranges. The paper surveys the fundamental and advanced topologies of reflectarray design implementations which are needed particularly for its broadband features. The realization of its design approaches has been studied at unit cell and full reflectarray levels for its bandwidth enhancement. Various design configurations have also been critically analyzed for the compatibility with the high frequency 5G systems.
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    Steerable Higher-order Mode Dielectric Resonator Antenna with Parasitic Elements for 5G Applications
    (IEEE, 2017-10-12) Shahadan, N. H.; Jamaluddin, M. H.; Kamarudin, M. R.; Yamada, Y.; Khalily, M.; Jusoh, M.; Dahlan, S. H.
    This paper presents the findings of a steerable higher-order mode (TEy 1δ3) dielectric resonator antenna with parasitic elements. The beam steering was successfully achieved by switching the termination capacitor on the parasitic element. In this light, all of the dielectric resonator antennas (DRAs) have the same dielectric permittivity similar to that of 10 and was excited by a 50Ω microstrip with a narrow aperture. The effect of the mutual coupling on the radiation pattern and the reflection coefficient, as well as the array factor were investigated clearly using MATLAB ver. 2014b and ANSYS HFSS ver. 16. As the result, the antenna beam of the proposed DRA array managed to steer from -32° to +32° at 15 GHz. Furthermore, the measured antenna array showed the maximum gain of 9.25 dBi and the reflection coefficients which are less than -10 dB with the bandwidth more than 1.3 GHz, which is viewed as desirable for Device-to-Device communication (D2D) in 5G Internet of Things (IoT) applications.
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    Textile antenna with simultaneous frequency and polarization reconfiguration for WBAN
    (IEEE, 2017-12-25) Salleh, S. M.; Jusoh, M.; Ismail, A. H.; Kamarudin, M. R.; Nobles, P.; Rahim, M. K. A.; Sabapathy, T.; Osman, M. N.
    This paper proposes the design of a reconfigurable circularly polarized textile antenna. The circular polarization feature in the proposed antenna is generated by the edge-truncation of a rectangular patch and the incorporation of a slotted ground plane, whilst the frequency re-configurability feature is realized by slot size modification via the use of three embedded RF PIN diode switches. Consequently, the antenna operation can be switched between six frequencies (1.57 GHz, 1.67 GHz, 1.68 GHz, 2.43 GHz, 2.50 GHz and 2.55 GHz) depending on the seven switch configurations. The proposed antenna is validated experimentally to be operable within the WBAN, WLAN and GPS range in a compact and wearable format, with gains of up to 4.8 dBi.