Samsul Haimi Dahlan
Universiti Tun Hussein Onn Malaysia (UTHM)

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Journal : TELKOMNIKA (Telecommunication Computing Electronics and Control)

Parametric Analysis of Wearable Vialess EBG Structures and Its Application for Low Profile Antennas Adel Y.I. Ashyap; Zuhairiah Zainal Abidin; Samsul Haimi Dahlan; Huda A. Majid; Zuraidah Muhammad; Muhammad Ramlee Kamarudin
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.v15i2.6108

Abstract

This paper is under in-depth investigation due to suspicion of possible plagiarism on a high similarity indexElectromagnetic Bandgap (EBG) structures are one class of metamaterial with attractive properties that unavailable in nature and widely used for improving the electromagnetic performance. Its In-phase reflection frequency band is indicated as operation frequency band, whose characteristic is closely related to the parameters of EBG structure, such as patch width (w), gap width (g), substrate height (h) and substrate permittivity (ε). The presence of via within EBG structure is associated with design and fabrication complexities, which led the researchers to study uniplanar EBG. These structures require no via and can easily be fabricated and integrated with RF and microwaves application.  Therefore, an investigation study on the effect of the parameters of the vialess EBG surface and some design guidelines have been obtained. An example of an antenna integrated with EBG is also studied. The result indicates that the EBG ground plane significantly improves the work efficiency of the antenna in a particular frequency band.
Design of wideband Rotman lens for wireless applications Mohammed K. Al-Obaidi; Ezri Mohd; Noorsaliza Abdullah; Samsul Haimi Dahlan
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 17, No 5: October 2019
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v17i5.11930

Abstract

An electrically steerable beam is an essential standard in the recent wireless application in order to increase the gain and reduce the interference. However, high performance of amplitude besides low phase error difficult to achieve without indicators are used to set lens parameters to desired optimum performance design level. In this paper, the introduced microstrip lens has examined a comprehensive explanation for parameters and indications amid a full wave structure methodology. Further, Phase and energy coupling between excited ports and received ports besides phase error and its relation with the lens parameters design are explained in detailed.  A wideband beamforming network based on a printed microstrip Rotman lens with a ±26o scanning angle was designed in this study. The designed lens operates at 2.45 GHz with 592 MHz bandwidth. The lens consists of five switchable ports (input ports) with four output ports that connected to the microstrip patch antennas. The five switchable ports were used to realize the scanning beams angle in the azimuth plane.  The proposed model is simulated by CST Microwave Studio and fabricated on FR-4 with 1.565 mm thickness and 4.2 permittivity.  A good agreement between simulation and measurement results were achieved.