36 research outputs found
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Wideband G-Shaped Slotted Printed Monopole Antenna for WLAN and WiMAX Applications
YesA novel wideband printed monopole antenna is proposed covering frequency spectrum of wireless local area network (WLAN) and the Worldwide Interoperability for Microwave Access (WiMAX). The total antenna size is 30 × 48 × 1.6 mm³ in which it consists of a G-shaped slotted printed antenna and a defected ground plane. Theoretical and experimental characteristics are presented and compared. The antenna yields an achieved impedance bandwidth of 95.1% between 2.374 GHz and 6.682 GHz at a reflection coefficient |S11| ≤ -10 dB.The results including S-parameters, surface current distribution, VSWR, radiation patterns and antenna gains; in addition to a reasonable and stable radiation pattern and power gain
Multiband monopole antenna for mobile applications
— In this paper, a multiband monopole antenna has
been proposed for mobile applications. The monopole antenna
has simple structure with a physical size of 15 cm × 7 cm. The
antenna consists of monopole shape loaded by a set of folded
arms with a varying length which lead to a better impedance
matching result and multiband performance. The simulated
results show that the proposed antenna provide multiband
frequency operation of 0.8 GHz, 1.8 GHz 2.1 GHz, 2.6 GHz
and 3.5 GHz which covers the range from 0 to 4 GHz. The
antenna is designed to operate at sub-6 GHz which proposed as
lower frequency band to deliver 5G in early stage. The
designed antenna has been fabricated and measured to validate
the simulated results. RF Coaxial U.FL Connector was used as
the port connector. The measurement results agrees well with
the simulated ones for all frequency bands
Analysis of the Effect of EBG on the Mutual Coupling for a two-PIFA Assembly.
yesSize constraints and mutual coupling on the
performance of a two-element PIFA assembly are investigated
for a design frequency of 2.4 GHz. A benchmark antenna
assembly, employing a normal metallic ground plane is
compared with an EBG modified ground plane. The height of the
antenna elements over the EBG is optimised, and an isolation
factor of 9.12 dB is achieved for a gap of 2.5 mm. Prototype
structures have been constructed and measured for both cases
Minimization of Mutual Coupling Using Neutralization Line Technique for 2.4 GHz Wireless Applications
YesThis paper presented a planar printed multiple-input-multiple-output (MIMO) antenna with a dimension of 100 x 45 mm2. It composed of two crescent shaped radiators placed symmetrically with respect to the ground plane. Neutralization line applied to suppress mutual coupling. The proposed antenna examined both theoretically and experimentally, which achieves an impedance bandwidth of 18.67% (over 2.04-2.46 GHz) with a reflection coefficient < -10 dB and mutual coupling minimization of < -20 dB. An evaluation of MIMO antennas is presented, with analysis of correlation coefficient, total active reflection coefficient (TARC), capacity loss and channel capacity. These characteristics indicate that the proposed antenna suitable for some wireless applications
Multi-criteria decision analysis integrated with GIS for radio astronomical observatory site selection in peninsular of Malaysia
No AbstractKeywords: site selection; radio astronomical observatory; multi-criteria decision analysis; geographical information system; Peninsular of Malaysi
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Design of 2x2 U-shape MIMO slot antennas with EBG material for mobile handset applications.
yesA compact dual U-shaped slot PIFA antenna with Electromagnetic Bandgap (EBG) material on a relatively low dielectric constant substrate is presented. Periodic structures have found to reduce mutual coupling and decrease the separation of antenna and ground plane. A design with EGB material suitable for a small terminal mobile handset operating at 2.4 GHz was studied. Simulated and measured scattering parameters are compared for U-shaped slot PIFA antenna with and without EBG structures. An evaluation of MIMO antennas is presented, with analysis of the mutual coupling, correlation coefficient, total active reflection coefficient (TARC), channel capacity and capacity loss. The proposed antenna meets the requirements for practical application within a mobile handset.Electronics and Telecommunication
Design, modelling and implementation of antennas using electromagnetic bandgap material and defected ground planes. Surface Meshing Analysis and Genetic Algorithm Optimisation on EBG and Defected Ground Structures for Reducing the Mutual Coupling between Radiating Elements of Antenna Array and MIMO Systems.
The main objective of this research is to design, model and implement several antenna
geometries using electromagnetic band gap (EBG) material and a defected ground
plane. Several antenna applications are addressed with the aim of improving
performance, particularly the mutual coupling between the elements.
The EBG structures have the unique capability to prevent or assist the propagation of
electromagnetic waves in a specific band of frequencies, and have been incorporated
here in antenna structures to improve patterns and reduce mutual coupling in multielement
arrays. A neutralization technique and defected ground plane structures have
also been investigated as alternative approaches, and may be more practical in real
applications.
A new Uni-planar Compact EBG (UC-EBG) formed from a compact unit cell was
presented, giving a stop band in the 2.4 GHz WLAN range. Dual band forms of the
neutralization and defected ground plane techniques have also been developed and
measured. The recorded results for all antenna configurations show good improvement
in terms of the mutual coupling effect.
The MIMO antenna performance with EBG, neutralization and defected ground of
several wireless communication applications were analysed and evaluated. The
correlation coefficient, total active reflection coefficient (TARC), channel capacity and
capacity loss of the array antenna were computed and the results compared to
measurements with good agreement.
In addition, a computational method combining Genetic Algorithm (GA) with surface
meshing code for the analysis of a 2×2 antenna arrays on EBG was developed. Here the
impedance matrix resulting from the meshing analysis is manipulated by the GA
process in order to find the optimal antenna and EBG operated at 2.4 GHz with the goal
of targeting a specific fitness function. Furthermore, an investigation of GA on 2×2
printed slot on DGS was also done.Ministry of Higher Education Malaysia and Universiti Tun Hussein Onn Malaysia (UTHM
Radio Astronomy Research in Malaysia: past, present and future
This paper will report on the progress in the research field of radio astronomy in Malaysia and also in South-East Asia. Radio astronomy research can be said to have only started being done actively in Malaysia in 2005. Fundamental setup and some basic research were done in the early parts. Jupiter radio bursts as well as radio meteor counting were the first few projects. Currently a medium-sized radio telescope which was recently purchased is being used to undergo more advanced research such as observing spectrum of galaxy clusters in order to study Dark Matter. This paper will also report on the latest results on the survey of Radio Frequency Interference (RFI), which is currently done on chosen candidate sites in Malaysia in order to setup on it a large radio telescope in the future. The best site with the lowest averaged REI level is found at Langkawi (-100.33 dBm or 4.4 x 10(6) Jy). The author is the chair for the Radio Astronomy Working Group for the South-East Asia Astronomy Network (SEAAN) and the Malaysian team is very much an important part of this group. This group will eventually be a research hub for the global projects of the Global-Very Long Baseline Interferometer (Global-VLBI) and the Square Kilometre Array (SKA)