Ali N. Obadiah
Universiti Teknologi Malaysia

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Improved Vivaldi Antenna with Radiation Pattern Control Features Delphine Abijuru; M.R. Hamid; Ali N. Obadiah
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 16, No 3: June 2018
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v16i3.9039

Abstract

Vivaldi antenna has been considered as a mitigation to the scattering effect of an antenna. However, the current performance of Vivaldi antenna suffers from multipath effect, interfering signals and radiation pattern control. This paper proposed an improved Vivaldi antenna which combined triple radiating slot to enable control of radiation pattern features. This is accomplished by controlling the position of the radiating element through the asymmetric arrangement of ideal switches to steer the beam in three desired-directions. The Using operating frequency lied between 900 MHz and 2.5GHz, the proposed design was fabricated and tested. Depending on the radiating element, the proposed antenna covered about ±90º with an almost equal gain at the three different focal in contrast to ±45º coverage of traditional rectangular microstrip antenna beam. The results satisfied pattern reconfigurability and the proposed design can be very useful for wireless communications where multipath fading problems are frequently encountered.
Evolution Process of a Broadband Coplanar- Waveguide-fed Monopole Antenna for Wireless Customer Premises Equipment Alishir Moradikordalivand; Tharek A. Rahman; Ali N. Obadiah; Mursyidul Idzam Sabran
Indonesian Journal of Electrical Engineering and Computer Science Vol 12, No 8: August 2014
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v12.i8.pp6238-6242

Abstract

In this paper a design process of a broadband printed monopole antenna using stepped cut at four corners (CSFC) technique is proposed. The CSFC is a technique that four corners a patch (rectangular/square) of planar monopole antennas are cut in order to enhance the impedance bandwidth. The technique can be used to design any different types of planar monopole antenna in specific frequency ranges. Therefore, to become more acquaintance with the CSFC technique an evolution process of single band to broadband antenna is represented. However, the proposed antenna is designed for wireless indoor customer premises equipment (CPE) using the coplanar waveguide (CPW) feeding technique. Moreover, the antenna is simulated using CST software and also fabricated and tested so as to validate the results. The simulated and measured -10 dB reflection bandwidth is 104% (850MHz to 2.7 GHz) to cover GSM (900 and 1800 MHz), WiFi (2.4 GHz) and LTE (2.6 GHz) applications. High efficiency and gain as well as omnidirectional and quasi-omnidirectional of radiation pattern at lower and upper frequencies have been achieved.