Tharek A. Rahman
Universiti Teknologi Malaysia

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Impedance Mathing Improvement of Half-Cut Broadband Printed Monopole Antenna with Microstrip Feeding Teguh Prakoso; Mochammad Facta; Razali Ngah; Tharek A. Rahman
International Journal of Electrical and Computer Engineering (IJECE) Vol 3, No 5: October 2013
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (313.557 KB)

Abstract

The requirement of wireless access networks and user equipments to support coexistence of many communication standards and frequency bands poses challenge on antenna to be broadband and small. The application of half-cut technique to broadband printed monopole with microstrip feeding worsens the resulted antenna’s impedance. To improve the half-cut antenna impedance mathing, two methods were investigated in this paper: (1) monopole and ground extension, (2) the application of microstrip line transformer and ground extension. The first approach only produces limited improvement, whereas method #2 can enhance the return loss significantly. The application of the second approach potentially produces antenna pair that has low mutual coupling, good return loss, and small size. Considering its radiation pattern, the antenna is suitable for diversity and MIMO. Its application in broadband microwave-photonic access point need special arrangement due to radiation null at 5 GHz band at right side.DOI:http://dx.doi.org/10.11591/ijece.v3i5.3376
Channel fading attenuation based on rainfall rate for future 5G wireless communication system over 38-GHz Ibraheem A. Shayea; Salim A. Alkhawaldeh; Mahdi A. Nisirat; Tharek A. Rahman; Mustafa Ergen
International Journal of Electrical and Computer Engineering (IJECE) Vol 12, No 5: October 2022
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v12i5.pp5104-5113

Abstract

In this paper, the effect of heavy rainfall on the propagation of a 38-GHz in a tropical region was studied and analyzed. Real measurement was collected, with a path length of 300 meters, for a (5G) radio linkage in Malaysia, installed at the Universiti Teknologi Malaysia (UTM) Johor Bahru campus. The employed system entails an Ericsson MINI-Link 38 E-0.6 mm, with a horizontal polarization (HP) antenna at the top integrated with a rain gauge and a data logger. Daily registered samples with a single minute span, for a full study period of 1 month, were collected and evaluated. The obtained rain rate was found as 56 mm/hr with a specific rain attenuation of 18.4 dB/km for 0.01% of the time. In addition to that, a calculated average rain attenuation of 5.5 dB for the transmission path of 300 meters length, was calculated. Based on these findings, a recommendation to update the International Telecommunication Union (ITU) specification of the rain attenuation for Malaysia is proposed. Based on the results, we suggest shifting the zone classification of Malaysia from zone P to zone N-P. Therefore, accurate design for future 5G systems would rely on more precise estimated attenuation levels leading to enhanced performance.
Production of strawberry using internet of things: a review Olakunle Elijah; Abdelmoneim A. bakhit; Tharek A. Rahman; Tien Han Chua; Siti Fatimah Ausordin; Rifhan Narrissa Razali
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 3: September 2019
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v15.i3.pp1621-1628

Abstract

Strawberry is a widely consumed fruit and cultivated globally but predominantly in cooler temperate zones because of its wealth of nutrients, vitamins and minerals. However, there are several challenging factors faced in the growing of strawberry such as temperature, seasonal production and short shelf-life. To overcome some of these challenges, the application of greenhouse and internet of things (IoT) are being used. In this paper, a review of the application of IoT in the greenhouse production of strawberry is presented. This includes a survey of existing literature on production of strawberry, types, method of growing strawberry and the application of IoT. The benefits and challenges of IoT in greenhouse strawberry production are discussed. The review highlights the need for use of low power wide area communication technology in the application of IoT in greenhouse strawberry production especially in tropical regions like Malaysia.
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.