S. K. A. Rahim

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—Rain attenuation is one of the most crucial factors to be considered in the link budget estimation for microwave satellite communication systems, operating at frequencies above 10 GHz. This paper presents a mathematical model for converting terrestrial rain attenuation data to be used for satellite applications at Ku-band. In the proposed technique, the(More)
This letter discusses the effect of antenna losses due to rain on a 26 GHz microwave link and the technique of extracting the losses from the measured rain atten-uation. A 2-feet parabolic dish antenna with horizontal polarization has been used in the study. The measurement results have been compared with those obtained from other locations in Malaysia and(More)
—This paper presents a mini multi-band printed omni-directional antenna with v-shaped structure for radio frequency identification (RFID) applications. The proposed multi-band antenna is developed from the initial v-shaped design which is only capable of working as a single-band antenna. By deploying a concept of dipole antenna to an initial design, the(More)
—Random antenna array (RAA) that uses the conventional beamforming method produces a poor beam pattern with high sidelobe level. This greatly reduces the performance and the efficiency of the antenna. The use of Genetic Algorithm (GA) to find the best positions for the antenna elements in RAA to lower the sidelobes has been widely researched. However, there(More)
—This paper presents the design of Dielectric Resonator Antenna (DRA) operating at 5.8 GHz, using the techniques of Two Segments DRA (TSDRA) and High-Aspect Ratio Structure. The aim of the paper is to reduce the size of the DRA while still maintaining its large impedance bandwidth. The requirements for WLAN applications are carefully taken into(More)
The results of rain attenuation on terrestrial microwave links in a tropical climate has been reported in this paper. The results are presented in the form of rate of change of attenuation with respect to rain rate, denoted by S.R %p /. This is in turn used for predicting the expected rain attenuation at any %p of the time rain rate is exceeded in any(More)
Distributed beamforming is a communication method in wireless sensor networks (WSNs) where the sensor nodes collaboratively create a virtual antenna to direct their radiating power towards the direction of an intended destination. This method could increase the transmission range of the network and save the sensors' energy. However, due to the random(More)
This paper proposes solution to optimize the peak side lobes level (PSLL) in a distributed random antenna array (RAA) when locations of the nodes in the array cannot be manipulated. Using the conventional beam forming method, RAA produces a poor beam pattern with high side lobe level, which greatly reduces the performance and the efficiency of the antenna.(More)
In a common method, user needs to refer an id number or label on the storage in order to identify the stock detail. The stocks that have been seal in a box or other storage will facing a problem to identify the items inside that storage, The purpose of this study was planned to develop a Portable Voice Based Device (PVBD) for stock identifications. PVBD is(More)
In this article, ultra-wideband (UWB) monopole antenna with circular polarization (CP) is designed and implemented. The proposed antenna consists of an asymmetric shaped radiator fed by a microstrip line and a limited ground plane on the back side of the substrate. The overall size of proposed antenna is 28 mm  29 mm, which is suitable for mobile devices.(More)