In the past few years, the prime focus of supplying electricity to the longhouse communities in the rural areas of Sarawak has been initiated based on the utilization of a single-source microgrid configuration. The existing AC power supply-based solar photovoltaic (PV) systems in these areas pose many problems, mainly owing to the stages of conversion, energy losses, and the quality of power transfer. As the solar PV system is a DC source and most of the appliances in longhouse communities could be operated using DC source, an opportunity to design a microgrid with high reliability and efficiency would be achieved by the implementation of an optimal DC microgrid configuration. With this aim, the paper proposes a multiple-source DC microgrid configuration for the longhouse communities in Sarawak. Initially, a framework has been developed to design simulation models for both microgrid configurations (single and multiple sources) using MATLAB Simulink. The configuration of each system consists of a solar PV and energy storage to form a standalone microgrid. Due to the change in system configuration of DC microgrid, in the modeling approach, the standard power flow equations are modified to include solely the DC parameters. To validate the proposed configuration with the associated modeling approach in terms of the power flow reliability, system efficiency, and power-voltage curve, an experimental setup representing the Simulink model has been designed for each standalone microgrid configuration. The configurations have been assessed in the same location with different daily weather conditions. The obtained simulation and experimental results confirm that the proposed configuration of multiple sources is more reliable and efficient than the existing single-source configuration.

This paper focuses the rain effect over FSO link medium in Malaysia environment. In this work, a rain data samples that collected from Malaysian Meteorological Department (MMD) to determine the scattering coefficient, atmospheric attenuation and total attenuation. From the analysis, the precipitation rate give different impact over FSO link which can cause the attenuation and bit error rate increase. The results also show the comparison parameter for optimal geometrical loss such as beam divergence, aperture size and receiver sensitivity.

This paper presents the design of parallel coupled line band pass filter with 10 GHz operating frequency that will be used in 5G applications. As 5G application requires big data usage and to cater the applications, the bandwidth of 5G devices need to be wider enough to support it. Thus, to improve the bandwidth performance of the designed filter, patterned ground structure (PGS) technique is implemented into it. The result shows that the bandwidth of the designed filter has been improved from 0.25 GHz to 4.98 GHz when PGS is implemented.

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Abstract. Free space optical communication fsoc is vulnerable with fluctuating atmospheric. This paper focus analyzes the finding of new technique dual diffuser modulation (ddm) to mitigate the atmospheric turbulence effect. The performance of fsoc under the presence of atmospheric turbulence will cause the laser beam keens to (a) beam wander, (b) beam spreading and (c) scintillation. The most deteriorate the fsoc is scintillation where it affected the wavefront cause to fluctuating signal and ultimately receiver can turn into saturate or loss signal. Ddm approach enhances the detecting bit '1' and bit '0' and improves the power received to combat with turbulence effect. The performance focus on signal-to-noise (snr) and bit error rate (ber) where the numerical result shows that the ddm technique able to improves the range where estimated approximately 40% improvement under weak turbulence and 80% under strong turbulence.