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Shaiful Nizam Mohyar
Preferred name
Shaiful Nizam Mohyar
Official Name
Shaiful Nizam, Mohyar
Alternative Name
Mohyar, Shaiful Nizami
Mohyar, Saiful Nizam
Mohyar, S. N.
Mohyar, Shaiful Nizam
Mohyar, Shaiful N.
Main Affiliation
Scopus Author ID
55534021900
Researcher ID
FJX-6667-2022
Now showing
1 - 10 of 12
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PublicationSignal propagation modelling for vehicle-to-infrastructure communication under the influence of metal obstruction( 2021-12)
;Jamie Siregar Cynthia Turner ;D L NdziM K N ZulkifliConnected car has become one of emerging technology in the automotive industries today. This development preludes a rise in vehicular communication studies that primarily targets radio channel modelling on vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication mode. Considering vehicular obstruction, vast channel propagation studies have focused more on V2V mode while others consider the typical urban scenarios consisting of high traffic volumes of moving vehicles. Due to challenging propagation mechanisms and high complexity in such areas, radio propagation models applied in simulators assume an obstacle-free environment rather than considering the least effect imposed by metal obstruction on communication signal. Besides, there are limited studies pertaining to metal obstruction that considers several under-explored environments such as actual parking lots, junctions and other road infrastructure support. As such, this paper demonstrates signal attenuation analysis caused by the presence of metal objects in low density over obstacle-free environment on actual parking lot via V2I mode. Two scenarios such as LOS and NLOS conditions consisting of obstacle-free, cars and buses as static metal objects are evaluated. The aim of this research is to characterize signal strength caused by metal blockage on radio wave propagation predicated on the presence of vehicles as a subject of obstruction in comparison to obstacle-free vehicular environment. The validity of data is shown through received signal strength indicator (RSSI) and approximation analysis (RMSE) to demonstrate the efficiency of obtained measurements. The results demonstrated that Log-normal shadowing model yields the best fit to low-density metal obstruction scenario with smallest RMSE of 4.78 under bus obstruction whereas 5.72 under car obstruction. -
PublicationLow noise figure 2.4 GHz down conversion CMOS mixer for wireless sensor network application( 2017-01-06)
;Izatul Syafina IshakRohana SapawiThis work proposed a low noise figure 2.4 GHz down-conversion CMOS mixer for wireless sensor network (WSN) application using 0.13-μm Silterra technology. The proposed down-conversion mixer converts a high radio frequency (RF) signal from 2.4 GHz to an intermediate frequency (IF) of 100 MHz through the use of a local oscillator signal (LO) of 2.3 GHz. The proposed mixer employs a double balance Gilbert-cell topology with integrated input matching at the input stage and a low pass filter at the IF stage. The simulation results indicate that the proposed mixer obtains lower noise figure (NF) of 5.21 dB with an input third-order intercept point (IIP3) of 0 dB. Furthermore, the conversion gain (CG) of 8.6 dB is achieved with the power consumption of 1.57 mW at 1.8 V supply voltage. -
PublicationA 46% PAE, 2.4-GHz Two-Stage Class E Power Amplifier Utilizing CMOS 0.13-µm Technology( 2024-01-01)A wireless device with a long battery life and great sensitivity becomes difficult to develop since there is a huge demand for low-power, low-cost wireless gadgets. The power amplifier (PA) is the most crucial part of radio frequency (RF) transceivers because of its massive power consumption. Consequently, in order to minimize power loss, a very effective and low-power consumption PA is needed. In this paper, high efficiency two-stage CMOS PA designed in 0.13-μm process for 2.4 GHz IoT transmitter applications is presented. The driver stage and power stage are the two stages that make up the two-stage topology of the proposed CMOS PA. To attain high efficiency and great power gain, a class E PA is used at the power stage. The LC matching network at the output is used for harmonic rejection filter at 2.4 GHz with an additional parallel capacitor helps for better harmonic rejection. In addition, a layout has been successfully designed and optimized. All the components in the proposed PA are designed on-chip. The pre-layout and post-layout simulations have been conducted to verify the proposed PA's performance. The pre-layout simulation of the proposed PA can deliver 19.19 dBm output power and 45.2% PAE at 2.0 V power supply into a 50-Ω load. On the other hand, the proposed PA produced an output power of 17.33 dBm and 46% PAE, according to the results of the post-layout simulation with a similar power supply of 2.0 V. The chip area for the proposed layout design is 1.05 mm2.
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PublicationDesign of CMOS low-dropout voltage regulator for power management integrated circuit in 0.18-μm technology( 2020-01-08)
;Sapawi R.Karim J.A low-dropout (LDO) voltage regulator is the main component used in the majority of portable electronic application since it is used as power management unit in those applications. In this paper, a LDO regulator for the power management integrated circuit in 0.18-μm CMOS technology using Cadence software is presented. The error amplifier of the proposed LDO employed seven transistors for current mirror. Meanwhile, the PMOS transistor is used as a pass element transistor to control the voltage variation. The resistors are used as a feedback network circuit while the capacitor is used to minimise the variation of output voltage. The simulation results show that the proposed design provides a 2.41 V constant output voltage for the supply voltage ranges of 2.55 V to 3.55 V. The dropout voltage of 140 mV is achieved with 1.48 mW power consumption. The line regulation is 1.0 mV/V and the load regulation is 0.41 mV/A, while the layout of the proposed regulator is 27 μm × 34 μm.1 -
PublicationA Study and Analysis of High Efficiency CMOS Power Amplifier for IoT Applications( 2021-03-01)
;Yi K.S.This paper presents a study and analysis of high efficiency CMOS power amplifier (PA) for Internet of Thing (IoT) application. The studied mainly focused on the topology employed in designing high efficiency PA in gigahertz range frequencies. This study covers the basic class-E PA and the topologies in designing class-E PA such as single-stage, two-stage, multistage and differential. The circuits structure and the performances of class-E PA is discussed. The analysis is focusing on the efficiency of the proposed PA. The latest CMOS PAs developments have been studied and a summarization of the performance specification for different topologies are elaborated.1 -
PublicationElectrical conductivity (EC) sensing system for paddy plant using the internet of things (IoT) connectivity( 2020-01-08)
;Othaman N.N.C.This paper presents the design and development of an IoT-based electrical conductivity system for measuring paddy soil nutrients. Relationship between electrical conductivity (EC) and the influence of soil temperature in precision farming will be discussed. In this work, the EC algorithm was modelled and verified using MATLAB and realized on Node MCU (ESP8266) microcontroller. Results showed that the measured data from the developed system is closed to the calibration solution conductivity that is 1.413mS/cm and 12.88mS/cm. It is also noted that the recorded electrical conductivity value increases with temperature. -
PublicationDesign and implementation of bluetooth microcontroller in system-on-chip (SoC)( 2024)
;Hang Suan Wang ;Zulfiqar Ali Bin Abd Aziz -
PublicationDesign of aquaponics water monitoring system using Arduino microcontroller( 2017-09-26)
;Rohana SapawiTen S.Y.This paper describes the design of aquaponics water monitoring system using Arduino microcontroller. Arduino Development Environment (IDE) software is used to develop a program for the microcontroller to communicate with multiple sensors and other hardware. The circuit of pH sensor, temperature sensor, water sensor, servo, liquid crystal displays (LCD), peristaltic pump, solar and Global System for Mobile communication (GSM) are constructed and connected to the system. The system powered by a rechargeable battery using solar energy. When the results of pH, temperature and water sensor are out of range, a notification message will be sent to a mobile phone through GSM. If the pH of water is out of range, peristaltic pump is automatic on to maintain back the pH value of water. The water sensor is fixed in the siphon outlet water flow to detect water flow from grow bed to the fish tank. In addition, servo is used to auto feeding the fish for every 12 hours. Meanwhile, the LCD is indicated the pH, temperature, siphon outlet water flow and remaining time for the next feeding cycle. The pH and temperature of water are set in the ranges of 6 to 7 and 25 °C to 30 °C, respectively. -
PublicationDesign of 3.1-6.0 GHz CMOS ultra-wideband low noise amplifier with forward body bias technique for wireless applications( 2020-01-08)
;Halim N.F.A.B.This paper presents a design of 3.1-6.0 GHz CMOS ultra-wideband low noise amplifier (UWB LNA) with forward body bias technique for wireless applications. The UWB LNA is designed and simulated using 0.13-μm technology in Cadence software. The proposed UWB LNA consists of two stage common-source (CS) amplifiers with a forward body bias technique. A source degenerated inductor is used at the first stage to achieve a wideband input matching and high linearity. At the second stage, a shunt-peaking inductor is employed to enhance gain at higher frequency. The simulation results indicate that the proposed UWB LNA achieves a power gain (S21) of 10 dB, an input return loss (S11) is less than -5 dB, a minimum noise figure (NF) of 8.5 dB in the frequency range of 3.1- 6.0 GHz with power dissipation of 17.2 mW. The linearity analysis shows a 1 dB compression point (P1dB) of -9 dBm and the third-order intermodulation intercept points (IIP3) of 4 dBm are achieved. The proposed UWB LNA's layout is 0.68 mm2.1 -
PublicationImage data compression using fast Fourier transform (FFT) technique for wireless sensor network( 2024-02-08)
;Haron M.H. ;Arshad M.A.M. ;Hussin R. ;Harun A.Agricultural settings present unique challenges for the transmission of huge amounts of images over long-range wireless networks. It is challenging to remotely gather data for transmission over a wireless network in research areas due to a lack of basic amenities like internet connections, especially in distant agricultural areas. In this research, the Fast Fourier Transform (FFT) method was used in conjunction with the Discrete Cosine Transform (DCT) method of image compression to achieve a higher compression ratio. In order for a Wireless Sensor Network (WSN) to provide compressed image data to a wireless based station, a LoRaWAN network has been identified. Low-power LoRaWAN networks may regularly transmit compressed images from an agricultural region to a monitoring system up to 15 km away. Images of golden apple snails were collected for this study from a variety of sources. The procedure was coded in MATLAB so that it could be run with input images being judged by the created algorithm. The input images can be compressed with a range of compression ratios (CR) from 3.00 to 50.00, as shown by the simulation results. Compressed image quality is measured not only by the above-mentioned criteria, but also by Mean Square Error (MSE) and Peak Signal to Noise Ratio (PSNR). According to the numbers, the best achievable compression ratio is 49.04, with an MSE of 172.72 and a PSNR of 25.75 at its highest.