Pusat Pengajian Kejuruteraaan Elektrik dan Elektronik - Monograf
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- Publication0.13 𝛍𝒎 cmos class f rf power amplifier for iot application(2019-05-01)Liew, Xin YeInternet of Things (IoT) industry keep growing in recent years. The design of RF power amplifier with high efficiency is thus crucial to reduce power consumption needed for data transmission which is high in capacity and speed. This project is a 0.13 μm CMOS Class-F Radio Frequency (RF) Power Amplifier (PA) which is designed for 2.45 GHz IoT application. The power amplifier design in this project consists of 3 parts including Input Impedance (IIP) match circuit, Class-F harmonics termination circuit and Output Impedance (OIP) match circuit. Smith chart for RF and Cadence software analysis tools are used in this design. For Bluetooth Low Energy (BLE), at least 4 dBm of output power is needed for signal transmission in BLE standard. In terms of performance, this PA design has power gain of 5.79 dB and output power of 5.79 dBm at operating frequency 2.45 GHz for the maximum Power Added Efficiency (PAE) of 31.62% with Output Third Order Intercept Point (OIP3) of 8 dBm. The maximum Output Third Order Intercept Point (OIP3) for this design is 15.7 dBm. At output power of 4 dBm (BLE standard), the PA’s power gain is 7.34 dB with PAE of 30% and OIP3 of 13 dBm. At the operating frequency of 2.45 GHz, the PA exhibits stability k-factor, 𝐾𝑓 value of more than 1 and thus the PA is unconditionally stable. Besides, the PA shows S-parameters performance of -19.25 dB for 𝑆11 and -13.97 dB for 𝑆22. These performances of PA are achieved at power supply of 1.2 V.
- Publication1.5-Bit stage analogue-to-digital converter (ADC)(2023-08)Ch’ng, Ooi KeatThis report presents the design of 1.5-bit stage Analogue-to-Digital Converter (ADC). In this project, with some assumption considered, the minimum open-loop DC gain, AOL required for this project is calculated as 40dB. Meanwhile, the minimum unity gain frequency, fu of the OTA must be at least 16.0MHz as the ADC designed in this project will be clocked at 8MHz. Average power consumption of the main OTA is expected to be less than 40mW. Silterra 180nm process technology is used in this work. The architecture of 1.5-bit stage ADC mainly consists of an operational transconductance amplifier (OTA) as the core element. Generally, the 1.5-bit stage is made up of a 2-bit comparator, a digital logic circuit and a residue amplifier. The main function of the comparators is to emonstrate that an input signal is either larger or less than a predetermined reference voltage. The digital logic circuit serves as switches to allow the residue amplifier to function by receiving a 2-bit digital input from the comparator. Based on the results obtained, the main OTA in this project has specifications such that 45.0dB for the open-loop DC gain, 470.11MHz for unity-gain frequency, 79.52° for phase margin, and 27.117mW for average power consumption for the main OTA. In short, all the specifications for this main OTA have all achieved the minimum requirement of the main OTA design. The three blocks for the overall design of 1.5-bit stage ADC, which are the 2-bit comparator, digital logic circuit, and lastly the residue amplifier, are all carried out their specific. functions successfully as all of them are verified throughout the testbench simulations with the desired outcomes.
- Publication10-bit digital-to-analog converter (dac) using partial binary tree network (pbtn) dynamic element matching (dem) approach(2019-06-01)Tan, Zi JunDigital-to-Analog converters (DAC) are an important element in many digital systems which demands high-performance data conversions. Due to factors like shrinking supply voltage and budget constraint, DAC highly relied on matched components to perform data conversion. However, matched components are nearly impossible to fabricate, because mismatch errors always occurred between designed and actual component value. One of the techniques to overcome the effect of mismatched components error is to use Dynamic Element Matching (DEM) method. This method randomizes the digital input codes before entering DAC block, making the time of each component position nearly equal. The drawback of this design is, it would suffer from excessive hardware complexity and causes glitches at the output signal. In this research, the DEM algorithm used is known as Partial Binary Tree Network (PBTN) algorithm. PBTN reduce the complexity of the circuit and produce an output signal with fewer glitches. In this research, the ideal Operational amplifier (Op-Amp) used to magnify the output current is replaced with an Op-Amp built by transistors. This thesis reports the simulation of 10-bit 1-MSB PBTN DAC using a non-ideal operational amplifier with DNL of -0.182979 LSB, INL of -0.959287 LSB and power consumption of 1.108 mW.
- Publication180° hybrid coupler implemented with 2x2 butler matrix(2019-06-01)Halmy, Nor Amylia MohdHybrid coupler is a four-port device where a directional coupler is designed to split power equally between two ports. Hybrid coupler can be used to decouple and increase the isolation between antenna ports. In this project, it is focus on how to design 180° Hybrid Coupler implemented with 2x2 Butler Matrix by using CST. The concept of transforming branch-line hybrid coupler into coupled-resonator network is presented in this project. The proposed of hybrid coupler with additional method with 2x2 Butler Matrix is to improve the isolation, size reduction, better terms of low production cost and good return loss. This project is focused on how to reduce the size of hybrid coupler so that it will obtain good S-Parameters. This design is fabricated using RO 4003C printed circuit board with dieletric constant, 𝜀(, 3.55 mm, thickness of substrate, H, 0.81 mm and thickness of copper, t, 0.035 mm. The design need to be operated at 2.4GHz. From the simulation and measured results, the 180° Hybrid Coupler implemented with 2x2 Butler Matrix nearly met the entire requirement needed such as return loss which is less than - 10 dB, isolation loss is nearly less than -5 dB. However, the isolation between ports is in the range frequency of 2.39 GHz to 2.54 GHz. It is still acceptable because the performance is not affected.
- Publication2–18ghz radar pencari arah(2006-11-01)Hussin, Mohd RidhuanThis report presents the design of radar direction finder which will be use to detect the receiving signal in the frequency range of 2GHz to 18GHz. This range of frequency is commonly use by the military for their operations. This system is design with the combination of several parts such as receiver antenna, low noise amplifier circuit, mixer down converter circuit, varactor tuned oscillator circuit, band pass filter circuit, RF to DC voltage converter circuit, amplifier circuit, analog to digital converter (ADC) circuit, digital to analog converter (DAC) circuit and finally the 8051 microcontroller trainer board. In this system, the receiver antenna that will be use is from the antipodal vivaldi antenna type. Its need exactly eight identical antenna to make this direction finder system to works well. Each design and simulation done in this project is using the software called HPADS. The control and process unit for this system is done by the 8051 microcontroller.
- Publication3d deformable circuit board for soft robotics(2021-07-01)Leong, Jun XianNowadays, the electronic components in the intelligent devices are getting more compact, making the device to be tiny but with many functions. However, there are still many electronic components which are rigid and cannot be deformable. In recent years, many researches have been done to develop a deformable or stretchable printed circuit board (SPCB). However, most of the SPCB exist as a single layer board. Besides, there is no conventional control circuit board that are suitable for soft robotics application. Thus, a 3D deformable control circuit board was proposed and built based on the schematic design of Arduino Uno board. In this project, an Arduino Uno R3 board was selected and transformed into a soft deformable circuit board. The electronic components on Arduino Uno board were desoldered and removed. Then, the schematic design of the Arduino Uno board was modified to reduce the complexity of the control circuit. The circuit layout of the board was designed based on the concept of kirigami structure. The circuit was printed onto the flexible printed circuit board (FPCB) and divided into many islands. These FPCB islands were arranged in kirigami structure and connected by meander-shaped metal tracks. Next, the whole circuit were encapsulated by silicone rubber. After the fabrication was done, mechanical tests for deformable board were carried out to test its stretchability and its robustness. The elongation limit of fabricated 3D deformable control circuit board was 35.90%, whereas the maximum twisted angle on deformable board was 95°. The compression force that can be withstood by the deformable board was 10.05N. The performance of deformable board was also compared with a rigid Arduino Uno board, and the results showed that the deformable board has higher stretchability and deformability than a rigid Arduino Uno board. Therefore, a 3D deformable control circuit board which was compatible for soft robotics applications was successfully fabricated. The comparison between deformable board and rigid board had also proven that deformable board was unique and more suitable to be used in soft robotics application. Besides, the strength and weakness of deformable board was listed and discussed. Suggestions were also given to improve the performance of 3D deformable circuit board in the future.
- Publication3D printer system design and development(2019-06-01)Fan, Jian RongThe advent of 3D printing has revolutionized the traditional subtractive manufacturing and being recognized as additive manufacturing where materials are added, joined or fused together successively layer by layer. However, due to open loop condition in 3D printer motion system, this may lead to layer shifting problem and result in failures and wastage of plastic. Therefore, this project aims to design a closed loop system in the stepper motion to rectify the layer shifting problem during printing. Therefore, a 3D printer is constructed with the help of Solidworks to design an innovative foldable mechanism to the printer structure as well as the installation of AVAGO incremental optical linear encoder on the XY gantry. The detection of input step and direction signal from firmware is conducted with the help of Arduino libraries, same goes to the detection of distance from linear encoder. A motor controller is designed using Arduino UNO as the control unit to receive the input signal from 3D printer firmware and generate output to the A4988 stepper motor driver to run the motor, where the response is monitored by linear encoder as the feedback for the closed loop system using bilinear transformation in order to interface with the Arduino microcontroller. The prototype of portable 3D printer is assembled and has proved to be working for its folding mechanism. The phase lead controller is being analyzed for its performance in terms of feedback of linear encoder, stability of the system, and accuracy of the controller. The linear encoder shows a dropping accuracy for longer distance in open loop system. This is due to its lower resolution compared to microstepping stepper motor. In terms of stability, a gain of K=0.25 is applied to the phase lead controller to obtain a stable response without oscillation. High accuracy is obtained for the phase lead controller and is maintained at average of 96.26% for X axis and 97.23% for Y axis. The print head is deliberately perturbed by an external force during the printing task to evaluate the designed controller performance in disturbance rejection. The system manages to rectify the error and shift back to the required position, showing the success of closed loop system in stepper motion to recover from layer shifting problem. All the objectives have been achieved.
- Publication3d robotic vision(2020-07-01)Silvarajoo, KamalappriyaOne of the most important part in our human body is our eyes. Our vision are key player in our body because of the hand – eye coordination. Hand eye coordination is the coordinated control of eye movement with hand movement and the processing of visual input to guide locate, identify and grasping an object with the use of proprioception of the hands to guide the eyes. In industrial world, identification of a subject is high priority since the position and orientation of a subject is highly recommended. The use of the vision system is to compute the locus and the orientation of a subject.2D robotic vision system was created to capture an image of a subject and 2D vision system are using two dimensional map (X, Y) of reflected intensity. The vision system are develop to 3D which is more convenient and advanced to compute the position and orientation of a subject. This project is designed to control the robotic arm via automated visual feedback accurately. In this project, the derivation of the transfer function which maps the camera and robotic coordination system in 3D. Results that obtain through this experimental, the real world ground image will be created. Day by day new innovation are making our life less complex. This 3D vision system could be one of the next technologies with betterment that bring the future nearer.
- Publication60μm memsoi low g memes accelerometer design(2012-01-01)Iberahim, Nik Mohd Amali FikriMEMS (Microelectromechanical Systems) refers to the technology integrating electrical and mechanical components with feature size 1~1000 microns. MEMS accelerometers have been successfully applied for air-bag deployment systems in automobiles. In this thesis, the design optimization of a poly-silicon surface-micromachined MEMS comb accelerometer is discussed. The device uses folded-beams. There are movable fingers from both sides of movable mass. Each movable finger has left and right fixed comb fingers surrounding it, so that a differential pairs is formed. Any acceleration along the sensitive direction will induce inertial force on movable mass and deflect the beams. Hence the differential capacitance gap will change. By measuring this differential capacitance change, the experienced acceleration can be measured. CONVENTORWARE FEM analysis simulation is used to extract the device sensitivity and resonant frequency of the device. By gradually varying the design parameters in CONVENTORWARE simulation, the relationship between the device sensitivity and various design parameters is derived. The curve of device sensitivity versus beam width, beam length and mass width are derived and they are good agreement with theoretical prediction. From analysis it is concluded that the device behavior strongly depends upon various design parameters. By adjusting design parameters, desired sensitivity can be obtained. Based on simulation results, a set of optimized design parameters for the comb accelerometer is decided.
- Publication65nm CMOS bandgap voltage reference circuit(2023-07)Low, Chee WengBandgap voltage reference is a circuit that produces a stable output reference voltage that is not affected by the variation of process, voltage and temperature (PVT). BGR is an essential and important component that is used in many applications such as power converters, flash memory controllers, PLL, LDO, A/D converters. In a bandgap voltage reference circuit, the output reference voltage is generated by the summation of two voltages (VPTAT and VCTAT) with opposite temperature coefficients. This voltage is then amplified and filtered to generate a stable output reference voltage that is relatively insensitive to the changes in process, temperature and supply voltage variations. In this project, TSMC 65nm CMOS Bandgap Voltage Reference Circuit is designed. A stable of output reference voltage of 1.23V with supply voltage of 2V is expected from the outcome of this project. Next, the phase margin of the two-stage operational amplifier should achieve larger than 45°. Temperature coefficient of the BGR should achieve lower than 30ppm/°C and power consumption lower than 300µW is expected. The workflow of this project starts from calculations of parameters of MOSFETs and passive components, schematic design of the two-stage operational amplifier and bandgap voltage reference circuits until pre-layout simulation of both schematic circuits. As the output from pre-layout simulations, the DC gain and phase margin of the op-amp achieve 73.04892dB and 84.63997° respectively while the output reference voltage recorded is 1.22847V ~ 1.23819V with 0.81% (± 10mV) of inconsistency for supply voltage from 2V to 4V. Next, temperature coefficient of 27.81ppm/°C is obtained for temperature ranging from 40°C to 125°C. Lastly, the power consumption of the BGR circuit is 298.1µW.
- PublicationA literature study of sabah sarawak peninsular Malaysia(2008-08-01)Loh, Swee AunNowadays, High voltage direct current (HVDC) is used to transmit large amounts of power over long distances or for interconnections between asynchronous grids and underwater or submarine transmission. It has become an integral part of the delivery of electricity in many countries throughout the world. This is because there are a number of advantages over AC transmission system in certain cases. The objectives of this literature survey are to study the application of HVDC and the reasons of using HVDC in transmission system. Some basic theories related to HVDC are also examined and analyzed in this survey. A case study on the Sabah/Sarawak-Peninsular Malaysia interconnection HVDC transmission system is discussed. This case study on the project is chosen because this transmission system will be the longest transmission system on the world and will benefit to Malaysia. This transmission system will launch in Malaysia soon. The analysis and discussion on the case study are done based on the theories studied.
- PublicationA 65nm CMOS constant current reference (CCR) circuit for sensory applications(2023-07)Nishant, KumaranDisclosed is a CMOS constant current reference circuit having a circuit configuration that includes transistors only of the COMS type. The circuit is capable of providing a constant current to a load, regardless of a variation in supply voltage and a variation in temperature. A constant current generating unit generates a constant bias current regardless of a variation of a supply voltage. A self compensation unit controls the constant current generating means to maintain the bias current generated therefrom at a constant level regardless of a variation in temperature. A starting unit establishes a current path adapted to activate the constant current generating unit. A constant current supply unit supplies the bias current generated from the constant current generating unit, at a constant level. Therefore, this paper presents a voltage threshold-based self-bias and can be used for integrated CMOS current source structure. When the power supply voltage changes from 0V to 2.5V, the current source can output 20 current constant currently and enable control terminal also be added that can effectively control the circuit open or closed. The circuit can be good for the other sub-circuit modules to provide a stable DC bias, so that they can work in a suitable quiescent point. Design was using Cadence virtuoso TSMC 65nm technology. The CCR circuit is suitable to be implemented in sensory applications.
- PublicationA comparison between levenberg-marquardt (lm) intelligent system and bayesian regularization (br) intelligent system for flow regime classification(2006-05-01)Sa'ad, Mohamad IqbalThe purpose of this project is to study the performance, leaning time and, output of Levenberg-Marquardt (LM) intelligent system and Bayesian Regularization (BR) intelligent system through a classification problem. These studies will help in choosing the right training algorithm for classification problem involved. These intelligent systems have to classify flow regimes in a closed line with the data are provided by Electrical Capacitance Tomography (ECT). ECT measured the different capacitance value of fluid and produced the data for the classification problem. Multilayed Perceptron (MLP), a type of artificial neural network (ANN) which is widely used in a classification problem is developed using MATLAB 7®. The comparison made showed that LM learning algortihm is a faster training algorithm compared to BR training algorithm meanwhile BR learning algorithm capable of building a superior intelligent system in term of the overall system performance.
- PublicationA grid-tied fuel cell multilevel inverter with pq control scheme(2023-10)Muhammad Haikal bin Muhamat MeriRecently, sustainable electrical power has captured the attention of the electric generation industry. Renewable Energy helps in reducing global warming as well as environmental pollution. This report will discuss a grid-tied fuel cell multilevel inverter with a PQ control scheme. This project consists of three main components: the Diode clamped multilevel inverter, Fuel cell stack and LCL filter. The fuel cells will produce electricity by a chemical reaction and generate DC power. The multilevel inverter converts DC power to AC power before connecting to the electrical grid. LCL filter circuit is used to reduce harmonic from the inverter. This project can be implemented in households or small offices where users can generate electricity and use it without interruption. It will help to reduce energy generation via fossil fuels, and if implemented by many people, this can positively impact the environment. This project has been carried out in MATLAB/Simulink software. It involved designing a multilevel inverter, fuel cell stack, LCL filter circuit and grid. The fuel cell stack generates 100kW to supply local load while exporting and importing power to the grid through the interfacing inverter, depending on the demands. From simulation of MLI with LCL filter that have been connected to fuel cell stack source, real and reactive power for 1200V 50Hz with 100kW power was obtained and recorded.
- PublicationA literature study of malaysia-thailand interconnection high voltage direct current (hvdc) transmission system(2008-05-01)Md Sharif, Ahmad FikriHigh Voltage Direct Current (HVDC) is a transmission system which is widely used all over the world whether through overhead cable or undersea cable. Converter station located between two-end lines have important impact in HVDC transmission system. It is important to evaluate converter station configuration before designing a converter station, so that the distortion and harmonic can be reduced. In this thesis, two converter station polarity commonly used that is monopole and bipolar is discussed. Next, the Graetz circuit arrangement that is 3-phase 2-way configuration is examined. The Graetz circuit is used in HVDC transmission system between Malaysia-Thailand, both in two converter stations at Gurun (Malaysia) and Khlong Ngae (Thailand). Several important parameters related to Graetz circuit has been proven in reducing harmonic. Finally, the technical specifications for HVDC transmission operation system between Malaysia-Thailand is examined.
- PublicationA Literature Study of Malaysia-Thailand Interconnection HVDC Transmission System(2008-08-01)Md Sharif, Ahmad FikriHigh Voltage Direct Current (HVDC) is a transmission system which is widely used all over the world whether through overhead cable or undersea cable. Converter station located between two-end lines have important impact in HVDC transmission system. It is important to evaluate converter station configuration before designing a converter station, so that the distortion and harmonic can be reduced. In this thesis, two converter station polarity commonly used that is monopole and bipolar is discussed. Next, the Graetz circuit arrangement that is 3-phase 2-way configuration is examined. The Graetz circuit is used in HVDC transmission system between Malaysia-Thailand, both in two converter stations at Gurun (Malaysia) and Khlong Ngae (Thailand). Several important parameters related to Graetz circuit has been proven in reducing harmonic. Finally, the technical specifications for HVDC transmission operation system between Malaysia-Thailand is examined
- PublicationA literature study of sabah/ sarawak- peninsular malaysia interconnection system(2008-05-01)Loh, Swee AunNowadays, High voltage direct current (HVDC) is used to transmit large amounts of power over long distances or for interconnections between asynchronous grids and underwater or submarine transmission. It has become an integral part of the delivery of electricity in many countries throughout the world. This is because there are a number of advantages over AC transmission system in certain cases. The objectives of this literature survey are to study the application of HVDC and the reasons of using HVDC in transmission system. Some basic theoriesrelated to HVDC are also examined and analyzed in this survey. A case study on the Sabah/Sarawak-Peninsular Malaysia interconnection HVDC transmission system is discussed. This case study on the project is chosen because this transmission system will be the longest transmission system on the world and will benefit to Malaysia. This transmission system will launch in Malaysia soon. The analysis and discussion on the case study are done based on the theories studied.
- PublicationA model-based framework for speed and direction detections of a moving object(2019-06-01)Wong, Chun SheungIntrusion detection can be defined as the detection of an unauthorized person or vehicle has accessed or attempting to gain unauthorized entry into designated areas. Basically, the microwave sensor is be chosen as the main component for the exterior intrusion detection. As the microwave sensor can generate an electromagnetic (RF) field between transmitter and receiver, the big detection area generated is suitable for the exterior intrusion detection. To increase the efficiency of the system, the main requirement is to increase the accuracy and minimize the error of detection of the microwave sensor. In this project, the Simulink S-function model for the microwave sensor and 3D gesture sensor have be created. To investigate the better position of the microwave sensor respect to the accuracy of detecting the moving object, a comparative experiment had been conducted. From the result, the microwave sensor at the high position can lead to the higher accuracy of speed detection exceeding more than 95%. The mechanism for detecting the direction of the moving object had been made using the 3D gesture sensor. The direction of the moving object is indicated by the digital value “1” for “right”, “2” for “left”, “3” for “down” and “4” for “up”.
- PublicationA pratical method for fault location determination on power transmission line(2007-05-01)Wong, Tai TiongThis project studies the practical method for fault location determination for single phase to ground fault on short type transmission line. When a fault occurs on power transmission line, it is very important to detect the fault location in order to restore the electricity as soon as possible to minimize the interruption of power supply. In this project, a simple fault location determination method is proposed based on impedance-based fault location techniques. The main idea of the method is by injecting two identical voltages to both end of fault phase transmission line, measuring the value of voltage and fault currents, and solving an equation to determine the fault location of the fault point. The mutual inductance effect toward the fault phase is ignored since there will be no current flow if the fault is not occur at the tested phase. This idea has been proved useful by using simulation and experiment in laboratory. The calculated fault location in simulation and experiment is independent from the fault current and the fault resistance. Besides, a fault location program is developed based on the fault location method proposed using C++ programming language. The program can be use to estimate the fault point on the transmission line using the information including line impedance, fault resistance and fault current. By using this program, the fault location on transmission line can be estimated quickly and accurately. For future development, it is hope that the fault location method can be used to determine fault location for all kind of faults for longer length of transmission line.
- PublicationA qualitative review on tradeoff relationship between usage behaviour and accuracy required for ips using rfid with landmarc approach(2012-06-01)Hong, Chii ChewPrior to this project, a hypothesis is made that the accuracy of an Indoor Positioning System (IPS) with LANDMARC approach, can be traded-off based on the usage behaviour. To study the validation of the statement, this project has implemented the IPS and a series of tests. The tests first define the parameters: Tradeoff, Usage Behaviour, and Accuracy. Tradeoff is defined as task success; while Usage Behaviour is defined as case study settings; for Accuracy is defined in Eq. 3.1. The tests manipulate Usage Behaviour to observe the Tradeoff and Accuracy. The way is using three maps of different landmark separations and two different task requirements: “Correct landmark as task success” and “Correct position within allowable trials as task success”. Consequently, the IPS software has found faulty during carrying out the accuracy tradeoff study. Thus, a proper investigation to the study cannot be completed. But based on the obtained results, the high accuracy happened by chance in a faulty IPS does not necessary help in making task success, for which the usage behaviour requires accurate position. Future study of the test is required.