Carrier velocity of lateral gate p-type silicon nano wire transistor (PSNWT) which is depending o... more Carrier velocity of lateral gate p-type silicon nano wire transistor (PSNWT) which is depending on silicon nanowire dimensions and physical structure of the transistor is analyzed. The effect of quantum confinement of the channel electronic structure can change the hole masses of the valence bands and the transmission properties. For the valence band of the wires, the simulation shows that in nanowires , more and more higher subbands with larger transport hole effective-masses, become populated and lowering the average hole velocity in p-type SNWTs. Abrupt source and drain junction accounting for the electric field dependence of carrier mobility, is investigated in this work.
In this paper, we have investigated the characteristics and transport features of junctionless la... more In this paper, we have investigated the characteristics and transport features of junctionless lateral gate transistors via measurement and simulations. The transistor is fabricated using an atomic force microscopy (AFM) nanolithography technique on silicon-on-insulator (SOI) wafer. This work develops our previous examination of the device operation by using 3D numerical simulations to offer a better understanding of the origin of the transistor operation. We compare the experimental measurements and simulation results in the transfer characteristic and drain conductance. We also explore the behavior of the device in on and off states based on the variation of majority and minority carriers' density, electric-field components, and recombination/generation rate of carriers in the active region of the device. We show that the device is a normally on device that can force the current through a depleted region (off state) and uses bulk conduction instead of surface conduction. We also found that due to the lateral gate design, low-doped channel, and lack of the gate oxide the electrostatic squeezing of the channel effectively forces the device into the off state, but the current improvement by accumulation of carriers is not significant.
Side gate p-type Junctionless Silicon transistor is fabricated by AFM nanolithography on low-dope... more Side gate p-type Junctionless Silicon transistor is fabricated by AFM nanolithography on low-doped (10 5 cm -3 ) SOI wafer. In this work, the simulation characteristic of the device using TCAD Sentaurus in on state will be studied. The results show that the device is the pinch off transistor, works in on state for zero gate voltage in depletion mode. Negative gate voltage drives the device into on state, but unable to make significant effect on drain current as accmulation mode. Simulation results for valence band energy, electric field and hole density are investigated along the active regions. The influence of the electric field due to the applied voltages of V DS and V G on charge distribution is much more when the device operates at the saturation region. The hole quasi-Fermi level has a positive slope showing the current flows from source to drain.
This paper presents an implementation of Multistructure PIDFLC. Modification has been made to str... more This paper presents an implementation of Multistructure PIDFLC. Modification has been made to structure of the proposed PIDFLC in order to make it acts as PDFLC, PIFLC or PIDFLC depending on two external signals. Two versions of this controller have been designed using VHDL language for FPGA implementation. A new package has been designed in VHDL code to implement trigonometric functions and fourth-order Runge-Kutta method to test the proposed design with nonlinear systems. The controller was able to produce an output in 0.3 µsec for linear plants and 0.7 µsec for nonlinear plant. Therefore, the proposed controller will be able to control many systems with high sampling rate.
Journal of Electromagnetic Waves and Applications, 2009
This paper presents an Ultra-Wide Band (UWB) microstrip filter which is initially modeled from a ... more This paper presents an Ultra-Wide Band (UWB) microstrip filter which is initially modeled from a quarter-wavelength short-circuited stubs, without the use of any vias. All vias that provide short circuit stubs are replaced by microstrip patches which have low impedance at high ...
2015 International Conference on Smart Sensors and Application (ICSSA), 2015
In this work, microfluidic channel was explored using dry film resist (DFR) method. Many of previ... more In this work, microfluidic channel was explored using dry film resist (DFR) method. Many of previous studies used SU-8 and PDMS as the medium to fabricate microfluidic channel for making a microfluidic chamber. Microscope slides were used as the substrate for the applications with bio components since it is inert and stable. The DFR serves to be the spacer to form the channel. Several processes which include cleaning, drying, prebaking, laminating, UV exposure and finally post-baking were involved in channel making. These processes need to be optimized in order to obtain a good chamber. Silicon rubber and UV glue were used to seal the chamber system to prevent any leakages.
Mass loading has been one of the major parameter need to be consider before any of a surface acou... more Mass loading has been one of the major parameter need to be consider before any of a surface acoustic wave devices can be fabricate. In this paper a finite element method (FEM) study of the mass loading on gallium phosphate surface acoustic wave resonator was done for high temperature sensing applications. A comparison with the previous experimental work has shown that FEM can be used to determine the effect of mass loading to the center frequency of the surface acoustic wave resonator.
Since division is not a standard operation for DSP processors and because it can be implemented i... more Since division is not a standard operation for DSP processors and because it can be implemented in several different ways, there is no specific algorithm clearly to choose. It all depends on the requirements, such as accuracy, size and speed. A few suitable algorithms should be selected and implemented in VHDL for evaluation. The implementation is expected to be a part of an existing baseband processor and should be able to handle the high speed requirements while keeping the size down. Here we implement complex division based on Newton Raphson method. This divider will be used in the Digital Predistortion for adaptation of the power amplifiers. Based on the requirements of the input signal, the divider that is implemented here has different features and makes it suitable for digital communication where we deal with complex values. The results of simulation show improvement in hardware resources as compare to other methods.
A large numbers of fuzzy control applications with the physical systems require a real-time opera... more A large numbers of fuzzy control applications with the physical systems require a real-time operation to interface high speed constraints; higher density programmable logic devices such as field programmable gate array (FPGA) can be used to integrate large amounts of logic in a single IC. This paper presents a design representation of the multipurpose fuzzy logic controller using hardware description language, in order to make a comparison between other designs in the physical systems. The controller is (Proportional -integral -derivative Fuzzy Logic controller (PIDFLC)), with programmable fuzzy sets and programmable rule table using VHDL language. The method used to design the fuzzy logic controller is to design it with the aid of conventional PID control to serve wide range of the physical systems efficiently. The design representation is presented using RTL viewer in the ALTERA Quartus II program. Timing test results for the proposed controller was very fast ranging from 20.8 nano second, and the controller has the ability to serve a wide range of the systems.
Efficient RF power amplifiers used in third generation systems require linearization in order to ... more Efficient RF power amplifiers used in third generation systems require linearization in order to reduce adjacent channel inter-modulation distortion, without sacrificing efficiency. Digital baseband predistortion is a highly cost-effective way to linearize power amplifiers (PAs), but most existing architectures assume that the PA has a memoryless nonlinearity. For wider bandwidth applications such as wideband code-division multiple access (WCDMA) or wideband orthogonal frequency-division multiplexing (W-OFDM), PA memory effects can no longer be ignored. In this paper we proposed a technique for adaptation of digital predistorter that considers memory effects in power amplifiers.
In this paper, An analytical and simulation solution for touch mode Micro-electromechanical syste... more In this paper, An analytical and simulation solution for touch mode Micro-electromechanical systems (MEMS) capacitive pressure sensor operating in harsh environment is proposed, The principle of the paper is to design, obtain analytical solution and compare the results with the simulation using coventor software for a circular diaphragm deflection before and after touch point. The material is considered to be used for harsh environment is SiC (Silicon Carbide), Because of SiC owing excellent electrical stability, mechanical robustness, and chemical inertness properties and the application of pressure sensors in harsh environments are, such as automotive industries, aerospace, oil/logging equipments, nuclear station, and power station. We are using coventor software for modeling and simulating of MEMS capacitive pressure sensor to optimize the design, improve the performance and reduce the time of fabricating process of the device. The device achieved a linear characteristic response and consists of a circular clamped-edges poly-SiC diaphragm suspended over sealed cavity on a poly-Sic substrate. The proposed touch mode MEMS capacitive pressure sensor demonstrated diaphragm ranging from 150ìm to 360ìm in diameter, with the gap depth from 0.5ìm to 6ìm and the sensor exhibit a linear response with pressure from 0.05 Mpa to 10 Mpa.
In this paper, a comprehensive study has been made on the detection of free fatty acids (FFAs) in... more In this paper, a comprehensive study has been made on the detection of free fatty acids (FFAs) in palm oil via an optical technique based on enzymatic aminolysis reactions. FFAs in crude palm oil (CPO) were converted into fatty hydroxamic acids (FHAs) in a biphasic lipid/aqueous medium in the presence of immobilized lipase. The colored compound formed after complexation between FHA and vanadium (V) ion solution was proportional to the FFA content in the CPO samples and was analyzed using a spectrophotometric method. In order to develop a rapid detection system, the parameters involved in the aminolysis process were studied. The utilization of immobilized lipase as catalyst during the aminolysis process offers simplicity in the product isolation and the possibility of conducting the process under extreme reaction conditions. A good agreement was found between the developed method using immobilized Thermomyces lanuginose lipase as catalyst for the aminolysis process and the Malaysian Palm Oil Board (MPOB) standard titration method (R2 = 0.9453).
The electrical behaviour of double lateral gate junctionless transistors, regarding to the variat... more The electrical behaviour of double lateral gate junctionless transistors, regarding to the variation of channel thickness is investigated, through 3-D numerical simulations. The simulation results explicitly show that how the device thickness affect the on and off current and threshold voltage behavior based on variation of the carriers density and recombination rates of the carriers. As the channel thickness is decreased, the amount of bulk neutral channel getting smaller which cause a decrease in the on state current. Meanwhile, the lateral gate influence on the channel is reinforced, which cause a decrease in leakage current in the off state. Threshold voltage is decreased as the channel thickness decreases. However, the recombination rate of carriers increases with decreasing the channel thickness, due to the accumulation of minority carries and shifted to the source side of the channel.
Carrier velocity of lateral gate p-type silicon nano wire transistor (PSNWT) which is depending o... more Carrier velocity of lateral gate p-type silicon nano wire transistor (PSNWT) which is depending on silicon nanowire dimensions and physical structure of the transistor is analyzed. The effect of quantum confinement of the channel electronic structure can change the hole masses of the valence bands and the transmission properties. For the valence band of the wires, the simulation shows that in nanowires , more and more higher subbands with larger transport hole effective-masses, become populated and lowering the average hole velocity in p-type SNWTs. Abrupt source and drain junction accounting for the electric field dependence of carrier mobility, is investigated in this work.
In this paper, we have investigated the characteristics and transport features of junctionless la... more In this paper, we have investigated the characteristics and transport features of junctionless lateral gate transistors via measurement and simulations. The transistor is fabricated using an atomic force microscopy (AFM) nanolithography technique on silicon-on-insulator (SOI) wafer. This work develops our previous examination of the device operation by using 3D numerical simulations to offer a better understanding of the origin of the transistor operation. We compare the experimental measurements and simulation results in the transfer characteristic and drain conductance. We also explore the behavior of the device in on and off states based on the variation of majority and minority carriers' density, electric-field components, and recombination/generation rate of carriers in the active region of the device. We show that the device is a normally on device that can force the current through a depleted region (off state) and uses bulk conduction instead of surface conduction. We also found that due to the lateral gate design, low-doped channel, and lack of the gate oxide the electrostatic squeezing of the channel effectively forces the device into the off state, but the current improvement by accumulation of carriers is not significant.
Side gate p-type Junctionless Silicon transistor is fabricated by AFM nanolithography on low-dope... more Side gate p-type Junctionless Silicon transistor is fabricated by AFM nanolithography on low-doped (10 5 cm -3 ) SOI wafer. In this work, the simulation characteristic of the device using TCAD Sentaurus in on state will be studied. The results show that the device is the pinch off transistor, works in on state for zero gate voltage in depletion mode. Negative gate voltage drives the device into on state, but unable to make significant effect on drain current as accmulation mode. Simulation results for valence band energy, electric field and hole density are investigated along the active regions. The influence of the electric field due to the applied voltages of V DS and V G on charge distribution is much more when the device operates at the saturation region. The hole quasi-Fermi level has a positive slope showing the current flows from source to drain.
This paper presents an implementation of Multistructure PIDFLC. Modification has been made to str... more This paper presents an implementation of Multistructure PIDFLC. Modification has been made to structure of the proposed PIDFLC in order to make it acts as PDFLC, PIFLC or PIDFLC depending on two external signals. Two versions of this controller have been designed using VHDL language for FPGA implementation. A new package has been designed in VHDL code to implement trigonometric functions and fourth-order Runge-Kutta method to test the proposed design with nonlinear systems. The controller was able to produce an output in 0.3 µsec for linear plants and 0.7 µsec for nonlinear plant. Therefore, the proposed controller will be able to control many systems with high sampling rate.
Journal of Electromagnetic Waves and Applications, 2009
This paper presents an Ultra-Wide Band (UWB) microstrip filter which is initially modeled from a ... more This paper presents an Ultra-Wide Band (UWB) microstrip filter which is initially modeled from a quarter-wavelength short-circuited stubs, without the use of any vias. All vias that provide short circuit stubs are replaced by microstrip patches which have low impedance at high ...
2015 International Conference on Smart Sensors and Application (ICSSA), 2015
In this work, microfluidic channel was explored using dry film resist (DFR) method. Many of previ... more In this work, microfluidic channel was explored using dry film resist (DFR) method. Many of previous studies used SU-8 and PDMS as the medium to fabricate microfluidic channel for making a microfluidic chamber. Microscope slides were used as the substrate for the applications with bio components since it is inert and stable. The DFR serves to be the spacer to form the channel. Several processes which include cleaning, drying, prebaking, laminating, UV exposure and finally post-baking were involved in channel making. These processes need to be optimized in order to obtain a good chamber. Silicon rubber and UV glue were used to seal the chamber system to prevent any leakages.
Mass loading has been one of the major parameter need to be consider before any of a surface acou... more Mass loading has been one of the major parameter need to be consider before any of a surface acoustic wave devices can be fabricate. In this paper a finite element method (FEM) study of the mass loading on gallium phosphate surface acoustic wave resonator was done for high temperature sensing applications. A comparison with the previous experimental work has shown that FEM can be used to determine the effect of mass loading to the center frequency of the surface acoustic wave resonator.
Since division is not a standard operation for DSP processors and because it can be implemented i... more Since division is not a standard operation for DSP processors and because it can be implemented in several different ways, there is no specific algorithm clearly to choose. It all depends on the requirements, such as accuracy, size and speed. A few suitable algorithms should be selected and implemented in VHDL for evaluation. The implementation is expected to be a part of an existing baseband processor and should be able to handle the high speed requirements while keeping the size down. Here we implement complex division based on Newton Raphson method. This divider will be used in the Digital Predistortion for adaptation of the power amplifiers. Based on the requirements of the input signal, the divider that is implemented here has different features and makes it suitable for digital communication where we deal with complex values. The results of simulation show improvement in hardware resources as compare to other methods.
A large numbers of fuzzy control applications with the physical systems require a real-time opera... more A large numbers of fuzzy control applications with the physical systems require a real-time operation to interface high speed constraints; higher density programmable logic devices such as field programmable gate array (FPGA) can be used to integrate large amounts of logic in a single IC. This paper presents a design representation of the multipurpose fuzzy logic controller using hardware description language, in order to make a comparison between other designs in the physical systems. The controller is (Proportional -integral -derivative Fuzzy Logic controller (PIDFLC)), with programmable fuzzy sets and programmable rule table using VHDL language. The method used to design the fuzzy logic controller is to design it with the aid of conventional PID control to serve wide range of the physical systems efficiently. The design representation is presented using RTL viewer in the ALTERA Quartus II program. Timing test results for the proposed controller was very fast ranging from 20.8 nano second, and the controller has the ability to serve a wide range of the systems.
Efficient RF power amplifiers used in third generation systems require linearization in order to ... more Efficient RF power amplifiers used in third generation systems require linearization in order to reduce adjacent channel inter-modulation distortion, without sacrificing efficiency. Digital baseband predistortion is a highly cost-effective way to linearize power amplifiers (PAs), but most existing architectures assume that the PA has a memoryless nonlinearity. For wider bandwidth applications such as wideband code-division multiple access (WCDMA) or wideband orthogonal frequency-division multiplexing (W-OFDM), PA memory effects can no longer be ignored. In this paper we proposed a technique for adaptation of digital predistorter that considers memory effects in power amplifiers.
In this paper, An analytical and simulation solution for touch mode Micro-electromechanical syste... more In this paper, An analytical and simulation solution for touch mode Micro-electromechanical systems (MEMS) capacitive pressure sensor operating in harsh environment is proposed, The principle of the paper is to design, obtain analytical solution and compare the results with the simulation using coventor software for a circular diaphragm deflection before and after touch point. The material is considered to be used for harsh environment is SiC (Silicon Carbide), Because of SiC owing excellent electrical stability, mechanical robustness, and chemical inertness properties and the application of pressure sensors in harsh environments are, such as automotive industries, aerospace, oil/logging equipments, nuclear station, and power station. We are using coventor software for modeling and simulating of MEMS capacitive pressure sensor to optimize the design, improve the performance and reduce the time of fabricating process of the device. The device achieved a linear characteristic response and consists of a circular clamped-edges poly-SiC diaphragm suspended over sealed cavity on a poly-Sic substrate. The proposed touch mode MEMS capacitive pressure sensor demonstrated diaphragm ranging from 150ìm to 360ìm in diameter, with the gap depth from 0.5ìm to 6ìm and the sensor exhibit a linear response with pressure from 0.05 Mpa to 10 Mpa.
In this paper, a comprehensive study has been made on the detection of free fatty acids (FFAs) in... more In this paper, a comprehensive study has been made on the detection of free fatty acids (FFAs) in palm oil via an optical technique based on enzymatic aminolysis reactions. FFAs in crude palm oil (CPO) were converted into fatty hydroxamic acids (FHAs) in a biphasic lipid/aqueous medium in the presence of immobilized lipase. The colored compound formed after complexation between FHA and vanadium (V) ion solution was proportional to the FFA content in the CPO samples and was analyzed using a spectrophotometric method. In order to develop a rapid detection system, the parameters involved in the aminolysis process were studied. The utilization of immobilized lipase as catalyst during the aminolysis process offers simplicity in the product isolation and the possibility of conducting the process under extreme reaction conditions. A good agreement was found between the developed method using immobilized Thermomyces lanuginose lipase as catalyst for the aminolysis process and the Malaysian Palm Oil Board (MPOB) standard titration method (R2 = 0.9453).
The electrical behaviour of double lateral gate junctionless transistors, regarding to the variat... more The electrical behaviour of double lateral gate junctionless transistors, regarding to the variation of channel thickness is investigated, through 3-D numerical simulations. The simulation results explicitly show that how the device thickness affect the on and off current and threshold voltage behavior based on variation of the carriers density and recombination rates of the carriers. As the channel thickness is decreased, the amount of bulk neutral channel getting smaller which cause a decrease in the on state current. Meanwhile, the lateral gate influence on the channel is reinforced, which cause a decrease in leakage current in the off state. Threshold voltage is decreased as the channel thickness decreases. However, the recombination rate of carriers increases with decreasing the channel thickness, due to the accumulation of minority carries and shifted to the source side of the channel.
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Papers by Mohd Hamidon