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The European Logarithmic Microprocessor (ELM) had been an outstanding breakthrough in logarithmic number system (LNS) research history. The processor successfully reaches the par ability of floating-point (FLP) processor with its rapid and accurate design towards FLP. The design was able to improve the LNS addition and subtraction procedure, which are the drawbacks of any implementation of LNS arithmetic...
Design of a fully integrated power amplifier (PA) with distributed active transformer (DAT) architecture is introduced in this paper. PA achieves high efficiency and high power performance necessary for long range internet of thing (IoT) wireless communication systems. The amplifier is implemented in a 0.18gm SiGe BiCMOS technology with 3.3 V supply voltage and achieves a peak output power of +32dBm...
The high voltage DC power supply widely used for space communication and for industry consist of multistage rectifier circuit. To produce 6KV output voltage, Cockroft-Walton multiplier circuits are applied by reducing number of stages from 1200 into 32 stages without using transformer. With the implementation of this technique, it can minimize the volume of the circuit to be integrated on a single...
Linear modelling of novel InGaAs/InAlAs/InP pHEMT for low noise applications is substantial to the future transistors that will operate in high speed and low noise conditions. The novel pHEMT is constructed by sandwiching two different materials together with different lattice constants, for instance InGaAs and InAlAs in order to form a heterojunction in between. However, InP is only utilised to be...
HEMT is a GaAs based field effect transistor that retains higher cutoff frequency compared to silicon based transistors. Alternatively, pHEMT enhance the performance of the HEMT in term of leakage, current conduction and the cutoff frequency of the device. The heterostructure of pHEMT improve the performance two-dimension electron gas (2DEG) in the channel layer. With these, pHEMT is believed could...
We report a comprehensive etching study on the gate recess step for the fabrication of the novel high speed pHEMT devices. The experiments focused on the elimination of “hump” structure as a result of an incomplete etching process at the InGaAs cap layer. In this work, two types of test samples were used, namely bulk InGaAs and epitaxial structure together with an etch stop layer. The result showed...
We report the enhancements on pHEMT epilayers to suite the high speed applications for IoT. Presented here are the DC and RF comparisons between XMBE #109 as the baseline of high speed pHEMT and VMBE #2100 as the enhanced epitaxial layer. The Hall data from Van der Pauw measurement shows higher sheet carrier concentration is observed on the improved epitaxial layer devices. The DC comparisons between...
Thermal effects and other properties of light emitting diode based on titanium dioxide material were successfully analyzed. Titanium dioxide has been chosen as the selected material due to its special characteristics such as excellent chemical stability, thermal stability and higher band gap energy. The main target of this work was to study the thermal effect and current-voltage characteristics towards...
This paper reports on the design, implementation, and characterization of a trench-filled capacitor in complementary Metal-Oxide-Semiconductor (CMOS) grade silicon. In order to achieve high capacitance value in MOS capacitor, trench technology is applied to improved capacitance. The simulation executed by using Synopsys's Sentaurus TCAD. A C-V measurement was done between two different structures...
This paper presents the carried out investigation on nonlinear effects in semiconductor optical amplifier (SOA); in particular two-photon absorption process and its induced free carriers. The simulation results show nonlinear phase shift and the spectral broadening is induced by nonlinear free-carrier effect after propagation through the SOA. The levels of injected carrier density in SOA are varied...
This work focuses on the effectiveness of different metal oxides act as sensing layer in the gas sensor. This is for sensing ethylene (C2H4) gas in fruit ripening detection. The study involved a computational approach, COMSOL Multiphysics whereby the ripeness detector is simulated and characterized. The paper presents a sensitives layer of metal oxides with a thickness of 0.5pm on Lithium Niobate...
The work presents a design of single stage integrated low noise amplifier using negative feedback and inductive source degeneration with DMS technique as the notch filter. Implementation of Super-low noise InGaAs HEMT MGF4937AM transistor which covers from 3.1–10.6 GHz for LNA. Due to interference from IEEE 802.11 WLAN at 5–6 GHz in UWB standard, a notch filter is used to attenuate the undesired frequency...
Many FSO communication systems are using a conventional technique that is OOK technique in the system. Some enhancement of technique is explained in this paper to decrease the error rate that occurs in the system. The comparison between OOK technique and DDM technique is investigated in order to compare the error rate and power received. The result shows that the performance of DDM technique generates...
In this paper, we present a new simulation model, called as sum-of-linear-frequency-modulation (SOLFM) model, based on the sum-of-cisoids (SOC) model. The new model has ability to simulate non-stationary fading channels under time-variant scattering environments. We also propose an effective parameter computation method, which can reproduce time-variant statistical properties of real-word channels...
Healthy environment is imperative to a healthy and happy community. With the age old system of hiring people to regularly check and empty filled dustbins, the process has been prone to human error and neglect. Additionally, due to different frequency of usage of dustbins in different areas, routine checks which are based on time crevices is inefficient because a dustbin might get filled early and...
This paper investigates the development of branchline coupler using parallel coupled transmission lines on planar microstrip using CST Studio Suite 2010 design tool. This project operates within 4 GHz to 8 GHz frequency band. Two designs are proposed in this project which are basic branch line coupler and branch line coupler with parallel line feeding technique. The main purpose of this study is to...
Novel tuneable dual-mode narrowband bandstop filter using loaded microstrip resonator is presented. The filter is designed by using coupled line coupling with the microstrip resonator. There is two different pair of loaded resonator that produces a dual band bandstop filter. The dual band bandstop resonance frequency can be tuned independently by adjusting the resonator width and length. To achieve...
This research paper employs a 3D tetrahedral meshing frequency solver as the main tool to simulate the electromagnetic effect of non-modified tip edge complementary asymmetric split ring (CASR) unit cell its modified triangular tip edge version. Behavior of these unit cells are intended to obtain an electromagnetic (EM) bandgap suitable to separate a beam wave into two direction as well functioning...
This paper showcases the work done to create an alternative surface impedance transmission line implemented using a 3D tetrahedral meshing frequency eigenmode solver. The work was performed based on a complementary asymmetric split ring (CASR) unit cell to identify its resonance characteristic and relevant dispersion diagram at 5.9 GHz. By using this CASR singularly into a guided transmission line,...
By taking the imperfect channel state information(CSI) into account, the optimal precoding matrix is deduced with the proposition that the full CSI of the source-relay link and the estimation errors and antennas correlation information of the relay-destination link are known by the relay node. Considering the maximum power constraint at the relay node, the precoding matrix is optimized based on the...
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