Propagation Characteristics in a Circular Waveguide for Feasibility Study of Terabit DSL

Due to the demand for higher data rates and greater download speeds by users and increasing number of deployed devices providing content-rich data, new cost-effective technologies which utilizes the concept of waveguides over copper that can enable the realization of terabit DSL need to be explored to meet the required demands. This paper presents the propagation characteristics of circular waveguide which include reflection/transmission coefficient, attenuation coefficient and surface current. The design and simulation process have been carried out using CST Microwave Studios at the frequency of 100GHz to 300GHz. The circular waveguide is varied for various radius and length to observe for the respective propagation characteristics. Based on the result, it is shown that the reflection coefficient decreases with the increase in radius and length and it is below -50dB. Besides, with the increase in frequency, the transmission coefficient shows that the waveguide is able to achieve 100% transmission (0dB) at 200GHz with the increase in radius and length. Moreover, the attenuation coefficient of the waveguide is low which is about 0.0022dB/mm and maximum surface current intensity of 81.5556A/m. The results obtained can be considered the first step on understanding the propagation characteristics of waveguide at terahertz frequency range towards the realization of Terabit DSL

Investigation of Waveguide Propagation of Terahertz Signal with Different Polarization Angle and Twisting Rate for Terabit DSL Application

When the demand for higher data rates grows, various telecommunications technologies are proposed; for these cases, the terabit DSL is investigated. Terabit DSLs provides solutions to the inevitable bottleneck that future wireless systems encounter. However, the propagation loss in twisted pairs becomes a massive concern in terabit DSL. Besides the attenuation, propagation characteristics at terahertz frequencies in twisted pair are not much explored by the researcher. Therefore, terahertz signal propagation characteristics in a waveguide based on surface plasmonic are investigated in this project by using simulation software CST MICROWAVE STUDIO. A circular waveguide with radius of 0.25 mm and length of 20 mm respectively has been simulated in between 360 GHz to 380 GHz. The reflection coefficient and transmission coefficient analysis of the circular waveguide are investigated in terms of the polarization angles and twisting rate. Based on the simulated results, it is discovered that the polarization angle influences the reflection coefficient and transmission coefficient of the circular waveguide. When the polarization angle difference is 90 degrees, it has the worst reflection. The circular waveguide with a polarization angle difference of 0 degrees and 180 degrees, it has the best transmission coefficient. The transmission coefficient of the circular waveguide, on the other hand, is unaffected by the twisting rate. Even though the highest twisting rate that has the highest transmission coefficient, it is still lower than 3 dB. Besides, the higher the twisting rate the lesser the number of resonances for the circular waveguide

Simulation of various resonators as viscometer for engine oils

The viscometer is an instrument used to identify the resistance of a fluid to shear or tensile stress. Accurate characterization of viscosity is important in analyzing many engineering situations, especially in the automation industries, which consume engine oils that associate with the functionality or performance of vehicles and machinery. Therefore, this work aims to simulate various sensors via resonators before the fabrication process is performed. The viscosity is justified based on the variation of dielectric properties of the fluid. T-resonator shows the highest sensitivity in all designs with an S11 value of -54.212dB and DSRR with Roger 3003 performs the best in terms of Q-factor with 1883. This simulation results can be verified through experimentation as future works

Investigation of dielectric constant variations for Malaysians soil species towards its natural background dose

The correlation of natural background gamma radiation and real part of the complex relative permittivity (dielectric constant) for various species Malaysian soils was investigated in this research. The sampling sites were chosen randomly according to soils groups that consist of sedentary, alluvial and miscellaneous soil which covered the area of Batu Pahat, Kluang and Johor Bahru, Johor state of Malaysia. There are 11 types of Malaysian soil species that have been studied; namely Peat, Linau-Sedu, Selangor-Kangkong, Kranji, Telemong�Akob-Local Alluvium, Holyrood-Lunas, Batu Anam-Melaka- Tavy, Harimau Tampoi, Kulai�Yong Peng, Rengam-Jerangau, and Steepland soils. In-situ exposure rates of each soil species were measured by using portable gamma survey meter and ex-situ analysis of real part of relative permittivity was performed by using DAK (Dielectric Assessment Kit assist by network analyser). Results revealed that the highest and the lowest background dose rate were 94 ±26.28 μR hr-1 and 7 ±0.67 μR hr-1 contributed by Rengam Jerangau and Peat soil species respectively. Meanwhile, dielectric constant measurement, it was performed in the range of frequency between 100 MHz to 3 GHz. The measurements of each soils species dielectric constant are in the range of 1 to 3. At the lower frequencies in the range of 100 MHz to 600 MHz, it was observed that the dielectric constant for each soil species fluctuated and inconsistent. But it remained consistent in plateau form of signal at higher frequency at range above 600 MHz. From the comparison of dielectric properties of each soil at above 600 MHz of frequency, it was found that Rengam-Jerangau soil species give the highest reading and followed by Selangor-Kangkong species. The average dielectric measurement for both Selangor-Kangkong and Rengam-Jerangau soil species are 2.34 and 2.35 respectively. Meanwhile, peat soil species exhibits the lowest dielectric measurement of 1.83. It can be clearly seen that the pattern of dielectric measurement for every soil at the frequency above 600 MHz demonstrated a specific distribution which can be classified into two main regions which are higher and lower between the ranges of 1.83 to 2.35. Pearson correlation analysis between the frequency of 100 MHz and 2.6 GHz with respect to exposure rate for every soil species was r = 0.38 and r = 0.51, respectively. This indicates that there was no strong correlation between both parameter, natural background dose and soils dielectric for each soils sample. This factor could be contributed by major and minor elements contained in each soils sample species, especially Ferum, Fe and Silica, Si

Investigation of dielectric constant variations for Malaysians soil species towards its natural background dose

The correlation of natural background gamma radiation and real part of the complex relative permittivity (dielectric constant) for various species Malaysian soils was investigated in this research. The sampling sites were chosen randomly according to soils groups that consist of sedentary, alluvial and miscellaneous soil which covered the area of Batu Pahat, Kluang and Johor Bahru, Johor state of Malaysia. There are 11 types of Malaysian soil species that have been studied; namely Peat, Linau-Sedu, Selangor-Kangkong, Kranji, Telemong- Akob-Local Alluvium, Holyrood-Lunas, Batu Anam-Melaka- Tavy, Harimau Tampoi, Kulai- Yong Peng, Rengam-Jerangau, and Steepland soils. In-situ exposure rates of each soil species were measured by using portable gamma survey meter and ex-situ analysis of real part of relative permittivity was performed by using DAK (Dielectric Assessment Kit assist by network analyser). Results revealed that the highest and the lowest background dose rate were 94 ±26.28 μR hr-1 and 7 ±0.67 μR hr-1 contributed by Rengam Jerangau and Peat soil species respectively. Meanwhile, dielectric constant measurement, it was performed in the range of frequency between 100 MHz to 3 GHz. The measurements of each soils species dielectric constant are in the range of 1 to 3. At the lower frequencies in the range of 100 MHz to 600 MHz, it was observed that the dielectric constant for each soil species fluctuated and inconsistent. But it remained consistent in plateau form of signal at higher frequency at range above 600 MHz. From the comparison of dielectric properties of each soil at above 600 MHz of frequency, it was found that Rengam-Jerangau soil species give the highest reading and followed by Selangor-Kangkong species. The average dielectric measurement for both Selangor-Kangkong and Rengam-Jerangau soil species are 2.34 and 2.35 respectively. Meanwhile, peat soil species exhibits the lowest dielectric measurement of 1.83. It can be clearly seen that the pattern of dielectric measurement for every soil at the frequency above 600 MHz demonstrated a specific distribution which can be classified into two main regions which are higher and lower between the ranges of 1.83 to 2.35. Pearson correlation analysis between the frequency of 100 MHz and 2.6 GHz with respect to exposure rate for every soil species was r = 0.38 and r = 0.51, respectively. This indicates that there was no strong correlation between both parameter, natural background dose and soils dielectric for each soils sample. This factor could be contributed by major and minor elements contained in each soils sample species, especially Ferum, Fe and Silica, Si

Synthesis and Microwave Absorption Properties of Doped Expanded Polystyrene with Silver Nanoparticles

Polystyrene (PS) is found to become a future major environmental issue and aggressive attempt by scientists to recycle PS into useful functional, recycle materials are becoming recent research trend. Polystyrene has been considered as a potential conductive and wave absorber materials. Doping PS with metal nanomaterials are found to enhance PS physical properties, thus enable the fine tuning of its conductive and wave absorbing properties. In this report, expanded polystyrene as source of PS waste materials are dissolved in tetrahydrofuran (THF), later added into deionized (DI) water to form precipitate polystyrene nanoparticles. This procedure enables easy access of dope silver (Ag) nanoparticles into PS in a colloidal form especially for homogeneity consideration. The UV-Vis spectroscopy (Ultra-Violet Visible), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transformation Infrared Spectroscopy (FTIR), and Vector Network Analysis (VNA) are used to investigate the doped PS nanocomposite of its morphology, molecular vibrations, electrical and electromagnetic properties. The results indicate promising effects of the electrical and electromagnetic properties of doped polystyrene metal nanocomposite as potential conductive and wave absorber material. Results show that these properties are highly dependent on the type of doping materials

Exploiting surface plasmon with dielectric coating in copper wires waveguide for the propagation of terahertz waves

Recently, metallic wires have gained popularity for utilization as waveguides in propagating sub-THz and THz waves through surface plasmonic polaritons (SPPs). Single and double metallic wire waveguides have demonstrated the ability to propagate these high frequencies with minimal loss and nearly zero dispersion. However, wires typically installed commercially are often coated with dielectric material. Therefore, this paper investigated the effects of using two and four metallic copper wires, both with and without dielectric coating. The impact of various gap distances on different propagation characteristics was also analyzed. Computer Simulation Technology (CST) Microwave Studio was employed in this study for electromagnetic simulations of both uncoated and coated configurations of two and four wires. The introduction of a dielectric coating led to an enhancement in reducing conductor losses and improving energy confinement, with the goal of enhancing the overall efficiency of waveguide signal propagation

Exploiting surface plasmon with dielectric coating in copper wires waveguide for the propagation of terahertz waves

Recently, metallic wires have gained popularity for utilization as waveguides in propagating sub-THz and THz waves through surface plasmonic polaritons (SPPs). Single and double metallic wire waveguides have demonstrated the ability to propagate these high frequencies with minimal loss and nearly zero dispersion. However, wires typically installed commercially are often coated with dielectric material. Therefore, this paper investigated the effects of using two and four metallic copper wires, both with and without dielectric coating. The impact of various gap distances on different propagation characteristics was also analyzed. Computer Simulation Technology (CST) Microwave Studio was employed in this study for electromagnetic simulations of both uncoated and coated configurations of two and four wires. The introduction of a dielectric coating led to an enhancement in reducing conductor losses and improving energy confinement, with the goal of enhancing the overall efficiency of waveguide signal propagation

Equivalent wire model and travelling wave mode method to analyse the radiated emission of a bent microstrip line

Nowadays, expeditious developments in the electrical and electronic territory due to endless demands from the markets have driven the operation frequency of the system into the gigahertz region. This had evolved into a more effectual-performance system, but also inflicts a lot of difficulties to the designers, for examples Electromagnetic Interference (EMI) problem and Signal Integrity (SI) issue. The integrity of circuit layout is inevitably compromised by bifurcated traces for examples T -junctions, Y -junctions, right-angle bends or left-angle-bends and steps planar transmission lines in order to fulfil the needs of a denser printed circuit boards. However, bifurcation often induces impedance mismatching resulting in reflection, radiated emission and power loss. This research is to investigate the radiated emission of 0°,45° and 90° bent microstrip lines by using an analytical fODnulation followed by computer simulation and experimental measurements for validation purposes. The novelty of this research is the implementation of travelling wave mode (TWM) method on bent microstrip line by adopting the equivalent wire model. The reliability of the formulation is proven from the agreement between the analytical results and computer simulation, especially in predicting the E¢ component. The analytical results clearly showed the significance of the bent in altering the radiation pattern of the microstrip line. Increasing the operating frequency and microstrip's width tend to produce more emission. One of the electric field components, Eo is almost symmetrical with respect to the bent angle/2 line on the plane of the microstrip line, while the E¢ component radiates strongly into the bent angle + bent anglel2 direction. The magnetic field on the bent microstrip line experiences an abrupt change at the location of the bent. This change becomes apparent as the bent angle increases. Future work should focus on improving the analytical fornmlation so that it can predict the Eo component with higher accuracy. FurtheDnore, effort can also be made on generating algorithm which takes into consideration the composite electric field radiation of all the bents on a practical printed circuit board

Dielectric Characterization Based On Complementary Split-Ring Resonator

Material characterization method based on radio frequency and microwave measurements is highly demanded. The dielectric properties is very important for electronic circuit design, food industry, medicine and health care. In this work, a complementary split-ring resonator (CSRR)-based sensor employed in the ground plane is proposed for dielectric measurement. This method enable the determination of both relative permittivity and relative permeability at the same time as well as simple sample preparation process. This project focuses on the design, simulation and the prediction formulae of the CSRR. This CSRR is resonating at 2.477 GHz with a quality factor of 128.91 in unloaded condition. Basically, there are shifting in the resonance frequency and the change of the quality factor when dielectric material is placed at the highest intensity of electric and magnetic fields in separate zones. Four predicted formulas are proposed, which they are depend on the dielectric constant, real permeability, normalized resonance frequency, inverse normalized quality factor, electric loss tangent and magnetic loss tangent of the materials. The prediction formulas are used to measure the permittivity and permeability of FR-4, Polyimide, and self-defined material. Based on the comparison, the percentage error between calculated result and reference data are 10% and 4.1% for electric and magnetic loss tangent respectively. The maximum percentage error in dielectric constant and real permeability are 4.5% and 4.29% respectively. Based on the percentage of error, it is convincing that the prediction formulas are reliable for dielectric measurement. Future work of this project should focus on verification of its actual performance through experimental measurement