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Artificial neural networks (ANN) are popular as efficient alternatives to conventional computational models like numerical modeling or analytical methods for RF and Microwave modeling and design[1]. Such models reduce both processing time and analytical complexity resulting in simpler computation process. Thus the technique has greater potential in the analysis of various problems in electromagnetism...
The relative complex dielectric function epsiv*(omega)=epsiv' - jepsiv" of pulverized samples of different grade limestone (cement grade, chemical grade, steel melting soap (SMS) grade and dolomite), coal (lignite) and limestone-coal mixtures (65 wt% + 35 wt%) were measured at 10.1 GHz over a range of bulk densities from loosely to tightly packed. It is found that for these powdered samples,...
This paper deals with the study of pillbox type dielectric window for X-band linac which is capable of handling average and peak powers of 2 kW and 2 MW, respectively, at spot frequency 9.4 GHz with VSWR and insertion loss of 1.1 and 0.1 dB, respectively. The HFSS software is used for computation of length of window, diameter and thickness of dielectric used for window. The theoretical values of VSWR,...
In this paper, we propose a new MOSFET design: Multi Layered Dielectric Four Gate MOSFET (G4-MLD MOSFET) and investigate its device performance through a two dimensional (2-D) analytical model by solving Poissonpsilas equation using parabolic potential profile approach. The 2-D analytical model gives physical insight into the electrical characteristics of this design in terms of surface potential...
The effects of a radome on the resonance and input impedance characteristics of a triangular microstrip antenna are experimentally investigated. To the best of our knowledge, this is the first time that the experimental results on superstrate loaded triangular microstrip patch are reported.
Real and imaginary parts of dielectric constant of soil of Alwar at different moist states under field conditions are determined at single microwave frequency 9.78 GHz using wave guide cell method. Dielectric parameters of soil related with various moisture retention states under field conditions like moisture less (dry), hygroscopic level, permanent wilting point, field capacity, transition moisture...
In this paper a comprehensive parametric study has been carried out to understand the effects of M patch antenna and to optimize the performance of the final design. The theoretical simulations are performed using SONNET software. The results are obtained for M-shaped antennas to compare the simulation results.
A cavity perturbation technique is presented for measurement of dielectric constant and dielectric loss of the dielectric materials at X-band microwave frequency. A tunable rectangular cavity to operate in TE103 mode was designed and fabricated. Tunable cavity is calibrated to read its resonance frequency directly from the micrometer screw arrangement attached with the cavity. Shift in resonance frequency...
Summary form only given. The characteristics of the uniplanar feed configuration to the rectangular dielectric resonator antenna based on the coplanar waveguide would be discussed. A comparative performance of the inductive, capacitive and the square loop feeds based on the coplanar waveguide would be addressed. It is observed that the capacitive feed to the antenna exhibits dual resonance with comparable...
A new wideband small size Crescent Slot Ellipse Shape Antenna (CSESA) with crescent slot is presented. A lossless material honeycomb dielectric of dielectric constant 1.11 is sandwiched between radiating patch and ground. The proposed antenna is excited by coaxial probe excitation technique. The main motivation for this work is to enhance the bandwidth of the Impedance. The simulation results verify...
Dielectric study of allyl bromide, formamide and their binary mixtures have been carried out over the frequency range from 10 MHz to 20 GHz at temperatures 288 K, 298 K, 308 K and 318 K using Time Domain Reflectometry (TDR) for 11 different concentrations. Static dielectric constant, relaxation time, Kirkwood correlation factor, Excess parameters were estimated information regarding the molecular...
The paper discusses the design of dielectric rod antenna at D band which can be used as a feed for dielectric lens antennas. This feed replaces the metallic corrugated / dual mode horns which are difficult to fabricate at these frequencies. Tapering of dielectric rod has been done to achieve low side lobe level. The designed antenna has been simulated on 3D EM software HFSS (high frequency structure...
The importance of measuring the dielectric constant of a liquid lies in the fact that it provides valuable information about intermolecular interaction and dynamics of molecules at molecular levels. In Nitrobenzene (NB) and Chlorobenzene (CB) molecules the charge distribution is shielded and H-bonds do not appear where as in 2-Ethoxyethanol (2-EE) molecules the charge distribution is exposed. In pure...
A two-dimensional analytical model for asymmetric multilayered gate dielectric surrounding gate MOSFET (AMGAD SGT) is presented and its effectiveness in suppressing short channel effects and hot carrier effects is examined. The expressions for potential and electric field have been obtained and the analysis is extended to obtain the threshold voltage and subthreshold slope of the device. It has been...
In this paper, aperture field distributions and radiation patterns of hollow dielectric wall diagonal horn antennas are studied theoretically and experimentally at spot frequency 9.418 GHz. The theoretical near field distributions at the aperture and the four side surfaces of a horn under study for TE to x and TE to y modes are obtained by solving the Helmholtzpsilas equation using the separation...
The values of complex permittivity for alcohol -dioxane mixtures with various concentrations have been determined in the frequency range of 10 MHz - 20 GHz using time domain reflectometry (TDR) method. TDR method involves the generation of step pulse with rise time of 25 picosecond in a coaxial line system and monitoring the change in pulse shape after reflection from the sample placed at the end...
In this paper, the impact of gate stack configuration onto the RF/analog and large signal linearity characteristics of insulated shallow extension (ISE) MOSFET is explored. The key factors affecting the device performance and the physics behind it are also scrutinized. The analog performance metrics- gm/ids, rout, vea (early voltage) & gm/gd gain and device linearity metrics-vip2 & vip3 and...
In this paper measurement of real part of permittivity and loss tangent of Zn1-x Mgx TiO3 (ZMT) ceramics in S-band of microwave frequencies is presented and the associated accuracy estimated. This approach is based on the measurement of transmitted power from the cavity at and off resonance. Details of the design and fabrication of the rectangular cavity and the input and output coupling are given...
The complex permittivity spectra of mixtures of methanol with 1-hexanol have been measured in the frequency range 10 MHz to 20 GHz using time domain reflectometry at different temperatures 288 K,298 K,308 K and 318 K respectively. The dielectric parameters such as static dielectric constant, relaxation time were obtained using the calibration method based on nonlinear least squares fit method. Using...
Wave guide reflectometer and voltage standing wave ratio (VSWR) methods have been used to study the Ku band (13-18 GHz) microwave permittivity and conductivity of soybean seeds (Glycine Max). The percentage of moisture (M) was varied from 4% to ~ 61% (fully soaked) calculated on a wet weight basis. The transmittance of the waveguide decreases and reflectance increases due to the seed. The real permittivity...
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