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Electromagnetic Theory

by Mitali Nayak
Type: PracticalInstitute: Biju Patnaik University of Technology Specialization: Electrical and Electronics EngineeringDownloads: 21Views: 406Uploaded: 8 months agoAdd to Favourite

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Mitali Nayak
Mitali Nayak
EXPERIMENT NO:01 AIM OF THE EXPERIMENT: To study the wave propagation in conductor and dielectrics using HFSS tool. EQUIPMENTS Operating system WINDOWS XP Software ANSYS HFSS TOOL THEORY ANSYS HFSS ANSYS HFSS (High Frequency Structure Simulator) offers multiple state-of-the-art high-frequency electromagnetic solvers. These powerful tools are based on the highly accurate and reliable finite element method (FEM), the large scale method of moments technique, and ultra-large scale asymptotic methods of physical optics (PO) and shooting and bouncing rays (SBR). When combined with ANSYS HPC technology, rigorous multi-solver hybrid techniques deliver advanced multi-scale, multi-fidelity computational electromagnetics available in an easy-to-use design environment. CONDUCTOR In physics and electrical engineering, a conductor is an object or type of material that allows the flow of an electrical current in one or more directions. A metal wire is a common electrical conductor. Electrical current is generated by the flow of negatively charged electrons, positively charged holes, and positive or negative ions in some cases. Pure elemental silver is the best electrical conductor encountered in everyday life. Copper, steel, gold, aluminum, and brass are also good conductors. In electrical and electronic systems, all conductors comprise solid metals molded into wires or etched onto circuit boards. Some liquids are good electrical conductors. Mercury is an excellent example. A saturated saltwater solution acts as a fair conductor. Gases are normally poor conductors because the atoms are too far apart to allow a free exchange of electrons. However, if a sample of gas contains a significant number of ions, it can act as a fair conductor. DIELECTRICS A dielectric material is a substance that is a poor conductor of electricity, but an efficient supporter of electrostatic fields. If the flow of current between opposite electric charge poles is kept to a minimum while the electrostatic lines of flux are not impeded or interrupted, an electrostatic field can store energy. This property is useful in capacitors, especially at radio frequencies. Dielectric materials are also used in the construction of radio-frequency transmission lines.
An important property of a dielectric is its ability to support an electrostatic field while dissipating minimal energy in the form of heat. The lower the dielectric loss (the proportion of energy lost as heat), the more effective is a dielectric material. Another consideration is the dielectric constant , the extent to which a substance concentrates the electrostatic lines of flux. Substances with a low dielectric constant include a perfect vacuum, dry air, and most pure, dry gases such as helium and nitrogen. Materials with moderate dielectric constants include ceramics, distilled water, paper, mica, polyethylene, and glass. Metal oxides, in general, have high dielectric constants. FACTORS RELATED TO CONDUCTORS AND DIELECTRICS In order to identify the conductors and dielectrics we need check the relationship among conductivity angular frequency and permittivity. i.e σ For conductors ωϵ σ For dielectrics ωϵ σ For perfect dielectrics ωϵ σ For perfect conductors RESULT CONCLUSION ωϵ >>1 <<1 =0 =∞
EXPERIMENT NO:02 AIM OF THE EXPERIMENT: • To design a rectangular wave guide using HFSS. • • Operating system WINDOWS XP Software ANSYS HFSS TOOL EQUIPMENTS THEORY In the microwave region of the electromagnetic spectrum, a waveguide normally consists of a hollow metallic conductor. These waveguides can take the form of single conductors with or without a dielectric coating. Hollow waveguides must be one-half wavelength or more in diameter in order to support one or more transverse wave modes. The dimensions of a Rectangular waveguide determine which wavelengths it can support. Typically the waveguide is operated so that only a single mode is present. The lowest order mode possible is generally selected. Frequencies below the guide's cutoff frequency will not propagate. It is possible to operate waveguides at higher order modes, or with multiple modes present, but this is usually impractical. Rectangular Waveguide PROCEDURE OF DESIGN In order to design a rectangular wave guide need to follow some procedure in a systematic manner 1) Insert HFSS Design : • On the Project menu, click Insert HFSS Design 2) Selecting the Solution Type : • On the HFSS menu, click Solution Type. The Solution Type dialog box appears 3) Setting the Model’s Units of Measurement:
• On the 3D Modeler menu, click Units. The Set Model Units dialog box appears. 4) Drawing a Model: • On the HFSS menu, click Draw. The Draw dialog box appears.Select Box 5) Assigning Materials: • Right click on the 3D Modeler Window to get the 3D Modeler menu On the 3D Modeler menu, click Assign Material 6) Assigning Boundaries 7) Assigning Excitations 8) Solution Setup • Frequency Sweep setup • 9) Run a Simulation 10) Check The Result RESULTS CONCLUSION

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