EE340–Electromagnetic TheorySmith chart and its applications

Pradeep Kumar K

Department of Electrical EngineeringIndian Institute of Technology Kanpur

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Smith Chart

Graphical plot of normalized resistance and reactance functions inreflection coefficient planeUseful in solving several problems; finding impedance at a pointon T-line, reflection coefficient away from load, matching networkdesign, determining VSWR etc.Best suited for lossless lines and qualitative understanding

Figure : P. H. Smith; inventor of Smith chart

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Smith chart

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Constant r -circles

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Constant x-circles

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Derivation of Smith chart

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Properties of constant r -circles

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Properties of constant x-circles

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Plotting impedance values on Smith chart

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