These two workbooks show various formulas that are used when dealing with transmission lines.
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T-Line Model.xls shows the details of the mathematical model for transmission lines that is used by the Zplots and TLDetails applications. |
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T-Line Measure.xls shows how the characteristic impedance Zo and the propagation constant γ (gamma) may be obtained from two basic impedance measurements, one with the transmission line terminated with an open circuit and a second with a short circuit termination. The math behind using open/short measurements to determine transmission line characteristics is described in section 7.5, pp. 134-136, of the Chipman text (Robert A. Chipman, Theory and Problems of Transmission Lines, 1968). You can read those three pages here. Also, W8WWV wrote up some thoughts on this technique. |
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Both workbooks make use of the Excel complex number functions. Under Excel 2003 and earlier, click on Tools > |