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Roy:
[snip] "Roy Lewallen" wrote in message ... In transmission line analysis, we're not free to rescale the forward and reverse voltage waves, unless we also scale all the voltages, currents and powers accordingly. The forward and reverse waves have to add to the total voltage in the line and at its ends, and the ratio of each component to the corresponding current component has to equal the Z0 of the line. [snip] I agree, that's why I say the definition of rho with Zo and not the conjugate is actually Mother Natures definition. Simply because that's the way the solution to the wave equation [The Telegraphists Equation] turns out. [snip] It's quite apparent that in S parameter analysis you're quite free to scale them as you wish, as you have. Vendelin et al didn't just scale them, but chose a set of V+ and V- which aren't even related to a and b by the same constant. [snip] Actually you are free! Just define the waves a and b as any linear combination of i and v and as long as the linear combination is non-singular you will be just fine! You can Engineer systems to your hearts content and get all the right answers. [It's sort of like the assumption of current flow in conductors from + to -, even though we "know" electrons flow the other way, it always gives us the correct Engineering answers, so who cares!] [snip] basic principles. And from it or other methods, we can conclude that when a transmission line is terminated in its characteristic impedance, there is no reflection of the voltage (or current) wave. When it's terminated in the complex conjugate of its characteristic impedance, or any other impedance except its characteristic impedance, there is a reflection. Roy Lewallen, W7EL [snip] Roy my friend we are in violent agreement! -- Peter K1PO Indialantic By-the-Sea, FL. |
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