Suppose that a complex impedance in magnitude - angle format is 1,25, 125 degree.
When expressed as a complex number(R + jX format), R < 1, i.e., negative. What does this mean physically, specifically if this value of R is to be used in a calculation, is it necessary to take the absolute value of R ? Thanks in advance.
What it means physically is that if you apply a voltage V across this compl ex impedance you will generate a current I through it with an absolute magn itude of V/1.25 amps, but 125 degrees out of phase with the voltage.
The in-phase current will be generating heat, but the quadrature current wo n't.
For a component to generate more than 90 degrees of phase shift, it have in ternal structure - which is to say it has to be built up out of several pur e resistances and reactances, or contain active devices. A transmission lin e will look like that at particular frequencies.
Is your question pureely hypothetical?
-- Bill Sloman, Sydney
plex impedance you will generate a current I through it with an absolute ma gnitude of V/1.25 amps, but 125 degrees out of phase with the voltage.
won't.
internal structure - which is to say it has to be built up out of several p ure resistances and reactances, or contain active devices. A transmission l ine will look like that at particular frequencies.
Thank you for the clarification. No, the question is not hypothetical. At work, a group of us are creating a software suite to perform utility RF related calculations(S -> Z parameter conversion, common emitter S parameter -> common base S parameter and so on.).
While testing our code standard available data(taken out of RF transistor d atasheets), we noticed the issues that I mentioned, and we were not sure of the underlying physical reasons. I mean that it is very clear mathematically why the negative sign appears, but the underlying physical reasons must be clear too.
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