CHAPTER 4 - Impedance Matching
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(
)
Now, just as in the R-C series case (Figure 4.2-9), the current leads the voltage, and hence
is
negative. However with the admittance we are looking at
, which is positive! This is an
important fact that always applies: impedance and admittance have opposite phases! Therefore our
admittance in polar form works out to be
Which
in Cartesian form translates to
[
( ) ( )
]
Now if we calculate our admittance algebraically we get
Which is just the same!
Figure 4.2-20 shows a graphical representation of this admittance on the complex plane.
Figure 4.2-20 Representation of or in the complex plane
Let us now consider the parallel R-L circuit shown in Figure 4.2-21.
As before, by using the values which may be read out from the markers in Figure 4.2-21, we may
calculate the admittance of our inductive network.
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In
polar form this works out to be
And
in Cartesian form
Again the analytical expression yields an almost identical result.
60.4ι
20
35.2j
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