4.4 Matching any two complex impedances - Smith Chart Matching
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Also all the points on the outer circle represent admittances which are purely reactive:
purely capacitive in the upper half and purely inductive in the bottom half. This is the exact opposite
of what we had for the impedance chart.
The first time I saw this, I thought to myself, "How confusing! These two things looks the
same but represent completely opposite things!". It is however possible to combine the two in such
a way as to leave no ambiguities. We will see this in the next section.
4.4.3 Admittance and Impedance Coordinates
Impedance coordinates are very useful when considering elements which are in series and
admittance coordinate are most useful when considering elements in parallel. Most circuits however
have both elements in parallel and series so it would be good to combine the two.
Ideally we would want to have both sets of coordinates to fit in one circle and also to overlap in such
a way as to represent the same points. This can easily be achieved if we rotate the admittance Smith
chart by 180ι as shown in Figure 4.4-11 and Figure 4.4-12.
Figure 4.4-11 Admittance Chart (left), Impedance Chart (right)
Figure 4.4-12
Admittance chart rotated by 180ι (left), Impedance chart (right)
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ADMITTANCE
IMPEDANCE
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ADMITTANCE IMPEDANCE
Conquer Radio Frequency
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