16.360 Lecture 9

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16.360 Lecture 9

• Last lecture

• Parameter equations
• input impedance

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16.360 Lecture 9
Parameter equations
Unit circuit
.
Short Circuit load
B
Open Circuit load
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16.360 Lecture 9
Parameter equations
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16.360 Lecture 9
An example
Smith Chart
Input impedance
Wavelength toward generator (WTG)
Smith Chart
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16.360 Lecture 9
An example
find Zin (-0.1?)
Smith Chart
Constant ? circle, SWR Circle
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16.360 Lecture 9
Today

• SWR, Voltage maxima and minima

• Impedance to Admittance transformations

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16.360 Lecture 9
SWR, voltage maximum and minimum
If
Smith Chart
Recall
when 2?z ?r 2n?.
when 2?z ?r (2n1)?.
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16.360 Lecture 9
An example
Smith Chart
Impedance to Admittance transformations
G conductance, B, susceptance
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16.360 Lecture 9
Normalized admittance
Smith Chart
z and y are directly opposite each other on
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16.360 Lecture 9
An example
A 50-? lossless line is terminated in a load ZL
(25j50)?. Use the smith chart to find a) voltage
reflection coefficient, b) the voltage
standing-wave ratio, c) the distances of the
first voltage maximum and first voltage minimum
from the load, d) the input impedance of the
line, given the line is 3.3?, and e) the input
admittance of the line.
Smith Chart
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16.360 Lecture 9
Next lecture

• Impedance matching

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