About the Smith Chart - Stanford University · The Smith chart is a plot of (9.2) in the r-plane as...

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1 About the Smith Chart

Transcript of About the Smith Chart - Stanford University · The Smith chart is a plot of (9.2) in the r-plane as...

Page 1: About the Smith Chart - Stanford University · The Smith chart is a plot of (9.2) in the r-plane as a function of r and x. Using Equation 9.2 and separating in terms of its real part

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About the Smith Chart

Page 2: About the Smith Chart - Stanford University · The Smith chart is a plot of (9.2) in the r-plane as a function of r and x. Using Equation 9.2 and separating in terms of its real part

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Im[Z]

Im[Z]

Re[Z]

Re[Z]

Γ-plane

Γ-plane

Mapping R’s

Mapping C’s

Page 3: About the Smith Chart - Stanford University · The Smith chart is a plot of (9.2) in the r-plane as a function of r and x. Using Equation 9.2 and separating in terms of its real part

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ZO

Page 4: About the Smith Chart - Stanford University · The Smith chart is a plot of (9.2) in the r-plane as a function of r and x. Using Equation 9.2 and separating in terms of its real part

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Page 5: About the Smith Chart - Stanford University · The Smith chart is a plot of (9.2) in the r-plane as a function of r and x. Using Equation 9.2 and separating in terms of its real part

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Example 6.12Y: 0.1,-0.3Z: 1.0,-3.0

Example 6.15Y:0.08,(-0.94+1.22)∆ZN= -3.32 (reactive)

3.0

0.3

Page 6: About the Smith Chart - Stanford University · The Smith chart is a plot of (9.2) in the r-plane as a function of r and x. Using Equation 9.2 and separating in terms of its real part

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A bit more discussion of Ex. 6.12Parallel -j333Ω corresponds to 1/jωCDoing the parallel to series conversion:QP=RP/XP=1000/333=3Using formula Parallel-to-Series--CS=[(QP

2+1)/QP2](1/ωXP)=[10/9](1/ω333Ω)

Therefore..1/ωCS=XS=300ΩReminder about the R’s…RS=RP/(QP

2+1)=1000/(9+1)=100ΩThe above two sets of #s related to Fig. 6.59Looking at all this on the Smith Chart…The series combination gets normalized by 100ΩThus, (100, 300)-> (1, -3)If we write it in terms of YN (corresponding to the parallel values)We get, ZP->YP-> 1000/100->10->1/10 andFor the capacitive term 333/100->3.3->1/3.3 so that…ZP of (1000, 333) goes to YN of (0.1, -0.3)

This is sort of messy…

And YOU need to do it yourself to have it make sense

Z1

Z2

See Smith Chart for example of Z1and Z2=ZO=50Ω

Wow! This looks familiar :)

Input of CE Amp. with re feedback

1.22=50/41

-0.94=50/53

0.08=50/600

∆ZN= -3.32