Download presentation

Presentation is loading. Please wait.

Published byNoel nolan Mace Modified over 2 years ago

1
Impedance Matching (1)

2
Maximum Power Transfer Choose an RL in order to maximize power delivered to RL.

3
Power Delivered to the Load

4
Numerical Example V TH =1 V R TH =50 Ω

5
Conclusion! Maximum power is delivered to the load resistor when R L is equal to R TH.

6
Max Power Transfer for Complex Source Impedance At resonant frequency, the series impedance of the inductor and capacitor is zero.

7
Summary R L >R S R S >R L

8
L Network Different L netowrk Difference bewteen highpass and low pass Examine butterworth filter from the point of view of matching….

9
Resistance Transformation (See derivation in the handout) R P must be larger than R S

10
Matlab Calculation

11
Simulation Results

12
High Pass Match Note: There is not a DC path to ZL. RS must be larger than RL! See derivation! QS=sqrt(RS/RL-1) QS=1/(ωR L C) QS=RS/(ωL)

13
Matlab Calculation

14
ADS Simulation

15
Dealing With Complex Load Absorption Approach Resonance Technique

16
Match Via Absorption Approach Ignore stray component Match the load resistance to the source resistance with an L-match Subtract the stray component from the L-match value

17
Absorption Example

18
Calculation Neglecting Stray Components

19
Account for Stray Components This technique will not work if the stray components is much larger than L match components. E.g. if 2pF is replaced by 6 pF, then this technique will not work.

20
Resonant Approach Resonate any stray reactance with an equal and opposite reactance at the frequency of interest!

21
Example Resonate the 40 pF with a parallel L.

22
Parallel Resonant Network

23
Determine the Matching Network

24
Resonant Approach Example

25
Series to Parallel Conversion for RC Circuits

26
Series to Parallel Conversion for RL Circuits

27
Intuition If the Q is sufficiently large, L S ≈L P and C S ≈C P. R P is Q 2 times R S.

28
Summary R L >R S R S >R L

29
Smith Chart Derivation

30
Smith Chart Derivation (2)

31
Smith Chart Construction (The center line represents an axis where X=0.) (+) (-)

32
z L =1±j

33
Adding a Series Capacitance to an Impedance

34
Use Smith Chart Matching

35
SmithChartMatch

36
Smith Chart Utility 1. Select Smith Chart Match 2.Click on Tools, then select Smith chart utility 3. Select first option

37
Change the Load Impedance to 75 Ohms

38
Lock Load/Source Impedance

39
Add a Shunt Capacitance

40
Negative Capacitance! Negative capacitance

41
Add a Series Inductor (1) (2) Double click on the smith chart to drop the component

42
Build ADS Circuit

43
Comparison with Matlab Vs. ADS ADSMatlab Shunt Cap1.511 pF1.5 pF Series L5.72 nH5.627 nH

44
Adding an Inductor in Series Insertion of a series inductor to an impedance moves the impedance upward, causing a rotation clockwise along a constant circle of resistance

45
Series Inductance Neg L High LLow L fixed frequency Insertion of a series inductor to an impedance moves the impedance upward, causing a rotation clockwise along a constant circle of resistance

46
Adding a Capacitor in Series Insertion of a series capacitor to an impedance move impedance downward, causes a rotation counter clockwise along a constant circle of resistance

47
Series Capacitance High C Low L Neg C fixed frequency Insertion of a series capacitor to an impedance move impedance downward, causes a rotation counter clockwise along a constant circle of resistance

48
Admittance

49
Admittance Example

50
Method 1

51
Method 2 1. Find the Z. 2. Rotate Smith Chart 180 degrees

52
Smith Chart Construction (The center line represents an axis where X=0.) (+) (-) Conductance circle Inductive susceptance Rotate the impedance chart by 180 degrees Capacitive susceptance

53
Enable Admittance Chart

54
Adding a Shunt Capacitance Insertion of a shunt capacitor causes a rotation clockwise along a constant circle of admittance

55
Adding a Shunt Capacitance High C Low C Neg C fixed frequency Insertion of a shunt capacitor causes a rotation clockwise along a constant circle of admittance

56
Adding a Shunt Inductance Insertion of a shunt inductor causes a rotation counter clockwise along a constant circle of admittance

57
Shunt Inductance Neg Ind High L Low L fixed frequency Insertion of a shunt inductor causes a rotation counter clockwise along a constant circle of admittance

58
Next Class Pi Network T Network Smith Chart Genesis

59
The Pi Network The virtual resistance must be less than RS and RL.

Similar presentations

Presentation is loading. Please wait....

OK

Lecture 03: AC RESPONSE ( REACTANCE N IMPEDANCE ).

Lecture 03: AC RESPONSE ( REACTANCE N IMPEDANCE ).

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on eisenmenger syndrome pregnancy Ppt on structure of human respiratory system Ppt on j&k tourism Ppt on satellite orbit magazine Ppt on series and parallel circuits pdf Ppt on particles of matter attract each other By appt only movie site Download ppt on emerging modes of business Microsoft office ppt online templates Ppt on brand equity