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ECE 3074
Experiment: Impedance Matching
Name: ______________________
Date: _____________________
Analysis
The original circuit
The equation for the voltage transfer characteristic of the circuit that does not have either a power factor
correction or impedance matching network is given by:
Insert the MATLAB plot of the voltage transfer characteristic from 40-60 kHz. Include
appropriate figure captions.
The power delivered to the load, RL and LL, in the original circuit is ___________.
Power Factor Correction
The capacitance, Cpf, that should be placed in parallel with the load impedance to force the load voltage
and current to be in phase (or as close as possible) is ____________.
The power delivered to the load, RL and LL, in the circuit with the power factor correction is
___________.
Matching Network and Designs
The component values for the three matching networks that will match the impedance of the source with
the load at 50 kHz are:
Network
Zm1
Zm2
Zm3
Q factor
L
T
Pi
The impedance of the load as seen from the source at 50 kHz is:
None
L Network
T Network
Pi Network
Magnitude of ZL
Phase of ZL
Real Component
of ZL
Imaginary
Component of ZL
The equation for the voltage transfer characteristic of the circuit with the  network, H() = VL/VS is
given by:
Insert the MATLAB plot of the voltage transfer characteristic for the circuit with the 
impedance matching network from 40-60 kHz. Include appropriate figure captions.
The power delivered to the load, RL and LL, in the circuit with the  impedance matching network is
___________.
Modeling
The original circuit
Insert the plot from the transient response performed using PSpice.
How quickly does the output voltage stabilize to its steady state value?
Insert the plot from the AC Sweep performed using PSpice.
The power generated by the source is _____________ and the power delivered to the load at 50
kHz is ___________.
The circuit with the  matching network
Insert the plot from the transient response performed using PSpice.
How quickly does the output voltage stabilize to its steady state value with the impedance
matching network in place?
Insert the plot from the AC Sweep performed using PSpice.
The power generated by the source is _____________ and the power delivered to the load at 50
kHz is ___________.
Measurements
The values of the components used in the circuits are:
RS
Thévenin
Resistance
of Function
Generator
Zm1
Zm2
Zm3
RL
LL
External
resistor
Original circuit
Insert the plots of the voltages across the load impedance and resistor used to determine the
current through the load as measured by the oscilloscope. Include appropriate figure captions.
Original Circuit
Parameter
Value
Voltage across the load impedance, ZL = RL + LL
Current through the load impedance
Magnitude of Vs
Power Generated by Vs
Power Delivered to ZL = RL + LL
H() where f = 50 kHz
Insert the Bode plots of the magnitude and phase angle of the voltages across the load
impedance and resistor used to determine the current through the load. Include appropriate
figure captions.
The circuit with the  matching network
Insert the plots of the voltages (a) at the node between the resistor connected to the arbitrary
function generator, Zm1, and Zm2 and (b) across the load impedance and resistor used to determine
the current through the load as measured by the oscilloscope. Include appropriate figure captions.
Circuit with  matching network
Parameter
Value
Voltage across the load impedance, ZL = RL + LL
Current through the load impedance
Magnitude of Vs (calculated in previous step)
Power Generated by Vs
Power Delivered to ZL = RL + LL
H() where f = 50 kHz
Insert the Bode plots of the magnitude and phase angle of the voltages across the load
impedance and resistor used to determine the current through the load. Include appropriate
figure captions.
The frequency where the load is impedance matched to the source impedance is __________.
The percent difference between design frequency and measurement frequency at the matching
condition is ______________.
Conclusions
Comment on why the Bode plots measured on the original circuit and circuit with the matching
network do not match the MATLAB plots of the transfer function.
Compare the power delivered to the load with and without the matching network determined
analytically, from the circuit simulations, and the calculated power from the measurements and
provide an explanation for any differences.
Comment on the differences between using a circuit to perform a power factor correction and an
impedance matching network.
Given your knowledge of ideal and real components, explain why the operation of the low-pass
 network should be closer to the predicted operation when compared to the low-pass T
network. Similarly, why should the operation of the low-pass  network should be closer to the
predicted operation when compared to the low-pass L network?