Two-Port Networks-1
सोमवार, 17 जनवरी 2022
Two-Port Network-1
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Thought of the Day
HAPPINESS is found
in DOING;
Not merely
in POSSESING.
सोमवार, 17 जनवरी 2022
Two-Port Network-1
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To be Discussed
Multi-Port Networks.
 Two-Port Network.
 Six Possibilities of Characterization.
 open-circuit, impedance, or z-paramters.

Circuit Using z-parameters .
 Conditions for Reciprocity and Symmetry.
 Equivalent

Short-circuit, admittance, or y-paramters.
Circuit Using y-Parameters.
 Conditions for Reciprocity and Symmetry.
 Equivalent
सोमवार, 17 जनवरी 2022
Two-Port Network-1
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Port
A port of a network consists of two
terminals — one for the entry of current
and other for its exit.
 The currents in the two terminals of a port
are equal.
 ‘Porte’ in French means ‘door’.

सोमवार, 17 जनवरी 2022
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Two-Port Network
The port variables are port currents I1 and I2
and the port voltages V1 and V2.
Note the reference directions of currents and
voltages.
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Assume linear time-invariant elements.
 May contain dependent sources but not
independent sources.
 We need two linear equations in portvariables to characterize such a two-port
network.
 Two can be taken as the independent
variables and the remaining two as the
dependent variables.
 The choice is just a matter of convenience
for a given applications.

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Six Possibilities
Open-circuit, impedance, or z-parameters.
 Short-circuit, admittance, or y-parameters.
 Hybrid, or h-parameters.
 Inverse hybrid, or g-parameters.
 Transmission, or ABCD-parameters.
 Inverse transmission, or abcd-parameters

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Two-Port Network-1
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Two-Port Network-1
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OPEN-CIRCUIT, IMPEDANCE, OR
z-PARAMTERS
Impedance Matrix
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1. Input driving point impedance,
V1
z11 
I1

I 2 0
2. Reverse transfer impedance,
V1
z12 
I2
सोमवार, 17 जनवरी 2022

I1  0
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3. Forward transfer impedance,
V2
z21 
I1

I2 0
4. Output driving point impedance,
V2
z22 
I2
सोमवार, 17 जनवरी 2022

I1  0
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Equivalent Circuit Using z-parameters
It is just a picturization of the defining
equations.
सोमवार, 17 जनवरी 2022
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Alternate way of drawing the equivalent circuit.
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Conditions for Reciprocity
A network is said to be reciprocal, if
I I
'
1
सोमवार, 17 जनवरी 2022
z12  z21
'
2
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Condition for Symmetry
A two-port network is said to be
symmetrical if its ports can be interchanged
without changing the port voltages and
currents.
V1
I1
I 2 0
सोमवार, 17 जनवरी 2022
V2

I2
or
z11  z22
I1  0
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SHORT-CIRCUIT, ADMITTANCE,
OR y-PARAMTERS
Admittance Matrix
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1. Input driving point admittance,
I1
y11 
S
V1 V 0
2
y11 
I1
S
V1 V 0
2. Reverse transfer admittance ,
2
I1
y12 
V2
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S
V1  0
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3. Forward transfer admittance
I2
y21 
V1
S
V2  0
4. Output driving point admittance
I2
y22 
V2
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S
V1  0
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Equivalent Circuit Using y-Parameters
Picturizing the defining equations,
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Alternatively,
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Conditions for Reciprocity and
Symmetry
y12  y21
I1
I2

V1 V 0 V2
2
सोमवार, 17 जनवरी 2022
or
y11  y22
V1  0
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Review
Multi-Port Networks.
 Two-Port Network.
 Six Possibilities of Characterization.
 open-circuit, impedance, or z-paramters.

Circuit Using z-parameters .
 Conditions for Reciprocity and Symmetry.
 Equivalent

Short-circuit, admittance, or y-paramters.
Circuit Using y-Parameters.
 Conditions for Reciprocity and Symmetry.
 Equivalent
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