chapter 18 two-port networks. four-terminal network the four terminals have been paired into ports...
TRANSCRIPT
![Page 1: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/1.jpg)
Chapter 18
Two-port Networks
![Page 2: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/2.jpg)
four-terminal network
the four terminals have been paired into ports two-port
network
At all times, the instantaneous current flowing into one terminal is equal to the instantaneous current flowing out the other.
KCL
i1
i2 i3
i4 i1 i4
i1+i2+i3+i4=0(KCL)i1=-i2 ; i3=-i4
![Page 3: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/3.jpg)
2221212
2121111
2221212
2121111
VyVyI
VyVyI
IzIzV
IzIzV
2221212
2121111
2221212
2121111
IgVgV
IgVgI
VhIhI
VhIhV
112
112
221
221
dIcVI
bIaVV
DICVI
BIAVV
The network is linear(without independent sources).
![Page 4: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/4.jpg)
Impedance ParametersImpedance or z parameters are defined by
impedance matrix Z
2221212
2121111
IzIzV
IzIzV
022
021
012
011
12
2
21
2
12
1
21
1
IIV
IIV
IIV
IIV
z
z
z
zOpen-circuit input impedance.
Open-circuit transfer impedance from port 1 to port 2
Open-circuit transfer impedance from port 2 to port 1
Open-circuit output impedance.
22221212
12121111
oc
oc
VIzIzV
VIzIzV
![Page 5: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/5.jpg)
Determining of the z parameters: (a) finding z11 and z21, (b) finding z12 and z22
Examples
![Page 6: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/6.jpg)
(a) T equivalent circuit (for reciprocal case only), (b) general equivalent circuit
![Page 7: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/7.jpg)
Admittance ParametersAdmittance or y parameters are defined by
2
1
2221
1211
2
1
V
V
yy
yy
I
I
2221212
2121111
VyVyI
VyVyI
admittance matrix Y
022
021
012
011
12
2
21
2
12
1
21
1
VVI
VVI
VVI
VVI
y
y
y
yShort-circuit input admittance.
Short-circuit transfer admittance from port 1 to port 2
Short-circuit transfer admittance from port 2 to port 1
Short-circuit output admittance.
22221212
12121111
sc
sc
IVyVyI
IVyVyI
![Page 8: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/8.jpg)
Determination of the y parameters: (a) finding y11 and y21, (b) finding y12 and y22.
![Page 9: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/9.jpg)
(a) -equivalent circuit (for reciprocal case only), (b) general equivalent circuit.
![Page 10: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/10.jpg)
Hybrid ParametersHybrid or h parameters are defined by
2221212
2121111
VhIhI
VhIhV
hybrid matrix Z
022
021
012
011
12
2
21
2
12
1
21
1
IVI
VII
IVV
VIV
h
h
h
hShort-circuit input impedance.
Open-circuit reverse voltage gain
Short-circuit forward current gain
Open-circuit output admittance.
![Page 11: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/11.jpg)
The h-parameter equivalent network of a two-port network
![Page 12: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/12.jpg)
Inverse hybrid parameters (g parameters)
2221212
2121111
IgVgV
IgVgI
The g-parameter model of a two-port network
![Page 13: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/13.jpg)
Transmission ParametersTransmission or T parameters are defined by
2
2
1
1
I
V
DC
BA
I
V
2222211
2122111
IaVaI
IaVaV
Transmission matrix T
0
0
0
0
22
1
22
1
22
1
22
1
VII
IVI
VIV
IVV
D
C
B
A Open-circuit voltage ratio
Negative short-circuit transfer impedance
Open-circuit transfer admittance
Negative short-circuit current ratio
![Page 14: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/14.jpg)
Inverse transmission parameters
112
112
dIcVI
bIaVV
![Page 15: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/15.jpg)
------------- linear and has no dependent source
If a two-port circuit is reciprocal, the following relationships exist among the port parameters:
1
1
21122112
2112
2112
bcadT
BCADT
gg
hh
yy
zz
Reciprocal Two-Port Circuits
![Page 16: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/16.jpg)
Symmetric Two-Port CircuitA reciprocal two-port circuit is symmetric if its ports can be interchanged without disturbing the values of the terminal currents and voltages.If a two-port circuit is symmetric, the following relationships exist among the port parameters: (besides those exist in reciprocal)
da
DA
ggggg
hhhhh
yy
zz
1
1
21122211
21122211
2211
2211
![Page 17: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/17.jpg)
Question: How many calculations or measurements are needed to determine a set of parameters of a two-port circuit?
For a general two-port with sources: 6
For a general linear two-port: 4
For a reciprocal two-port: 3
For a symmetric two-port: 2
![Page 18: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/18.jpg)
Relationships between parameters
Example: z parameters y parameters
2221212
2121111
IzIzV
IzIzV
2221212
2121111
VyVyI
VyVyI
z
zy
z
zy
z
zy
z
zy
1122,
2121
,12
12,22
11
21122211 zzzzz
where
![Page 19: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/19.jpg)
Interconnection of networksSeries connection of two two-port networks
ba ZZZ
![Page 20: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/20.jpg)
Parallel connection of two two-port networks ba YYY
![Page 21: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/21.jpg)
Cascade connection of two two-port networks ba TTT
![Page 22: Chapter 18 Two-port Networks. four-terminal network the four terminals have been paired into ports two-port network At all times, the instantaneous current](https://reader037.vdocuments.us/reader037/viewer/2022102604/56649e715503460f94b7014a/html5/thumbnails/22.jpg)
Transistor amplifier with source and load resistance