ii)If the characteristic impedance of the transmission line is 20 Ω and the AC signal has a frequency of 50 Hz, what is the input impedance seen at the Liverpool side?
iii)If the characteristic impedance of the transmission line is 20 Ω and the AC signal has a frequency of 10 kHz, what is the input impedance seen at the Liverpool side?
iv)
Use the results obtained from Questions Q1b-i) to Q1b-iii) to explain why
the characteristic impedance is generally a very important parameter at high
frequencies, but not so important at low frequencies.
5
Total
35

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question (or part of a question). Total marks available are 100.
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Q2.a)i)A lossless microstrip transmission line has a characteristic impedance of 50 Ω. If the length of transmission line is doubled, what will be the characteristic impedance of the microstrip line? Justify your answer.
ii)
A lossless transmission line has a characteristic impedance of
Z
0
= 70 Ω and
a phase constant of
β
=2 rad/m at 1 GHz.
Calculate the values of the primary
constants
R
,
G
,
L
and
C
of the line.
10
b)
Find the scattering parameters of a parallel impedance
Z
a
= 50 Ω connected in a
two-port 50 Ω system, as shown in figure Q2b.
Figure Q2b
10
c)

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- Fall '18
- JIAFENG
- Electromagnet, Transmission line, long transmission line, Elec 311