In this assignment we will use Bode’s asymptotic tracing technique to find a rational
function approximations to for a tranmsission line characteristic impedance function
Zc(ω). Use the data in the Data Assign04.txt file of Assignment 4 for the zero sequence
mode. To increase the frequency resolution for a better fit, it is suggested to create 10
points per decade by interpolation of the given data points.
1. Find a rational function fit of Zc(ω) using only four poles, for the frequency range
from 10−1 Hz to 107 Hz.
2. Compare the magnitude fit and the phase angle fit. Plot the original function and
the rational approximation on the same graph.
3. Obtain the network synthesis of Zc(ω) in terms of series blocks of parallel RC
branches. Calculate the values of the R’s and the C’s of these branches.
4. Comment on your results:
(a) Comment on the magnitude fit and the phase fit.
(b) What strategy did you use to obtain a good fit?
(c) Do you have any suggestions on how the procedure could be improved so
that you could get a better fit with the same number of poles and zeroes?
(d) Other comments?