Problem 13.7 - Frequency Response with Widely Separated Poles
*
* When the poles (critical frequencies) of a transfer function are
* widely separated the actual voltage response becomes an easily
* predictable function of the pole locations. The errors between the
* actual curve and the approximate curve agree with Table 13.2 for
* the magnitude curve. The phase curve is somewhat more complicated,
* but also predictable. (Note that these observations are also true,
* but not quite so obvious, when the poles are not widely separated.)
*
* Follow the instructions of the problem statement to construct a
* straight line (approximate) Bode plot consisting of three different
* line segments. Also construct the approximate phase plot. Measure
* the errors between the actual and approximate curves and compare
* with the error values in Table 13.2.
*
* AN EXTRA SPECIAL CHALLENGE! See if you can write the expression for
* the lines with -20 dB/decade and -40 dB/decade slope and use PROBE
* to plot them on the graph of the magnitude response. Also write the
* expression for the line with -45 degrees/decade slope and plot it on
* the phase response curve. NOTE: If you are using PSpice Version
* 4.04, you will have to plot R(Log10(x)) to get the correct result.
*
* Why are the magnitude and phase errors both equal to zero at f=1000?
*
.OPT NOPAGE NOBIAS ; This program is complete and ready to run.
; The exercise is in the graph work.
V1 1 0 AC 10
R1 1 2 3183
C1 2 0 500N
EAMP 3 0 2 3 1E10
R2 3 4 3183
C2 4 0 5N
.AC DEC 10 10 1E6
.PROBE
.END