HP 54753A - Page 204

TDR Fundamentals
Instrument Configuration
9-30
where
therefore
The resultant circuit is actually a third order Butterworth filter. Refer to
Figure 9-27. The bandwidth of the resultant Butterworth filter has the same
bandwidth as the initial single pole filter. Since the risetime of the step to be
transmitted is much greater than the risetime of either the single pole or
Butterworth filter there will be little effect on the transmitted step.
CC1 C2+=
C1 C2
L
Z
o
2
--------
0.6 pF===