Anritsu 37 C Series, Operation Manual

Page: 158 / 603

Consideration must also be given to selecting the
breakpoint frequency. Divide the frequency range to
satisfy the 9:1 rule for any given pair of lines. The
range is thus divided by the frequency breakpoint
into the intervals [f1, f2] and [f2, f3]. Based on these
intervals, next determine the appropriate length dif-
ferences; the longer difference is associated with the
lower interval [f1, f2]. Note that if the differences
are equal to each other, concurrent frequency ranges
are implied and only two lines need be used.
Select a line 1 reference (L1) around which to place
these two differences. Use any combination of posi-
tive or negative differences around line 1. The soft-
ware selects which interval is associated with either
of line 2 or line 3 by comparing the absolute values
of the differences with line 1. Data from the two
lines, which make up the larger absolute difference,
are used for the interval [f1, f2]. Data from the two
lines, which make up the smaller absolute differ-
ence, are used for the interval [f2, f3].
37XXXC OM 7-41
MEASUREMENT CALIBRATION LRL/LRM CALIBRATION