I
-
Using Instrument Functions
Using limit Testing
Example 2.
In this example, the analyzer has been set up with the following parameters:
Start frequency = 90 MHz
Stop frequency
=
210 MHz
Number of points = 11
Maximum limit line begin frequency
=
90 MHz
Maximum limit line end frequency = 200 MHz
Refer to the illustration below for the discussion. Here, the data trace passes
through the limit line, and is above it, but this test passes because the last
point
tested
is at 198 MHz. The last point (210 MHz) does not cause the limit
test to fail because it is past the limit line stop frequency of 200 MHz. But
there is an area on the data trace between 198 MHz and 200 MHz that is
above the displayed limit line.
END LIMIT
at 200 MHz
MAXIMUM
DATA
1.
LIMIT LINE
IN QUESTION
1
II
‘i
,I’
NEXT
/I’ I
DATA POINT
at 210 MHz
.,*
l ’
,’
)-~*---~---~-~*-----)---~
---.’
I
I
i
A
.-,
:.
.-.
.-.
.-.
:.
:.
.-.
:.
’
90 102 114 126 138 150 162 174 186 198
DATA POINTS
(MHz)
Figure 4-18. limit lines Example 2
4-49