Measuring Phase Distortion - Agilent Technologies 8753ET User Manual

The measurement value that the analyzer displays represents the electrical length of your device relative
to the speed of light in free space. The physical length of your device is related to this value by the
propagation velocity of its medium.
NOTE
Velocity factor is the ratio of the velocity of wave propagation in a coaxial cable to the
velocity of wave propagation in free space. Most cables have a relative velocity of about 0.66
the speed in free space. This velocity depends on the relative permittivity of the cable
dielectric (

You could change the velocity factor to compensate for propagation velocity by pressing
MORE
Cal
analyzer to accurately display the equivalent distance that corresponds to the entered
electrical delay.
Figure 1-35 Example Best Flat Line with Added Electrical Delay
8. To display the electrical length, press
In this example, there is a large amount of electrical delay due to the long electrical length of the SAW
filter under test.

Measuring Phase Distortion

This portion of the example shows you how to measure the linearity of the phase shift over a range of
frequencies. The analyzer allows you to measure this linearity and read it in two different ways: deviation
from linear phase, or group delay.
) as
r
VELOCITY FACTOR
Scale Ref
Measuring Electrical Length and Phase Distortion
Velocity Factor
(enter the value)
ELECTRICAL DELAY
Making Measurements
1
= ------- -

r
. This will allow the
x1
.
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