3-30
Making Time Domain Measurements
Range
Range
In the time domain, range is defined as the length in time that a measurement can be
made without encountering a repetition of the response, called aliasing. A time domain
response repeats at regular intervals because the frequency domain data is taken at
discrete frequency points, rather than continuously over the frequency band.
where ∆F is the spacing between frequency data points
For example:
Measurement range
1
∆F
-------=
Measurement range
number of points 1–
()
frequency span Hz()
--------------------------------------------------------------=
Measurement
201 points
=
Frequency Span = 1 GHz to 3 GHz
Frequency Spacing ∆F()10 MHz=
Range
1
∆F
-------
or
number of points
1–()
frequency span
-----------------------------------------------------------------=
Range
1
10 10
6
×()
-------------------------= or
201 1–()
210
9
×()
----------------------
Range
100 10
9–
× seconds
=
Electrical Length
range
the speed of light
310
8m
s
----
×
×=
ElectricalLength 100
10
9–
s
×
3
10
8
m
s
----
×
×=
ElectricalLength
30 meters
=