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
10 106
×()
-------------------------=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
×
3108m
s
----
×
×=
ElectricalLength 30 meters
=