Concepts and Features
R&S
®
ZNB/ZNBT
222
User Manual 1173.9163.02 ─ 53
5.7.4.3
Intermodulation Measurements
Option R&S
ZNB/ZNBT-K14
The intermodulation measurement requires option R&S
ZNB/ZNBT-K14 and, as a pre-
Frequency Conversion Measurements
option R&S
ZNB/ZNBT-K4.
The "Intermodulation Wizard" facilitates the measurement configuration and the selec-
tion of results (see
Chapter 6.12.4, "Intermod. Tab"
An intermodulation measurement is performed with two RF signals of equal power but
different frequencies termed the upper and lower tone. The purpose of the measure-
ment is to test the properties of a DUT that is supplied with a signal that covers a fre-
quency band, typically a modulated RF channel. To simulate this scenario, the fre-
quency difference ("tone distance") between the upper and lower signal is chosen to be
small compared to the frequencies of the two tones:
f
L
≈
f
U
or
Δ
f = f
U
- f
L
≪
f
L
A nonlinear behavior of the DUT causes emissions at frequencies which correspond to
sums and differences of the upper and lower tone frequencies and their integer multi-
ples. These intermodulation products can be near the upper and lower tone frequen-
cies, as long as their order is odd.
The analyzer measures the intermodulation products of k
th
order IMk (where k = 3, 5,
7, 9) at the lower tone frequency minus (k – 1)/2 times the tone distance and at the
upper tone frequency plus (k – 1)/2 times the tone distance; see also
For a two-port R&S
ZNB, a test setup with an external generator and a combiner is
required.
VNA
1
2
Upper Tone
DUT
1
2
Lower Tone
Optional Extensions and Accessories
