Keysight Technologies N9340B, User Manual

Page: 58 / 172

Making Measurements

Making Distortion Measurements
52
Third-Order Intermodulation Distortion
Two-tone, third-order intermodulation (TOI) distortion is
a common test in communication systems. When two
signals are present in a non-linear system, they may
interact and create third-order intermodulation
distortion products that are located close to the original
signals. System components such as amplifiers and
mixers generate these distortion products.
In this example we test a device for third-order
intermodulation using markers. Two sources are used,
one set to 300 MHz and the other to 301 MHz.
1 Connect the equipment as shown in figure below.
This combination of signal generators and directional
coupler (used as a combiner) results in a two-tone
source with very low intermodulation distortion.
Although the distortion from this setup may be better
than the specified performance of the analyzer, it is
useful for determining the TOI performance of the
source/analyzer combination.
Frequency
Enter
7 MOD
On/ Off
RF
4
1
0
2
9
6
3
On/ Off
Amplitude FM
Utility
LF Out
Preset
Local
AM I/ Q
File
Trigger Pulse M
·
Sw eep
8
5
Remote
Standby
On
N9310A RF Signal Generator 9 kHz - 3.0 GHz
REVERSE PWR
4W MAX 30 VDC
LF OUT RF OUT 50
FUNCTIONS
Frequency
Enter
7 MOD
On/ Off
RF
4
1
0
2
9
6
3
On/ Off
Amplitude FM
Utility
LF Out
Preset
Local
AM I/ Q
File
Trigger Pulse M
·
Sw eep
8
5
Remote
Standby
On
N9310A RF Signal Generator 9 kHz - 3.0 GHz
REVERSE PW R
4W MA X 30VDC
LF OUT RF OUT 50
FUNCTIONS
Signal generator
Signal generator
Directional
coupler